The reference for locomotives and railcars


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Alsace-Lorraine S 12
French State Railway 1-231 A 301 to 304 and 306 to 308 and Luxembourg Railways No. 3711 to 3713
Germany | 1908 | 8 produced
Die Lokomotive, June 1909

In order to obtain a more powerful express locomotive than those with the 4-6-0 wheel arrangement, the Reichseisenbahnen in Alsace-Lorraine had some of the first Pacifics built in Europe in 1908. However, in order to be able to use existing turntables and at the same time allow a large tender, the trailing axle had a very small distance from the third driving axle

This meant that the Belpaire firebox had to be moved between the driving wheels, so the G 12 was not one of the typical Pacifics with a wide firebox. Typical of French-influenced areas, they had four cylinders based on the de Glehn system. Other features included serve tubes in the boiler and an exhaust system with a variable cross-section and cloverleaf shape.

Since the boiler and firebox were too small compared to other Pacifics and ten-wheelers, only eight S 12 were built. The seven that remained after the First World War came to SNCF in 1938 as 1-231 A. After the Second World War, three came to Luxembourg, two to the GDR and two to Poland. While they were used in Luxembourg until 1950 and in the GDR until 1953, the two in Poland were decommissioned in 1946 without actually being used.

Axle config4-6-2 (Pacific) 
Gauge4 ft 8 1/2 in (Standard gauge)
Dimensions and Weights
Length70 ft 6 7/16 in
Wheelbase33 ft 11 1/2 in
Fixed wheelbase14 ft 1 5/16 in
Empty weight166,449 lbs
Service weight182,102 lbs
Adhesive weight105,822 lbs
Total weight288,585 lbs
Axle load35,274 lbs
Water capacity5,548 us gal
Fuel capacity13,228 lbs (coal)
Power sourcesteam
Estimated power1,341 hp (1,000 kW)
Optimal speed45 mph
Top speed62 mph
Starting effort19,119 lbf
with start valve22,943 lbf
Power Plant
Driver diameter80.3 in
Boiler pressure218 psi
Expansion typecompound
Cylindersfour, HP: 14 15/16 x 26 in
and LP: 23 5/8 x 26 in
Grate area34.7 sq ft
Firebox area187.1 sq ft
Tube heating area1,968 sq ft
Evaporative heating area2,155 sq ft
Superheater area414.4 sq ft
Total heating area2,569.5 sq ft
Calculated Values
steam locomotive
De Glehn compound
last changed: 01/2024

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