OKe1

 

 

KPEV T51 Altona 1561 (Henschel 5737/1901), factory photo. Source: Lokomotiven der alten deutschen Staats- und Privatbahnen by Hermann Maey and Erhard Born, Transpress, 1983.

 

 

OKe1-4 (Henschel 6779/1904) in German service, Czeremcha depot, 1941 or 1942. The locomotive still bears PKP service number. Source: www.pl.wikipedia.org.

 

 

 

T51 side drawing from TB vol 2, © Lokomotiv-Revue.

 

Between 1905 and 1908 all locomotive types of Prussian state railways KPEV were re-designated within the framework of new system introduced in 1903. Tank engines were designated by capital letter T (for Tenderlokomotive) plus a number which – at least initially – indicated the power group: the higher number, the higher the power. Even and odd numbers were assigned to locomotives running on superheated and saturated steam, respectively. Both these rules were not strictly obeyed, especially later. Class T5 ultimately included as many as six distinct types (including one superheated!), which differed even in such basic features as axle arrangements, having two or three coupled axles.

By far the most numerous was sub-class T51. First locomotives of this type were ordered from Henschel by Berliner Stadtbahn in 1895, in order to replace older 1-2-0s and 0-2-1s (later class T2). Prototypes (4140/1895 and 4141/1895) became Berlin 2011 and Berlin 2012, respectively, and were standardized as Musterblatt III 4i, 1.Auflage. Production engines (Musterblatt III 4i, 2.Auflage) were slightly longer, albeit axle base of 6800 mm was retained, and fitted with large steam dome. Total output was 309 examples, all from Henschel, the last one being 7106/1905. Twenty more, also classed T51, were delivered between 1907 and 1921 by Hanomag to Großherzoglich Oldenburgische Eisenbahn. First five were very similar to production T51s built for KPEV, the rest had axle base increased to 7000 mm, overall length remaining unchanged.

T51 featured the 1-2-1 axle arrangement with leading and rear Adams axles that facilitated similar running qualities in both directions. They were thus rather versatile and found quite widespread use. With the appearance of more powerful types they were gradually relegated to branch lines and switching. Although newly-formed German state railways DRG in 1923 intended to retain as many as 115 examples in service, only 26 were actually kept, classed 710. The last one, 71 021 (Henschel 7092/1905) was withdrawn in 1931. Several were sold to private railways. The machines from Oldenburg, numbered 71 401 through 71 420, were withdrawn between 1927 and 1930, so two enjoyed service life of mere nine years.

Five examples taken over by PKP were classed OKe1 and assigned to regional managements in Wilno and Białystok. Three were written off between 1936 and 1938. OKe1-2 (Henschel 5725/1901) was taken over by Lithuanian railways LG and re-numbered T5 801. In 1940, following the annexation of Lithuania, it was impressed into NKPS. OKe1-4 (Henschel 6779/1904) also fell into Soviet hands, but was later captured by Germans and probably served with DRG, but its service number, if any, is not known. Ultimate fate of both these locomotives remains unknown. No T51 has been preserved.


Main technical data

 

No.

Parameter

Unit

Value

1.

Years of manufacture

-

1895 – 1921  

2.

Total built / used in Poland

-

329 / 5

3.

Tender class

-

-

4.

Axle arrangement

-

1-2-1

5.

Design maximum speed

km/h

75

6.

Cylinder bore

mm

2 X 430

7.

Piston stroke

mm

600

8.

Engine rating

kW/hp

9.

Tractive effort

kG

10.

Boiler pressure

MPa

1.22

11.

Grate dimensions

m X m

1.57 m2

12.

Firebox heating surface

m2

6.6

13.

Distance between tube plates

mm

4 000

14.

Number of flue tubes

-

171

15.

Heating surface of flue tubes

m2

88.1

16.

Number of smoke tubes

-

-

17.

Heating surface of smoke tubes

m2

-

18.

Evaporating surface, total

m2

94.7

19.

Superheater heating surface

m2

-

20.

Diameter of drivers

mm

1 600

21.

Diameter of idlers front/rear

mm

1 000 / 1 000

22.

Total weight, empty

kg

41 500

23.

Total weight, working order

kg

53 100

24.

Weight on drivers, working order

kg

31 400

25.

Weight with tender, empty

kg

-

26.

Weight with tender, working order

kg

-

27.

Maximum axle load

T

15.7

28.

Axle base (with tender)

mm

6 800

29.

Overall length (with tender)

mm

11 685

30.

Brake type

-

 

Note: all data for production locomotives for KPEV.

 

References and acknowledgments

 

-         Lietuvos Geležinkelių Garvežiai 1919-1940 m. / Steam Locomotives of Lithuanian Railways 1919-1940 by Toms Altbergs (Zidex, Lithuania, 2012);

-         LP, TB vol. 2;

-         Lokomotiv-Archiv Preußen Band 3 by Andreas Wagner (Bechtermünz Verlag, 1996);

-         www.pl.wikipedia.org.