Th20

 

 

An unknown JDŽ class 127 (former kkStB class 56) locomotive; location and date also unknown. Photo courtesy Tadej Brate.

 

 

Side drawing of the ČSD class 324.1 with class 412.3 (kkStB class 66) tender. Source: EZ vol. 1.

 

 

KkStB 5641 (later 56.41, WrN 3270/1889) photographed around 1905, location unknown. This engine went to PKP and was withdrawn between 1927 and 1936; its service number is unknown. Source: LAÖ.

  

 

 

 

 

 

 

 

 

 

 

Contrary to many earlier locomotive types, Austro-Hungarian class 56 was supplied not only to state railways kkStB, but also to several private and local operators. It was developed from earlier class 48, of which 23 examples were built between 1885 and 1888. Inner frame was introduced, which gave the locomotive a more modern look, and Gooch valve gear replaced earlier Allan unit. Prototype was built by Wiener Neustadt (3199/1888) and this type remained in production until 1895, with one additional engine delivered in 1900. In all, 153 examples were built, by Wiener Neustadt (81), WLF (69) and StEG (three). The majority went to kkStB. Other recipients were Lemberg-Czernowitz-Jassy Eisenbahn (two), Unterkrainer Bahnen (eight), Eisenbahn Lemberg-Bełżec (four), Valsuganabahn (six) and Göpfritz-Groß Siegharts Eisenbahn (one, built in 1900) – all these locomotives had kkStB service numbers. As many as seven different types of three-axle tenders were coupled with them. Class 56 underwent two re-boilering programs; the first one was initiated in 1893 and the second one in 1912. This type was considered successful and enjoyed a good opinion among footplate crews. It was capable of hauling a 450-tonne draft at 35 km/h. Due to good running qualities, class 56 was sometimes used with passenger trains on secondary lines.

In 1918, 152 engines of this type were still in use (kkStB 5668, WLF 698/1889, was destroyed by boiler explosion in 1895). Austrian state railways BBÖ were left with 38 examples; most were withdrawn in late 1920s and early 1930s, but thirteen survived until Anschluss. They were taken over by DRG, classed 5371, returned after the war and remained in use until 1950s – the last one, ÖBB 253.7140 (former 56.122, WLF 904/1893) was written off in November 1959. Czechoslovakian state railways ČSD received 21 examples, of which twenty were classed 324.1; withdrawals started in 1935 and the last one survived until 1950. Italian state railways FS took over eighteen 56s, including all originally built for Valsuganabahn, which ran between Trento and Venice; classed 261, they were withdrawn between 1927 and 1930. Romanian state railways CFR received twelve examples, which retained their original numbers. The last of them, 56.75 (WLF 780/1891) was written off in 1937. Five went to the Kingdom of Serbs, Croatians and Slovenians and four of them were later included in JDŽ class 127 (together with former kkStB classes 48, 59 and 155); all were withdrawn in the 1930s. Two locomotives ended up in the USSR and their fate is not known.

Polish railways were the major recipient of this type. In all, 56 examples were taken over, including two from Unterkrainer Bahnen and two from Eisenbahn Lemberg-Bełżec. They were operated in south-eastern Poland. Freighters enjoy longer service lives compared to passenger locomotives, so in 1927 as many as 46 examples were still in use, by that time classed Th20. Assignment of new PKP service numbers to individual examples is unknown. Until 1931 nineteen Th20s had been withdrawn and until 1936 this type had completely disappeared from the company’s rosters. Despite considerable number of these engines, not a single one has been preserved.

 


Main technical data

 

No.

Parameter

Unit

Value

1.

Years of manufacture

-

1888 – 1900

2.

Total built / used in Poland

-

153 / 56

3.

Tender class

-

?

4.

Axle arrangement

-

0-3-0

5.

Design maximum speed

km/h

50

6.

Cylinder bore

mm

2 X 450

7.

Piston stroke

mm

632

8.

Engine rating

kW/hp

400 / 545

9.

Tractive effort

kG

10.

Boiler pressure

MPa

1.12

11.

Grate dimensions

m X m

1.81 m2

12.

Firebox heating surface

m2

8.0

13.

Distance between tube plates

mm

4 165

14.

Number of flue tubes

-

166

15.

Heating surface of flue tubes

m2

124.0

16.

Number of smoke tubes

-

-

17.

Heating surface of smoke tubes

m2

-

18.

Evaporating surface, total

m2

132.0

19.

Superheater heating surface

m2

-

20.

Diameter of drivers

mm

1 258

21.

Diameter of idlers front/rear

mm

- / -

22.

Total weight, empty

kg

37 000

23.

Total weight, working order

kg

41 500

24.

Weight on drivers, working order

kg

41 500

25.

Weight with tender, empty

kg

52 000

26.

Weight with tender, working order

kg

74 000

27.

Maximum axle load

T

13.9

28.

Axle base (with tender)

mm

10 620

29.

Overall length (with tender)

mm

15 156

30.

Brake type

-

Hand / Hardy

 

Note: dimensions and weights with kkStB class 66 tender.

 

References and acknowledgments

 

-       www.pospichal.net/lokstatistik (website by Josef Pospichal);

-       KT vol. 2, LP, EZ vol. 1, ISRSL, LAÖ;

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