TKh4b

 

 

TKh4b-9, photographed at the Konin Marantów briquetting plant on February 27, 2004.

 

 

 

Further two pictures, taken on this occasion; boiler domes fairing has been removed and probably replaced by a makeshift steam collector cover. The other engine is the TKi3b-48.

 

 

Yet another picture of the TKh4b-9, showing steam engine and motion gear.

Demand for fireless engines in Poland appeared in late 1940s and resulted from rapid expansion of chemical industry, with inherent fire and explosion hazard problems. There were no diesel locomotives suitable for works transport (and in fact they appeared in substantial numbers only in 1960s), so fireless steam locomotives, simple and undemanding, were in those times an ideal solution.

A handful of fireless locomotives were purchased in Germany in late 1940s and early 1950s, but basically, until the appearance of purpose-built type 1U, needs were satisfied by conversions of old freight machines. These included class Tp4, ex-Prussian class G81 (DRG 5525-56), one of the most numerous ones in the PKP service (described under a separate entry). After WWI, Poland acquired 412 G81s and further fifty identical machines were built in Germany against Polish orders in 1921. Few returned after WWII, but again PKP acquired a number of German engines, so post-war class Tp4 numbered 302 examples. They survived in the PKP service until 1972 and with industrial operators, mainly sand railways, until early 1980s.

In 1951, ZNTK (Railway Stock Repair Establishment) of Wrocław undertook manufacture of steam containers for fireless locomotives. Initially they were of entirely riveted construction, later welding was introduced. It was decided to mount these on frames from withdrawn ‘normal’ steam locomotives. Class TKi3 (ex-Prussian T93) was found most suitable, as only minor frame and undercarriage modifications were necessary. Tp4, which was also available in some numbers, proved more troublesome. In order to provide proper position of the steam container with respect to cylinders, fourth axle was removed and frame was substantially shortened. This resulted in a layout with three coupled axles, so designation was changed to TKh4b, small ‘b’ standing for ‘bezogniowy’, or fireless. Axle load increased to 18 tonnes – quite much for many tracks at industrial establishments. No axle had any side-play, so maximum speed had to be reduced to 20 km/h – for works transport this was, however, sufficient. Of course, ‘new’ engine worked on saturated steam and was fitted with steam brakes, actuated by a single cylinder. Boiler domes were covered with a long fairing, extending forwards and down, which was sometimes removed in service to facilitate easier maintenance.

First eight TKh4bs were delivered in 1953; four followed in 1954, fourteen in 1955 and two in 1956, when purpose-designed 1U made its appearance. This makes a total of 28 engines; all had consecutive numbers, TKh4b-1 through 28, although went to various users. Most were delivered to coking plants, steelworks and chemical plants. Their service, although not particularly eventful, was in some cases surprisingly long. At least six survived until late 1980s and one, TKh4b-9, remained operational at the Konin Marantów lignite briquetting plant probably until 1998. When this plant was closed down, it was intended to preserve this unique locomotive – the only surviving TKh4b – which was in good condition. Unfortunately, despite being recognized as an object of historical value, it was scrapped in August 2004. In my humble opinion, it was a crime.

 


Main technical data

 

No.

Parameter

Unit

Value

1.

Years of manufacture

-

1953 – 19561) 

2.

Total built / used in Poland

-

28 / 28

3.

Tender class

-

-

4.

Axle arrangement

-

0-3-0

5.

Design maximum speed

km/h

20

6.

Cylinder bore

mm

2 X 600

7.

Piston stroke

mm

660

8.

Engine rating

kW/hp

257 / 350

9.

Tractive effort

kG

9 700

10.

Boiler pressure

MPa

1.22

11.

Grate dimensions

m X m

-

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

-

19.

Superheater heating surface

m2

-

20.

Diameter of drivers

mm

1350

21.

Diameter of idlers front/rear

mm

-

22.

Total weight, empty

kg

 

23.

Total weight, working order

kg

54 000

24.

Weight on drivers, working order

kg

54 000

25.

Weight with tender, empty

kg

-

26.

Weight with tender, working order

kg

-

27.

Maximum axle load

T

18.0

28.

Axle base (with tender)

mm

3 150

29.

Overall length (with tender)

mm

10 150

30.

Brake type

-

steam

 

1)      Reconstruction.

 

References and acknowledgments

 

Most information has been taken from a monographic article by Tomasz Roszak in SK vol. 7/2003.