While the class 344D 4-6-4s were still under construction, Tešlov was already at work on the next locomotive in his new motive power concept. In having the same boiler and many smaller details as the 4-6-4, the 433C was very much a standard design. The running gear, which had already appeared on the 433B 2-8-0 a year before, used three-cylinder simple proplusion, the layout of the valve gear being inspired by the Prussian class P10 2-8-2s of 1920 (later class 39 of the German State Railway). Having so much in common with the 344D, the 433C shared some of its problems, too. These included occasional shyness of steam and a tendency for the trailing bogie to derail when reversing over the sharp curves and uneven track of shed yards. In early 1939, a number of 433Cs received the same tapered boilers as the 344DDs, with the same measure of success, to become class 433CC. After the Second World War, the surviving locomotives were rebuilt in the same way and for the same reasons as the 344Ds. The last survivor was withdrawn in 1969.

Text and graphics © Norman Clubb 2012