Om101

 

 

KWStE No. 2011 (Esslingen 3572/1911), 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).

 

 

 

 

 

 

 

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. 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 four were taken over by French state railways ­ETAT. Three were numbered 231.997 through 999 and assigned to the Le Mans depot. 37 examples left for German railways were later classed 181 by newly-formed DRG. Of these, 27 served with DB after the war. Last two in service, 18 133 and 18 136, based in Ulm, were withdrawn in May 1955. The sole Polish Om101-1 (former KWStE 2010, Esslingen 3571/1911) was obtained from France in 1919. 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. 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. Basically this question remains open. 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

-

20D1011)

4.

Axle arrangement

-

2-3-1

5.

Design maximum speed

km/h

115

6.

Cylinder bore

mm

420 / 6203)

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 m2

12.

Firebox heating surface

m2

15.00

13.

Distance between tube plates

mm

5 500

14.

Number of flue tubes

-

174

15.

Heating surface of flue tubes

m2

16.

Number of smoke tubes

-

24

17.

Heating surface of smoke tubes

m2

18.

Evaporating surface, total

m2

205.14

19.

Superheater heating surface

m2

54.43 / 65.003)

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

26.

Weight with tender, working order

kg

27.

Maximum axle load

T

15.9

28.

Axle base (with tender)

mm

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)      Since 1914.

3)      430 / 635 mm in 2012 through 2024.

 

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.