English: Victoria Railways 5'3" gauge A H Ahlston Class 'H' 4-8-4 No.H220, built by VR Newport in 1941, withdrawn in 1958, at the Victoria Railway Museum, North Williamstown, 2 April 2016. H220 has a duplex chimney (not sure how that is different to a double chimney), combustion chamber, thermic syphons, roller bearings on all axles, bar frames, Henschel conjugated valve gear, power operated reverse and mechanical stoker. The 'H's' were designed to eliminate double heading by Class 'A2' 4-6-0's on 'The Overland' on the steeply graded Melbourne - Adelaide line, once heavier rails had been laid to take the heavy axle load of the 'H's'. However, the design process was protracted (it was originally intended to be a 4-8-2 withGresley valve gear but that had fell out of favour because of maintenance problems on the 'S' Class Pacifics) and the first of three was not completed until 1941, when completion on two others that were in the course of construction was put on hold because of the war. The upgrading of the Melbourne - Adelaide route was also postponed so H220 was put to work on heavy troop trains and militray freight trains on the North East Line (Melk - Albury - Wadonga) until the end of the war. They proved immensely powerful and reliable. After the war, it was intended to complete it's sisters but in the event construction was abandoned. H220 contined to work heavy freight trains very successfully and occasionally handled the prestige 'Spirit of Progress', where it proved to have a good turn of speed. H220 was nicknamed 'Heavy Harry': it had a 68 sq. ft grate area (the biggest in Australia), 220 psi boiler pressure, 5'7" driving wheels, three 21.5" x 28" cyliners, 55,000 lbs tractive effort. 4,760 sq. ft. total heating surface and had a designed output of 3,600 dbhp. The engine alone weighed 146 tons 10 cwt.