Tw1-90 + 17C1-7 (Borsig 10438/1919) at the Kościerzyna loco heritage park...




... and the same machine posing alongside Ty2-1401 (Esslingen 4705/1943). Both photos taken in August 2000.




Another picture of Tw1-90, taken on August 13, 2004 – a very rainy day. My wife Anna held the umbrella.




And yet another: September 23, 2013.




Tw1-90 again, but this time in service: Gdańsk Zaspa, April 18, 1975. Photo by Roman Witkowski (postcard from my collection).




Side drawing of 5710-35 from TB vol.1





Beautifully preserved TCDD No. 55047 at the National Railway Museum, Ankara; photo courtesy




Another Turkish engine: TCDD 55037 at the Çamlik locomotive museum.  Photo taken in August 2002 (courtesy Adrian Raduta).




Another photo from Adrian Raduta (thanks a lot!): CFR 50.378 (Reşiţa 99/1929, with 50.115 plates in the place of stolen originals) at the Muzeul locomotivelor cu abur in aer liber, Reşiţa; photo taken in August 2003.




Tw1-140, photographed in Gdańsk in 1961. Photo from my collection.




Another picture of TCDD 55037 at the Çamlik museum, taken on September 30, 2007.




Former KPEV ‘Halle 5607’, then 57 2559 (Borsig 11262/1922), in the DR service somewhere in Eastern Germany. Photo from my collection.




This locomotive is most probably KPEV Cöln 5101 (Henschel 9629/1910), taken over by Belgian railways in 1919 and re-numbered 9001; location and date unknown. Photo from my collection.




57 3297 (Hohenzollern 4401/1923), photographed somewhere in Eastern Germany, date unknown. Photo from my collection. This engine was withdrawn in August 1973 and has been preserved.



Turkish 55034, photographed in Gumusgün on April 17,1984. Photo from my collection.



Another photo from my collection: KPEV Halle 6016, Rheinmetall 558/1922. This locomotive later became DRG 57 3096 and survived in the DR service until 1957.



57 3486, DB (Orenstein & Koppel 10072/1924), photographed at the Haltingen depot on April 16, 1968. This engine was withdrawn in December 1968. Postcard from my collection; a bicycle on the running board really looks great!



ÖGEG collection includes former CFR 50.770 (Malaxa 299/1938), which now displays Austrian-style service number 657.2770; Lokpark Ampflwang, August 25, 2016.



Another picture of the 657.2770, taken on the same occasion.



Factory photo of the first locomotive built by Krupp: KPEV Elberfeld 5494, delivered in 1919. Source: Die Lokomotive September 1920.



Back to Kościerzyna: Tw1-90 undergoing external refurbishment. August 12, 2020.



Hanomag 10083/1923 with initial incorrect number 33 2262. Re-numbered 57 3262 in 1925, it was sold to CFR in 1926 and remained in use until 1990s as 50.289. Location and date unknown. Postcard from my collection.

In 1902 Prussian state railways KPEV (Königlich Preußische Eisenbahnverwaltung) received first G8 freight locomotives with 0-4-0 axle arrangement, soon followed by improved class G81. Combined output of these two classes reached about 6000 examples, which makes them one of the most numerous European steam locomotive types. These engines, designed by Robert Garbe and derived from earlier G71 and G72, were powerful for that time, but axle load of 16.4 tonnes was unacceptable for many tracks. There was thus a need for a heavy freighter with lower axle load, but at least equal tractive effort. In 1907 Garbe suggested to marry frame and motion gear of the T16 tank engine with slightly modified boiler taken from P8 – one of the most successful passenger locomotives of early 20th century. New locomotive, designated G10, had maximum axle load reduced to 14.6 tonnes, but tractive effort increased from 12.2 to 15.2 tonnes.

Production for KPEV started at Henschel in 1910. During the production run, several modifications were introduced. Initially Gölsdorf layout (as in the T16) was used, wherein 1st, 3rd and 5th coupled axles had side-play, but running qualities left something to be desired, so later 3rd axle was made fixed and 4th axle wheel flanges were narrowed. Maximum speed was increased from 50 to 60 km/h and the same modification was introduced in the T161 tank engine, derived from the T16. According to some sources, boiler was also slightly modified (number of flues is sometimes given as 127), although basically it remained interchangeable with that of P8. Additional steam dome and second sand dome were also added later. Boiler pressure, however, remained unchanged at only 12 bar. In all, modifications increased overall weight by about seven tonnes and maximum axle load to 15.4 tonnes.

Until 1924, 2580 examples were built for KPEV (later for DRG) by eight companies: Borsig (664), Grafenstaden (10), Hanomag (452), Henschel (712), Hohenzollern (48), Krupp (287), Orenstein & Koppel­ (117) and Rheinmetall (290). Furthermore, 35 engines were built by Borsig, Grafenstaden and Henschel for railways of then-German Alsace and Lorraine. Between 1922 and 1925, Hanomag, Rheinmetall and Schwartzkopff supplied additional 27 machines to Eisenbahndirektion des Saargebietes (Saar Basin railways). More orders came from abroad. In 1917, Henschel built twenty machines for Austro-Hungarian military railways (K.u.k.Hb. – class 680). In 1924, Schwartzkopff supplied twenty examples to Turkey, followed by five more from Henschel two years later and eighteen from Swedish Nohab between 1927 and 1928; these engines supplemented six ex-KPEV G10s supplied during WWI and all were later given TCDD service numbers 55001 through 55049. By far the largest orders came from Romania. CFR (Căile Ferate Române) found this type, classed 50.100 (sometimes given as 50.1), particularly suited for their needs and ordered it in large numbers. 231 brand new examples from various German manufacturers, supplied in several batches between 1921 and 1930, were supplemented by 42 second-hand ones from DRG (CFR service numbers 50.253 through 50.294). 520 were built in Romania by Reşiţa (261, between 1926 and 1944) and Malaxa (259, between 1928 and 1940). Reşiţa production includes ten engines with Lentz poppet valves, built in 1936 and designated 50.1001 through 50.1010. This makes class 50.100 the most numerous CFR freight locomotive type. Last examples, built by two Romanian factories from 1938 onwards, had enlarged boilers and were heavier by about three tonnes in working order.

After WWI, German railways were left with 2358 examples (later DRG class 5710-35); 222 G10s were distributed among several countries. First engines of this type came to Poland shortly after the Armistice from Austro-Hungarian military railways KuKHB (class 680): PKP took over all twenty examples used by this service. Further 35 were acquired from KPEV between 1921 and 1922 – most of them (29) had been previously used in Upper Silesia. Thirty examples were built by Schwartzkopff against Polish order in 1922. All these locomotives were classed Tw1; ex-KPEV examples were given service numbers from 1 to 26 and from 47 to 55, former Austro-Hungarian 680s – 27 through 46 and new machines from Germany – 71 through 100. The reason for this gap in service numbers is that it was intended to give highest numbers to brand new engines and the exact number of those to be taken over from Prussian railways was still not known when they were assigned, so a ‘margin’ was provided. Most were coupled with  ex-KPEV 3 T 16,5 three-axle tenders (PKP class 17C1), but four-axle 16D1, 16D2 and 17D1 were also used. Tw1s performed particularly well on weaker tracks, for which more powerful Tr20s, Tr21s and Ty23s were too heavy, so most of them operated in southern and south-eastern Poland. No wonder, thus, that in September 1939 the majority (71) fell into Soviet hands: only nine were captured by Germans and impressed into DRG class 5710-35. The Soviets found this type particularly useful for their conditions, especially in newly acquired Western territories, with many comparatively weak tracks, although its narrow firebox must have demanded high-grade coal. All retained their Polish service numbers, written in Russian script; 27 later fell into German hands. The fate of five remaining engines is not known. According to some sources, they were brought by retreating Polish forces to Romania and impressed into CFR service in 1939.

Fortunes of war brought about further redistribution of these useful machines between 1939 and 1945. Many Soviet examples (captured in Poland and later in Romania) fell into German hands after Fall Barbarossa. After 1945, this class shared the fate of other German locomotives. DB were left with 730 examples, withdrawn until 1970; last of 112 engines serving with DR survived until 1971. Romania acquired twelve ex-DRG machines (service numbers 50.901 through 50.912), bringing the grand total in CFR service to 805 examples; some older sources give slightly different numbers. In October 1945 Romania was forced to hand over 25 engines of this type to the USSR – most of them were brand new machines, taken directly from Reşiţa, that had their CFR numbers already assigned, but in fact saw no service. Other pre- and post-WWII users include:

-        France (PLM class 5B, Paris-Orléans class 050, AL numbered from 5401 to 5435, SNCF class 050B),

-        Belgium (SNCB class 90),

-        Italy (FS class 473),

-        Yugoslavia (JDŽ class 35),

-        Czechoslovakia (ČSD: 22 examples purchased in France in 1922 and classed 534.1, in service until 1970, one ex-DRG 57 2740 impressed in 1945 and designated 535.1500, nine ex-CFR examples, taken over in 1945 and returned in 1952, no ČSD service numbers having been assigned),

-        Greece (OSE class Ka),

-        The Netherlands (NS class 48),

-        Norway (NSB class 61a, DRG service numbers retained),

-        Austria (ÖBB class 657, in service until 1969),

-        Luxembourg (PH class K, CFL class 52, the latter purchased in Belgium in 1934),

-        Syria (CFS class 050.5),

-        Soviet Union (examples from Poland, Romania and Germany, taken as war booty or from reparations; according to LOZD, they numbered about 900, many converted to 1524 mm track and later designated class TShCh, or TЩ in Russian script, withdrawn about mid-1960s).

After WWII, only ten ex-PKP Tw1s came back to Poland, but many more former DRG machines were impressed into PKP service, bringing their total number to 141. Several more were not impressed into service, but returned to their former owners or scrapped; in particular, three ex-CFR engines: 50.470, 50.487 and 50.488 were assigned to the Szczecin regional management and scrapped in 1964. Compared to Ty2s (DRG class 52), most numerous post-war freight locomotives in Poland, Tw1s had lower tractive effort and inferior economy (boiler pressure of only 12 bar) at almost the same axle load, so most of them were relegated to switching and secondary duties, serving mainly in northern Poland (regional managements on Gdańsk and Poznań). Several were converted to oil firing. Four engines (Tw1-56, -73, -93 and -98) were leased by military railways in the 1950s – due to low axle load they were found particularly useful on military sidings. They were returned in late 1950s or early 1960s. A dozen or so, converted to 1524 mm track, served at transfer stations along Eastern border; all had interchangeable standard-gauge wheelsets. Most European railways started withdrawing their former G10s in early 1950s. In Poland their service was longer; on January 1, 1960, PKP still had 116 examples, but during next twelve years their number dwindled to 37. Few were used by industrial operators, but were generally considered too weak for heavy industry establishments, like collieries or steel plants. Last PKP engine, Tw1-90 (Borsig 10438/1919, KPEV Kattowitz 5495, DRG 57 1658), was withdrawn in December 1976. This machine can now be seen at the Kościerzyna heritage park and is the only example preserved in Poland. Three are in Germany: 57 3088 (Rheinmetall 550/1922, KPEV Halle 6011) in Betzdorf, 57 3297 (Hohenzollern 4401/1923) in Chemnitz and former CFR 50.227 (Rheinmetall 913/1926) at the Bayerische Eisenbahnmuseum in Nördlingen; the latter has been given fictitious DRG number 57 3525 and is probably still in working order. Austrian ÖGEG society has four, all from CFR: 50.459 (AEG 4414/1930), 50.519 (Malaxa 45/1931), 50.770 (Malaxa 299/1938) and 50.608 (Malaxa 144/1934); the latter is based in Cluj, Romania, and has retained its original designation, the remaining have been given fictitious ÖBB numbers, 657.3549, 657.2519 and 657.2770, respectively. Three engines can be seen in Turkey. TCDD 55047, built by Schwartzkopff in 1924, can be seen at the National Railway Museum in Ankara; 55022 (Borsig 1913, ex KPEV), recently restored, is on display at the Rahmi M.Koç museum in Istanbul and 55037 (Schwartzkopff 1922) at the Çamlik Buharli Lokomotif Muzesi (Çamlik steam locomotive museum). List of surviving Romanian steam locomotives, available at, gives fourteen examples, but two have since been sold to ÖGEG and one has probably been scrapped.

Prussian class G10 has had an unexpectedly rich history, as one of the most widely used freight steam locomotives in Europe. Its story parallels perhaps only that of later Kriegsloks, mainly DRG class 52, in fact also designed for comparatively high tractive effort at moderate axle load.



Main technical data







Years of manufacture


1910 – 1943


Total built / used in Poland


34871) / 85 – 1412)


Tender class


17C1, 16D1, 16D2, 17D1


Axle arrangement




Design maximum speed




Cylinder bore


2 X 630


Piston stroke




Engine rating


920 / 1250


Tractive effort


15 200


Boiler pressure




Grate dimensions

m X m

2.63 X 1.01


Firebox heating surface




Distance between tube plates


4 700


Number of flue tubes




Heating surface of flue tubes




Number of smoke tubes




Heating surface of smoke tubes




Evaporating surface, total




Superheater heating surface




Diameter of drivers




Diameter of idlers front/rear


- / -


Total weight, empty


70 5003)


Total weight, working order


76 6003)


Weight on drivers, working order


76 6003)


Weight with tender, empty


92 5003)


Weight with tender, working order


122 1003)


Maximum axle load




Axle base (with tender)


14 050


Overall length (with tender)


18 910


Brake type


steam, Knorr,



1)      Approximate number; includes 18 engines built in Sweden and 520 in Romania.

2)      After WWII.

3)      Refers to the final production variant with 17C1 tender, typical in PKP service.


References and acknowledgments


- (website maintained by ‘Doctor’),

-       monographic article by Paweł Terczyński (SK vol. 4/1996),

-       LP, RR, LOZD, EZ vol. 3, TB vol. 1, ITFR,

-       Polish State Railways as a means of transportation for the Warsaw Pact armed forces by Zbigniew Tucholski (IHN PAN, Warsaw, 2009),

-       Adrian Raduta (private communication – thanks a lot!).