Polish State Rwys 4-6-0 Locomotives in Poland

Class Ok203 (Locobase 13563)

Data from Tomas Galka's Polish steam locomotive website [] (last accessed 21 December 2011) and from InterLok's page at [] . Poland had received 500 Tr 203s from the production of UNRRA (United Nations Relief and Rehabilitation Administration) 2-8-0s (US Army S160) that had been distributed among several nations in Europe after World War II. The PKP found that the boiler was modern and efficient, but the small drivers and other elements of the running gear proved unsatisfactory. The first of the Ok203s was created by the ZNTK (Railway Stock Repair Works) of Pila in northwestern Poland by taking the boiler of Tr203-167 (a Lima-built engine, works number 8452) and mating it to a modified frame of an Ok22 (Locobase 1684) that had been damaged. Thus, a satisfactory running-gear design was served by a much newer boiler.

It was a stubby engine, but trials proved that only minor adjustments, such as mounting a taller stack, were necessary. A second Ok 203 followed in 1955, but any thoughts of a series build based on the third engine (See Locobase 13564 for the all-new Ok55-3) evaporated when the administration shut down all steam locomotive development work .

The two engines eventually were reclassified Ok22-89 and 90, withdrawn in the late 1970s, and scrapped. Hermann Schmidtendorf of InterLok (the for-profit successor to the ZNTK) says that the third engine, designated Ok55-3 (and the other two retroactively dubbed Ok55-1 and Ok55-2), was an all-new locomotive. The all-welded boiler was fitted with a smokebox preheater, the thicker frame allowed for Polish-design roller bearings, and much more

Class Ok22 (Locobase 1684)

Data from Tomasz Galka's Polish Steam Locomotives website ([], last accessed 21 December 2011) and A[nthony] E[dward] Durrant, The Steam Locomotives of Eastern Europe (Newton Abbot:David & Charles, 1966)/

First five built by Hanomag and described by Durrant, were "simply a Prussian P8 chassis on which was mounted a large, high-pitched boiler, with wide firebox, and a big cab." Chrzanow delivered 185 more from 1928-1934. Inner diameter for the tubes

Galka says that the "fairly conservative" boiler design was modified by raising it 400 mm (15.7 in) to permit a larger firebox with a substantially larger grate to burn lower-calorie coal. In addition, fire tube count increased by 56 and the superheater flues now numbered 28. The conservatism is reflected in the low boiler pressure rating and the relatively small superheater.

Still, the engines proved very useful and popular. Like most of the rest of Poland's locomotive stock, the Ok22 class were divided up as spoils between the Nazis (112 locomotives redesignated BR 38 4501-38 4612) and the Soviet Union (75). Most of the latter were converted to the Soviet 5' (1,524 mm) gauge. Some were added to the German holdings after the 22 June 1941 invasion of the Soviet Union. (Galka describes the complicated journey of one Ok22: "the only Ok22 in the CFR service was the Ok22-112 (Fablok 433/1930), captured by the Soviets in 1939, then taken over by Wehrmacht, transferred to Romania and re-numbered 230.903, to fall into the hands of Soviets again in 1944 v a colorful life indeed!").

At the end of World War II, the Polish government was able to reclaim 51 Ok22s; 31 more came from East Germany in 1955 and headed directly to the scrap heap. The remaining engines served well into the 1970s, in part because new developments in steam locomotives were abandoned by fiat in the latter 1950s in favor of diesel and electric power.

Two of the wrecked Ok22s still lingering in Polish railyards were converted to "Ok203s" in the mid-1950s. See Locobase 13563.

Class Ok55-3 (Locobase 13564)

Data from Tomas Galka's Polish steam locomotive website [] (last accessed 21 December 2011) and from InterLok's page at [] . As noted in Locobase 13563, the PKP's trials of the first two Ok203s proved encouraging enough to explore an even more up-to-date variant. Hermann Schmidtendorf of InterLok (the for-profit successor to the ZNTK) says that the third engine, designated Ok55-3 (and the other two retroactively dubbed Ok55-1 and Ok55-2), was an all-new locomotive. The all-welded boiler was fitted with a smokebox preheater that supplemented the already considerable increase in superheater area and the thicker frame allowed for Polish-design roller bearings. Also, the wheels in the leading truck were reduced in diameter from 1000 to 850 mm.

Tests showed that the Ok55-3 was a powerful, free-running design. Alas for steam power, the railway authorities had decreed that no new steam development would be pursued and the Ok55-3 remained unique. Galka comments acridly that the history of this design "...reflects the railway authorities attitude: obsessed with rapid introduction of electric and diesel locomotives, irrespective of costs, they had completely neglected steam machines that, due to inevitable problems and delays, remained in service for much longer than expected v even into times when they were considered an unique curiosity, at least by European standards."

One of those was the Ok55-3, which was rebuilt in 1965. The roller-bearing running gear was gone, replaced by the traditional Ok22 assembly and cab. Galka notes that the reason for the changes isn't clear, but may have been due to frame fatigue. Ok55-3 was redesignated Ok22-91 in 1970, ran until 1976-1978, was withdrawn and scrapped.