Class 534A 2-20-2 (1928)

Class 534A 3-Cylinder Compound Experimental Locomotive
Designed by Bela Šahlmeti in 1928

While still blissfully unaware that his new high-pressure 4-8-2 was to be his undoing, Šahlmeti had his drawing office sketch out the 2-10-2 goods version shown here, using the same boiler and other details. In the event, the engine was never built (hardly a surprise, considering the situation), but Šahlmeti had certainly ordered traffic analyses to justify its acquisition. The trouble with proposals like this, in which a boiler is retained above newly-arranged running gear, is that important design work tends to be skimped on the assumption that what worked already will work again. The inside connecting rod would have needed to be quite short not to clash with the leading driving axle and the weight distribution at the rear end (a problem already recognised in the 434A) would have needed a four-wheeled bogie. 

Text and graphics © Norman Clubb 2012