The G&SWR was formed in 1850 from a merger of the Glasgow, Paisley, Kilmarnock and Ayr Railway (GPK&AR) and the Glasgow, Dumfries and Carlisle Railway (GD&CR). A number of other companies were absorbed by the G&SWR or its predecessors, including the Ardrossan Railway, the Paisley and Renfrew Railway and the Kilmarnock and Troon Railway. One notable feature of the G&SWR’s locomotive stock was its aversion to tank engines. Until very late on in the company’s history these were used only when circumstances absolutely demanded it. James Manson (1845-1935) was born in Saltcoats and trained with the Glasgow & South Western Railway in Kilmarnock Works. He became Locomotive Superintendent of the Great North of Scotland Railway in 1883 but returned to Kilmarnock as Locomotive Superintendent of the G&SWR in 1891, a post he held for twenty years until his retirement in 1911. He was responsible for the 4-4-0 No. 11, the first four-cylinder simple locomotive in Britain, and designed some impressive double-bogie tenders for his large 4-6-0 engines. As originally constructed No. 11 had an inadequate grate area and boiler capacity for supplying its four cylinders, a defect that was subsequently remedied by Robert Whitelegg.