Decauville --- Built in 1902 by W.G. Bagnall & Co. Stafford, UK, for the strategic lines on North West Frontier Railway. This narrow-gauge loco with 2-4-2 wheel arrangement, has a peculiar arrangement of a saddle tank and surprisingly one arm of the safety valve is used as the steam manifold. 'Decauville' takes its name from the french engineer P. Decauville (1846-1922), the inventor. It is a railway system suited for mines, yards, etc, with the track (the gauge is in the range of 50-60 cm) laid directly on the ground. It is suited for hand pulled carts, or very small locomotives. It can be easily disassembled and transported like a model train. It is very common in yards, mines and tunnel works. This loco christened as Decauville Primrose, now having its gracious presence at National Rail Museum, New Delhi. Photographed by Rudranil RoyChowdhury. D.O.P. - 19th September 2018.