Class 423Q 2-8-4T (1924)

Class 423Q 2-Cylinder Passenger Tank Locomotive
Designed by Bela Šahlmeti in 1924

An early response of Bela Šahlmeti to the problem of increasing suburban train weights was this slim-boilered 2-8-4T. At first glance, the eight coupled driving wheels of modest size would seem ideal for this sort of traffic. However it is also apparent that the cylinders would have developed a high tractive effort and drained the boiler of steam. Ironically, Šahlmeti recognised a similar problem with his later 2-6-4Ts of class 323B, for which he designed a larger boiler. One is tempted to say "if only", since the 323BB boiler would most likely have suited the 423Q very well, as shown below:

Class 423QQ 2-8-4T (1924)

Text and graphics © Norman Clubb 2016