In 1914 Glasgow had the largest concentration of locomotive building works in Europe, with two railway company works also building carriages and wagons, and the three works of the North British Locomotive Company Limited (NBL), which built largely for colonial markets. The largest vehicle building concern was probably the Glasgow Corporation Tramways Department's works in Pollokshields, but there were also the Albion Motor Works in Scotstoun, making lorry and bus chassis, the Halley Motor Co, a similar company in Yoker, and several smaller motor body builders such as William Park. Alley & MacLellan were making their very successful Sentinel steam wagons in Polmadie.
The First World War saw the NBL making large numbers of locomotives for the war, but also vast quantities of munitions. The two large motor builders both increased their capacity to deliver large quantities of army lorries, but Alley & MacLellan moved production of Sentinel lorries to Shrewsbury. The post-war rationalisation of the railways ended new locomotive construction in the two Glasgow railway works and a low level of demand for the NBL's products led to that company's near-closure in the early 1930s. Albion and Halley both returned to civilian production, but Halley did not survive the 1930s depression. Beardmore turned some of their surplus munitions capacity to making motor cars but this was a short-lived venture.
The Second World War saw Albion and NBL again making substantial contributions to the war effort. After the war both of these companies benefited from a more prolonged post-war boom and remained prosperous until the mid-1950s. Throughout this period, apart from the two World Wars, the Corporation Tramway workshops built new trams and modernised older ones.