Tp5

According to the note, this engine was built by Hanomag in 1910. The only G9 with service number 5108 was, however, Breslau 5108 (Schichau 1805/1909), so either this note is incorrect or the photo has been retouched. Source: www.de.wikipedia.org.

Early production engine (albeit already with the Heusinger valve gear), still classed G7 and numbered Kattowitz 4425. This locomotive was later re-numbered G9 Kattowitz 5004. Rebuilt with steam superheating and numbered 55 2316, it was withdrawn in 1933. Source: Lokomotiv-Archiv Preußen Band 2 (see References).

Side drawing of the G9, © Lokomotiv-Revue (source: TB vol. 1).

An unknown G9, damaged during hostilities; location and date unknown, possibly early 1918. Photo from my collection.

Retouched photo of DRG 55 2370 (ex KPEV Breslau 5017, then Breslau 5117, Hanomag 6001/1910), location and date unknown. This locomotive was rebuilt and fitted with superheater, but withdrawn in December 1932. Source: www.commons.wikimedia.org.

In 1906 Prussian state railways KPEV (Königlich Preußische Eisenbahnverwaltung) took delivery of their first freight locomotive running on superheated steam. Classed G8, this engine proved very successful and over 1000 examples were eventually built. Its development, class G8¹, was one of the most numerous locomotive types ever built, total output exceeding 5000 examples. In retrospective, advantages of steam superheating seem obvious, but there were also certain problems. Superheated locomotives were more complex and higher steam temperatures required high-quality lubricants. This perhaps explains why between 1908 and 1911 KPEV took delivery of 200 0-4-0 freighters running on saturated steam. They were classed G9; the same designation was assigned to 27 rather unsuccessful Mallet-type engines, built between 1893 and 1898 by Grafenstaden and known as Bauart Mallet, of which two briefly served with PKP as class Tp8.

Class G9 was developed by Schichau (prototype 1634/1908) from earlier class G7¹, the main difference being enlarged boiler, cylinders of increased diameter and 1250 mm drivers. In fact first production examples retained the G7¹ class designation and were referred to as Bauart Schichau; they were given service numbers 44xx and 47xx. Tractive effort gain was about 20 percent. This type was standardized as Musterblatt III-3m with service numbers 50xx, 51xx and 58xx. Production was divided between Schichau (79), Hanomag (73), Henschel (40) and Borsig (eight). First ten examples had Allan valve gears; later Heusinger units were standardized. Breslau 5111 (Hanomag 5775/1910) was experimentally fitted with Lentz-type poppet-valve gear; Breslau 5121 (Hanomag 6005/1910) initially had Knorr feedwater pump, which was later removed. G9s were coupled mainly with three-axle 3T12 tenders, on occasions with larger 3T15s. This type was the last mainline freighter running on saturated steam ordered by KPEV, as advantages of superheating were soon appreciated, much owing to renowned railway engineer Robert Garbe.

During WWI many G9s were used by German military railways; on December 31, 1917, their fleet included 105 examples. After the war 58 G9s were handed over to Belgian railways and one to newly-created railways of the Saar region. DRG were left with 133 examples, later classed 55^23-24. In early 1920s 36 of them were rebuilt by Hanomag and fitted with superheaters and feedwater heaters, but their designation and service numbers were retained. Of these, a handful survived in service until 1945, to be written off in late 1940s; the last one was 53 2389 (Schichau 1762/1909), rebuilt in 1921 and withdrawn by DR in December 1959. Several were sold to private railways or to industry. All G9s running on saturated steam were withdrawn from DRG until 1933.

According to TB vol. 1, Poland received eight G9s, but the Ministry of Transport 1927 list gives only seven, so possibly one was written off earlier. Later they were classed Tp5. Compared to ex-KPEV G8¹s (PKP class Tp4), they developed tractive effort lower by about ten percent and their maximum speed was only 45 km/h: despite comparatively young age they were thus much less useful. Tp5-6 (Hanomag 6126/1911) and Tp5-7 (Schichau 1929/1911) were withdrawn in January 1937, but nonetheless were taken over by the Soviets in September 1939. Later they became German war booty and served with Ostbahn. The remaining five Tp5s were written off in February 1939. No locomotive of this type has been preserved.

Main technical data

No.	Parameter	Unit	Value
1.	Years of manufacture	-	1908 – 1911
2.	Total built / used in Poland	-	200 / 8
3.	Tender class	-	12C1
4.	Axle arrangement	-	0-4-0
5.	Design maximum speed	km/h	45
6.	Cylinder bore	mm	2 x 550
7.	Piston stroke	mm	630
8.	Engine rating	kW/hp	680 / 925
9.	Tractive effort	kG	12 800
10.	Boiler pressure	MPa	1.22
11.	Grate dimensions	m x m	3.05 m^2
12.	Firebox heating surface	m^2	11.8
13.	Distance between tube plates	mm	4 500
14.	Number of flue tubes	-	292 (296)^1)
15.	Heating surface of flue tubes	m^2	185.7 (188.2)^1)
16.	Number of smoke tubes	-	-
17.	Heating surface of smoke tubes	m^2	-
18.	Evaporating surface, total	m^2	197.5 (200)^1)
19.	Superheater heating surface	m^2	-
20.	Diameter of drivers	mm	1250
21.	Diameter of idlers front/rear	mm	- / -
22.	Total weight, empty	kg	51 300 (52 200)^1)
23.	Total weight, working order	kg	59 000 (60 000)^1)
24.	Weight on drivers, working order	kg	59 000 (60 000)^1)
25.	Weight with tender, empty	kg
26.	Weight with tender, working order	kg	94 800 (95 800)^1)
27.	Maximum axle load	T	14.75 (15.0)^1)
28.	Axle base (with tender)	mm	11 775
29.	Overall length (with tender)	mm	16 758
30.	Brake type	-

1) Data in brackets refer to early production examples with Allan valve gear.

List of vehicles can be found here.

References and acknowledgments

- LP, TB vol. 1;

- www.beitraege.lokomotive.de (Ingo Hütter’s locomotive database);

- Charakterystyka parowozów (Steam Locomotive Characteristics) by A. Czeczott (Ministry of Transport, 1927);

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