Tr7

 

Tr7_1

 

Tr7-3 (ex DRG 56 4103), Jaworzyna Śląska depot, October 11, 2000.

 

Tr7_2

 

The same locomotive, photographed on August 4, 2004.

 

Tr7_3

 

Another picture of the Tr7-3, taken by John Bryant in June 2008 (thanks for permission!).

 

 

 

 

 

 

 

 

 

 

In 1940, Tanko Coal Mining Co. of Manchuria (occupied by Japan, though formally independent) placed an order with German Maschinenbau und Bahnbedarfs A.G. – former Orenstein & Koppel – for four freight locomotives with the 1-4-0 axle arrangement. They were roughly similar to DRG class 5620-29,30 (Prussian G82), but had smaller drivers (1300 mm instead of 1400 mm) and larger fireboxes. Probably they were designed to develop comparable tractive effort while burning low-grade local coal.

These locomotives were serialled 13330 through 13333; according to www.lokomotive.de (impressive German locomotive database by Ingo Hütter) they were built in 1940, while most Polish sources give 1941. Due to war situation they could not be delivered to Manchuria; most probably it had been intended to send them via the USSR, but this was not done before June 1941. Eventually, in June 1942, all four were purchased by DRG and classed 5641 (service numbers 56 4101 through 4104). All were based in Poznań and fell into Soviet hands in 1945. Soviet ministry of transport NKPS probably were not interested in these untypical, though almost brand new engines, so they were duly handed over to PKP and classed Tr7. All four were transferred to the Warsaw regional management in 1948 and remained there throughout their lives; all except Tr7-2, on which I have no detailed information, were based in Skierniewice. Tr7-2 was withdrawn in 1964, Tr7-1 two years later and Tr7-4 in 1970. Tr7-3 was the last to go; after a few months in an unglorious role of a stationary boiler it was formally written off in April 1972, then transferred to the Railway Museum in Warsaw and finally, in 1991, to the former locomotive depot in Jaworzyna Śląska (now Industry and Railway Museum). After external refurbishment in 1998 the machine is in a good condition. It is coupled with an unidentified tender, probably German four-axle 2’2’T21.5, erroneously designated 22D23.

There is something peculiar about this class. Of four examples built one has survived, although its importance for either country or origin or country where it spent almost all life (to say nothing of Manchuria!) is marginal. Many much more numerous and important classes have completely disappeared. In fact, little is known about these engines and even TB does not mention them. For this reason, the specification below is far from complete. I shall be very grateful for any information.

 

 


Main technical data

 

No.

Parameter

Unit

Value

1.

Years of manufacture

-

1941

2.

Total built / used in Poland

-

4 / 4

3.

Tender class

-

 

4.

Axle arrangement

-

1-4-0

5.

Design maximum speed

km/h

65

6.

Cylinder bore

mm

2 X 630

7.

Piston stroke

mm

660

8.

Engine rating

kW/hp

 

9.

Tractive effort

kG

 

10.

Boiler pressure

MPa

1.43

11.

Grate dimensions

m X m

3.4 m2

12.

Firebox heating surface

m2

 

13.

Distance between tube plates

mm

 

14.

Number of flue tubes

-

 

15.

Heating surface of flue tubes

m2

 

16.

Number of smoke tubes

-

 

17.

Heating surface of smoke tubes

m2

 

18.

Evaporating surface, total

m2

167.4

19.

Superheater heating surface

m2

53.1

20.

Diameter of drivers

mm

1300

21.

Diameter of idlers front/rear

mm

850 / -

22.

Total weight, empty

kg

 

23.

Total weight, working order

kg

 

24.

Adhesive weight, working order

kg

 

25.

Weight with tender, empty

kg

 

26.

Weight with tender, working order

kg

130 000

27.

Maximum axle load

T

 

28.

Axle base (with tender)

mm

 

29.

Overall length (with tender)

mm

16 995

30.

Brake type

-

Knorr

 

 

References and acknowledgments

 

Concise information can be found in AP and PSMK railway fan association website (www.psmk.org.pl).