Class B9A 4-Cylinder Tandem
Compound Express Passenger Locomotive
Designed by Karel Belčamin
Rebuilt in
1903 from Class S by RSR Works, Bevice-Akohniçe, Ruhnia
The
last express passenger design to appear from the drawing board of Marek
Luršimonš, the class S (later B9), was both an anomaly and a white elephant.
Belčamin
kept the engines however for experimental purposes and applied various
amendments to the boiler, running gear and other details. In 1903 one
locomotive was fitted with a completely new design of boiler, which
went on to be the prototype for that of the new 4-4-0s of 1906, but
without superheater. The running gear remained unchanged and retained
also the original slide valves. The higher boiler pressure brought an
increase in power but Belčamin realised
quite rightly that only through superheating could the locomotive deliver a
level of performance commensurate with its size. On top of this, the increased
weight placed excessive demands on the running gear and hot boxes became an
everyday occurrence. After less than a year in this form, the engine was rebuilt
more drastically into class B9B.
Text and graphics © Norman Clubb 2012