Class 533E 2-10-4T (1968)

The locomotive history of the RSR is littered with designs that looked invincible on paper but proved disappointing on the track. One such is the 2-10-4T seen here. At the time of its construction, there were, it is true, large-wheeled tank locomotives in service in the form of the very solid and reliable class 423E 4-8-4Ts, which were ably augmented by their tender 4-8-0 cousins, the 423Ds. The existing ten-coupled tank locos, however, all had small driving wheels, which were ideal for slogging up the gradients in southern highlands but were more a hindrance on the plains. Hence the large-wheeled 533E. To exploit the adhesive weight of some 110 tonnes, a three-cylinder drive was fitted, with (initially) Walschaerts valve gear. Ketterik evidently thought that poppet valves could wait. There were several points to the design which, with hindsight, cannot have boded well. The boiler was a stretched version of that fitted to the 423E, but with the firebox left unchanged, which didn't do the steaming much good. The long wheelbase was not at all happy on many of the more sharply curved lines. Despite its Krauss-Helmholtz leading axle, the engine was suspected of spreading the track. The back end of the loco was identical with that of the 423E and the bogie was not adequate for the greater weight and sheer bulk of the 533E, so bunker-first running suffered also. A total of four engines were built - the problems noted above ruled out any more - and the last was withdrawn in 1977.

Text and graphics © Norman Clubb 2012