Class 323FF 4-6-2 with poppet valves

Class 323FF 2-Cylinder Passenger Locomotive
Designed by Mikhail Rodnivacek
Rebuilt in 1957 from class 323F by RSR Works, Bevice-Akohniçe, Ruhnia

The success of the taper-boiler 533BB 4-10-0s prompted Rodnivacek to apply the same amendments to the Tešlov 323F 4-6-2s. The original version of both classes carried identical boilers and so did the rebuilds. The opportunity was also taken of fitting poppet valves, boxpok wheels and Vanderbilt tenders. The new boilers were a great improvement on the earlier, parallel ones, allowing much harder continuous steaming, and the new poppet valves raised the efficiency and power of the engines beyond recognition, admitting the 323FFs to express passenger turns on the northern plains. During the 1980s, the mainframes of many engines developed hair-line fractures, which were attributed to unfavourable weight distribution an the rear end. Certainly the large firebox was heavier than that of the original parallel boiler. Strangely, this problem did not occur with the 533BBs. At any event, there were by this time sufficient numbers of newer, more modern locomotives on the RSR's roster, with the result that a cracked frame was virtually an automatic death sentence. The last 323FF was withdrawn in 1992.