Class C4 4-6-0 (1896)

Following the success of his class D5 2-8-0s, Karel Belčamin next set about creating a mixed-traffic locomotive for the RK main line and the southern highlands. The D5s had proved themselves well, except that their tandem compound cylinders gave rise to large reciprocating forces and the piston rod glands between high and low pressure were awkward to maintain. The de Glehn arrangement seemed to be what was needed. An initial order of twelve of these 4-6-0s was delivered by Škoda during 1896. Only a few were in service, however, when it became clear that all was not well with the Belčamin pioneer 4-6-0. The front bogie did not provide adequate guidance, making the engines very rough-riding and causing two derailments in the space of four months; running was also very sluggish, due, evidently, to constricted steam passages, an unfavourable cylinder volume ratio of 1:1.68 (a low figure compared to that being used by Belčamin's contemporaries) and a high exhaust back-pressure, applied in an attempt to improve the extremely unreliable steaming, which prompted more than one motive power depot manager to insist on double-heading. Since these problems stemmed from basic faults in the design (of itself a damning indictment of Belčamin's engineering ability and of the RSR's successor grooming policy), they could not be corrected by tinkering. Belčamin's solution was radical but effective. All twelve engines were withdrawn as soon as enough of the new class C5 4-6-0s were available to substitute for them and scrapped within a few years. This was not the last time that Belčamin adopted a "slash and burn" policy to deal with unsatisfactory engines.

Text and graphics © Norman Clubb 2012