Om101

KWStE No. 2002 (Esslingen 3445/1909), location and date unknown – possibly a factory photo. From my collection.

The only photograph of the Om101—1 known to me is that taken in Warsaw in 1926, with a group of Polish children from Lille, France. Inscription on the buffer beam indicates that this engine was based in Warsaw at that time. Source: National Digital Archives (used by permission).

Class 18¹ side drawing; source: TB vol.1

(© Lokomotiv-Revue).

This photo was taken to commemorate a training course for drivers; details, however, are lacking. No. 2008 (Esslingen 3569/1910) later served with DRG as 18 107. Taken over by DB, it was withdrawn in May 1954. Photo from my collection.

Most German locomotives taken over by Polish state railways after WWI were of Prussian origin, but some – often represented by single examples – were of more exotic descent. Among the latter was the sole representative of the KWStE (Königlich Württembergische Staats-Eisenbahnen) class C, affectionately referred to as ‘Die Schöne Württembergerin’. Despite having 1800 mm drivers, it was classed a passenger engine by PKP and numbered Om101-1.

Class C appeared in 1909 (prototype Esslingen 3444/1909) and was developed as the principal express locomotive for KWStE, as a replacement for older classes Ac, E, AD and ADh. Running on superheated steam and fitted with four-cylinder compound steam engine, it was easily recognizable due to characteristic silhouette, with V-shaped front cab wall and large ashpan. Until December 1915, Maschinenfabrik Esslingen built 29 examples, numbered 2001 through 2029. Production was resumed in 1919 and further twelve examples followed until 1921 (2030 through 2041). In 1914 superheater was enlarged, from 54.43 to 65.00 sq.m. Later examples (from 2025 onwards) ran with larger tenders.

All class C engines were initially assigned to Stuttgart Nordbahnhof depot and hauled prestigious express trains. They were considered a very successful design. After the war, 37 examples remained in Germany and were later classed 18¹ by newly-formed DRG. Of these, 27 served with DB after the war. Last two in service, 18 133 (former No. 2037, Esslingen 3978/1921) and 18 136 (former No. 2040, 3981/1921), based in Ulm, were withdrawn in May 1955. Four were taken over by French authorities. Three were impressed into state railways ETAT, numbered 231.997 through 999 and assigned to the Le Mans depot. The fourth (former KWStE 2010, Esslingen 3571/1911) finally ended up in Poland. It belonged to a batch of 100 engines, taken over by Polish authorities between May and October 1919, pending an international agreement on war reparations. Together with a single Prussian G12 three-cylinder heavy freighter, this untypical engine was intended mainly for evaluation. In 1926 it was numbered Om101-1. It was initially assigned to the Łódź Kaliska depot and remained in use until September 1939, often running with express trains. Information on its fate after the outbreak of war is not entirely consistent. According to one version, it went with an evacuation train to Romania (some claim that this train carried the gold reserve of Polish national bank – this, however, has not been confirmed). Impressed into CFR service as 231.901, it was scrapped in Romania after the war. According to other sources, however, Om101-1 was taken over by the Soviets and most probably not re-gauged, becoming Romanian booty in June 1941. The latter version seems more probable; Om101-1 is included in the list of Polish locomotives taken over by NKPS (Soviet ministry of transportation), available at www.scado.narod.ru. Not a single example of this graceful engine has survived until today.

Main technical data

No.	Parameter	Unit	Value
1.	Years of manufacture	-	1909 – 1921
2.	Total built / used in Poland	-	41 / 1
3.	Tender class	-	20D101^1)
4.	Axle arrangement	-	2-3-1
5.	Design maximum speed	km/h	115
6.	Cylinder bore	mm	420 / 620^2)
7.	Piston stroke	mm	612
8.	Engine rating	kW/hp	1353 / 1840
9.	Tractive effort	kG
10.	Boiler pressure	MPa	1.53
11.	Grate dimensions	m X m	3.95 m^2
12.	Firebox heating surface	m^2	15.00
13.	Distance between tube plates	mm	5 500
14.	Number of flue tubes	-	174
15.	Heating surface of flue tubes	m^2	193.00
16.	Number of smoke tubes	-	24
17.	Heating surface of smoke tubes	m^2	15.00
18.	Evaporating surface, total	m^2	208.00
19.	Superheater heating surface	m^2	54.43^3)
20.	Diameter of drivers	mm	1800
21.	Diameter of idlers front/rear	mm	1000 / 1250
22.	Total weight, empty	kg	76 300
23.	Total weight, working order	kg	85 200
24.	Weight on drivers, working order	kg	47 800
25.	Weight with tender, empty	kg	97 600
26.	Weight with tender, working order	kg	131 800
27.	Maximum axle load	T	15.9
28.	Axle base (with tender)	mm	17 410
29.	Overall length (with tender)	mm	20 430
30.	Brake type	-	Westinghouse

1. Equivalent to 2’2T20 – later locomotives of this class ran with larger 2’2T30 tenders.

2. 430 / 635 mm in 2012 through 2024.

3. Since 1914.

References and acknowledgments

- TB vol.1, LP;

- Lokomotiv-Archiv Württemberg by Hermann Lohr and Georg Thielmann (Transpress, 1988);

- www.marklinfan.net/classe_c.htm;

- www.pl.wikipedia.org;

- www.scado.narod.ru (website by Vyacheslav Sokolov);

- www.beitraege.lokomotive.de (locomotive database by Ingo Hütter);

- Die Lokomotive, February 1910.