Th15

KkStB 5103 (former KRB 96 ‘Maglern’, later 50.28, WLF 52/1873). After the war taken over by ČSD and re-numbered 312.024, withdrawn in November 1925. Location and date unknown. Source: www.commons.wikimedia.org.

Side drawing of class 50; source: EZ vol. 1.

The question of assignment of new PKP designations to several locomotive classes of Austro-Hungarian provenance is somehow academic, as most of these engines had already been withdrawn when new system came into use. Reliable sources restrain from authoritative answers and it seems that this question will never be solved, unless hitherto unknown documents are revealed. This refers also to class Th15. According to www.pospichal.net/lokstatistik, this designation was assigned to two kkStB class 50 engines, but further confirmation is lacking. If this was actually the case, the assignment was purely formal, as both these locomotives were returned to Czechoslovakia in early 1920s.

Austro-Hungarian class 50 included 25 freight 0-3-0s originally built by WLF for Prag-Duxer Eisenbahn (PDE) – 21 between 1872 and 1873 plus additional four in 1883. Further three, classed IV, were ordered by Kronprinz Rudolph-Bahn (KRB) in 1873, also from WLF; they differed mainly in boiler details. From 1884 PDE was operated by state railways kkStB and locomotives, initially distinguished only by individual names, were given service numbers 5001 through 5025 (from 1905. 51.01 through 25); the railway was nationalized in 1892. KRB was taken over by kkStB in 1884; three IVs initially became 5101 through 5103, but, as they were almost identical with class 50, were later re-numbered 50.26 through 28. Class 50 locomotives were coupled with various three-axle tenders, typically class 30.

All but three locomotives of this type were after WWI handed over to Czechoslovakian state railways. In 1925 they were classed 312.0 (except 50.16, 50.23 and 50.26, withdrawn earlier). Former 50.27 (WLF 51/1873) went to Italian FS and was designated 219.001, but it was withdrawn in December 1922. 50.24 (former PDE ‘Chlumčany’ WLF 472/1883) and 50.25 (former PDE ‘Lenešic’, WLF 473/1883) were initially taken over by PKP, but later handed over to ČSD and numbered 312.022 and 312.023, respectively. Last example, 312.017 (former 50.18, WLF 49/1873) was withdrawn in March 1940 and converted into a stationary boiler. No engine of this type has been preserved.

Main technical data

No.	Parameter	Unit	Value
1.	Years of manufacture	-	1872 – 1883
2.	Total built / used in Poland	-	28 / 2
3.	Tender class	-	?
4.	Axle arrangement	-	0-3-0
5.	Design maximum speed	km/h	45
6.	Cylinder bore	mm	2 X 445
7.	Piston stroke	mm	632
8.	Engine rating	kW/hp	250 / 340
9.	Tractive effort	kG
10.	Boiler pressure	MPa	1.12
11.	Grate dimensions	m X m	1.94 m^2
12.	Firebox heating surface	m^2	8.5
13.	Distance between tube plates	mm	4 170
14.	Number of flue tubes	-	196
15.	Heating surface of flue tubes	m^2	130.9
16.	Number of smoke tubes	-	-
17.	Heating surface of smoke tubes	m^2	-
18.	Evaporating surface, total	m^2	139.4
19.	Superheater heating surface	m^2	-
20.	Diameter of drivers	mm	1175
21.	Diameter of idlers front/rear	mm	- / -
22.	Total weight, empty	kg	35 000
23.	Total weight, working order	kg	39 500
24.	Weight on drivers, working order	kg	39 500
25.	Weight with tender, empty	kg	45 500
26.	Weight with tender, working order	kg	65 000
27.	Maximum axle load	T	13.4
28.	Axle base (with tender)	mm	10 617
29.	Overall length (with tender)	mm	14 924
30.	Brake type	-	Hand / Hardy

References and acknowledgments

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

- TK vol. 2, LP, EZ vol. 1.