Pe101

Belgian class 12, location and date unknown (probably during WWI). Source: www.mikes.railhistory.railfan.net.

SNCB-NMBS No. 2154, location and date unknown. Postcard from my collection.

No. 195, the triple-boiler version of class 12; location and date unknown. Source: Die Lokomotive January 1913.

Side drawing of class 12; source: SK vol. 5/1997 (see References).

An unidentified SNCB-NMBS class 12 locomotive; location and date unknown, possibly a factory photo. Source: Die Lokomotive December 1917.

Among the most peculiar (but perhaps not the most beautiful) steam locomotives ever used in Poland were three ex-Belgian state railways class 12 express engines. Captured by Germans in Belgium during WWI they were brought to Warsaw and assigned to Militär-Eisenbahndirektion 4 (class S2). Left there after German withdrawal in 1918, they were impressed into PKP. Their most unusual feature, shared with several other Belgian classes of late 19^th century (e.g. 1-3-0 class 6 express locomotive or 0-3-0 class 25 freight tank engine), was massive stack of square cross-section, designed to improve boiler draught. Benefits of such design are not known in detail, but it was never used in any other country.

Despite its curious look, class 12 was basically a successful express locomotive of sound design. It was ordered to supplant older class 1 engines, which were becoming too weak for heavy trains. Class 12 featured the 1-2-1 axle arrangement with 2100 mm drivers and boiler with a wide Belpaire-type firebox. Large grate, 4.7 sq.m in area, had complex shape and combustion was not entirely satisfactory, as grate width was larger than that of the ashpan and air flow was very uneven. After 1910 the locomotives that still remained in service were fitted with redesigned boilers of more conventional design, grate area being reduced to 3 sq.m. Steam pressure was increased to 12 bar and tractive effort improved accordingly. Modified engines were referred to as class 12bis. These locomotives were typically coupled with three-axle tenders, but some had smaller two-axle tenders previously used with class 1. In all, 114 examples were built between 1888 and 1897 by Cockerill, Tubize and Société de St Léonard. Last were withdrawn from use in early 1930s and none has been preserved.

The above-mentioned three Polish locomotives of this type (Cockerill 1589/1890 and 1798/1894, Tubize 813/1891, German service numbers 4215, 4217 and 4252) were initially classed S2^Bg, with Bg standing for ‘Belgia’. New class designation Pe101 was probably intended for them, but never assigned. Square stacks found little appreciation with Polish railwaymen and were described as extremely ugly; later they were replaced with more typical ones. Very little is known about their service with PKP and no photographs are known to exist. All were withdrawn from use before 1927 – one source gives 1924. According to SK (see References) they were sold or handed over to Latvian railways. This, however, is not confirmed by Latvian sources, which state that LVD in fact had three ex-Belgian 12s, but taken over directly from German authorities in Königsberg in January 1919. Numbered An 29 through 31, they were withdrawn between 1921 and 1923.

Class 12 might look unusual, but it was further developed into a true monstrosity. In 1888 Société de St Léonard built, for comparison purposes, a triple-boiler locomotive which retained frame, wheelsets and cylinders of its predecessor, but was fitted with three parallel boilers which shared common firebox and smoke-box. The aim was to improve steaming capacity without excessive rise of the center of gravity, while burning coal of very poor quality. Quite surprisingly, this contraption proved successful, although improvement over class 12 was not high enough to justify series production. During tests in similar conditions the triple-boiler engine developed 1,235 hp, compared to 1,189 hp of the ‘ordinary’ class 12. Lack of the running board made this locomotive unpopular with footplate crews and obviously did not contribute to the ease of maintenance. It was, however, accepted by state railways. Numbered 195, it was used on the Brussels-Ostend line. After an explosion of one of the lateral boilers in 1902 it was withdrawn from use. Class designation 12 was used again in 1938 by Belgian state railways, by then known as NMBS/SNCB, this time for a beautiful streamlined 2-2-1, built in six examples.

Main technical data

No.	Parameter	Unit	Value
1.	Years of manufacture	-	1888 – 1897
2.	Total built / used in Poland	-	114 / 3
3.	Tender class	-
4.	Axle arrangement	-	1-2-1
5.	Design maximum speed	km/h	110
6.	Cylinder bore	mm	2 x 500
7.	Piston stroke	mm	600
8.	Engine rating	kW/hp	875 / 1 189^1)
9.	Tractive effort	kG	5 710 / 6 860^2)
10.	Boiler pressure	MPa	1.02 / 1.22^2)
11.	Grate dimensions	m x m	4.7 / 2.93 m^2 2)
12.	Firebox heating surface	m^2	12.5
13.	Distance between tube plates	mm	3 500
14.	Number of flue tubes	-	242
15.	Heating surface of flue tubes	m^2	112.17
16.	Number of smoke tubes	-	-
17.	Heating surface of smoke tubes	m^2	-
18.	Evaporating surface, total	m^2	124.67 / 113.4^2)
19.	Superheater heating surface	m^2	-
20.	Diameter of drivers	mm	2 100
21.	Diameter of idlers front/rear	mm	1 200
22.	Total weight, empty	kg	46 000 / 51 500^2)
23.	Total weight, working order	kg	49 200 / 54 300^2)
24.	Weight on drivers, working order	kg	31 400
25.	Weight with tender, empty	kg	62 400 / 67 900^2)
26.	Weight with tender, working order	kg	83 900 / 89 000^2)
27.	Maximum axle load	T	15.8
28.	Axle base (with tender)	mm	13 535
29.	Overall length (with tender)	mm	17 845
30.	Brake type	-	Westinghouse

Note: all data with three-axle tender.

1) Attained during tests.

2) Class 12 /class 12bis.

References and acknowledgments

- www.mikes.railhistory.railfan.net;

- www.nonsequitur.freeforums.org;

- article on Belgian locomotives in PKP service by Krzysztof Zintel (SK vol. 5/1997);

- Stare parowozy (Old steam locomotives) by Zdenék Bauer (Sport i Turystyka, 1986);

- LP;

- Toms Altbergs and Piotr Staszewski (private communication).