Tr1

Warschau 4464, Deutsche Heeresbahn, Esslingen 3808/1917, location and date unknown. This locomotive later became 56 003 and was withdrawn before 1926. Source: Lokomotiven der alten deutschen Staats- und Privatbahnen by H. Maey and E. Born (Transpress, 1983).

Side drawing of class G7³, © M. Kratochvil (TB vol. 1).

KPEV Hannover 2001 (Hanomag 2500/1893). This engine remained in Germany and was withdrawn before 1925. Source: Die Lokomotive March 1919.

One of the locomotives built during the war for military railways: Warschau 36 (Maffei 4740/1917), later re-numbered Warschau 4436; location and date unknown. I have no information on the further fate of this locomotive. Source: as above.

One of two G7³s operated by LBE: No. 85 (Krauss 7268/1917). Originally delivered to military railways as Warschau 52, later Warschau 4452, then Osten 4452, sold to LBE in 1922, rebuilt with single-expansion engine in 1936, taken over by DRG as 56 001 in 1938. Ended up in Yugoslavia as JDŽ 24-101, later 142-001. Pretty interesting life! Location unknown, 1932. Photo by Werner Hubert (source: www.commons.wikimedia.org).

Prussian class G7³ was developed from earlier G7², built in considerable numbers (1646 examples, plus several more for other railways). The intention was to reduce axle load and improve running qualities, so that new locomotive could work freight trains on demanding lines with tight curves. For this purpose, lead Adams truck was used, certainly not typical with maximum speed of merely 45 km/h. Compound steam engine of class G7² was retained and boiler was slightly enlarged.

Two prototypes (Hanomag 2499/1893 and 2500/1893) were assigned to the Hannover regional management. Due to general improvement of track quality and increase of acceptable axle loads, class G7³ enjoyed a very modest production run, only fifteen examples being built by Hanomag between 1893 and 1895. They were typically coupled with three-axle 3T12 tenders. During the war it was found that such locomotive might be very useful on Eastern front, where track quality was generally inferior to that typical for the KPEV network. Further orders were thus placed and between 1916 and 1917 seventy examples were delivered to Militär-Eisenbahndirektion Warschau by Maffei (39), Krauss (thirteen) and Esslingen (eighteen). These featured boiler pressure increased from 12 to 14 bar and typically ran with larger three-axle 3T16,5 tenders. After the war only six examples were kept by DRG, but one (Hanomag 2669/1894) was erroneously included in former class G7² and numbered 55 701; the rest were classed 56⁰. All were withdrawn before 1926, but in 1938 DRG acquired two more G7³s, sold to Lübeck-Büchener Eisenbahn in 1924; both survived until 1945, with one ending up in the Soviet Union and the other one in Yugoslavia (JDŽ 24-101).

As many as 33 locomotives of this type, left by retreating German forces, were taken over by Polish railways after the war. Later they were classed Tr1. Due to their low axle load and ability to negotiate tight curves they served in eastern and south-eastern Poland, so all fell in 1939 into Soviet hands, except Tr1-3 (prototype Hanomag 2499/1893), which was withdrawn in February 1938. One (Tr1-14, Maffei 4722/1916) was captured by Germans and finally ended up in Romania (CFR 40.921). The fate of the remaining Polish Tr1s is not known, but none was returned. According to one source (Jukka Nurminen – www.scado.narod.ru), these locomotives were impressed not into NKPS, but into Gulag railways; confirmation is lacking and this question requires further study. No G7³ has been preserved.

Main technical data

No.	Parameter	Unit	Value
1.	Years of manufacture	-	1893 –1917
2.	Total built / used in Poland	-	85 / 33
3.	Tender class	-
4.	Axle arrangement	-	1-4-0
5.	Design maximum speed	km/h	45
6.	Cylinder bore	mm	500 / 750
7.	Piston stroke	mm	630
8.	Engine rating	kW/hp	650 / 880
9.	Tractive effort	kG
10.	Boiler pressure	MPa	1.22 / 1.43^1)
11.	Grate dimensions	m x m	2.28 m^2
12.	Firebox heating surface	m^2	10.8
13.	Distance between tube plates	mm	4 100
14.	Number of flue tubes	-	235
15.	Heating surface of flue tubes	m^2	136.1
16.	Number of smoke tubes	-	-
17.	Heating surface of smoke tubes	m^2	-
18.	Evaporating surface, total	m^2	146.9
19.	Superheater heating surface	m^2	-
20.	Diameter of drivers	mm	1250
21.	Diameter of idlers front/rear	mm	1000 / -
22.	Total weight, empty	kg	49 700 / 54 100^1)
23.	Total weight, working order	kg	56 200 / 60 500^1)
24.	Weight on drivers, working order	kg	50 500 / 52 500^1)
25.	Weight with tender, empty	kg
26.	Weight with tender, working order	kg
27.	Maximum axle load	T	12.6 / 13.1^1)
28.	Axle base (with tender)	mm	13 025 / 14 105^1)
29.	Overall length (with tender)	mm	16 318 / 17 352^1)
30.	Brake type	-

1) Second production run (1916 – 1917).

References and acknowledgments

- www.beitraege.lokomotive.de/datenbank (databank by Ingo Hütter);

- LP, TB vol. 1;

- Lokomotiv-Archiv Preußen Band 2 by Andreas Wagner (Bechtermünz Verlag, 1996).