Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 148,101 pages of information and 233,633 images on early companies, their products and the people who designed and built them.
of Clyde Iron Works, Greenock, near Glasgow
1786 Thomas Edington and William Cadell, Junior, in association with Carron Iron Works, built Clyde Iron Works, on the north bank of the river Clyde, a few miles south east of Glasgow, primarily to relieve the pressure on Carron for armaments.
Later became James Dunlop and Co
1897 Calderbank Iron Works was taken over by James Dunlop and Co and work picked up.
1914 Iron and coal masters and steel manufacturers. Specialities: hematite, "Clyde" and "Monkland" brands of pig iron; sulphate of ammonia, pitch, tar and oil; steel plates (Siemens-Martin). 
1920 Lithgows purchased steel makers James Dunlop and Co
1931 Lithgows agreed to merge their holdings in Dunlop with David Colville and Sons, as a consequence of which the Lithgow brothers joined the board of the Colville companies, forming Colvilles. It was decided to centralize pig iron manufacture at the former Dunlop's Clyde Iron Works. This resulted in the blast furnaces at Glengarnock closing down and the old rolling mill was also closed down.
1934 Lithgow brothers bought the shares of the Steel Company of Scotland. Their ownership of these shares posed a threat to the growing monopoly of the Colville group in supplying the shipbuilding market, and encouraged the Colville group to incorporate the Steel Company of Scotland in its rationalization scheme.