Class 434D
3-Cylinder
Compound Express Passenger Locomotive
Designed by Jochann
Ketterik
Built in 1962 by
RSR Works, Bevice-Akohniçe,
Ruhnia
Throughout the
1950s,
the bulk of express passenger traffic was in the hands of Tešlov's
4-6-2 rebuilds
and his new 4-8-2s of 1950, which were essentially a passenger version
of the 533A. Ketterik set out to develop a new engine to serve the
RSR
for the coming quarter century. The experience gained from the solitary
trial balloon, the 434C, was invaluable in optimising the dimensions of
the 434D for maximum efficiency and performance. Major aspects of the
development were a tapered boiler, boxpok wheels and poppet valves. On
test, no. 434D.001
hauled a train of 890 tons gross up Rovniebera bank at 125 km/h, the
boiler
pressure holding perfectly steady at 18.7 atm. Starting on the bank was
also no problem, despite the lack of a booster. Subsequently, a further
49 engines were turned out by the Akohniçe works in 1962 and
another
50 in 1963. With its low running and maintenance costs and high
availability,
the class 434D was, like the later 564B, a first-class investment, and
continues to serve the RSR to this day.
Text and graphics © Norman Clubb 2012