1938 Institution of Mechanical Engineers: Visits to Works
Note: This is a sub-section of 1938 Institution of Mechanical Engineers
CARDIFF CORPORATION ELECTRICITY DEPARTMENT ROATH POWER STATION
The power station was built in 1904 as a generating station for the tramways system, which was inaugurated in that year. It is situated on the Newport Road, and the circulating water is obtained from a small brook which passes through the site. The initial installation consisted of four 300 kW. generators, placed between the high-pressure and low-pressure cylinders of the vertical mill type engines, which were supplied with steam at 150 lb. per sq. in. from Lancashire boilers. The capacity of the initial plant was augmented in later years by the addition of two further 900 kW. generators and two 1,000 kW. alternators, driven by engines of the same type. All this plant has been removed during the reconstruction of the station at various periods.
Three 2,000 kW. turbo-alternators and water-tube boilers were installed in 1909, 1914, and 1917, with steam pressure at 150 lb. per sq. in. and generating at 6,600 volts, three phase, 50 cycles per second. In 1921 a reconstruction period was commenced, and all Lancashire boilers were removed and replaced with water-tube boilers, each evaporating 40,000 lb. per hr. at 200 lb. per sq. in., superheated by 200 deg. F. The mill type engines were dismantled and replaced by three 5,000 kW. and one 12,500 kW. turbo-alternators. As the load increased, wooden cooling towers were installed as the existing water supply was insufficient.
Part of the present 6,600-volt switchgear was supplied with a rupturing capacity of 350,000 kVA., and with the advent of the grid, this was increased to 500,000 kVA. by the addition of explosion pots. A number of Whitehead's oil pump circuit-breakers have been added to the 6,600-volt switchgear at the power station.
No major generating plant has been installed since 1928, and excess requirements are taken from the grid. The station is a selected station for generating electricity to the requirements of the Central Electricity Board, and operates as a two-shift station. It was originally connected to the grid through 132/6.6 kV. transformers, but when a supply was given to a large steel works at 33 kV., these transformers were replaced and the supply to the undertaking is now taken at 33 kV. through a new substation built adjacent to the power station.
CARDIFF CORPORATION LLANDOUGH HOSPITAL
The City of Cardiff Municipal General Hospital, situated at Llandough, approximately 3 miles from Cardiff, on grounds occupying about 38 acres, is constructed on the pavilion system. It contains at present five two-story ward blocks, projecting southwards from a central corridor. Each block comprises two ward units, one on each floor, and each ward unit accommodates thirty-four beds. At the south end of each main ward is a solarium having spacious "Vita" glass windows. The wards are equipped with a patients' luminous silent call system. A visual code-signalling system, enabling any member of the staff to be located with a minimum of delay and disturbance, is installed throughout the hospital. The internal automatic telephone system is supplemented at all vital points by Post Office telephones. To guard against electric light failure, a trickle-charged emergency lighting system is provided, by which the operating theatre lights and certain other strategic lights can be maintained.
In the centre of the hospital is the administrative block, containing offices and receiving rooms, main laboratory, and quarters for the matron and resident medical staff. The main kitchen, and the dispensary, X-ray, and theatre units, are situated on the north side of the central corridor. The theatre unit at present comprises two operating theatres, with adjacent anaesthetizing, sterilizing, surgeons', students', and nurses' rooms, but it is planned for ultimate extension to six theatres and recovery wards. The engineering block, laundry, and mortuary are situated away from the hospital proper, but are connected thereto by means of an underground passage from the main basement corridor, which runs throughout the length of the hospital and carries the main pipes and cables. Traffic to and from these buildings passes through the basement, thereby obviating noise and disturbance. Other measures for reducing noise include the provision of special flooring for the corridors, the substitution of visual for audible signals, and special devices in the doors of all the electric lifts.
With the exception of a part of the theatre unit, the whole of the hospital is warmed by hospital-pattern radiators supplied from an accelerated low-pressure hot water system. The domestic hot water system is similarly accelerated. Both systems are supplied from central steam-heated calorifiers, thermostatically controlled, located in the engineering block. The accelerator pumps are steam turbine driven, the exhaust steam, together with that from boiler house auxiliaries, being utilized in low-pressure calorifiers. The operating theatres, anaesthetizing rooms, and sterilizing rooms are heated by ceiling panels, thereby leaving the floors of the rooms free from obstruction. The panels are supplied with hot water from an independent steam-fed calorifier, allowing the theatre unit to be warmed in summer, when the main heating system is shut down.
The main kitchen lies behind the administrative block. The steaming ovens, boiling pans, hot closets, and kettles are steam-heated, and a gas boiling table is provided. Electricity is used for roasting, grilling, and frying. The hot food is placed in heat-insulated containers, which are transported to the various wards and dining-rooms by electric trolleys, the use of which enables the difficulty of serving meals simultaneously to be overcome without undue multiplication of staff. The food-preparing plant comprises the usual potato-peeling, mixing, slicing, and dish-washing machines, etc. The refrigerating plant for the cold rooms, milk-cooling equipment, and ice-making equipment are electrically operated. The main larder is fitted with a large automatic electric refrigerating cabinet. Similar cabinets of smaller size are provided in the ward kitchens. The laundry contains a steam disinfector, washing machines, hydro-extractors, a multi-roll ironing machine, a continuous dryer, presses, gladiron, etc. Except for one or two small electrical appliances, the laundry machinery is steam-driven. The exhaust steam from the engine serves a calorifier providing hot water in the laundry, any surplus steam being utilized in the main heating and domestic hot water calorifiers.
The sterilizers in the theatres and surgical wards are steam-heated. Those in the medical wards, dental rooms, etc., are electrically heated. The mortuary comprises a post-mortem room and chapel; the body chambers are provided with an independent cooling system. A refuse destructor for incinerating putrescible domestic refuse, surgical and medical refuse, etc., is placed behind the engineering block, remote from the hospital and residential quarters. The destructor flue discharges into the main chimney stack, before reaching which unburnt particles are intercepted. The products of combustion are thus discharged without offence. An engineering workshop, furnished with such power-driven machine tools as are needed for repairs, is provided in the engineering block, as is also a fully equipped carpenters' shop. Both are driven electrically.
Water for all purposes is supplied by the Cardiff Corporation, and is of exceptional purity. To ensure continuity of supply, separate supplies are taken from two different reservoirs by means of independent connexions. The incoming supply is delivered into high-level storage tanks. The level of the water in the tanks is sufficient to afford an adequate head for fire-fighting purposes without the use of pumps.
Steam for all purposes is supplied by three coal-fired Lancashire boilers, two of which are normally in service. Condensate returned from the steam distribution system and steam-using appliances — plus the make-up, for which cooling water discharged from the mortuary refrigerating plant is used — is pumped back into the boilers through an economizer. The boilers are machine-fired, coal gravitating into the hoppers from overhead bunkers. Coal is brought in lorries running direct from the road to the tops of the bunkers, into which it is tipped through suitable screens. Natural draught only is employed, the stack being of a height sufficient to carry the gases clear of the highest hospital buildings, and to afford the draught required for combustion under all load and weather conditions.
Electricity is supplied in bulk by the local supply authority, three-phase alternating current with a frequency of 50 cycles per sec. being taken at 6,300 volts and transformed to 400 volts in a substation which forms part of the engineering block. Two incoming cables are provided, each connected to a different feeder, thus minimizing the chance of interruption to the supply.
The hospital is so planned that additional ward blocks, up to a total of twelve, can be added as need arises, and the engineering services are so designed that they can be extended without modifying existing sections.
CARDIFF CORPORATION WATERWORKS
The River Taff and shallow wells no doubt provided a reasonably pure supply of water to the town of Cardiff from its earliest history. The first Bute Dock was opened in 1839. The population of Cardiff was then less than 10,000, but had more than doubled in ten years, and the prospect of an even more rapid growth of the town made the inauguration of a piped supply imperative. The Corporation gave the matter consideration but ultimately a company was formed in 1850. This company obtained a supply from the River Ely, whose watershed was not then being developed for mining. They constructed a pumping station on the river 3 miles west of Cardiff, and a service reservoir at Llandaff, and the supply was commenced in 1852. The pumping plant at Ely consisted of two Cornish boilers and two beam pumping engines, each capable of pumping 1 million gallons per day against a head of 70 feet. One engine was of the jet condensing type and the other non-condensing, but fitted with a drop expansion valve. The pumping plant was used constantly until about 1887 and intermittently until 1936, when it was dismantled.
The Corporation acquired the undertaking of the company in 1879 and obtained an Act of Parliament in 1884 to utilize the waters flowing from a catchment area of 10,400 acres situated at the source of the River Taff in Breconshire, approximately 35 miles north of Cardiff, and to construct three impounding reservoirs in connexion therewith. The area was divided into two portions, and the Corporation immediately proceeded with the construction of the Cantref Reservoir on the upper area (4,000 acres). The reservoir and the pipe line to the existing reservoirs in Cardiff were completed by 1892, and from that date water from the Taff Fawr source has been supplied to the whole of the town and district. The construction of the Beacons Reservoir, the second on the upper area, was afterwards proceeded with and completed in 1897. The supply then available from the upper area was about 6 million gallons per day during a dry summer, in addition to the compensation water of 3 million gallons per day to the River Taff.
By 1908 the summer consumption had practically reached this limit, although every effort had been made by waste inspection and other means to keep it at the lowest possible quantity. The Corporation therefore proceeded to construct the Llwynon Reservoir and to utilize the waters from the lower catchment area of 6,400 acres at Taff Fawr. The War interrupted the work, but the reservoir was ultimately completed in 1926, and 7.75 million gallons per day are now discharged from the Llwynon Reservoir for the whole catchment area. This rearrangement of the compensation water enabled the 3 million gallons per day from the upper catchment area to be utilized for the purpose of supply and obviated the immediate necessity of drawing from the Llwynon Reservoir for that purpose.
The water first obtained from Taff Fawr was sent to the reservoirs which had been constructed near Cardiff at Rhiwbina and Heath for storage and subsequent filtration. It was found, however, that the action of the soft peaty moorland water on the internal surface of the cast iron pipe line had reduced its carrying capacity from about 11.5 to 7 million gallons per day. Pipe scraping was resorted to in the years 1910-11, but while the flow was temporarily increased thereby, it again decreased rapidly. The Council, therefore, proceeded to lay a second pipe line from Cantref Reservoir to Llanishen, Cardiff, and also to install a system of rough filtration immediately below the Cantref Reservoir. The filters were brought into commission in 1926, and the second pipe line was completed in 1930.
The consumption, however, steadily increased and in 1933 it became necessary to install a temporary pumping and chlorinating plant to utilize the water from Llwynon Reservoir for the purpose of supply to the city during the summer. Ultimately the water from Llwynon will be discharged through a main to be laid down the valley, below the hydraulic gradient until it connects to the existing pipe lines to Cardiff, near Cefn, three miles from Llwynon. Until this main is laid, however, the water is pumped by means of a 90 h.p. Petter atomic Diesel engine coupled direct by helical gearing to a Pulsometer centrifugal pump, and a Gilkes and Gordon Francis turbine coupled by Hele-Shaw clutches to a Pulsometer centrifugal pump at one end of the shaft and an electrical generator at the other. The turbine is operated by the compensation water discharged from the reservoir into the river. The whole plant is capable of pumping 4 million gallons per day through an 18-inch rising main (350 yards) to the pipe lines passing from Cantref to Cefn along the adjacent road at about 120 feet above the Llwynon Reservoir.
Rapid gravity filters with a capacity of 5 million gallons per day are now being constructed at the Llwynon filter plant to purify the water obtained from that reservoir. These, together with the filters at Cantref (which are being reconstructed), will filter the whole of the water supplied to the city and district. The Corporation have also taken measures to protect the catchment area and have demolished a number of farmhouses and buildings. The whole of the enclosed land belongs to the Corporation and is reserved for sheep grazing and afforestation. Under the Cardiff Corporation Act of 1934 the Corporation are permitted to reduce the compensation water of 7.75 million gallons per day discharged from the catchment area to 6 million gallons per day as long as 7.75 million gallons per day are passing over the Ffrwd weir constructed by them at a point on the River Fawr Taff approximately 3 miles below the Llwynon embankment, which will also receive the run-off from an area of 3,440 acres on limestone formation. The gauges on the two weirs will be electrically connected so that the rate of flow at the Ffrwd and Llwynon gauges will be recorded on adjacent dials situated at Llwynon.
In addition to the works in Breconshire the Corporation have constructed a large storage reservoir with earthen banks at Llanishen and a large storage reservoir of concrete at Wenallt near Cardiff in which water from Breconshire is stored. Subsequently it is filtered in slow sand filters at the Heath before passing into the city. A number of service reservoirs have also been constructed in various parts of the area of supply. The waterworks company also obtained water from a catchment area at Lisvane on the hills immediately north-east of Cardiff. This supply has recently been developed for commercial purposes and is available for consumers not requiring potable water.
The prevention of waste of water throughout the area has been given considerable attention and modern methods of waste detection by meter have been installed. The testing of all fittings and the supervision of plumbing work has also been carried out for many years. A modern station for the testing of water fittings has been erected at the Works depot, North Road, Cardiff.
The statutory area of supply comprises 51 square miles and is divided into two main districts, the City or low-level district, and the high-level district which supplies the upper parts of the city, Penarth, and the other surrounding areas. The average consumption per day for the year 1937 was 9,694,000 gallons. The total storage of water is 2,376 million gallons. The estimated population supplied is 264,000.
THE CARDIFF GAS LIGHT AND COKE COMPANY
The manufacturing plant is centralized at Grangetown, Cardiff, where the total area of the company's land is 56 acres, apportioned as follows: 25.5 acres in actual use for works purposes, 6.5 acres utilized as a recreation ground, 3 acres leased to other industrial undertakings, and 21 acres as yet undeveloped. The works have direct access to the Penarth Harbour (Great Western) Railway from which high- and low-level sidings are available for deliveries.
The plant for gas manufacture includes vertical and horizontal retort houses, also carburetted water gas plant. In addition there are residual plants for the manufacture of sulphate of ammonia, concentrated ammonia, and dehydration of tar. Purification plant includes dry purifiers with two sections of washing and scrubbing plant. There are also laboratories, stores, workshops, coke-grading plant, locomotive running sheds, garages, etc.
The coal carbonizing plant is in two sections, namely, No. 1 retort house, containing Glover-West vertical retorts, and No. 2 retort house, equipped with horizontal retorts.
No. 1 retort house comprises fifteen settings of Glover-West vertical retorts, the first installation of ten settings having been erected in 1914 and a further five settings added as a separate unit in 1920. The complete installation comprises 120 retorts, each having a daily throughput of 2.5 tons of coal, and the gas-making capacity of the plant is rated at 3,750,000 cu. ft. per day.
Waste heat from the fifteen settings is utilized for raising steam in three waste-heat boilers of the Spencer-Bonecourt type, by means of which approximately 18,000 lb. of dry steam at 100 lb. per sq. in. pressure is generated hourly. This is utilized for the steaming process in the vertical retorts and for two steam engine dynamo units, which, in conjunction with three gas engine dynamos, generate 120 kW. per hour for the electrical operation of the retort house, etc. Steam from the waste-heat boilers is also used to augment the general supply for works purposes.
Coke is discharged from the retorts into skips and, after being quenched, is elevated and conveyed to the storage hoppers by means of an overhead telpher system.
No. 2 retort house comprises 40 settings of eight horizontal retorts, each 22 inches x 16 inches x 20 feet long. These are arranged in three tiers, and are charged and discharged mechanically. This plant is capable of carbonizing 430 tons per day. The retorts are maintained at a temperature of about 1,260 deg. C., to carbonize completely charges of 9 cwt. of coal in 8 hours. The stoking machinery consists of two electrically driven Fiddes-Aldridge simultaneous discharging-charging machines for which power is obtained from the No. 2 power house which adjoins the retort house and contains two steam-driven dynamo units, each of 40 kW. capacity.
Carburetted water gas is generated in two Humphrey and Glasgow plants, each set forming a complete unit capable of producing 2,000,000 cu. ft. of gas per set per day. The waste blow gases are utilized in two waste-heat boilers, each capable of evaporating 3,500 lb. of steam per hour.
Coke is supplied direct from the retort houses into the feed storage hoppers of the plant by a travelling crane and thence over screens to the generators. This travelling crane also handles the ashes from the plant.
No. 1 section of the washing and scrubbing plant comprises two annular and two water-cooled sets of condensers, four tower scrubbers, and two rotary washer scrubbers. No. 2 section is composed of one set of vertical, part annular and part water-cooled condensers, also one set of Graham type condensers, with two Livesey washers and four rotary brush washers of the Holmes type.
The dry purification plant consists of four sets of purifiers, each of six boxes as follows: on the ground floor Nos. 1 and 2 sets, dimensions 38 feet x 16 ft. 3 in. and 24 feet x 24 feet respectively; No. 3 and 4 sets are elevated, dimensions 40 feet x 24 feet and 50 feet x 30 feet respectively. The latest set, No. 5, is also elevated and consists of four boxes each 40 feet x 30 feet. The sulphate of ammonia plant consists of two units, each of 6 tons capacity per day, and is equipped with neutralizing and drying apparatus. The sulphate of ammonia produced is perfectly dry, neutral in quality, and contains 21.12 per cent nitrogen.
The gas is measured through three station meters, two with capacities of 175,000 cu. ft. each and one of 100,000 cu. ft. per hour. From these it is delivered into six telescopic gas holders having a total capacity of nearly 7 million cu. ft. The tar dehydration plant is of the modern continuous type, and consists of two units each capable of dealing with 4,000 gallons of crude tar per 24 hours. The finished tar is graded to suit the Road Board specifications.
The company's area of supply is about 66 square miles, with a population of 250,000. The number of gas consumers is over 68,000. The sale of gas for the year 1937 was 1,702,000,000 cu. ft. The various districts are connected direct to the works through individual governors, the chief feeder mains ranging from 12 inches to 24 inches in diameter, and then through branch mains of varying sizes. To augment the pressure during periods of exceptional demand, three Rateau fans of a total capacity of 2.5 million cu. ft. per hour are employed. In addition, two Belliss and Morcom compressors, capable of compressing 300,000 cu. ft. of gas per hour at 15 lb. per sq. in. pressure, deliver gas through a 12-inch steel main to a transformer station at Whitchurch, 5 miles distant.
THE CONCORDIA ELECTRIC SAFETY LAMP COMPANY, LTD., LUMA WORKS, CARDIFF
The firm, which had had many years' experience in the use of lead acid type batteries for hand lamps, was reconstituted in 1930 to manufacture and market lamps embodying the Edison type of alkaline battery, more especially for the use of miners and mines officials. Police, fire brigade, and watchmen's types of lamps and dry battery torches approved by the Mines Department and Home Office for use in "gassy" atmospheres are also manufactured, and the works include a modern electroplating plant to give cadmium, nickel, and chromium finishes. Photometric equipment of various types is also installed for the quick and accurate measurement of the output of light of the lamps. An exhibition of old and new types of lamps for miners' use will be displayed.
GREAT WESTERN RAILWAY COMPANY'S CARDIFF DOCKS HYDRAULIC AND PUMPING SYSTEM, AND DOCKSIDE MACHINERY
- West Dock. Opened 1839. 20.5 acres water area
- East Dock. Opened 1859. 46.5 acres water area
- Roath Basin. Opened 1874. 13 acres water area
- Roath Dock. Opened 1887. 33 acres water area
- Queen Alexandra Dock. Opened 1907. 52 acres water area
- Total water area 165 acres
The trade at the docks during the year 1937 amounted to 1,738,234 tons of imports, and 5,927,197 tons of exports, totalling 7,665,431 tons; 4,410 vessels arrived, and the aggregate net registered tonnage of vessels arriving was 3,769,963. The principal export traffic dealt with is the shipment of coal and coke, which last year amounted to 5,429,848 tons. Other considerable exports are patent fuel, iron and steel rails and ironwork, grain and flour, and oil. Of the imports, the chief traffics are iron ore for the "Dowlais" iron and steel works (situated on the docks), grain and flour (mainly for Messrs. Spillers, who have a large silo and mill at Roath Dock), timber, and mining timber. Cardiff is one of the principal timber importing centres of the country, and many of the importing firms have large depots at the docks. Other imports are semi-manufactured iron and steel, foodstuffs, and fruit. There is a very substantial importation of Jaffa oranges direct from Palestine. Another special traffic is the importation of Canadian cattle.
The following information in regard to the power systems and mechanical appliances has been compiled by the Chief Mechanical Engineer of the Great Western Railway, Mr. C. B. Collett, O.B.E., M.I.Mech.E.
No. 1 Power House. This power house incorporates both hydraulic and dock impounding pumps, all being steam driven. The boiler plant consists of a battery of six Babcock and Wilcox boilers fitted with automatic stokers, ash-handling plant, and Green's economizers, and delivers steam at 180 lb. per sq. in. The hydraulic power plant consists of seven pumping engines with a total capacity of 3,800 gal. per min. against a pressure of 800 lb. per sq. in. Six of these are of the vertical marine triple-expansion type, the other being a horizontal Duplex tandem compound engine. All engines are fitted with surface condensers.
The impounding pumps, of which there are three sets, are the largest at the South Wales docks, and have a capacity of 5,000,000 gal. per hour each. The pumps are of the centrifugal type and the engines are of the vertical marine triple-expansion type, fitted with surface condensers.
Coal Hoists, Queen Alexandra Dock. The whole of the South Quay is equipped with a battery of nine movable coal hoists fed by electrically operated traversers. The traversers are fitted with electrically operated tilting tables to facilitate the transfer of loaded wagons to the hoists and empty wagons to the runaway. The main lifting and tipping motions of the hoists are performed hydraulically and the travelling and shoot-operating gear are electrically driven. All these machines are capable of hoisting and tipping wagons of 20 tons capacity. The average speed of lifting and lowering is 180 ft. per min., and Nos. 2 and 4 are fitted with "Norfolk spades" to facilitate the discharge of sticky coals such as washed duff.
Coaling Appliances, Roath Dock. These consist of two conveyers and four coaling cranes of the Lewis-Hunter type. No. 1 conveyer is an electrically driven telescopic belt fed by a hydraulically operated tipping turntable which also has slewing and tilting motions, the latter for sending the emptied wagons away from the table. The table can handle wagons of up to 20 tons capacity. The conveyer is equipped with an electrically driven anti-breakage appliance of the Handcock type, and can be moved along the quay, as the main conveyer framing is hinged at the feed bunker for this purpose. Its capacity is 500 tons per hour. No. 2 conveyer is similar to No. 1 except that it is not movable, and so works in a fixed position on its jetty. The four coaling cranes have all motions hydraulically operated and the coaling boxes are fed by means of hydraulic tipping tables situated between the pits. The coaling boxes have a capacity of 12 tons.
No. 3 Hydraulic Power House. This power house is equipped with four sets of electrically driven turbine hydraulic pumps each with a capacity of 800 gal. per min. against a pressure of 800 lb. per sq. in. The motors are of 650 b.h.p. running at 1,450 r.p.m. with a supply at 6,600 volts, three phase, and 50 periods per second frequency. The pumps are semi-automatic in control. It is only necessary to start the first pump by hand; the others will start one by one as the demand increases and stop as the demand falls. This station also has two electrically driven centrifugal pumps for pumping fresh water from the East Bute Dock into an overhead concrete tank. This water is used for supplying the hydraulic pumps both at No. 1 and No. 3 power houses.
Cargo Cranes, Queen Alexandra Dock. The north-west side of Queen Alexandra Dock is equipped throughout with 21 movable electric cargo cranes varying in capacity from 1.75 tons to 15 tons. Twelve of these, erected in 1931, are of 3 tons capacity and are of the latest level huffing type. The nine cranes situated on the King's and Schroeter's Wharves are hydraulically operated movable huffing cranes of 2 tons capacity with the exception of one l.75-ton crane.
125-ton Floating Crane. This is usually stationed at Cardiff Docks. The main crane is mounted on a pontoon and is capable of luffing but not slewing. Two steam-driven winches supply power for the lifting and luffing motions, the latter being transmitted through two luffing screws situated at the tail of the jib. When lifting, the winches may be operated separately or in connexion with each other, as each winch is equipped with complete lifting tackle of 62.5 tons capacity. The crane also has a light-lift system of 18 tons capacity.
No. 4 Hydraulic Power House. This is equipped with two sets of electrically driven turbine hydraulic pumps each with a capacity of 500 gal. per min. against a pressure of 800 lb. per sq. in. The motors are of 400 b.h.p. running at 1,475 r.p.m. with a supply at 440 volts, three phase, and 50 periods per second frequency. These pumps are fitted with complete automatic gear and will start automatically upon a fall of pressure in the mains and stop when the demand decreases. Two small electrically driven centrifugal pumps are also installed to supply the hydraulic pumps with fresh water from East Bute Dock.
Coaling Appliances, Roath Basin. These consist of two hydraulic coal hoists capable of handling wagons of 20 tons capacity. The two hoists are of the fixed suspended-cradle low-level type, all motions being performed hydraulically. No. 1 is fitted with a Norfolk spade, No. 2 with screening facilities, and both with Handcock-type antibreakage appliances. The height of lift in each case is to 60 feet above quay level.
Coaling Appliances, East Bute Dock. These consist of seven fixed hydraulically operated direct-acting high-level coal hoists each capable of handling wagons of 20 tons capacity. Partial counterbalance of the cradle is effected in each case by means of deadweights. No. 7 hoist is fitted with a Norfolk spade and No. 6 with a Handcock-type antibreakage appliance fitted with rubber trays.
Coaling Appliances, West Bute Docks. These consist of four hydraulic coal hoists each capable of handling wagons of up to 12 tons capacity. Three of these tips have gravity lowering motion and hydraulic tipping, but the fourth is hydraulic in all motions.
Cargo Cranes, Roath Dock. The north-west side of Roath Dock is equipped with ten hydraulic cranes and four electric cranes. The former range from 1.75 tons to 6 tons capacity, and the latter are all 3-ton movable level luffing cranes.
Cargo Cranes, East Bute Dock. The west side of East Bute Dock is equipped with twenty movable hydraulic cranes of capacities varying from 1.75 tons to 6 tons.
MESSRS. GUEST KEEN BALDWINS IRON AND STEEL COMPANY, LTD., EAST MOORS WORKS, CARDIFF
Coal-Handling and Washing Plant. The original East Moors Works at Cardiff were built by the Dowlais Iron Company, Ltd., in 1889-93, and comprised blast furnaces, an open-hearth shop and a plate mill. When the firm's successors were amalgamated in 1930 to form The British (Guest Keen Baldwins) Iron and Steel Company, Ltd., the control of works at Port Talbot, Dowlais, and Cardiff was unified and it was decided to discontinue steel making at Cardiff, although the blast furnaces remained at work. After the introduction of import duties on iron and steel, however, the advantage of Cardiff as a site for the production of billets and sheet bars became apparent, and it was decided in 1934 to erect a complete iron and steel plant with a pig iron capacity of 500,000 tons a year and a steel capacity of 350,000 tons a year. Only the blast furnace and sinter plants of the old works were retained. For the new works it was necessary to construct a coal washery, a by-product coke oven plant, and an ore-handling plant. New gas-cleaning plant and gas holders have been installed, also an open-hearth plant, rolling mills, and accessories. Production commenced in January 1936, the chief items being pig iron (basic and haematite), billets, sheet bars and small sections, also coke oven by-products.
Incoming coal and shale wagons travel respectively to the wagon hoist and tipplers and the shale-weighing machine. The sidings, which are laid on a gradient so that gravity assists the wagon movements, will hold 100 20-ton wagons. There are two recording and indicating double weighbridges; and after being weighed and tipped into two receiving hoppers, the coal travels by an inclined belt to the washery. Oversize coal, which will not pass the 2-inch wire mesh inclined vibrating screen at the delivery end of the belt, is crushed, in a single-roll breaker, to a convenient size for washing. All coal then passes through a dust-removal plant to the wash box, which is 17 feet in length and 14.5 feet in mean width, with air chambers divided into five compartments. The air valves are of the piston type, driven by eccentrics; and the rotary shale extractors are automatic, driven by a variable gear controlled by floats at each end of the box. The washed coal is flushed with water along two central troughs built above the sixteen drainage bunkers. Water carrying washed coal to any of the drainage bunkers first fills the bunker and then overflows into a trough leading to slurry-settling tanks; these tanks are 20 feet square, with conical bottoms and they have a total capacity of 110,000 gallons. The water is then recirculated, whilst the slurry passes over vibrating sieves, where the water content is removed, and then falls on to a worm conveyer and paddle mixer where it is mixed with dust from the hoppers of the dust-removal plant. The worm conveyer delivers the mixture to an inclined belt carrying the washed coal to swing-hammer mill crushers. The effluent from the slurry screens is either recirculated or stored in external ponds. In practice it is found that all slurry and dust is returned to the washed coal, and the drainage system employed keeps the water comparatively clean.
The two swing-hammer crushers can each deal with 170 tons per hour, and will give 90 per cent through an 0.125-inch square-mesh sieve. The crushed coal is conveyed by belts to service bunkers capable of holding 2,200 tons of dry coal, and divided into two compartments which are for coal with high and low phosphorus content respectively.
Coke Oven Plant. The plant, which has a capacity of 6,000 tons per week of blast furnace coke, consists of two batteries, each with 29 ovens. The length of the ovens is 34 feet; the mean width is 18 inches, and the height 12 ft. 6 in. There are 120 regenerator chambers, filled with firebrick chequer work; the installation differs from previous batteries of Becker ovens built in this country in that there are eight cross-oven flues built over every other oven chamber, whereas in earlier batteries there have been only six. The normal reversal of the cycle of operations is carried out by an automatic timing switch; should the reversal not take place at the appointed time, a Klaxon horn gives warning, and an auxiliary steam engine is started, if breakdown is due to an electrical fault. The ovens are of the compound type and can be heated either by coke oven gas or blast furnace gas; in the former case the regenerators are used for preheating air and absorbing heat from the waste gases; and in the latter case the blast furnace gas must be heated by taking the incoming main along the bottom of the regenerators and passing the gas and the air through alternate compartments. Combustion then takes place at the bottom of the vertical tubes. The coke pusher machine is provided with electrical interlocks to prevent the machine from being traversed before pusher ram, leveller bar, and extractor head are withdrawn from the ovens. Eleven additional ovens are at present under construction.
A coke-quenching car conveys hot coke to the quenching station and thence to the coke wharf. The bottom of the car is inclined, and the discharge doors are operated by compressed air. Quenched coke is discharged on to a sloping wharf paved with blue bricks and provided with gates feeding on to a rubber conveyer carrying the run-of-oven coke to a screening plant. An automatic weighing machine and totalizer is installed. There are two coke screens, dealing respectively with coke from the Cardiff ovens and coke from outside markets. The graded run-of-oven coke travels to the blast furnace bunkers on conveyers having a capacity of 120 tons per hour.
By-Product Plant. Here tar, ammonia, and benzol are removed from the crude gas produced by carbonizing coal in the ovens, after which the gas passes into a 1,000,000 cu. ft. Klonne gas holder. Gases leaving the ovens are sprayed to reduce their temperature to 95-100 deg. C before entering the suction main; the pressure at the outlet of the collecting main is 5 mm. water gauge and is controlled by Reavell-Askania regulators. After cooling and separation of the liquor and tar the gas is drawn out by single-stage Rateau turbo-exhausters, of which there are two, each with a capacity of 900,000 cu. ft. per hour. Tar is removed in two electrostatic "detarrers", which remove the tar fog remaining in the gas by maintaining an intense electrostatic field supplied by high-tension direct-current generators in series. In the ammonia-removal plant the ammonia-laden vapour passes through saturators containing acid baths, in which ammonium sulphate is formed. The liquid content of the sulphate is then separated by revolving it in a centrifugal basket at high speed, and after passing through a neutralizing and drying machine the sulphate is bagged and weighed automatically. Benzol is removed in a special plant consisting of three sections, dealing respectively with the creosote oil from the scrubbers through which the gas has just passed, the conversion (in a fractionating column) of crude benzol into a "once-run" product, and the rectification of once-run benzol into motor spirit, etc. The disposal of the sludge from the benzol-washing process, which is in many cases a troublesome problem, is carried out by providing a lead-lined tank full of hot water, into which the sludge is run. A submerged steam coil agitates the contents, causing the acid tar in the sludge to rise to the surface as hard pitch, which is easily removed.
Blast Furnace Plant. There are three blast furnaces, and a fourth under construction as already mentioned, each with an average output of 3,000-3,500 tons per week. Both home and foreign ores are used, some being mined locally at Llanharry. Limestone comes from the company's quarry at Creigiau. If necessary, all incoming ores can be crushed and screened. The ore and limestone, after being weighed, are raised to the gantry by an electric hoist. The ore-stocking space is spanned by an ore transporter with a 12-ton grab.
The four blast furnaces, 95 feet high and 16 feet diameter, are designed on American lines, each consisting of a steel shell supported by steel columns. The hearth jackets are riveted steel plates and are sprayed with water on the outside. Nos. 1 and 3 furnaces have copper-cooled boshes, whilst the other two furnaces have spray boshes. Each furnace has ten tuyeres and two slag notches, and each is fitted with a standard McKee top, which gives very good distribution. There are ten hot-blast stoves, each 95 feet high and 24 feet diameter; they are fitted with Steinbart automatic combustion control burners. Each furnace has automatic blast-temperature control apparatus. All pyrometers and other instruments are arranged in a central house and can be seen through the windows, without the necessity of going inside. Automatic stockline controllers are installed, and recording pyrometers show the temperature of the blast furnace stack at different points. The greater part of the pig iron produced is taken molten, in 60-ton and 120-ton mixer type ladles, to the steelworks; part of the slag is taken to the foreshore and part to a Tarmac dump.
The blowing equipment comprises one impulse multistage turbine driving a single-flow blower delivering 56,000 cu. ft. per min. of free air against a pressure of 15 lb. per sq. in., two five-stage high-pressure Curtis turbines driving three-stage blowers, each delivering 42,000 cu. ft. per min., and (as reserve) two Parsons reaction turbines driving blowers, each delivering 38,000 cu. ft. per min.
Gas-Cleaning Plant. This consists of a two-stage electric filter designed to deal with 8,000,000 cu. ft. per hour at 15 deg. C. and 30 inches of mercury. The main, which has a maximum diameter of 10 ft. 6 in., serves as a collecting point for the gases from the three blast furnaces. The gas is first cooled to 93 deg. C. by water-flushing nozzles, which also remove about 50 per cent of the dust remaining in the gas. The cooling water is run into a Dorr thickener, which separates slurry from the water. A 10-foot hoppered distribution main conveys the cooled gas to the pretreaters, which measure 48 feet x 19 feet, and are 34 feet high. Each contains six banks of electrodes. Mechanical rapping gear dislodges the collected dust. On leaving the pretreaters the gas (at 70 deg. C.) passes to four final coolers, where its temperature falls to 22-26 deg. C. Each cooler is 65 feet high and 14 feet diameter, and gas and water pass through in opposite directions. Fine dust is then separated from the gas in four fine-dust treaters, generally similar to the pretreaters. The electrical equipment includes seven oil-immersed transformer sets for dust precipitation, and seven synchronous rotary rectifiers and high-tension switches. An instrument panel carries all the associated recording instruments.
Melting Shop. This shop was designed as an integral part of a balanced iron and steel works, in which the only fuel used in steel production was to be the by-product gases from coke ovens and blast furnaces. To increase the flexibility of operation, a battery of five Morgan gas machines is installed. A mixture of blast furnace and coke oven gas is used, having a calorific value of 220 B.Th.U. per cu. ft. The shop contains three tilting furnaces of 200 tons capacity, a 600-ton mixer, and two fixed furnaces. In addition two 230-ton tilting furnaces are under construction.
At foreplate level the mixer is 50 feet long x 18 feet wide, and is 6 ft. 7 in. deep on the centre line. Tilting is effected by rack and pinions driven by a 180 b.h.p. motor; the mechanism is fitted with a "dead man" pedal, so that the furnace returns to dead centre if pressure on the pedal is released. The reversing valve system consists of watersealed gas inlet valves, with exhaust valves of the water-cooled sliding-damper type. Waste-heat boilers are attached to all the tilting furnaces, and to the small furnaces and mixer, the steam generated by the former being 20,000 lb. per hour and by the latter 10,000 lb. per hour. The tilting furnaces are essentially of the same design as the mixer, the hearth being 47 feet x 14 feet, and 3 ft. 7 in. deep.
Iron from the mixer is discharged on the casting side into a ladle on a transfer car which passes under the mixer and is lifted through a hatch for charging into the steel furnaces; this arrangement ensures that the charging of the mixer or furnaces does not interfere with tapping the steel. Test pieces from the mixer are sent by pneumatic tube to the laboratory. After pouring, the ingots pass to a stripper house where the moulds are removed; overhead cranes then carry the ingots to the soaking pits.
Soaking-Pit Plant. The heated ingots pass, after stripping, into holding pits, which have a combined capacity of 140 ingots; here they are stored until required in the soaking-pit furnaces. There are seven twin-pit soaking-pit furnaces, each half pit accommodating ten ingots of 3-4 tons weight. The pits are very uniformly heated with blast furnace gas introduced cold before mixing with preheated air. This arrangement enables great flexibility of temperature control to be obtained.
Blooming Mills. The rolls are 40 inches diameter and 8 feet long, capable of rolling 3-ton ingots down to 5-inch blooms at the rate of 90 tons per hour. The mill is driven by an 18,800 h.p. reversing electric motor through a Bibby flexible coupling, and the screw-down gear by two 75-150 h.p. motors. The mechanical guides have electrically operated manipulator fingers driven by 30 h.p. motors, mounted on the guides, through the medium of worm gear boxes and connecting rods. The rollers of the working tables are of forged steel, other rollers being of cast iron. All rollers run in whitemetal oil-lubricated bearings. Lubrication of the pinions and pinion bearings is effected by oil under pressure, and that of the manipulators and screw-down gear by multifeed grease pumps. The roll necks run in fabric bearings lubricated with water only. When rolled, the blooms pass to a shear of the vertical upcutting type driven by a 350 h.p. motor, and capable of dealing with 12-inch x 12-inch sections. A motor-driven measuring stop to measure up to 20 feet is provided. The crop pit is situated beside the shear and contains three crop-end buckets which are emptied into specially designed wagons. If required for the continuous mill, the cropped bloom, weighing 3-4 tons, passes on to that mill without reheating. Cut blooms are pushed on to a pawl type transfer bank and distributed as required, by overhead cranes.
Continuous Sheet-Bar and Billet Mill. This mill comprises six horizontal stands of rolls with two vertical edging stands, and can roll billets down to 2-inch x 2-inch sections and sheet bars down to 1/4-inch thickness and 16 inches maximum width. The full-load output of the main motor is 4,000 h.p. and that of each of the edging mill motors is 125 h.p. Blooms are cut or cropped, whilst in motion, by a shear of the pendulum type, before entering the mill. When rolled, the billets or bars are cut to length by a steam-driven flying shear controlled electrically from the measuring device, and then pass on to a double cooling bank, each section being 84 feet long and 30 feet wide. Sheet bars are delivered to pinch rolls and a bar-piling frame from which the bars are lifted by an overhead claw crane.
Light-Section Mill. The 21-inch light-section mill is of the three-stand three-high type, with motor-driven tilting tables in front of and behind each stand. The two roughing stands are coupled together and driven from the pinion housing by a 1,500 h.p. motor, through single-reduction gear. The control gear will give any rolling speed between 130 and 60 r.p.m. A variable-speed 1,200 h.p. motor drives the finishing rolls; the maximum mill speed is 160 r.p.m. All the chocks have water-lubricated fabric type bearings.
Blooms for this mill are heated in a continuous furnace, of the cross-fired automatic reversing type, fired with blast furnace gas. Air only is regenerated, the gas being preheated in metal recuperators. The heating capacity is 25 tons of 8-inch x 8-inch x 16-foot blooms per hour. The sections rolled in the mill are delivered to two motor-driven saws, which are adjustable so as to ensure the maximum throughput when cutting multiple lengths. Finished material, after cooling on either of two cooling banks 60 feet wide and 72 feet long, is pushed into delivery pockets and removed by overhead crane for dispatch or transfer to the finishing departments.
Gas Distribution. A Klonne 3,000,000 cu. ft. waterless gas holder acts as a storage and pressure-balancing medium for the works supply. The piston weighs 275 tons and the sealing ring consists of two bands of special composition packing. At present 1,200,000,000 cu. ft. of gas are cleaned and consumed per week. The scrubbed coke oven gas has its own Klonne gas holder and distributing system; about 65,000,000 cu. ft. is distributed per week, of which 80-85 per cent is consumed in the melting furnaces. Each melting furnace has its own apparatus for mixing blast furnace and coke oven gases. Orifice plates and flow recording meters are fitted into each main to show whether the mixture is correct. Pressure regulators are fitted to the mains supplying the soaking pits and the billet reheating furnace.
The works automatic telephone system places the control house attendant in communication with all consuming units; arrangements have been made so that telephones on the gas distribution system have priority over all others. Loud-ringing relay bells are worked in conjunction with the telephone service in order to attract the immediate attention of the furnace operators. The control house attendant is informed of the gas stock available by the movements of a mechanical gas-stock indicator on each gas holder, which actuates Midworth distance repeaters and electrical transmitters. Gas shortage in any holder is signalled by an alarm relay which sounds a Klaxon horn and causes a red light to show.
Steam-Raising Plant. There are two principal sections, the main boiler plant and the waste-heat boiler plant, delivering steam at 160 lb. per sq. in. into common mains. The main boiler plant consists of six Babcock and Wilcox water-tube boilers with combustion chambers fitted with Harrison gas burners; each boiler is rated at 12,000 lb. of steam per hour, and can burn blast furnace gas, coal, or coke breeze, and arrangements have been made to fit oil burners. There are also four Spearing water-tube boilers, each rated at 12,000 lb. per hour, and two 30-foot x 9-foot Lancashire boilers, each rated at 8,000 lb. per hour, and, in addition, two Babcock and Wilcox water-tube boilers which may be fired with blast furnace gas or powdered fuel. Four John Thompson water-tube boilers were installed in 1936, each having a heating surface of 7,000 sq. ft. Forced draught and chain-grate mechanical stokers are provided, suitable for burning coal, coke breeze, or a mixture of both. Each boiler normally evaporates 35,000 lb. per hour.
The waste-heat boilers receive waste gases from the steel furnaces and mixer furnace. Each 200-ton tilting furnace is provided with a Spencer-Bonecourt twin-drum boiler, evaporating 15,000-20,000 lb. per hour. The mixer and the two 80-ton fixed furnaces each have an Adamson single-drum boiler evaporating 8,000-12,000 lb. per hour. Incoming feed make-up water can be softened in a Kennicott plant when necessary.
The total hourly consumption of steam in the works is 180,000-190,000 lb., of which approximately 100,000 lb. is consumed by the blast furnace turbo-blowers and the blast furnace water-cooling pumps. This water is condensed and returned as boiler feed. The remainder of the steam is used by the coke ovens exhauster engine, hydraulic engines, direct-current turbo-generator, and general works services.
MESSRS. WILLIAM HANCOCK AND COMPANY, LTD. THE BREWERY, CARDIFF
The firm was founded in 1883, and during its growth has absorbed numerous brewery concerns throughout Wales; at the present time there are about 1,100 employees. The brewery and bottlery at Cardiff have been kept up-to-date by the constant adoption of new types of plant. A reconstruction of the main fermentation wing of the brewery has just reached completion, and the bottlery, which has been remodelled only recently, is about to acquire still further additions of equipment.
MESSRS. LOVERIDGE, LTD. CARDIFF
The business was established over 50 years ago and specializes in the manufacture of pulley blocks, straining screws, and ships' steering-gear buffers of every type and size up to the largest capacity. These are afterwards tested on a hydraulic testing machine, certified by the Board of Trade, which is capable of exerting a pull of 100 tons. The firm also carries on an extensive business in general engineering work of all kinds, manufactures feed water heaters and steam dryers, and a gravity boat davit. Profiling work by means of "oxy-coal" gas and oxy-propane flame cutting is also carried out.
MOUNTSTUART DRY DOCKS, LTD.
The firm owns three dry docks in Cardiff, with repairing jetties and berths of the following dimensions No. 1, 440 feet long x 53 feet wide; No. 2, 440 feet long x 62 feet wide; No. 3, 550 feet long x 66 feet wide. The Channel Dry Dock (635 feet x 75 feet) and the Bute Dry Dock (600 feet x 56 feet) are also owned by the firm, in addition to the 335-foot Channel Pontoon. The equipment of the workshops enables repairs to be carried out to vessels of all types, and the company has made a speciality of Diesel engine overhauls. The Mountstuart Dry Docks are situated outside the wet docks, so that vessels can come straight from sea to the dry docks, and return to sea without incurring port or harbour dues. The Bute Dry Dock has been specially adapted for dry-docking fully laden vessels. Equipment is also available for emergency repairs to breakdowns in all wet docks and in roads.
MESSRS. D. MORGAN REES AND SONS, LTD., WHITCHURCH, CARDIFF
In the works can be seen all the processes in the manufacture of wire and wire ropes. The wire is drawn from steel rods, obtained principally from Cardiff, and every quality and size of wire is made for the requirements of the wire rope department established by the firm on the same site. The principal finished products are winding, haulage, and ropeway ropes for collieries and mines, also wire ropes for the engineering, shipping, and deep-sea trawling industries, and for all other purposes.
MESSRS. SPILLERS, LTD. CARDIFF
The firm was founded by Joel Spiller, of Bridgewater, who established a business as a flour merchant in 1830. He later took over the milling side of the business and by 1850 he controlled three water mills and one steam mill. He later went into partnership with Mr. Samuel Browne, who developed the firm's market in South Wales. In 1890 an amalgamation with Messrs. William Baker and Company, of Bristol, took place, and the business was for many years known as Spillers and Bakers, before reverting to its present title.
The firm has recently built a complete new group of silos, flour mills, factories, and warehouses on a site alongside the Roath deep-water dock, to replace the older separate buildings scattered over various sites. The unloading of grain, etc., from the larger vessels into barges for conveyance to the mills is thus eliminated, as the present jetty is 800 feet long, so that two 10,000-ton vessels can be unloaded simultaneously.
The new buildings form a quadrangle, and cover 44 acres. The south side is occupied by the eight-story reinforced concrete silo, which is 174 feet high and has a capacity of 30,000 tons. A seven-story screen room and flour mill forms the east side, and contains, first, the machinery for screening, scouring, and washing the wheat, and second, the mill proper, which consists of a series of graduated milling machines. The engine rope race, which divides the building into these two sections, is surmounted by a sprinkler tower, in case of fire. The west and north sides of the quadrangle are respectively given up to the animal foods factory and to the seven-story warehouse. The other buildings on the site include a bakery for dog biscuits and ships' biscuits, and the administrative offices and staff dining-rooms.
On arrival at the jetty the grain is unloaded by electrically driven intake plants which draw the grain from the holds on to covered conveyers travelling to the silo. The maximum rate of discharge is 250 tons per hour, with the whole plant in operation. All the grain is weighed automatically, the quantities being recorded in 2-ton units, before the preliminary cleaning process. The setting of the direct and cross-arm chutes determines the route of the grain to its appropriate bins in the silo. Although primarily flour millers, the company also produce large quantities of foods for cattle, dogs, and poultry.
After screening, blending, scouring, and washing, the grain passes to the crushing and refining processes. The flour-milling machines are driven by a 1,300 h.p. electric motor, and the total hourly output is 100 sacks of 280 lb.
The various grades of flour travel by conveyers to the warehouse, where an interesting series of spiral sack chutes is installed. The railway sidings lie between the warehouse and the dock, and belt conveyers are used for loading both railway vans and barges or steamships. The vessels berth against the dock end, as the jetty is reserved for vessels with import cargoes. There are in addition a number of loading platforms at the north side of the warehouse, which are devoted to the dispatch of the firm's products by road motor vehicles.
THE UNIVERSITY COLLEGE OF SOUTH WALES AND MONMOUTHSHIRE
University College, Cardiff, is one of the four constituent colleges of the University of Wales, the sister colleges being those of Aberystwyth, Bangor, and Swansea. The college was opened in 1883, in buildings which were formerly the old Infirmary, in Newport Road, but it was not until ten years later that the University of Wales was established. Later still, 5 acres of the Bute estate in Cathays Park were secured, and new buildings were designed by the late Mr. W. D. Carne. The first of these was opened in 1909, and the Tatem Laboratories of the chemistry and physics departments were added in 1930. In the completed scheme it is envisaged that the buildings will extend along the four sides of a central court. At present only the main block along the front, and the Tatem Laboratories along the north side have been built. In these "New College" buildings in Cathays Park are housed the administration offices, the Drapers' Library, the departments of the Faculty of Arts, and certain of the science departments. In the "Old College" buildings on the Newport Road site are other science departments, some of which will ultimately be transferred to New College, and the Welsh National School of Medicine, which no longer forms an integral part of the College. On the Newport Road site are also the applied science departments, including the engineering, metallurgy and fuel technology, mining, and geology departments.
Department of Engineering. The Engineering Department, which was opened in 1890, is divided into four branches: (1) civil, (2) mechanical, (3) electrical, and (4) building. The Testing of Materials Laboratory contains a 100-ton hydraulically operated horizontal universal Buckton machine, an electrically driven 50,000 lb. universal Riehle, a 10,000 lb. Olsen, an Avery torsion, Charpy and Izod impact, Amsler and Howden hardness testing machines, cantilever, and other fatigue testing machines, with various extensometers and subsidiary apparatus. In the structures laboratory are various instruments for the mechanical analysis of rigid frames, a soap bubble apparatus, etc. There is a separate laboratory for cement and concrete work, with the usual equipment, and sand-blast and other apparatus for the testing of building materials.
The steam plant comprises a Babcock and Wilcox water-tube boiler, designed for a working pressure of 250 lb. per sq. in., fitted with a superheater; a vertical compound Belliss and Morcom steam engine, arranged to drive either a Bruce Peebles dynamo or a Belliss air compressor; and a Marshall horizontal compound steam engine fitted with drop valves and Meyer expansion gear. There is also a De Laval steam turbine, driving a 10 kW. generator, arranged to supply direct current or three-phase alternating current. Other heat engines are a 5 h.p. Crossley gas engine, an Aster petrol-electric set, and a Petter oil engine.
The hydraulics plant includes a motor-driven three-throw plunger pump, a Mather and Platt two-stage centrifugal pump, a V-notch tank and Lea recorder, a Venturi meter, and apparatus for measuring the flow of water in pipes, etc.
In the electrical laboratory a comprehensive range of measuring instruments including high-accuracy potentiometers, etc., is available for calibration purposes. Two oscillographs are included in the equipment, one being of the cathode ray type. The machines for experimental purposes include direct-current shunt, series, and compound excited machines and various types of motor-generator sets, with auxiliary equipment; and alternating-current machinery comprising single-phase and three-phase induction motors, a commutator motor, a synchronous induction motor set, a three-phase rotary converter, and various single-phase and three-phase transformers. There is also available a large range of apparatus such as thermionic valves and accessories, from which can be built valve generators, amplifiers, bridge networks, etc.
The Department of Metallurgy and Fuel Technology. In addition to the usual equipment for practical work in assaying, chemical analysis (including the determination of oxygen and nitrogen in steel), microscopy, and physical metallurgy, the department has well-equipped fuel laboratories, with standard apparatus for the testing of gaseous, liquid, and solid fuels.
The mechanical laboratory includes the machinery for the preparation of specimens for the general mechanical testing of metals and alloys, an electrically driven 60 lb. power hammer giving 250 strokes per minute, and a Robertson three-high, 24-inch non-reversing mill with a rolling speed of 60 ft. per min.
The heat-treatment plant includes gas and electric furnaces, pyrometers, thread recorder, a Cambridge automatic temperature-control outfit, and a nitriding plant. The department has an interesting museum and an up-to-date library.
The Department of Mining. This department is equipped for the training of mining engineers, and includes a number of laboratories in which the varied branches of mining technology are studied. Amongst these is a laboratory for the analysis of mine air, and a well-equipped laboratory for the study of mine illumination. Facilities are available for the study of coal preparation, and the preparation of minerals. A compressor has been installed, and a number of machines are operated by compressed air; fans and fan ducts are utilized for the study of ventilation.
WESTERN MAIL AND ECHO, LTD. NEWSPAPER OFFICES, CARDIFF
The present firm is the result of the amalgamation some years ago of the two daily and two evening newspapers published in Cardiff, and constitutes one of the largest of the provincial newspaper offices.
The automatic printing telegraph equipment includes the new "Creed" five-unit start-stop direct printer. The composing room comprises thirty-eight type-setting machines, of which thirty-four are "Intertype", one "Linotype", and three "Ludlow" machines. The installation of "Intertype" machines is one of the largest in the country. The formes of type are passed to the matrix rolling machine, after which the metal slugs of type are remelted. The foundry and machine room are situated in the basement. Rotary drying machines heated by gas are used to dry the matrices. Casting takes place in "Junior" autoplate machines, each machine carrying 5 tons of molten metal. The cast plates are transferred to an "Autoshaver", which bores them out to the correct thickness within one thousandth of an inch, before they are placed on the presses. The latter comprise seven individual machines, each capable of producing 60,000 copies of an 8-page newspaper per hour. They can, however, produce papers of up to 32 pages at a correspondingly lower delivery rate, and the flexibility of the plant is still further increased by the fact that six of the machines are so placed that they can be coupled up in pairs to form three big machines, each capable of printing a 64-page paper.
Power is supplied by the Corporation mains. There is an electrical control room in the basement, of very recent design. Each of the presses is driven by a 50 h.p. motor situated directly beneath the machine, but controlled from the control room. The process department for the production of half-tone blocks is capable of producing a complete page of pictures in two hours.
ABERDARE CABLES, LTD.
The factory was built last year in response to the Government's appeal to industrialists to establish new works in the Special Areas. The main building is of steel, concrete, and glass, and is 450 feet long and 150 feet wide. Electrolytic copper rod 1/4-inch in diameter is used in wire-making and, after being drawn, is tested for chemical and mechanical properties. Annealing is then carried out in either of two 75 kW. furnaces with thermostatic control. The correct finish is provided by passing the wire through an atmosphere of inert gases; it is then allowed to cool to 180 deg. C., after which cooling to room temperature is effected by water.
The annealed copper strands, from 7 to 127 in number, travel to stranding machines equipped with pre-twisting devices. The insulation (wood pulp or Manila paper) is then applied to the copper core by machines fitted with tangential heads to ensure tight lapping and correct registration. Laying-up machines take the lapped cores; they carry micrometer adjustment on each flyer to ensure that the pre-twisted cores are set in their correct positions. Oil-impregnation is then carried out in jacketed vats. Oil for this process arrives direct from the refinery in 12-ton heated tankers, and is dehydrated and filtered. Drying ovens first remove all moisture from the cables before impregnation, which can be effected at any pressure from atmospheric to 80 lb. per sq. in. The vats are heated by superheated hot water, and a vacuum of 1 mm. of mercury is maintained.
Lead presses, which can extrude lead covers up to 4 inches in diameter, receive the impregnated cables; they are provided with electrically heated die-blocks furnished with thermostatic control. Twin melting pots for the lead are so arranged that the dross rises to the top of the first pot, and pure lead is drawn off into the second, which supplies the press. Steel-tape and wire armouring machines apply both jute and Hessian servings, after which the finished cables are coiled for testing in either a wet or a dry tank in accordance with the requirements of the British Standard Specification. Cables for all voltages up to 11,000 are manufactured.
The firm manufactures its own cable drums, and has taken great pains to secure interchangeability of machine parts. All bobbins, for instance, are of one size, and are common to all the machines. A high-pressure La Mont boiler supplies steam for heating and process work, and a hot-water main carrying a pressure of 120 lb. per sq. in. is installed throughout the works. The circulating pump is installed on the return side of the boiler, instead of the flow side, so that if any abnormal flow occurs the maximum pressure is that of the boiler, which will cause isolating valves in the pump circuit to close automatically. The boiler is fired by a "Robot" mechanical stoker, and there is a large independent storage drum to which a second boiler could also be connected. Electrical power is obtained from the South Wales Electrical Power Company at 11,000 volts, and is transformed in the factory substation to 400 volts.
ABERTHAW AND BRISTOL CHANNEL PORTLAND CEMENT COMPANY, LTD.
The company was incorporated in 1912, and to-day owns two Portland cement works, one at Rhoose about 13 mild west of Cardiff, the other at Aberthaw about 2 miles farther west. The Rhoose works were acquired in 1919. The manufacture of Portland cement was commenced at Rhoose in 1913, and at Aberthaw early in 1914. Both works are situated on the famous blue lias limestone deposit. At Aberthaw the company has about 300 acres of leasehold land, and at Rhoose about 150 acres of freehold and leasehold land, thus ensuring almost inexhaustible reserves of raw material.
The raw material consists of limestone and shale and at Aberthaw is quarried by means of an electrically operated excavator mounted on caterpillars, having a bucket capacity of 4.33 cu. yards. The material is transported to the crushers and screening plant, and the excess shale is disposed of by means of an aerial ropeway. The screened raw material passes to classification silos; thence to the wet milling department, consisting of three mills of the latest type. The thick slurry then passes to the correction and storage mixers, two of which are of recent design with air agitation, etc., preparatory to calcination.
At Aberthaw works there are three kilns, each 200 feet long, with separate coolers. Two of the kilns are being equipped with patent slurry dryers and enlarged coolers, while the third kiln is fitted with the chain system. At Rhoose works there are two kilns, 212 feet long, of the solo type, which will shortly be fitted with chains, and which will be fired with the latest type of air-swept coal mill. The total potential output of the two works is about 450,000 tons per annum.
A feature of the Aberthaw plant is that the old system of conveyers and elevators has been superseded by the overhead crane and grab system for handling clinker from coolers to store and from store to the clinker grinding plant. The same crane also handles the gypsum. The clinker grinding plant consists of two 24-ton combination mills, each equipped with a 1,000 h.p. alternating-current motor. The product of the mills is transported to the storage silos by the Fuller-Kinyon air pumping system. The capacity of the cement silos at the two works is 24,000 tons.
A modern power station at Rhoose, with two 3,250 kW. generators, supplies power to both works, that required at Aberthaw being conveyed by means of a 33,000-volt transmission line. A transformer at the receiving point reduces this voltage to 3,300. A point of interest is that the standards supporting the line are 1,000 feet apart; this is the first high-voltage line in England to have such long spans. Two modern lime kilns have been constructed at Aberthaw for the production of hydraulic lump and ground lime.
The proximity of both works to the South Wales ports affords excellent facilities for dispatch. Cement is sent coastwise in the British Isles, and exported to all parts of the world. The chief method of packing is in paper sacks, but the company also packs cement in jute sacks, metal drums, and wooden casks (a cooperage at Rhoose is capable of producing 200,000 casks per annum), while facilities are also available for loading in bulk.
Constant laboratory tests are made during manufacture by a highly trained staff, who are also employed in testing samples of aggregate, sand, etc., received from customers. The cement manufactured by the company always provides a very considerable margin of superiority over the requirements of the British Standard Specification.
THE BRITON FERRY STEEL COMPANY, LTD. ALBION STEEL WORKS, BRITON FERRY
The firm was founded in 1889 and has gradually grown until to-day it owns and operates two steelworks, nine tinplate and "blackplate" works, consisting of forty-five tinplate mills and seven blackplate mills, one stamping works, and one foundry and engineering works. The range of products covers all qualities of steel ingots, sheet and tinplate bars, and billets. The blackplate and sheet works specialize in "silver finish" sheets, whilst the engineering works manufacture ingot moulds, special tinplate cleaning machines, and other equipment. This group of works is the second largest in Great Britain for the manufacture of tinplates and black sheets, and has an annual production of 300,000 tons of steel bars and billets, 2.25 million basis boxes of tinplates, and 100,000 tons of blackplates and other sheets and "tiles".
Both the Albion and Briton Ferry steel works are admirably situated, on either side of Briton Ferry Dock, with their own private wharves on the river side. During recent years the company have concentrated on the modernization of their Albion steel works.
The smelting shop contains six open-hearth furnaces (a seventh being under construction) with a total capacity of 3,600-4,000 tons per week. The furnaces are of the conventional type, and it is the intention of the company in the near future to install modern gas machines to work in conjunction with them. Steam is supplied by two water-tube boilers of the Stirling type, with chain-grate stokers of special design suitable for burning anthracite duff as fuel. Each boiler has a capacity of 36,000 lb. of steam per hour, and the plant is operated in parallel with six waste-heat boilers attached to the steel furnaces and soaking pits.
As the steel works mill and generating station are of such recent construction, a detailed description of each will be of interest. The ingots, which weigh 30 cwt., are heated in soaking pits of the Stein and Atkinson non-reversing recuperative type, the mill being the first in the country depending entirely on pits of this design for heating. After stripping, the ingots are passed from the casting pit by means of a gravity chute, whence they are picked up by the ingot charger. They are then conveyed from the soaking pits by means of an ingot carriage running on a track direct to the roughing mill, thus reducing crane work to a minimum. The mill rolling train is of the two-high type, and comprises a roughing stand with rolls 32 inches diameter by 83 inches long, and a finishing stand with rolls 30 inches diameter by 71 inches in body length. Both the roughing and finishing stands are equipped with electrically operated screw-down and balancing gear, a special feature of the finishing mill being the pre-selector screw-down gear.
Provision is made on the finishing mill for vertical edging rolls, thereby converting this stand into a universal mill. At the front and back of the roughing mill are electrically operated manipulators with a tilting arrangement on the front side of the stand. An extended roller track connects to a blooming shear, capable of cutting blooms and billets up to 7 inches square and slabs up to 24 inches by 2 inches. A live roller track, 250 feet in length, each roller being independently driven by its own motor, extends to a planishing mill.
The planishing mill comprises a three-high stand with rolls 28 inches, 14 inches, and 24 inches diameter by 32 inches wide, and electrically operated screw-down gear. This planishing mill is fitted with a special bar scraper gear working in conjunction with an air hydraulic accumulator, delivering water at a pressure of 1,000 lb. per sq. in. From the planishing mill the motor roller track continues a further 250 feet to the finishing shears. Foundations are also laid down for the requisite number of similar stands for producing steel strip 20-28 inches wide by 10-16 I.W.G.
Power for operating the mill is provided by a Metrovick turbo Ilgner generator set of the self-contained type. The condensers are constructed integral with the turbine, and the set requires no basement. All the auxiliaries are directly driven. The drive is provided by two turbines, each of 4,200 h.p., arranged one on each end of the set, and operating with steam at 160 lb. per sq. in. pressure and 200 deg. F. superheat. Automatic control is provided for the purpose of sharing the load evenly between the turbines, which operate at 5,000 r.p.m. and drive through double reduction gearing, giving a generator speed of 500 r.p.m. Since the drives to the roughing and finishing mills are by direct current with Ward-Leonard control, the generator set includes two separate 2,400 kW. 650-volt d.c. generators for the power supplies to these motors. The set also includes two 1,000 kW. 220-volt d.c. generators, supplying power to the 750 h.p. polishing mill motor, the mill auxiliary drives, which are operated by direct current, and a motor-generator set for certain auxiliaries fitted with alternating-current motors.
The roughing and finishing mills are arranged in line, and a mechanical coupling is provided between them so that either motor can drive both mills at reduced load when required. The control arrangements for the main motors automatically provide for limitation of the peaks and rates of acceleration and deceleration if necessary. Apart from safeguarding the plant, this system helps to avoid unnecessary stoppages, since the circuit breaker is tripped only in cases of emergency. During the rolling of the ingots the power consumed on each "pass" is automatically recorded in the power station. This enables a close check to be maintained on the rolling operations throughout manufacture.
GREAT WESTERN RAILWAY COMPANY CAERPHILLY LOCOMOTIVE WORKS
Caerphilly Works, situated about 6.5 miles north of Cardiff, is one of the principal locomotive repairing depots of the Great Western Railway, and employs approximately 700 men. It stands on about 17 acres of land and comprises the following main shops: erecting, boiler, boiler mounting, heavy, and light machine, wheel, smith, and spring, coppersmiths' and whitemetalling, grinding and polishing, together with several minor shops and appropriate stores. The whole of the plant is electrically driven.
The erecting shop, which has space for some 60 locomotives of the tank type with which the works deal exclusively, consists of two main bays and a traverser between them, while over each bay is an 80-ton gantry crane having two heavy and two light lifts, and sufficient headroom to lift a completed engine over the top of engines standing on adjacent roads. The boiler shop has a capacity for about twenty boilers in two bays, each served by a 35-ton overhead gantry crane.
The works are well situated geographically, close to junctions leading to all parts of South Wales and the Midlands, and at the time of the grouping of the railways were selected to be brought up-to-date to deal with tank engines working in the South Wales area. The development of Caerphilly works made possible the closing of other works in the area and the transference of the men to Caerphilly, thus centralizing locomotive repair, storage of spares, etc.
Carriage and wagon repairs, which had been carried on at Caerphilly prior to the grouping, were discontinued in 1932, and the work transferred to other depots in the district, but an up-to-date carriage lifting and painting shop is now being built alongside the old carriage shops, which have been modernized, and on completion of the new buildings a certain amount of carriage repair work will again be undertaken at Caerphilly.
THE MOND NICKEL COMPANY, LTD. CLYDACH
The ore from which the nickel is derived is mined in the Sudbury district of Northern Ontario. After concentration, the crushed nickel ore is conveyed first to roasting furnaces, and then to basic-lined converters, where sulphur and other impurities are removed. From the resulting matte the copper is separated by heating in a cupola. A second smelting is then carried out, and the nickel-rich product is calcined to remove further sulphur before it is shipped to South Wales.
The refining process carried out at Clydach is derived from a chance discovery made fifty years ago by Dr. Ludwig Mond. Some nickel valves used in his process for distilling ammonium chloride began to leak through the formation of a black crust. This was found to be carbon, deposited from carbon monoxide, which was present in the carbon dioxide used to sweep ammonia from the apparatus. Further investigations showed that carbon monoxide had a much greater affinity for nickel than for other metals, uniting with it to form a gaseous compound, nickel carbonyl. Mond used the fact that the volatile nickel carbonyl is easily decomposed at 180 deg. C. into nickel and carbon monoxide, as the basis of his process for refining nickel. This essential process has remained unchanged since the Clydach works were built thirty years ago.
The material received at the refinery contains a little sulphur and copper and a small proportion of the precious metals. It is conveyed to a 100-ton storage hopper feeding two ball mills of the three-chamber air-swept type, in which it is pulverized. A cyclone separates the fine material from the coarse, which is returned to the mills via a magnetic separator which removes uncrushable magnetic material. The fine material then passes to one of six 300-ton storage bunkers. Calcination takes place in twelve single-hearth rotary calciners, the hearths being 8-10 metres in diameter, and rotated by a 3 h.p. motor driving through a three-speed gearbox. Three producer gas burners maintain the temperature in the calciners at 650-700 deg. C. The capacity of the calciners is 1,500-2,000 lb. per hour. The flue gases pass through dust catchers to precipitators of the twin-rod curtain type, working at about 48,000 volts, with a dust-catching efficiency of 99 per cent. After calcining the material passes along water-cooled conveyers to mobile containers which are taken to the "nickel plants" for the last three stages of nickel extraction, namely, reduction, volatilization, and decomposition.
One side of each nickel plant is occupied by reducers and volatilizers, and on the other side the nickel carbonyl is decomposed to give nickel and carbon monoxide. There are five reducers in each plant, in which about 70 per cent of the nickel oxide is reduced to fine "metallics". It then passes forward to six volatilizers in series, where some 36 per cent of the total nickel fed is volatilized as carbonyl. The material from the sixth volatilizer passes through two more reducers and then four more volatilizers. After a final last reduction in another reducer, it passes through three more volatilizers, and is finally discharged as "concentrate 1".
The first reducer is continuously fed at a rate of about 36,000 lb. per day, while a further 12,000 lb. per day is fed to the sixth reducer, to mix with the residual material leaving the first six volatilizers. The total time for the complete passage through the plant is 10.5 days, i.e. about 5 hours for each reducer and 16 hours for each volatilizer.
The reducers are vertical, gastight structures, built up of twenty-one cylindrical cast iron sections, 6 feet in diameter, with a central hole 22 inches in diameter. In each section is fitted a horizontal cast iron plate with a central hole and six supporting lugs, which fix the plate in the middle of the box. A central vertical shaft carries and rotates a series of scrapers on each box and plate. The material falls on the top plate, is pushed to the outer edge by the scrapers, and thence falls to the bottom of the first box. From this position it is pushed to the central hole through which it falls to the next plate and so on, until it enters the exit conveyer at the bottom.
A reduction temperature of 350-400 deg. C. is maintained by a hot-air circulating system, the hot gases passing through a cylindrical heating box in each section. The necessary heat is derived from a combustion chamber, fired by producer gas, on the inlet side of the fan. Temperature control is maintained by thermocouples.
Water gas, entering the top and leaving the bottom of the reducer, provides the necessary hydrogen for the reduction process, which is interesting in that it is accomplished at so low a temperature that the carbon monoxide effects only about 3 per cent of the reduction, about 97 per cent being due to hydrogen. The reaction with hydrogen, although an endothermic one, is, at the temperature employed, from 20 to 40 times as rapid as the exothermic reaction with carbon monoxide. The result of the greater activity of hydrogen in the reduction is to give an "end gas", which, after removal of the water formed by the hydrogen, is very rich in carbon monoxide and is thus suitable for the formation of nickel carbonyl in the volatilizers.
The volatilizers are similar to the reducers, except that no heating appliance is necessary. The reaction is exothermic, and the heat evolved is dissipated by radiation and conduction, a temperature of about 60 deg. C. being maintained. The reduced material travels downwards through each volatilizer, where it is brought into intimate contact with an upward stream of "plant gas" of high carbon monoxide content.
In the decomposing apparatus the carbonyl gas comes into contact with nickel pellets heated to a temperature of about 180 deg. C. This causes the dissociation of the carbonyl, nickel being deposited on the pellets and carbon monoxide being liberated. Close temperature control is necessary, since at 200 deg. C. the carbon monoxide is liable to break down into carbon and carbon dioxide.
A decomposer consists of a cylindrical cast iron base, carrying six cast iron decomposer boxes, one above the other. Each box carries an external gas ring with burners, and is heated by producer gas. The decomposer is filled with nickel pellets before being put in circuit and holds about 9 tons. In order to prevent the pellets from cementing together with freshly deposited nickel, they are kept moving, being returned from the bottom box to the top box of the decomposer by a bucket elevator. The deposition of nickel on the pellets naturally increases their size and a conduit is provided so that the excess at the top of the decomposer overflows into a box at the base. The contents of this box represent the "make" of the particular decomposer.
The ingoing gas is supplied to a central vertical tube and passes from this through shielded outlet holes in the middle of each decomposer box. After percolating between the pellets and depositing its nickel it leaves through a water-cooled outlet ring placed between each pair of boxes, is collected in a common vertical main, and is recirculated through the volatilizers. This plant gas circulates between the decomposers and volatilizers in a closed circuit, wastage being made up with carbon monoxide formed by the decomposition of liquid nickel carbonyl supplied by a medium-pressure plant. There are forty decomposers in each nickel plant.
The medium-pressure plant utilizes "concentrate 1", which is recalcined, passing through additional reducers before being charged to pressure volatilizers. Here it is subjected to gases at 300 lb. per sq. in., containing 60 per cent carbon monoxide. The exit gases pass through coolers, where most of the carbonyl is condensed, the balance being recovered from the residual gases by allowing them to expand to atmospheric pressure.
Special qualities are required in the water gas used at Clydach. It is essentially an agent in a chemical process, and the proportions of inert gases such as nitrogen and carbon dioxide must be kept to a minimum. As the methane content must also be kept low, anthracite or coke must be used as fuel. The general methods of production are, however, the same as for ordinary water gas, but the gas made during the first half-minute of each steam blow is rejected because of its high content of inert gases.
A subsidiary industry at Clydach is the production of nickel sulphate and nickel ammonium sulphate, which are much used in electroplating. The process is carried out on the reduced material, which is "leached" with sulphuric acid. Iron is removed by oxidation and filtration, and the remaining liquor is concentrated in vacuum evaporators, for conversion into large crystals (by slow cooling) or powder (by rapid cooling in mechanically agitated containers). Nickel ammonium sulphate is made by adding the requisite ammonium sulphate solution to purified nickel sulphate liquor and crystallizing the double salt.
MESSRS. RICHARD THOMAS AND COMPANY, LTD. EBBW VALE
There have been iron and steel works at Ebbw Vale since the year 1786. In 1935 the present company purchased the works, which included a site 2.5 miles long by 3/4 mile wide, as well as five collieries and the iron ore field at Irthlingborough, Northants.
The site had the following advantages: coal and limestone were adjacent; it was in a distressed area with plenty of labour available; it was near a seaport; it was well served by railways; power and water were available; and finally, in time of war it was remote from attack. The output of the new plant is 600,000 tons per annum of finished and semi-finished products direct from the essential raw materials.
Coal is converted to coke in the new coke ovens, to which is attached a complete by-product plant, The coke is conveyed into bunkers behind the blast furnaces, and the gas is conveyed to a 1,000,000 cu. ft. holder for use in the works. Limestone is stored in 7,000-ton bunkers, and ironstone in a stockyard capable of holding 175,000 tons. Sintering and crushing are carried out at Irthlingborough, so that the ironstone is received at Ebbw Vale ready for use. The two blast furnaces each have a capacity of 3,500 tons of pig iron per week. Alongside them is an electrostatic plant for cleaning the blast furnace gas, which is then conveyed to a 2,000,000 cu. ft. gas holder for use in the works, Slag-grinding and lime-burning plants are also installed.
South of the blast furnaces is a new high-pressure boiler plant, consisting of three boilers, each working at 350 lb. per sq. in. and producing 100,000 lb. of steam per hour, in addition to the old battery of boilers, consisting of two 40,000 lb. per hour and eighteen 20,000 lb. per hour boilers, all working at 160 lb. per sq. in. In the adjacent power house is one 12,500 kW. high-pressure turbine and three 5,000 kW. low-pressure turbines as standby, the remainder of the power, some 40,000-50,000 kW., being obtained from the national grid.
Hot metal from the blast furnaces is taken direct to the steel works. In addition, a pig-casting machine is provided to deal with any surplus pig iron that may not be immediately required. The steel works are capable of producing 9,000 tons of ingots per week and consist of three open-hearth furnaces, four Bessemer converters, and two mixers for "duplex" steel. This combination gives great flexibility combined with lowest possible cost. From the steel works the ingots are taken direct to the soaking pits, which are connected to four waste-heat boilers with a capacity of 10,000 lb. of steam per hour. The hot ingots are placed in the soaking pits and brought to the required temperature and then passed through the slabbing or blooming mill, which is capable of dealing with 750,000 tons of ingots per annum.
Slabbing Mill. Ingots, weighing up to 10 tons each, are delivered to the slabbing mill approach table in a remote-controlled "ingot buggy" arranged with a tilting pawl and cam device for automatically depositing the ingot on the table. The two-high slabbing mill is driven by a 7,000 h.p. reversing electric motor (using direct current, with variable speed and Ward-Leonard control) and is fitted with reversing tables in front and back. Here ingots are reduced to slabs of any desired size up to 52 inches maximum width. Mechanical manipulators are provided both in front of and behind the mill for placing the ingot in position. Motor-operated lifting fingers turn the slab for edge rolling. Slabs are conveyed over driven rollers to the electric slab shear where the ends are cropped square and the slab sheared into accurate lengths if so desired.
From the shear, slabs are delivered either to the continuous hot-strip mill, or to storage, or to the entry side of the slab reheating furnaces.
Hot Strip Mill. Slabs are charged into and pushed through the reheating furnaces by means of heavy motor-operated double pushers. Slabs up to 18 feet in length are charged, or alternatively two rows of half-length slabs may be heated. Two reheating furnaces are installed, each capable of heating 60 tons of steel per hour. They are continuous in operation and are arranged with automatic temperature control. Over- and under-firing is provided in the heating zone and over-firing in the soaking zone. Each furnace is 80 feet long x 20 feet wide. Heated slabs are discharged on line roller tables which convey them to the continuous hot-strip mill.
The hot-strip mill consists of eleven stands of rolls arranged in tandem. The first is a two-high roughing scale breaker which loosens the primary scale formed on the slab in the reheating furnaces. High-pressure water sprays sweep the loosened scale from the slab, which then passes to a horizontal slab reducer, in which it is squeezed to accurate width with properly formed parallel edges.
The slab is then passed through three two-high roughing mills and one four-high roughing mill. Each of these mills is driven by a 2,500 h.p. synchronous motor. At the entrance to the second and fourth roughing mills vertical edging rolls are provided with high-pressure water sprays to remove secondary scale at each mill. Between the roughing and finishing mills the strip is conveyed over an air cooling table where the temperature is automatically recorded and regulated, before finish-rolling to exact thickness is commenced. A two-high finishing scale breaker then loosens secondary scale, which is swept away by high-pressure water sprays.
From the scale breaker the strip enters the finishing train of mills. There are five four-high mills in tandem in the finishing train, and strip may be rolled continuously in all five stands at one time. Each mill is driven by a 3,370 h.p. variable-speed direct-current motor. Strip is delivered from the hot strip mill at speeds up to 1,850 ft. per min.; and single strips may be as long as 1,700 feet. Widths from 12 inches to 50 inches and a thickness of 0.050 inch and heavier may be rolled.
On delivery from the rolling mills the strip may be coiled or sheared into multiple lengths. Lengths from 8 feet to 32 feet are sheared by an automatic flying shear located directly behind the last finishing mill. The sheared lengths are conveyed to an automatic piler. Stacks of sheets are transferred from the piler by chain conveyer, and are then taken by overhead crane to storage racks for cooling. Strips to be coiled are conveyed over the hot-run table to either of two automatic down coders. Coils are formed having an inside diameter of 30 inches and a maximum outside diameter of 52 inches. The coilers are so arranged that either is operating while a coil is being removed from the other. Coils of strip are discharged into "upenders" which place them on chain conveyers for cooling; they are subsequently stored in the hot-mill coil storage building or transported to the cold mill pickler.
Hot-Strip Finishing Department. This department receives the products of the hot-strip mill and prepares them for commercial use. A machine is provided for uncoiling, side-trimming, levelling, and end-shearing coiled strip into accurately squared multiple lengths. An automatic doubler prepares hot rolled strip for further rolling on hand mills. Two tempering mills are provided for final preparation of the surface and temper of hot-rolled sheets. One of these mills is arranged with an uncoiler and tension reel for temper-rolling coiled strip steel. There is also a continuous normalizing and annealing furnace for heat treatment, and a unit is also arranged for the hot levelling of heavy strip. A pickler, for the removal of scale, and a scrubbing and drying machine, for the removal of pickling stains, have also been installed.
All the finishing mills are fitted with large roller bearings to which is connected an automatic pressure lubricating system which has a continuous circulation through coolers and cleaners, and loopers are provided between each mill for controlling any slackness in the strip and ensuring that it is kept at even tension. The overall length of the hot mill building, including the soaking pits, is 2,260 feet and the greatest width is 235 feet. At the end of the hot mill building is a water-cooling and recirculating plant, where all usable water is collected from the hot and cold mills, cleaned, cooled, and recirculated.
The total installed horse-power in the hot and cold mills is 69,811, including 26 high-speed cranes which have a longitudinal speed of 750 ft. per min.
Continuous Cold Strip Mill: Continuous Pickling Department. The cold finishing mills are 1,440 feet long and 484 feet wide, with an extension for pickling which is 640 feet long and 90 feet wide. Coiled hot-rolled strip is conveyed to the pickling department and loaded by overhead crane to storage conveyers at the entry of either of the two continuous pickling lines. From the storage conveyer the coil is charged into an uncoiler of the "processing" type to loosen scale and "cold-process" the steel before pickling. The ends of the strip are then squared in a shear. Strips are stitched together to form an endless ribbon. After stitching, the strip is delivered through various pickling and washing tanks to a drying machine; the stitch is then removed in a shear, and the strip is oiled and recoiled on an up-type coiler and delivered over gravity conveyers either to the tinplate tandem mill or the sheet tandem mill.
Continuous Cold Sheet Mill. Coils of steel from the pickler are transported by mobile crane to a cold-reduction sheet mill, consisting of three stands of four-high mills in tandem (driven by 1,500 h.p. variable-speed motors) through which the strip is reduced to finished sheet gauges. This mill will roll strip in widths from 20 inches to 50 inches at a maximum delivery rate of 800 ft. per min. Finished coils are 30 inches inside diameter and 52 inches maximum outside diameter. Electric flying micrometers continuously indicate the thickness of the rolled strip. To dissipate the heat generated by the cold reduction of strip and to lubricate the metal between the rolls, a coolant is sprayed on the rolls at the rate of 500 gal. per min. After cold reduction, the coiled strip is transported by mobile crane to the annealing department or to flying shears.
The cut up line consists of an uncoiler, side trimmer, leveller, flying shear for cutting into accurate multiple lengths, and an automatic piler. The process is continuous and automatic and produces accurately sheared sheets, which are then transported in stacks to the annealing department.
The four-high cross-rolling mill, driven by an 800 h.p. variable-speed direct-current motor, is provided for the cold reduction of sheets up to 74 inches wide. After reduction, the sheets are continuously delivered through a four-high roller leveller to a piler, and thence to the annealing department.
There are twenty-five portable radiant tube-annealing furnaces, complete with eighty-one refractory bases. Automatic temperature control and recording instruments ensure complete and accurate control of heat treatment. Deoxidizing gas, manufactured from coke oven gas in a separate plant, is introduced under the inner covers of the welded alloy steel sheet to prevent discoloration of the annealed product. Coils up to 50 inches and sheets up to 74 inches wide and 258 inches long can be annealed.
After annealing, the coils or stacks of sheets are removed to an adjacent building for finishing. There are two four-high tempering mills (driven by 250 and 800 h.p. variable-speed direct-current motors) for tempering sheets, each mill having a roller leveller in tandem. A special machine is provided for accurately side-shearing coiled strip or slitting it into multiple narrow widths.
Continuous Cold Tin Mill. Coils of steel from the continuous pickler are transported by mobile crane to a cold-reduction tin mill, consisting of five stands of four-high mills in tandem through which the strip is reduced to finished tinplate gauges. This mill will roll strip in widths from 12 inches to 36 inches at a maximum delivery speed of 1,100 ft. per min. Finished coils are 20 inches inside diameter and 44 inches maximum outside diameter. Flying micrometers continuously indicate the thickness of the rolled strip. After cold reduction, the strip is transported by overhead crane to one of the three electrolytic cleaning lines, where its surface is thoroughly cleaned and freed from grease, and recoiled before passing to the tin annealing department.
For annealing tinplate in coil form, seven portable radiant tube-annealing furnaces, with twenty-four refractory bases, are provided. The bases are fitted with fans for circulating the heated gases under the welded steel inner covers to ensure uniform temperatures. The process is similar to that in the sheet annealing department. After annealing, coils are transported to one of the three four-high skin-pass mills. These mills are fitted with drag generator uncoilers, tensioning rolls, and tension reels. After skin-passing, the strip is recoiled and transported to the flying shear lines, of which there are five. Stacks of the sheared tinplate are transported to either of two types of tinning plant.
Plate to be coated with tin in the Poole-Davis tinning equipment is pickled in a white pickling plant and loaded into water boshes for transporting by special mobile crane to the tinning plant. Nine 64-inch two-way and one 75-inch two-way Poole-Davis tinning machines are provided, as well as eight six-way tinning machines. In each of these units plate is automatically fed, classified, tinned, cleaned, and piled. Automatic control is provided for maintaining tin and palm oil temperatures. A central carburetting plant supplies gas for the immersion heating used in the tinning equipment, and a fume removal plant and dust collecting plant for the dry cleaners are also installed. The tinned plate is transported to the assorting room, in which the temperature is automatically maintained, for inspection and grading. From the assorting room the plate travels to a warehouse fitted with automatic temperature control.
NATIONAL OIL REFINERIES, LTD. LLANDARCY
The refinery, which was officially opened in 1922, occupies nearly 700 acres of land, and is operated by National Oil Refineries, Ltd., a subsidiary of the Anglo-Iranian Oil Company. Crude oil is shipped from Iraq and Iran in 10,000-ton tankers and pumped through pipe lines to a tank farm, where it is stored in 10,000-ton tanks. From the tank farm the crude oil is pumped to the refinery.
General Processes. The primary process is separation of the crude oil into less complex mixtures, of more restricted boiling-point range, by fractional distillation. Distillation is carried out by pumping the oil at high velocity through pipes enclosed in a furnace rather like a water-tube boiler, and then into a fractionating column of the "bubble-cap tray" type provided with reflux condensers. Distillates of differing boiling points are drawn off at different heights up the column and a residual oil containing the highest boiling point compounds from the bottom. In modern practice three heaters and three columns are used, the residual oil from the first column, which is operated at several atmospheres pressure, passing to the second heater and column at approximately atmospheric pressure, and thence to the third heater and column, which operates under vacuum so that distillation of the less volatile fractions can be carried out without raising them to decomposition temperature. The final residue from the last column is bitumen. If distillation is stopped at the second stage the residue is commercial fuel oil.
Before marketing, benzenes, kerosenes, and gas oils require chemical treatment, which is carried out as far as possible in continuous plants. Kerosene, for instance, is treated successively with cold liquid sulphur dioxide, sulphuric acid, and lime water and then filtered through roasted granulated bauxite before it reaches the market. The sulphur dioxide dissolves selectively aromatic hydrocarbons, which are recovered and incorporated in petrol on account of their high antiknock value, and the other treatments remove small amounts of other compounds which, if allowed to remain, would detract somewhat from the clean-burning qualities of the kerosene.
Wax is removed from lubricating oils by chilling the oil to low temperatures with or without the use of a solvent; the precipitated wax is then removed either by filtration or by centrifuging. In a new wax-removal plant under erection, the whole of the waxy lubricating oil fraction will be diluted with a mixture of sulphur dioxide and benzole and the wax filtered out in vacuum rotary filters after chilling.
The refining of lubricating oil generally consists of treatment first with sulphuric acid and then with finely divided activated clays. Oils thus treated are eminently suitable for a great variety of purposes; but for high-efficiency internal combustion engines lubricating oils must be stable under exacting conditions. They must resist oxidation, sludging, and excessive loss of viscosity due to crankcase dilution.
They can be obtained by the extraction of certain constituents by means of solvents, e.g. liquid sulphur dioxide or a mixture of sulphur dioxide and benzol in a special plant combined with the wax-removal plant. Such oils are finally treated with activated clays at high temperature.
Crude paraffin wax obtained by the filtration process contains a proportion of oil which is removed by slowly heating ("sweating") the solidified mass. The oil-free product is then treated to remove any colour and odour and the finished wax is slabbed and packed into bags.
The heavy bituminous residue from crude oil distillation, produced in several grades of hardness, is used as road asphalt. Hard asphalt is run from the distillation plant into shallow setting tanks, and after solidification is broken up and loaded into railway trucks. Softer bitumens are kept fluid in heated tanks, from which they are run into steel drums or lagged tank rail cars for distribution.
Cracking. The decomposition or "cracking" of hydrocarbons in petroleum was introduced to increase the amount of light spirit obtainable from crude oil, but it was subsequently found that the spirit thus produced by cracking was superior, in ensuring freedom from knock, to "straight-run" spirit obtained by simple distillation. It was also found that the anti-knock properties of straight-run spirit could be greatly improved by cracking (known in this case as "reforming"). In consequence nearly all the motor spirit on the market to-day is subjected to this process. The plant used for cracking consists mainly of heaters and fractionating columns similar generally to those used for distillation, but designed for higher temperatures and pressures. Great use is made of recently developed alloy steels resistant to high-temperature corrosion and creep. In cracking, part of the oil is converted into hydrocarbon gases, which include large quantities of the unsaturated compounds propylene and normal- and iso-butylenes, as well as the saturated hydrocarbons that compose the gas evolved in crude-oil distillation. The technique of separating the unsaturated gases and their polymerization and hydrogenation to form aviation spirits with anti-knock properties not hitherto commercially attainable, is advancing rapidly, and there is in Llandarcy a plant for selectively polymerizing the iso-butylene in cracked gas to form an octene, which is then hydrogenated to iso-octane, one of the most valuable aviation fuels known at present.
Engineering Features. (1) Process Plant. The condensing, cooling, and heat-exchanging equipment ranges from simple cast iron pipes, surrounded by a water box, to the more complicated and efficient multistage tubular heat exchangers fitted with small-diameter bundles of steel or bronze tubes, arranged in a steel or cast iron jacket.
In the fractionating towers, each fractionating plate contains a number of "bubble caps", for bringing vapour and liquid into contact, returning the liquid down the column, and passing vapours forward up the column. The very large towers fractionating lubricating oil "cuts" are operated at absolute pressures of 10-50 mm. of mercury; most, however, work at a gauge pressure of a few pounds per square inch, while two which fractionate gasolines and liquid gases work at 200 lb. per sq. in. gauge.
(2) Welding. The use of welding is now universally adopted in the construction of tanks, pipe lines, and general refinery equipment, including high-pressure vessels.
(3) Fire Protection. The inflammable nature of all the material handled demands special precautions against fire. Ample water service points at high pressure are provided throughout the area, and chemical fire-fighting appliances are available in the shape of special tanks and mixing pumps to produce foam in large quantities. All tanks and steel-framed buildings are earthed to the water pipe system, as are all portions of the electrical equipment.
(4) Steam, Electrical, and Water Services. Electricity for refinery purposes is obtained partly by generation in the refinery power station and partly by purchase from the national grid. The proportions in which these supplies are used is roughly fixed by the amount of electricity which can be generated by pass-out turbines supplying low-pressure steam for process requirements, while at the same time a steady load factor is maintained on the grid system.
Process steam is supplied by eight boilers, six of which have a capacity of 30,000 lb. per hour, and two of 45,000 lb. per hour, a total of 270,000 lb. per hour.
Four of the 30,000 lb. per hour coal-fired boilers are fitted with forced draught compartment chain-grate stokers and the two 45,000 lb. per hour boilers with underfeed "louvre" type stokers, also with forced draught. All grates are suitable for burning small South Wales coal. To obtain flexibility in the boiler house, and also to utilize fuels produced in the refinery, two boilers have been fitted with combined oil and gas burners with forced draught; the other boilers are also fitted to burn gas and refinery waste products by means of special burners. Steam, generated at 200 lb. per sq. in. with 200 deg. F. superheat, is supplied to the power house for the turbines and to certain parts of the refinery requiring high-temperature process steam. A grit-arresting plant installed on each of the main flues, deals with the emission of fine grit due to using forced draught with small coal, and a small vacuum plant removes any accumulation of dust in economizer pits and boiler passages.
The boilers are fed at will, either by a high-speed steam turbine-driven feed pump or by an electrically driven feed pump, either being capable of supplying the total boiler capacity.
A rotary tippler discharges coal into two gravity bucket conveyers, each capable of lifting 50 tons an hour to the coal bunker above the boilers. Each boiler has its own bunker, which holds 48 hours' fuel supply.
Fuel oil for use in the boiler house and for various oil-fired furnaces at the distillation plants, is circulated on a ring main system at 200 lb. per sq. in. gauge pressure and about 180 deg. F. Constant pressure is automatically maintained by a small steam turbine driving a pump at the boiler house.
The generating station is equipped with three pass-out steam turbines, each coupled to a 2,500 kW. alternator running at 3,000 r.p.m. and generating electricity at 3,300 volts, three phase, 50 cycles per second. Steam is drawn off at 40 lb. per sq. in. gauge, up to a designed total of 90,000 lb. per hour, from each turbine. Under these conditions each generating set is capable of supplying 2,000 kW. and the balance is supplied by additional steam passing to the condenser.
In addition to the main condensers, a small auxiliary jet condenser is installed, capable of condensing 12,000 lb. of steam per hour at a vacuum of 24.5 inches of mercury, and the exhaust steam from either turbine can be diverted to this condenser. The circulating pump of the auxiliary condenser is supplied with boiler feed water and thus acts as a feed water heater. The supply from the national grid is brought also into the power station and terminates in a duplicate busbar metalclad switchboard. The switching arrangements are such that either a part or the whole of the refinery's requirements can, in emergency, be taken from the grid as required.
Immediately below the switchboard is a transformer substation, equipped with three 750 kVA. 3,300/440-volt, three-phase transformers, supplying the boiler house, power house, and a low-tension ring main in the centre of the refinery.
Owing to the large area of distribution high-tension lines are necessary and some of the largest pumping units, water and oil pumps of up to 480 h.p. each, are unavoidably situated at a considerable distance from the power station. Four other transformer substations are located in the refinery area. Distribution is effected partly by high- and low-tension overhead lines, and partly by cables, all recent feeder cables being laid solid underground.
Particular care is taken to keep the overhead lines away from any tank, to avoid fire in case of a wire rupturing. Other precautions include the use of oil-immersed motor and power circuit switches, and the adoption, on all new plant, of flame-proof switches. Where it is necessary to use wandering leads, a special flame-proof switch plug is installed with flame-proof hand lamps.
A substation has been built to house the two 11,000-volt feeders from the grid, three 2,500 kVA. transformers, and the outgoing 3,300-volt supply to the refinery. A set of instruments indicating the total load at the grid substation is installed in the power station 1,200 yards away. The supply is taken to a substation 700 yards away and led into a duplicate busbar metal-clad switchboard, the second set of busbars being supplied from the refinery power station, thus giving an alternative supply in case of grid failures. From this point the supply to the main water pump house is taken, and owing to the steady nature of the demand this is usually coupled to the grid supply. From this substation the grid supply goes direct to the power station.
The water supply, which is of the utmost importance, is drawn from (a) the Rural District Council, for drinking water, boiler feed water, and special process work; (b) a local canal service by means of electrically driven turbine pumps; (c) the firm's own reservoir, which has a capacity of 83,000,000 gallons and covers 23 acres. This water is used for process purposes generally.
Three pumps are installed at the canal pump house, two of which are driven by 100 h.p. motors, and deliver 24,000 gal. per hr. at 520 feet head, and one by a 450 h.p. motor, delivering 144,000 gal. per hr. against the same head.
Six pumps supply the refiner requirements (item (c) above). Three are of 420 h.p., capable of delivering 4,000 gal. per min. against a head of 210 feet, and three of 280 h.p. delivering 4,500 gal. per min. against 165 feet head. A reserve pump house some distance away is supplied by a separate high-tension feeder and is equipped with a 450 h.p. pump.
Pumping the products through the various processes and ultimately to stock, as well as the circulation of water for refinery requirements, also forms a very large item in the refinery. There are in all some 700 electric motors on the refinery and docks, totalling over 20,000 h.p. Power for the docks transit site and jetties, which are situated about 4 miles from the refinery proper, is at present taken in bulk from the Great Western Railway Company's dock supply. The maximum demand is 800-1,000 kW. at 3,300 volts.
Approximately 12,250,000 units were generated at the power station during 1937, while the supply purchased for the docks was 750,000 units, and from the grid system 12,500,000 units, the latter at a load factor of over 85 per cent for the year.
THE GLAMORGAN HEMATITE IRON ORE COMPANY, LTD. LLANHARRY
In this mine, which was established in 1901, is obtained the brown haematite iron ore occurring in extensive deposits in the carboniferous limestone. The ore contains a high percentage of iron, and is non-phosphoric and therefore suitable for either Bessemer or Siemens acid and basic processes. From a metallurgical point of view it is readily fusible, being remarkably free from rock gangue. The percentage analysis is: iron (as received), 53.18; silica, 4.79; sulphur, 0.023; phosphorus, 0.013; moisture, 5.78.
The reserves in the mines are extensive, and large bodies of ore have yielded to date some 5,000,000 tons. Over 2,500,000 tons have already been mined and marketed, and there are approximately 2,500,000 tons in ore reserves awaiting markets. The total output of the Llanharry mine is at present 5,000 tons per week.
AMALGAMATED ANTHRACITE COLLIERIES, LTD. CEFN COED COLLIERY, NEAR NEATH
This is the most modern colliery in the anthracite area, producing approximately 2,000 tons of grade 3 anthracite per day. Coal was first raised in this colliery about eight years ago from workings 700 yards deep. The colliery is equipped with two pulverized-fuel boilers firing anthracite duff collected on the screens, whilst additional steam is obtained from a battery of Lancashire boilers. This steam is used for a Worsley Mesnes winder on the downcast shaft where coal is raised, and a Charles Markham steam unit is used on the upcast shaft. For supplying air below ground, a ventilating fan with a capacity of 200,000 cu. ft. per min. is installed; it is driven by a compound tandem steam engine.
The power house is equipped with a mixed-pressure turbo-compressor and a 3,000 kW. turbo-alternator. There is electrical connexion with other colliery power houses in the district, overhead lines carrying current at 11,000 volts, which is stepped down to 3,300, and further to 500 and 110 volts for use in the colliery. The engines for the winders and ventilating fan discharge into a Ruths low-pressure accumulator which supplies steam for the turbo-compressor and the pithead baths. This system discharges to atmosphere at 4 lb. per sq. in.
THE METAL BOX COMPANY, LTD. EAGLESBUSH TINPLATE WORKS, LTD., NEATH
These works were formerly owned by Messrs. Baldwins, Ltd., and were purchased by the Metal Box Company, Ltd., in April 1935. A comprehensive scheme of reconstruction was at once arranged in such a way as to cause minimum interference with production by the then existing plant. The new equipment was installed during holidays, and although the reconstruction programme was of some magnitude, there was no important interference with production.
The steel bars are delivered from a local steel works to a site adjacent to the bar cutter. After cutting into short lengths according to the size of the plate, a multiple of which it is proposed to roll, the bars are heated and rolled in five stages, the pieces finally consisting each of eight layers, corresponding to sixteen sheets of the size required, since each pack is rolled "two lengths" of the final size. The eight-ply packs are then sheared to the necessary length, allowance being made for a slight elongation at a later stage. The plates have a tendency to stick together, and the conditions must be closely regulated during the heating and rolling operations. They are then separated by girls and are ready for "black pickling".
In the pickling machine the plates are treated with a solution of sulphuric acid for the removal of the black oxide and scale formed during rolling. To remove the internal stresses imposed by hot rolling, annealing is necessary. The plates are piled on cast iron stands, over which a cover is inverted and sealed with sand, and are then transferred by overhead cranes to bogies, which are pushed by electric power through the black annealing furnace. The temperature gradient in the furnace provides a preheating zone, a soaking zone, and a cooling zone. The furnace, when loaded to capacity, contains fourteen bogies, and a "push" is made at approximately one-hour intervals.
After cooling, cold rolling is necessary to provide a suitable surface for tinning. The cold rolls are of cast iron with chilled surfaces, and the pressure exerted is of the order of 100 tons on each bearing. This produces the stretch for which allowance was made when shearing. Cold rolling tends to re-impose the stresses which black annealing removed, and it is necessary to re-anneal at a lower temperature.
At this stage it is found that "blue edges" have been formed on the plates due to the leakage of air through the sand seal. It is therefore necessary to re-pickle them with a weaker solution of sulphuric acid than was necessary in the black pickling. The machine used in these works for "white pickling" is an exact duplicate of that used for "black pickling", so that in the event of breakdown, both processes could be carried out in one machine. The plates are not allowed to dry after white pickling but are stored in water-filled boshes which are conveyed by power trolleys to the tinning house.
In the tinning pots the plates pass first through a layer of liquid flux (chloride of zinc), then through the tin bath, and finally in a vertical direction through the grease pot, the plates being moved by suitably disposed rolls and guides. The grease pot contains three pairs of steel rolls arranged in a frame, with means for adjusting the pressure without stopping the machine. Excess tin is removed from the steel rolls by asbestos brushes. The grease pot machine is immersed in palm oil, which floats on top of the tin and keeps it fluid, thus allowing the rolls and brushes to fulfil their function.
On leaving the palm oil region, the tinned plates are covered with grease which is afterwards removed in a cleaning machine, consisting of a series of rollers built up of calico or swansdown disks, and rolls covered with sheepskin in the final passes. The rolls run at various speeds so as to produce a scrubbing action on the plates. Suitable cleaning material is fed automatically over the rolls to absorb the grease. The finished plates are conveyed to the assorting room where they are examined for defects. They are then counted and packed for transport by rail or lorry.
The power plant includes two main mill engines, the redesign of which formed part of the reconstruction programme undertaken when the works were purchased. No. 1 engine is a cross-compound with a 28-inch high-pressure and a 52-inch low-pressure cylinder, the stroke being 48 inches. Steam pressure is 160 lb. per sq. in., and when running at 38 r.p.m. this unit develops approximately 1,000 i.h.p. It drives three hot mills and ten pairs of cold rolls. No. 2 engine is a tandem compound, with cylinders of the same size, and drives four hot mills. Steam is supplied from a battery of 30-foot x 8 ft. 6 in. Lancashire boilers fitted with forced-draught furnaces.
Electricity is supplied to the various crane motors and other auxiliary machinery by a Belliss and Morcom — Mather and Platt turbine generator. A standby turbine generator is in course of installation. The current is 230 volts d.c. The "Galusha" gas producer is capable of producing 100,000 cu. ft. of gas of 150 B.Th.U. per cu. ft. gas calorific value, when using anthracite peas, and approximately 80,000 cu. ft. per hour when using grains.
A new component factory adjacent to Eaglesbush tinplate works has recently been completed, and covers an area of approximately 90,000 sq. ft. After investigating the nature of the ground and the live and dead loads to be imposed on the floor of the factory, it was decided to drive piles. 902 concrete piles, each approximately 50 feet long, support the reinforced floor, which varies in thickness according to the nature and magnitude of the load at each point. The processes carried out in this factory are the lacquering of tinplates and the formation of "ends".
In the lacquering process the plates are fed by girls into a series of long gas-fired ovens. At the entry to the ovens the lacquer is distributed evenly over the plates by special apparatus. The plates are then conveyed through the oven, in which close temperature control is essential. At exit girls stack the lacquered plates for transport to the "end-making" department of the factory. Here they are cut into such shapes and widths as will cause the minimum of wastage. The ends are then formed in special high-speed presses and liners for subsequent transport to the various factories of the company engaged in the mass-production of cans, of which these lacquered ends form component parts.
All the plant in the new factory is electrically driven. The motors operate at 400 volts, three phase, 50 cycles per second. A small direct-current load is imposed by various control units, the current for which is produced by motor generators. Electrical energy is purchased from the Neath Corporation at a pressure of 11,000 volts, which is transformed to 400 volts in a substation adjacent to the factory. Gas is also purchased from the Neath Corporation and is transmitted from the gas works through an 8-inch main, approximately 1,000 yards long, to the factory meter house. A special fire pump is installed, drawing its water from the adjacent canal.
A well-equipped canteen is provided at which hot meals can be obtained at prices which all employees can afford, and there are rest intervals during the day in which all may visit the canteen for light refreshments. To organize the sports and social activities of the employees, the Eaglesbush General Welfare Society has been formed, and is now a very active body. The company have provided a sports field, of about 10 acres in area, situated in the country about 2 miles from the works. At both the tinplate works and the new component factory there are well-equipped surgeries under the constant supervision of a qualified nurse and of the part-time supervision of a local doctor, At the Eaglesbush Tinplate Works surgery, ultra-violet ray and infra-red treatment is available for the employees of both factories.
NEWPORT CORPORATION EAST POWER STATION
The Newport Corporation commenced to generate electricity in 1895 at a works situated in Llanarth Street, Newport, established principally to supply electricity for lighting. After seven years it became necessary to build a new generating station to meet the demands for electricity for other purposes. This was established in Corporation Road, and is known as the East Power Station, the Llanarth Street works having been converted into the Corporation's central distributing substation. The East Power Station is a selected station for the South West England and South Wales electricity area, and is at present producing, under the directions of the Central Electricity Board, an output of some 100,000,000 units of electricity per annum.
The boiler plant at the East Power Station consists of eight Babcock and Wilcox boilers having a total normal evaporative capacity of 420,000 lb. per hour, and the generating plant comprises four turbo-alternators, three by Escher Wyss and one by Fraser and Chalmers, having a total capacity of 28,750 kW. The circulating water required for the generating plant is pumped from the River Usk by three pumps having a total capacity of 3,500,000 gal. per hr.
These pumps are housed in a pumping station which is of exceptional interest and unique design. As it is situated on the bank of the River Usk, which is a tidal river with a maximum variation of 42 feet between tide levels, it was essential to ensure that at all times the pumps would be flooded and full advantage taken of the syphonic action. For this purpose a ferro-concrete caisson was sunk in the river bank to a depth of 56 feet below the pump house floor level, and 4 ft. 6 in. below the level of the river bed. The main pump house building is placed over the caisson, which is divided into two sections, each having an entirely independent supply through the intakes from the river. A part of the caisson provides accommodation for the vertical band screens, a separate screen being provided for each pump unit. The pumps are driven by motors of the vertical type placed in the pump house and connected to the pumps by means of vertical shafting. The operation of the pumps and the maintenance of full supplies are practically automatic.
The Central Electricity Board have recently authorized a considerable extension of the East Power Station, involving the provision of a 30,000 kW. turbo-alternator unit, complete with condensing plant, to be installed in an extension of the present turbine house, and the provision of a new boiler house and the installation therein of two boiler units having a total evaporative capacity of 300,000 lb. per hr. The boilers will be suitable for a working pressure of 625 lb. per sq. in. and a final superheat temperature of 875 deg. F. The extension also includes the provision of the necessary draught plants, grit arresters, etc., to be placed on the boiler house roof.
In the river pumping station an additional circulating-water pump unit will be installed having a capacity of 1,500,000 gal. per hr., together with the necessary screening plant. The extension also includes the provision of a considerable amount of switchgear, reactors, and other ancillary items. The estimated total cost of this extension is £387,730, and it is anticipated that it will be completed by July 1940. The total capacity of the generating plant will then be 58,750 kW., with a boiler plant capacity of 720,000 lb. per hr., and a pumping plant capacity of 5,000,000 gal. per hr.
The Corporation's area of supply is 53 square miles, and the total number of consumers 25,000. At the present time all the industrial concerns within the Corporation's area take their supplies of electricity from the Corporation, and this involved the closing of two private generating stations of considerable size.
THE NEWPORT AND SOUTH WALES TUBE COMPANY, LTD., NEWPORT
The company has historical associations of great interest to engineers and steel manufacturers, as it was at the Landore steel works that Sir William Siemens commenced in 1868 his experimental work on the Siemens-Martin open hearth process of steel manufacture. These early experiments were confined to such products as ships' plates, rails, and tyres. The first steel vessels made from plates produced at these works were the warships Iris and Mercury.
Realizing the suitability of this class of steel for tube making, a company was formed acquiring the British patent rights of the Mannesmann process, and in the year 1889 the first seamless steel tubes were put on the market by the Mannesmann Tube Company, which took over the assets of the Siemens Company. This company operated until 1899, when an annual production of 3,000-4,000 tons of steel tubes was attained. At the present time, the capacity of the Landore works is about 30,000 tons per annum.
The company changed hands in 1899 and until 1936 was known as The British Mannesmann Tube Company, Ltd., whose business increased to such an extent that in 1913 a site was sought for a new works. A site of about 107 acres was found at Newport, Mon., on which new tube works of the latest design were brought into operation in 1918. At the same time the company decided to confine the manufacture of tubes of the smaller size to the Landore works, whilst tubes above 6 inches and up to 16 inches outside diameter are produced at the Newport works. To-day the capacity of the Newport works is well over 60,000 tons of seamless tubes alone per annum.
In 1922 an additional section was laid out, in which the manufacture of tubes of the larger sizes could be carried out by the water-gas roller welding process. These, classified as lap-welded steel pipes, range from 14 inches to 72 inches bore. The productive capacity of this section is about 20,000 tons per annum. The total capacity of the company's two works is 90,000 tons of seamless steel tubing and 20,000 tons of lap-welded steel pipes, with a range of inch to 72 inches bore. In 1936 the company again changed its directorate, and became known as the Newport and South Wales Tube Company, Ltd.
The boiler house at Newport works contains three Babcock and Wilcox water-tube boilers with chain grate stokers and Green's economizers, each capable of evaporating 20,500 lb. of water per hour. The working pressure is 200 lb. per sq. in. and the superheat temperature 600 deg. F., and the boilers supply power to the tube mills which are steam-driven. The electrical supply is taken from the Newport Corporation at 6,000 volts, and is transformed to 3,000 volts, three phase, 50 cycles per second, and further stepped down to 400 volts, three phase, 50 cycles per second, for auxiliary units generally. A supply of direct current at 460 volts is also available from a 250 kW. rotary converter. There are 298 motors with a total output of 6,038 h.p.
Hydraulic power is provided by four pump units, housed in a separate building, at a pressure of 1,500 lb. per sq. in., and with the aid of intensifiers a pressure of 2 tons per sq. in. is maintained for operating staving presses and test pumps. A pressure of 4 tons per sq. in. is available at the large test pump housed in No. 10 bay. The motors on the pump units are of 250 h.p., operating on the 3,000-volt a.c. supply. Air pressure is available at 100 lb. per sq. in., provided by three air compressors driven by 3,000-volt a.c. motors.
The tube mills are under a roof of four bays, each 234 feet long and 78 feet span, and in this section are two reheating furnaces capable of an output of about 475 tons per 24 hours. Both furnaces are fired with pulverized fuel at a temperature of about 1,400 deg. C., and the ingots from these furnaces are fed to a rotary type piercer. The piercing mill is driven by a 2,500 h.p. tandem compound steam engine, transmitting power by cotton ropes through a wheel 18 ft. 6 in. in diameter to a second motion shaft carrying a wheel 21 feet in diameter. The product of the piercer is in the form of a hot hollow bloom and is conveyed to one of two "Pilger" or tube-finishing mills by an electrically operated bogie. The two Pilger mills are of the Mannesmann type, operated by a 2,500 h.p. steam engine which is a duplicate of the one driving the piercer, the engine being situated between the two mills.
During normal rolling, tubes up to 60 feet long are produced in these mills. Tubes longer than this are frequently made for use as ships' masts and derricks, and one tube has been made 8 5/8 inches outside diameter X 0.212 inch thick x 178 feet long. Other uses to which tubular material is put include mains for gas, water, and sewage conveyance, oil pipe lines, well casing, etc., tubular lighting and traction poles, ships' davits and deck pillars, hydro-electric lines, and high-pressure steam mains. Extensive finishing departments are necessary and occupy three bays, each 78 feet span and 1,045 feet long, with two additional bays 660 and 550 feet long. This gives ample space for the manipulation and inspection of material. Tubular equipment for oilfields is made in accordance with the specifications of the American Petroleum Institute, and a special room is set aside for the storage of various master gauges with which all working gauges are checked at frequent intervals. This room is maintained at a constant temperature and before any threading tool or chaser is issued to the operator it is checked by projecting the outline on to a screen showing the profile of the thread magnified 50 times.
For the water-gas hydraulic roller welding department there are three gas producers, capable of a combined production of 1,000,000 cu. ft. of gas per 24 hours. There are five welding machines in this section, which comprises two bays, each 660 feet long and 78 feet span, together with a gas-fired plate furnace, plate-bending machines, and auxiliaries such as socket-forming machines, staving presses, and test pumps.
The warehouse, or dispatch department, is situated at the extreme end of the building, to which all material flows during manufacture. All bays are equipped with electrically operated overhead cranes, of which there are 21 in the works. There is a large engineering shop, in which maintenance work is carried out. The laboratories are well equipped and include apparatus for determining the limit of proportionality, rate of creep, etc., at elevated temperatures.
THE WHITEHEAD IRON AND STEEL COMPANY, LTD. NEWPORT
The firm's original works at Tredegar were established in 1903, at the time when steel was beginning to replace wrought iron. New methods of continuous and semi-continuous rolling were being developed in the United States, and after closely studying these processes it was decided to adopt them at Tredegar. The Morgan Construction Company accordingly installed a new mill, which had a much wider range of production than its American prototypes. At the same time the Whitehead Iron and Steel Company, Ltd., was formed. After much costly experimental work, the pioneer British mill proved successful. It embodied the first attempt to make continuous rolling a "general utility" process, instead of one which required several highly specialized mills. The firm acquired in 1914 the 30-acre site on which the present Courtybella works are situated, but owing to the War, all constructional work was suspended until 1919.
Continuous Hoop and Tube Strip Mill: No. 2 Mill. The first rolling mill at the Courtybella works consisted of a combined 12-inch strip and hoop mill, the design of which was influenced by that of the 8.5-inch Morgan semi-continuous mill which had been working for twelve years successfully, and by a new type of Morgan continuous hoop mill then being erected in Chicago. The new mill, the first of its kind in the world, was designed for the continuous production of hoop and tube strip and commenced working in 1922.
The furnace is of the standard inclined type with suspended arch roof. Billets are pushed down the incline to the furnace hearth by a steam pusher, which is operated so that the leading billet lies on the hearth in the correct position for discharge into the roughing mill. The roughing mill comprises seven stands of 12-inch horizontal rolls in a continuous train, and one independently driven stand of vertical edging rolls; and the finishing mill consists of a train of six stands of 12-inch rolls placed at rather greater centres than in the roughing mill train. To expedite roll changing, the finishing mill is provided with a duplicate set of roll housings which are set up with clean rolls and all guide tackle while the other set is in use. The strip, which leaves the mill at speeds of 1,500-3,000 ft. per min., is either reeled in coils or delivered in straight-cut lengths. Included in the mill equipment is plant for the re-coiling, splaying, and varnishing of hoops. In the larger sections, the output of the mill has now reached the limiting output of the furnace. On 3-inch to 4-inch tube strip, for example, 250-300 tons have been rolled per 8-hour shift.
Cold-Rolling Mills: Auxiliary to No. 2 Mill. The primary object of this plant is the salvaging of any irregularly rolled material from the No. 2 continuous strip mill, and provision is made for pickling, slitting, and annealing. It has been found in practice, however, that less than 5 per cent of the irregular strip had to be treated in this way; consequently the cold rolling department has become a valuable adjunct to the hot rolling.
The plant consists of sixteen 8-inch x 8-inch mills set in four lines of four rolls, each in tandem. This arrangement enables each line of tandem rolls to be operated continuously if required, a method which is of considerable advantage when dealing with heavy coils, though apart from this and some minor advantages, it does not afford the same advantage as in hot rolling. Each mill can be operated as a separate unit, if required. The latest addition to the plant is an American four-high reversing mill, capable of dealing with strip up to 12 inches wide, and embodying several interesting electrical devices. A group of slitting machines is installed between the mills and the annealing department, which is equipped with electric furnaces throughout.
Auxiliary Bar Mill No. 1. This mill was operated for several years in connexion with the continuous strip mill, sharing a common furnace and roughing and edging rolls. It was originally laid down to relieve the pressure of orders on the Tredegar bar mill, and was adapted from the continuous strip mill, by using the existing roughing stands and installing four new stands of rolls. Recently, however, this mill has been converted to an entirely separate unit; provision for this eventuality was made in the original layout. The mill is now one of the most up-to-date of its kind and is used for the manufacture of small rounds, flats, hoops, etc.
12-14-inch Semi-Continuous Bar Mill: No. 3 Mill. This mill, which was installed in 1931, was designed to replace the last of the three-high mills at Tredegar, which had become obsolete, and to reduce transport costs between the Newport and Tredegar works. The present layout is designed to deal with rounds and squares from 3/8 inch to 2.25 inches, and with flats from 1.5 inches to 6 inches wide. Provision has been made for increasing the range and for including strip up to 8 inches wide. The furnace, which incorporates features both of the Morgan Construction Company's and the owners' designs, is of the sloping type, and has a hearth 36 feet in depth and 32 feet in width. There is a roughing mill consisting of seven stands of continuous rolls divided into two groups, the first comprising three stands of 14-inch rolls 31.5 inches wide, and the second (placed with an intervening space of 24 feet between it and the first group) comprising four stands of rolls 24 inches wide, the diameters decreasing from 13 inches to 12 inches. The finishing mill consists of four looping trains of 12-inch x 24-inch rolls.
The cooling bed is of the original Edwards saw-tooth type, with certain features of the Whitehead Company's design; the bed is 250 feet long and 36 feet wide. There is a loading bay with provision for over 50 wagons. Special machinery is installed in this department for the correct bending of bars for ferroconcrete construction, which forms one of the principal applications of the firm's products.
A new proving house has been erected, in which are installed the usual standard 100-ton and 30-ton Buckton hydraulically operated tensile testing machines, and a hydraulic machine for carrying out bend tests. In addition to this equipment, provision is made for carrying out Brinell and Erichsen hardness tests, especially in the cold-rolled material.
MESSRS. BROWN, LENOX AND COMPANY, LTD. PONTYPRIDD
The firm, founded by Captain Brown, of the Royal Navy, in 1808, have been contractors to the Admiralty without a break since that date. The manufacture of stud link chain cable has been carried on throughout the firm's history, and chains of the largest size that have yet been made have been produced in the works. In addition to the chain shops there is a steel foundry with a Heroult electric furnace, a proving room, smiths' shops, and forges. A chain-testing machine manufactured in 1868, and still in use, is of considerable interest.
SWANSEA CORPORATION ELECTRICITY UNDERTAKING TIR JOHN POWER STATION
The Swansea Corporation obtained powers to generate electricity in 1889. A site between the North Dock and the Strand, now near the centre of the town, was chosen, and a power station erected from which a supply was first given on 10th December 1900. Continual increase in the consumption of electricity led in the early "twenties" to consideration of the erection of a new station on a more commodious site, possessing abundant supplies of water for condensing purposes. It was decided to seek a site suitable for a station of 100,000 kW. capacity, which it was estimated would meet the needs of this area for some years.
The valley of the River Tawe was searched for a site, but in 1928 the Electricity Commissioners considered a station of 100,000 kW. to be inadequate to meet the potentialities of the district, and as cooling water sufficient for a larger station could not be obtained from the river all the year round, attention was turned to the seaboard. Here the enormous depth to the rockhead, coupled with the serious difficulties due to tides, proved insuperable obstacles on economic grounds. An area not yet explored was that surrounding the docks, and eventually the Tir John site was selected. It was relatively cheap, allowed ample room for extensions, has abundant supplies of cooling water, and has immediate access to sea, road, and rail.
The erection of the initial section of 60,000 kW. commenced in September 1931. Provision has also been made for the installation in the present building of a further 60,000 kW. set and the necessary boiler plant, while the scheme provides for an ultimate capacity of 240,000 kW. by the further addition of a 120,000 kW. set. Commercial operation began in November 1935. The construction of this power station has been in advance of the programme originally drawn up by the Central Electricity Board, and in return for this concession the Corporation, under agreement, exports at coal cost plus 10 per cent, all surplus energy to the grid. The station, though at present not "selected", is scheduled to become a selected station not later than the 1st January 1940.
The station embodies two features which are without precedent in the operation of large power stations, namely, the use of pulverized anthracite duff for firing the boilers, and the washing of the exhaust gases to eliminate sulphur oxides and dust. Originally the station was designed for burning steam coal on mechanical stokers, but extensive experiments in the combustion of anthracite duff, a low-volatile coal (6-7 per cent of volatile matter) of high calorific value (12,500 B.Th.U. per lb.) showed that under certain conditions it could be burned satisfactorily, and the station was redesigned to suit this method of firing the boilers.
The steam-raising plant consists of four tri-drum vertical-tube type boilers, each capable of evaporating 240,000 lb. of water per hour at a pressure of 625 lb. per sq. in., with a feed-water temperature of 350 deg. F. At the superheater outlet the steam is at 825 deg. F. The effective heating surface of each boiler is approximately 14,000 sq. ft. Economizers of the gilled steel tube type are fitted between two banks of plate type air heaters, which are designed to preheat the air for combustion to 700 deg. F.
The anthracite duff is pulverized in four Hardinge ball mills, complete with classifier, cyclone separator, and exhauster fan. Each mill is capable of grinding 10 tons of coal per hour, containing not more than 4 per cent of moisture, to a fineness of 99 per cent through a 100-mesh 1 mm. sieve, and 85 per cent through a 200-mesh 1 mm. sieve. The raw coal from the overhead bunkers is delivered to each mill through an automatic weigher. From the mill, the pulverized coal passes a classifier, which rejects and returns to the mill any oversize particles. The coal-laden air passes from the classifier to a cyclone separator, in which the coal is separated from the air, the air being returned to the mill circuit by an exhauster fan. From the cyclone separator the pulverized coal is delivered to a motor-driven fuel transport pump, consisting of an enclosed screw conveyer, which feeds the coal into a stream of compressed air. By this means the coal is transported through cast iron pipe work to the pulverized-fuel coal bunkers. The fuel transport pipes are so arranged that the pulverized coal can be delivered from any milling unit to any of the four pulverized-coal bunkers. An overhead raw-coal bunker having a capacity of approximately 600 tons is provided for each pair of boilers, and each pulverized-fuel bunker has a capacity of approximately 120 tons.
The pulverized fuel is introduced into the furnace chamber through twelve burners per boiler. The burners are designed for a "U" flame with a flame travel of about 50 feet. For lighting-up purposes three auxiliary burners are provided. The combustion chambers are constructed with refractory surfaces of the sectionally supported hollow-wall type at the front, and for a portion of the side walls. Automatic combustion and superheat control apparatus, electrically operated, is provided for the four boilers. Provision is made for individual control so that any boiler can be under automatic or hand control. Space is available for two more boilers.
The turbine plant consists of two 30,000 kW. turbo-alternators and a 750 kW. Diesel engine driven alternator for auxiliary purposes, while space is available for a further 60,000 kW. set. The plant is designed to operate at a steam pressure of 600 lb. per sq. in., with a total temperature of 825 deg. F.
Each unit is a two-cylinder tandem turbine driving a three-phase alternator at a speed of 3,000 r.p.m. The turbines are of the pure reaction type, bladed with stainless steel. The generating pressure is 33,000-36,000 volts. Each turbo-alternator is provided with a surface condenser with a cooling surface of 30,000 sq. ft.
The condensing water is obtained from the King's Dock and returned to the Queen's Dock, by means of low-level tunnels. The shafts at the station are 300 feet deep and at the docks 250 feet and 240 feet deep respectively, the difference in levels being due to the gradients given to the tunnels for the purposes of drainage during construction. The shafts are 14 feet in diameter and the horseshoe-shaped tunnels driven through solid rock are about 9 feet in diameter and lined with 9 inches of concrete. The intake tunnel is about 0.5 mile long and the discharge tunnel about 0.75 mile. The only difficulty in this contract was experienced at the docks during the sinking of the shafts. As the depth of the water-bearing strata was too great to allow the use of compressed air, the ground had to be frozen to the necessary depth by sinking a ring of circulating pipes through which a freezing mixture was passed. The shafts were then sunk and lined and the ground allowed to thaw. The circulating water system is capable of supplying 6,000,000 gal. per hr. to the station, which would be required for the full capacity of 120,000 kW.
The 33,000-volt switchgear is installed on the ground floor of the switchgear house adjacent to the Central Electricity Board's outdoor substation, and the whole of the 132,000-volt and the 33,000-volt switchgear is operated from the control room in the power station. The switchgear is of the oil-filled vertical-isolation metal-clad type, and the circuit breakers have a rupturing capacity of 750,000 kVA. The busbars are in duplicate, each set of three phases being arranged on either side of the switchgear with a space in the centre for access. The flue-gas washing plant is installed to remove sulphur oxides and dust from the flue gases. It consists of four unit scrubbers, i.e. one self-contained unit for each boiler. The scrubbers are arranged on the floors above the boilers, between the gas outlets from the preheaters and the induced draught fans. The scrubbers are of steel plate construction and form large chambers through which the flue gases pass in a vertical direction. The chambers contain a series of wooden grids, the surfaces of which are continuously irrigated by water from head tanks forming the tops of the scrubbers. The bottoms of the head tanks are provided with a number of nozzles sufficient to give an even distribution of water over the surfaces of the grids. From the grids the wash water passes to bottom hoppers and thence to delay tanks, consisting of large-diameter pipes, provided for the purpose of allowing the time necessary to complete the chemical reactions. From the delay tanks the water is returned to the head tanks and recirculated through the system. A certain quantity of liquor is continuously drained from the system, by which means the solids are removed and conveyed by troughs and down-pipes to a swirl pit provided at ground level at the north end of the boiler house. The grit and dust is scrubbed out of the flue gases by the recirculated water, which is treated with lime for the purpose of fixing the acids.
Water required to make up the losses due to evaporation in the scrubbers is drawn from the Crymlyn Bog. For this purpose a pumping plant is provided, which delivers the water to storage tanks on the boiler house roof. The pumps are housed in a separate building on the bog bank and rotating screens are provided in the pump section pit. The lime-handling plant is contained in a separate building at the north end of the boiler house and consists of unloading gear, storage hoppers, mixing tanks, stock tanks, and pumps for delivering the milk of lime to the scrubbers.
Tir John is connected with the old Strand Station by means of a duplicate underground 33,000-volt main, and from the latter station the energy is transmitted to a network of substations at 6,600 volts.
SOUTH WALES AND MONMOUTHSHIRE TRADING ESTATES, LTD. TREFOREST ESTATE
The Treforest Trading Estate has been established by the Commissioners for Special Areas and, with the similar trading estates in Scotland and on the North-East Coast, forms one of the principal means adopted by the Government for permanently improving industrial conditions in the areas most seriously affected by unemployment. The trading estates are operated by independent and formally established limited liability companies, and are intended to work on usual commercial lines. The success they have so far attained has exceeded expectations.
The Treforest Trading Estate has an area of approximately 300 acres located on both sides of the main road from Cardiff to Pontypridd and on both banks of the river Taff. The main road provides the most important factory frontages of the estate. The length of the estate from north to south is approximately 1.25 miles, and the width 580 yards. The complete development of the estate will cost about £2,750,000, assuming the building of some 100 factories of varying sizes. Care has been taken to carry out the modern conception of the design of industrial buildings in rural surroundings.
Work on the estate was commenced in January 1937. In the subsequent eighteen months all the essential services had been completed and over thirty factories of varying types had been built or were in course of being built, involving about 500,000 sq. ft. actually under roof. The main road through the estate has been reconstructed, re-aligned, regraded, and provided with dual carriageways, grass central and side strips, cycle track, and ample width between building lines; it is intended to line this road with trees. Other estate roads, of which a total length of 2,800 lineal yards has already been completed, are single carriageways constructed in concrete, and provision is made for garage accommodation, service, car parks, etc.
Considerable variation in the flow of the river has necessitated raising the general level of the estate by 3 feet, and to date 530,000 cu. yards of "fill" have been consolidated. In addition a flood embankment has been provided on the river side, and is used as formation for the estate railway. Soil sewage and trade effluent are discharged into the trunk sewer passing beneath Main Avenue. For the northern part of the estate, it is necessary to pump over the railway bridge which has been built over the river Taff for the estate railway. For this purpose two automatically actuated "Stereophagus" sewage pumps, electrically driven, have been installed in a pumping station adjacent to the bridge.
Railway communication is secured by direct connexion to the Great Western Railway, and exchange and marshalling sidings and a goods depot are provided. At least half the factories can be given direct rail service. To link the railway facilities between the north and south parts of the estate a new steel bridge, mentioned above, of two spans, each of 116 feet, has been provided across the river Taff. A total length of 7,000 yards of estate railway lines has been laid.
The Upper Boat power station of the South Wales Electric Power Company has enabled steam to be supplied in bulk for use by factories on the estate, and this is already being done on a scale probably exceeding that in any other part of Great Britain; the present arrange- ments cover a supply of 100,000 lb. per hour. Steam is transmitted at a pressure of 350 lb. per sq. in., and a temperature of 750 deg. F. The steam is led from a feeder in the boiler house of the power company and is conveyed by a 9-inch internal diameter pipe carried on steel trestles for almost the whole of the length of the estate, a total length of approximately 2,000 yards serving, with branches, 120 acres. The pipes are of solid-drawn steel, flanged, with plastic insulation, and protected with sheet steel. Expansion bends are furnished at suitable positions. The condensate is returned to the power station through a 4-inch steel pipe which runs alongside the steam main. The steam main is provided with steam drainage traps at suitable intervals which discharge direct into the condensate main. Provision for expansion is also made in the condensate main.
The pressure of the steam is generally too high for ordinary factory process purposes and for some factories it has been necessary to provide steam-heated evaporators, the condensate from the high-pressure steam being returned to the power station to eliminate wastage of treated water. In other cases de-superheaters have been used. It has been found possible to supply steam economically at charges ranging from ls. to 2s. 6d. per 1,000 lb., operating with a two-part tariff, the figures depending upon the load factor.
After examination and consideration of all available sources of water supply it was decided to utilize the river Taff for both potable and process water demands. The rise in temperature of the river water of approximately 5 deg. F. caused by the Upper Boat power station determined the location of the point of intake. To augment supplies during extreme drought, an auxiliary intake will also be provided some distance below the station. One factory also pumps cooling water direct from the river.
The intake works consist of duplicate horizontal intake pipes 8 inches diameter, provided at the inlet end with reflux valves and at the shore end with flexible joints to enable the pipes to be raised vertically for examination and cleansing of the reflux valves. Immediately before the pumping equipment on the suction side there is a manifold fitted with three quick-release basket type strainer boxes, with overhead lifting gear for removing the strainers ; either of the two pumps provided can use one or more strainers. The intake pumps are of the centrifugal type, running at 1,450 r.p.m., giving 60,000 gal. per hr. against an approximate head of 36 feet. They are controlled electrically, in common with the pumps in the filter house, by the level of the water in the service reservoir. The delivery from the intake pumps, through two 12-inch diameter asbestos-cement pipes, is further controlled by a flow controller in the pumping mains. This equipment is due to the need for equating intake to demand at all river levels. Integrating recorders indicate the flows, and a Dorr clarifier tank, a somewhat unusual feature in British waterworks, has been provided on account of the large amount of matter in suspension in the river water. From it the water flows over a weir to a settling tank. Coagulants are introduced in the Dorr clarifier tank as well as the sedimentation tank if the condition of the river so requires. From the end of the sedimentation tank a cheap supply of clarified industrial water is drawn off for certain factories, given at a maximum pressure of 30 lb. per sq. in. Four factories are already using this water. The necessity of a storage tank for this supply is obviated by the provision of automatic pressure-actuated electric switchgear, which for small demands actuates the small pump and starts the larger pump when occasion arises. For domestic and potable water supplies, the water is delivered from the settling tank to gravity filters, which allow a total flow of 55,000 gal. per hr. to the clear water tank. Thence the water is delivered to a closed reservoir, situated on the adjacent hillside, by two high-lift centrifugal pumps, each capable of 60,000 gal. per hr. and driven by 80 h.p. protected type slip-ring motors.
The pH value of the filtered water is mechanically recorded. Immediately before the pumps chlorination is carried out by an automatic chlorinator, itself controlled by an automatic chlorine residual content controller which is new to this country. A residual chlorine content recorder is also provided, actuated on principles similar to those used in the controller. Arrangements are made for pre-chlorination when necessitated by the state of the river.
Sludge gravitates from the clarified and sedimentation tanks to an adjacent sludge tank and is thence pumped through to a sludge filter press in the pump house. A complete system of ring mains of asbestos-cement pipes is provided for domestic and potable water supplies. Stringent safeguards have been adopted to ensure the purity of the potable water supply and a detailed scheme of tests and analyses has been fully worked out.
Electricity is supplied from the South Wales Electric Power Company's Upper Boat station at 11,000 volts, three phase, 50 cycles per second, to the two substations situated in the north and south parts of the estate. Each substation is capable of an output of 3,000 kVA. at 400 or 230 volts, but a high-tension supply is also available to tenants if required. The subject of street-lighting on the estate generally, and especially along Main Avenue, has received considerable attention, and the advice of the Royal Fine Arts Commission was sought. Gas is purchased in bulk from the Pontypridd Gas Company and distributed as required to factory tenants; spun cast-iron pipes have been used for the mains.
The following are among the industries already carried on on the estate: the manufacture of coated papers, dry ice, chrome leather, surgical adhesives, toys, toilet accessories, steel rods, batteries, fabrics, and electrical equipment, and silk printing. A centre has been built for the Ministry of Labour with accommodation for 150 trainees. The estate is providing an administration centre, banks, shops, canteens, and restaurants, and will give all business and recreational facilities to employees.
BRITISH COATED BOARD AND PAPER MILLS, LTD. TREFOREST MILL
The mill has been laid out for the production of coloured art papers and boards. The demand for such art papers and boards is due to the requirements of the half-tone process of printing illustrations, where a very smooth absorbent surface is required to take the ink. Art papers require a very close even-surfaced body paper for which considerable skill in manufacture is required, as the slightest variations affect the ultimate product. The body papers and board to be used will be supplied by the Ely Mills of Messrs. Thomas Owen and Co., Ltd., who have a modern plant for the production of "Esparto" papers, a material which results in the best body papers and boards, although sulphite wood pulp enters largely into the finish of medium qualities. This material is largely required for carton boxes such as are used for cigarettes, show cards, and similar purposes.
The coating mill is provided with machines for single-sided and double-sided coating, and with machines for glazing, calendering, and brushing the papers after coating. As it is very necessary that all operations should be carried out in an atmosphere as free as possible from dust, great care has been taken to filter all air discharged to the mill and supplied to the process machines. The floors of the mill are also designed to be free from dust; and arrangements have been made so that all parts of the mill can be cleaned by means of a vacuum plant.
In the single-sided coating machine, the paper, after passing through the machine, is carried on a series of festoons through heated chambers, where it is dried by hot air supplied through nozzles placed at intervals along the chambers. In the latter part of its course it passes through a region where the air is automatically regulated to produce the correct temperature and humidity for re-damping the dried paper before reeling. On leaving the festoon chambers the paper is rewound on to reelers and conveyed to the calendering machines and to any further process machines which may be required by the particular type of paper being manufactured.
The colouring material is prepared, before application to the papers, in a colour kitchen on the first and second floors of the multi-story building, and is led from the storage tanks in this building to the troughs on the machines as required. In addition to the machines provided for the coating of paper, a tunnel board-coating machine is installed for the treatment of various types of boards. A number of machines are provided for cutting paper to the size required by customers, and embossing machines are also installed for making paper or board of various patterns, such as imitation leather.
Three-phase electric current is brought into the mill at 400 volts, and all constant-speed, motors and the lighting are supplied with alternating current. Variable-speed motors are in some cases necessary for driving the machines; these are supplied with direct current derived from rectifiers situated in the switchboard room in the centre of the mill.
After the paper or boards have gone through the various processes they are inspected, sorted, and packed for dispatch either by rail or lorry. The whole of the mill and offices are protected by Grinnell sprinklers against fire; and a "Mulsifyre" apparatus is provided in the switchboard room as a protection against oil fires. The building is heated by means of unit steam heaters, each of which is provided with an air filter to prevent access of dust through the ventilating system.
The steam required for the mill is taken from the Trading Estate Company's main, and the temperature and pressure are automatically regulated in a de-superheating plant situated outside the north wall of the building, all the condensed water from the machines being returned to the power house of the South Wales Electric Power Company by means of automatically controlled centrifugal pumps.
SOUTH WALES ELECTRIC POWER COMPANY, LTD. UPPER BOAT POWER STATION
The Upper Boat Power Station is a modern plant of 63,000 kW. capacity, the boiler house containing chain-grate boilers burning exclusively coal from the bituminous coalfields of South Wales. In addition to the connexion to the national grid, the power station serves a large network of 33,000 and 11,000-volt transmission mains that extend throughout most of South Wales. New plant is now in course of installation which will operate at 650 lb. per sq. in. boiler pressure and 850 deg. F. steam temperature. The present extensions include two boilers with a normal evaporative capacity of 160,000 lb. per hour, and a maximum continuous rating of 182,000 lb. per hour, supplying steam to a 30,000 kW. turbo-alternator generating direct at 33,000 volts, together with the necessary auxiliary plant and switchgear.
A complete new coal-handling equipment is being installed, comprising a revolving wagon tippler, screens and crusher to deal with coal over 0.75 inch in size, and Redler conveyers; the arrangement is such that the new plant can feed the existing belt conveyer which distributes the coal to the bunkers in the old boiler house, while the existing conveyer system will be able to feed the twin Redler conveyers, which are to feed the new boiler house. It has been thought advisable to supply the boilers with coal which would in the initial stages pass through a 0.75 inch mesh, and in order that this may be uniform for both old and new plant, the existing belt conveying system is being modified to include a screen and crusher.
The two high-pressure boilers are to be fired with pulverized fuel, the grinding unit being of the table and roller type, arranged for unit operation, with three mills per boiler. The boilers are to be fully automatically controlled, with Bailey walls and a two-stage superheater. The superheater will have a damper between the first and second stages, which will automatically control the superheat by allowing a portion of the flue gases to short-circuit the second stage. For draught control both the forced and induced fans will be vane-controlled. The economizers are to be of the gill tube type, with Ljungstrom air heaters, and the chimney discharge will be cleaned by electrostatic precipitation of the dust.
The ash-handling plant forms a separate contract and is of the hydraulic jet type. It will also remove the dust from the precipitation plant and back passes of the boilers. From the operating floor upwards the boiler house will have walls entirely of glass, which will greatly facilitate the operation and the conditions of working. The boiler feed plant, situated in the engine room annex, will consist of two electrically driven pumps, and one steam-driven standby pump.
The 30,000 kW. turbine is of the two-cylinder impulse-reaction type, with double-flow exhaust, running at 3,000 r.p.m. with three stages of bled steam. The surface condensing plant comprises duplicate two-stage air ejectors, duplicate extraction pumps, feed-heating equipment, and evaporator. An interesting innovation in the turbine equipment is that the emergency oil pump is electrically driven. The direct-coupled alternator is of standard design, generating at 33,000 volts, with direct-coupled main and pilot exciters.
The circulating water plant consists of two new central-flow band screens, and two vertical-spindle centrifugal circulating water pumps. There will be a low-water dividing wall down the centre of the river, which will divert the flow during times of low water past the screens. It is also intended to install a concrete cooling tower 160 feet high to augment the circulating water supply at times of low water.
The auxiliary plant connected with the extensions will be operated at 3,000 volts, and to avoid fire risks the switchgear will be of the air-blast type. Provision has been made by means of pressure-reducing and de-superheating apparatus for the existing 350 lb. per sq. in. pressure turbines to be run from the new boiler plant if necessary.
The extensions have necessitated structural alterations to the existing engine room, and advantage has been taken of these alterations to alter considerably the general layout. The switch house is being enlarged to accommodate all the 11 kV. switchgear at present in the station, and this will also necessitate the enlargement of the present control room, and the erection of a new fitting shop and stores, as well as the alteration of the office accommodation.
The extensions will increase the capacity of the station to 93,000 kW., and it is anticipated that the station will be working at almost its maximum capacity as soon as the extensions are complete.
THE TREFOREST CHROME LEATHER WORKS, LTD.
The premises consist of a warehouse for the storage of raw skins, wool, and hair, a beam shop for the preparation of the skins preparatory to the tanning processes by removal of hair and wool, a tanning and colouring room, three drying rooms, and a finishing and storage room. The company commenced production on 1st March 1938, and is still in an experimental stage, training unskilled workmen. The products manufactured are fine washable gloving leather, mainly capes; peccary skins; and fine suede leather for shoes.
The machinery is of the usual type employed in tanneries, namely, revolving drums, fleshing and un-hairing machines, setting-out machines, freizing machines, staking machines, buffing and polishing wheels, and measuring machines. Most of the units are driven independently by electric motors. There is a complete wool-scouring and drying installation and several hot air units for the heating of the factory as well as for drying purposes.
Steam is supplied from the adjacent power station of the South Wales Electrical Power Company, at a pressure of 375 lb. per sq. in. and a temperature of 375 deg. C., and as the condensed water has to be returned in full, the process steam is supplied by a steam generator at a pressure of 60 lb. per sq. in. Hot water is supplied by a steam calorifier and stored in a storage tank.
The premises in their present shape are large enough for the production of 1,000 dozen skins per week, which come into the factory in a raw state and leave as coloured and finished leather, and would ultimately find employment for 100 to 120 hands.
TREFOREST MOULDINGS, LTD.
The firm was founded in August 1937 with the assistance of the Lord Nuffield Trust and of the Swedish parent company, C. C. Ohlsson Eftr, Tidaholm. The latter business, which was established in 1890, is in close connexion, for the wood department, with the International Match Trust, so that the wood refuse from the manufacture of matches can be utilized.
The works are divided into three departments, dealing respectively with lead, stenolite, and wood, of which the first two are moulding departments. The moulds are of especial interest; they are constructed to the firm's own designs, to suit the materials employed in the firm's particular moulding process, which embodies methods previously unknown in this country.