Prussian S 9

Prussian S 8, S 9 DRG Class 14.0 SNCB Type 69
Type and origin Builder Hanomag Build date 1908ff. Total produced 99 (2 were "S8"s)
Specifications Configuration: ​  • UIC 4-4-2  • German S 8: S 2/5 h4v S 9: S 2/5 n4v Gauge 1,435 mm (4 ft 8+1⁄2 in) Leading dia. 1,000 mm Coupled dia. 1,980 mm Trailing dia. 1,250 mm Wheelbase: ​  • Overall 10,750 mm Length: ​  • Over beams 21,860 mm Axle load 16.5 t Adhesive weight 33.0 t Empty weight 68.0 t Service weight 74.7 t Water cap. 21.5/30.0/31.5 m3 Boiler: ​ No. of heating tubes 272 Heating tube length 5,200 mm Boiler pressure 14 bar Heating surface: ​  • Firebox 4.00 m2  • Radiative 14.10 m2  • Tubes 222.00 m2  • Evaporative S 8: 229.71 m2 S 9: 182.54 m2 Cylinders 4 High-pressure cylinder 380 mm Low-pressure cylinder 580 mm Piston stroke 600 mm
Performance figures Maximum speed 110 km/h
Career Numbers DRG 14 001, 002, 031 Retired 1926

The Prussian S 9 was a class of express steam locomotive with the Prussian state railways, first built in 1908. It had a 4-4-2 (Atlantic) wheel arrangement and a four-cylinder compound engine. It was developed by the firm of Hanomag in Hanover who delivered a total of 99 engines of this class.

There were also some high-speed trials locomotives which were classified as S 9s, but did not belong to this particular class. These included two cab-forward 4-4-4 locomotives Altona 561 and 562.

Although at the time superheated technology was widespread, the state of Prussia still wanted to have saturated steam engines delivered by Hanomag. The locomotives procured as a result had a very powerful boiler and, at 4 m², the largest grate area of any Prussian steam locomotive. The quantity of steam generated was however more than the high-pressure cylinders could cope with. As a result, the performance of the S 9 was little better than the considerably smaller superheated locomotive, the Prussian S 6. Nevertheless, the S 9 initially formed the backbone of express train services from Berlin to Hanover. Like all German Atlantic locomotives, the S 9 quickly proved too underpowered for the increasingly heavy trains it had to haul.

Two locomotives (Hannover 903 and 905) were fitted with superheated boilers in 1913 and 1914 and reclassified as S 8s.

After 1919 17 locomotives had to handed over to Belgium and 4 to France. Only three of them, the two S 8s and a saturated steam engine, were taken over by the Deutsche Reichsbahn as DRG Class 14.0. The two S 8s were given numbers 14 001 and 14 002; the S 9 ("Essen 907") number 14 031. All three were retired by 1926.

The locomotives were equipped with Prussian tenders of classes pr 2'2' T 21.5, pr 2'2' T 30 und pr 2'2' T 31.5.

Belgian engines managed to outlive German engines by several years since they were only written-off in 1948. They were used on fast trains on the lines around Antwerp.

See also

• Prussian state railways
• List of Prussian locomotives and railcars

References

• Vandenberghen, J (1989). La guerre 1914 - 1918 et les locomotives "Armistice", 2. Description des locomotives K.P.E.V. (PDF) (in French). Brussels: SNCB. pp. 73–78.
• Weisbrod, Manfred; Müller, Hans; Petznik, Wolfgang (1976). Dampflokomotiven deutscher Eisenbahnen, Baureihe 01–39 (EFA 1.1) (in German) (3rd ed.). Düsseldorf: Alba Buchverlag. pp. 92–94. ISBN 3-87094-081-6.