David Colville and Sons
Colvilles, of Dalzell Steel Works, Motherwell, near Glasgow, and Ravenscraig.
1871 Company founded by David Colville. The Motherwell works date from 18th October 1871, having started as a malleable iron works, manufacturing bars, beams, etc.
1880 The firm switched to steel production. To meet the rapidly-growing demand for mild steel in boilermaking and shipbuilding, David Colville built the Dalzell steel works on ground adjoining his ironworks, manufacturing steel by the Siemens process. The new plant was completed by February 1881
1888 Glasgow International Exhibition. Siemens plates, rolled bars and hammered blooms. 
1895 Incorporated as a private limited company.
1914 Manufacturers of steel and iron, Siemens open hearth mild steel, high tensile steel and nickel steel, boiler, ship and special quality plates, angles, bulb angles, channels, zed bars, tee bars, rounds and other sections, billets, blooms, ingots for forgings etc. 
1915 Colvilles took over the Clydebridge Works
1916 Colvilles had also purchased Glengarnock Iron and Steel Co in June 1916, and as submarines had become active, the Ministry requested Colvilles to undertake large expansions, to meet the acute demand for steel plates to build Standard Ships. The enlargement of both works began in October 1916, at a cost of £1½ million.
1919 The Engineer published a summary of the company's history, read it here.
1926 The firm's Dalzell Works reopened in December.
1930 Became a public company
1931 The Lithgow brother agreed to merge their holdings in James Dunlop and Co with David Colville and Sons, as a consequence of which they 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.
Clydebridge Steel Works
"The Clydebridge Steel Works of David Colville and Sons, Ltd., are equipped for an output of over 5000 tons of plates per week, and, so far as the new portion of the works is concerned, represent the latest methods in steel works practice. Before giving a detailed account of the new plant, which we propose to so in what follows, reference may be made to the origin of the Clydebridge works and the development which has taken place during the last ten years." From The Engineer 1923/08/31.
Read the series of articles on The Clydebridge Steel Works
No. I - The Engineer 1923/08/31
Sources of Information
- History of Clydebridge