Amongst the most celebrated express engines of their day were the London and North Western "Bloomers," designed by J. E. McConnell. The first twenty engines of the class were built by Sharp, Stewart and Co in 1851-2, and the firm built five more in 1861.
The cylinders were 16in. by 22in., leading wheels 4ft. 6in. diameter driving 7ft. diameter, trailing ft. diameter, wheel base 16ft. 10in. The fire-box of the first ten engines had a transverse midfeather. The total heating surface was 1448 1/2 square feet, of which the fire-box supplied 146.3 square feet. The second lot of ten engines differed from the first series in having a longitudinal midfeather, and the fire-box heating surface was increased to 165 1/2 square feet. Their weight in working order was 29 1/2 tons. In these engines McConnell broke boldly away from the standard practice of that period in using a working pressure of 150 lb. per square inch, and in discarding the low centre of gravity theory so long and tenaciously held by almost every other locomotive engineer. For more than twenty-five years these engines worked the fastest and heaviest express trains on the southern division of the London and North Western Railway, on which they did excellent service.
Sources of Information
- The Engineer 1923/08/24