London and North Eastern Railway. These were the Class V2 and Class V4 mixed traffic locomotives which totalled 186 locomotives between them. In contrast, 2-6-2T locomotives were very widely used on suburban passenger services, particularly by the Great Western Railway (GWR), who built four main classes between 1903 and 1947. These include the 'Large Prairies' (5100, 3150 and 6100 classes), the 'Small Prairies' (4400, 4500 and 4575 classes) and the non-standard 3901 class rebuilt from 0-6-0 tender engines. The Railway Operating Division received 70 2-6-2 Saddle tank engines built by Baldwin Locomotive Works in the United States. They were shipped to France and used near the front line. These engines, nicknamed "tortoises" were probably inspired by the Saddle tanks used on forest railways in the USA ; they had very small drivers and could run tight curves. After the war, all remaining engines (63) were sold to the Belgian State Railways. The rest was probably destroyed during the war and some of them may have been cannibalised for spares. Sir Henry Fowler of the London Midland and Scottish Railway (LMS) introduced a successful class in 1930, which became the basis of further similar classes by Stanier in 1935 and Ivatt in 1946. Sir Nigel Gresley of the London and North Eastern Railway (LNER) introduced his V1 and V3 classes in 1930. The last new 2-6-2T locomotives in Britain were the British Railways standard class 2, built between 1953 and 1957. The design derived from the earlier LMS Ivatt Class 2 2-6-2T. Narrow gauge The 2-6-2T layout was popular for large narrow gauge engines, but the design was modified to allow the use of a firebox much wider than the track gauge. A standard gauge 2-6-2T normally has inside frames and the firebox is placed between the second and third coupled axles. A narrow gauge one, on the other hand, has outside frames and the firebox is placed behind the third coupled axle and clear of the wheels. To minimise the rear overhang, the fuel is therefore carried in side-bunkers alongside the firebox, instead of in a rear bunker. Preserved examples include the Welsh Highland Railway's Russell and the Vale of Rheidol Railway locomotives. United States Narrow gauge The gauge Sandy River and Rangeley Lakes Railroad in Franklin County, Maine, was a major narrow gauge user. Standard gauge In the United States, the type evolved from the 2-6-0 (Mogul) configuration. The