The 1250 Ton Testing Machine in this building was used by Dorman Long to test the girders for the Sydney Harbour Bridge amongst many others.
The site is now run by Durham Lifting and their website carries the following detail :-
The largest testing house in the UK holds Lloyds approval to undertake tensile and compressive testing up to 1250 tons. Its 50ft long bed can accept specimens 30ft wide and up to 4ft deep. The recent manufacture of a 1.6 mechanical advantage lever assembly for the test machine now allows tensile testing of 2000 Ton to be carried out.