Although prototype diesel locomotives ran in Britain before World War II, the railways of both the Republic and Northern Ireland changed over much more rapidly from steam to diesel traction than those in Britain, due to the island's limited coal reserves and (in the Republic) an ageing steam locomotive fleet. Northern Ireland operated several diesel shunters as early as the 1930s. CIE's first diesels consisted of five shunters built by CIE in 1947/48. The initial two diesel mainline locomotives were also built in Inchicore, in 1950/51, and fitted with Sulzer engines and MV traction equipment. This was followed in the mid 1950s with a large order from Britain fitted with Crossley engines, with notably poor results. From the early 1960s, locomotives with more reliable engines from General Motors Electro-Motive Division were adopted. In the late 1960s the Crossley engines were replaced by EMD 645 units in a major re-enginging programme. Since the early 1960s all new locomotives on the two Irish rail systems have been purchased from EMD, with the exception of three from Hunslet Engine Company of Leeds, England, for NIR in 1970. Ireland Mass dieselisation In 1948, CIÉ commissioned a report from Sir James Milne (General Manager of the British Great Western Railway) on the problems of upgrading its rail services. Despite his recommendation to continue with steam traction, CIÉ decided to push for the complete dieselisation of its railway system, expecting substantial economies of scale. The first of the two mainline diesel locomotives built by CIÉ at Inchicore Works, each with a Sulzer engine built by Vickers Armstrong, Class 113, entered service in April 1950, following completion of trials. Subsequently, CIÉ placed one of the largest orders of its time, for 94 locomotives (60 Metro-Vick Class 001, or A Class, and 34 201 Class, or C Class locomotives) with a consortium of four British companies: Diesel engines from Crossley. The engine used in the A Class was the Crossley HST V8 of 1,200 horsepower (895 KW), relatively untested for railway use although the same engine was used in the 48 Western Australian Government Railways X and XA class locomotives built by Metropolitan Vickers in 1954-6 and the small build of 20 Type 2 Co-Bo locomotives for British Railways (later British Rail Class 28) of 1958–9 Mechanicals from Metropolitan Cammell Electrical components from both the English Steel Corp. and the Metropolitan-Vickers Electrical Co. Delivered to Inchicore Works between