William Hamilton and Co
William Hamilton and Company of Port Glasgow.
1873 Operated the Newark Yard, Port Glasgow.
1889 See 1889 Shipbuilding Statistics for detail of the tonnage produced.
1891 William Hamilton branched out on his own, purchasing the Glen yard at Port Glasgow from John Reid who had gone bankrupt. Here the name of William Hamilton and Co. was established.
1890s The yard made sailing ships until 1904.
1896 John Hamilton retired
1900s Although the Glen yard made six ships a year, no ships were made in 1903. However, orders soon picked up again, as local orders for tramps kept the yard afloat.
1904 William Hamilton converted the company to limited liability status, with capital of £170,000, divided into 1700 shares of £100 each
WWI The yard made over a dozen warships including sloops, "X" craft lighters, merchant ships, tankers and cargo liners.
1919 Hamilton retired and sold the yard to the Lithgow Brothers who inherited the yard's impressive list of liner customers.
1920s As with many other yards, the 1920s saw a period of slow business but the yard continued making passenger ships, cargo-liners, tramps and tankers. 25 such ships were made between 1920 and 1930.
1928 Private company.
1933 Name changed.
1934 The yard closed in November 1934, having made a series of tankers.
1935 Reopened in 1935 to build the first company ship to have refrigerated capacity: Marwarri. Orders also came in from African and local companies.
WWII The yard built six standard "Empire" tramps, and five others to private order along with five cargo-liners as well as some rebuilding work.
1945/50s The main output of the yard was cargo-liners which accounted for half of the ships built. The other half was for tankers.
Between 1948 and 1964, the yard built 19 tankers and 37 cargo-liners.
1961 Shipbuilders. (Berths up to 520 feet; floating docks and pontoons). 900 employees. 
In 1963, the yard completed its last ship and also launched its last ship (Treneglos and Freetown respectively). The Glen yard was then merged with the East yard of Lithgows who absorbed it into their ambitious modernisation programme.
Sources of Information
- British Shipbuilding Yards. 3 vols by Norman L. Middlemiss
-  Wikipedia