Prussian S 4

The Prussian S 4's were German superheated express steam locomotives with the Prussian state railways, later grouped as DRG Class 13.5 in the Deutsche Reichsbahn. They were an evolutionary development of the Prussian S 3. The first locomotive was built in 1898 by Vulcan, Stettin as a modified S 3. She was the first superheated locomotive in the world.[1] She was initially designated as Hannover 74 and towards the end as the S 4 Cassel 401. Two further trials locomotives appeared in 1899 and 1900 as Hannover 86 and Berlin 74 also classed as S 3's. They were later reclassified as S 4's Hannover 401 and Posen 401.[1]

Prussian S 4 DRG Class 13.5, 13.4
Number(s)	DRG 13 501–504
Quantity	104
Manufacturer	Borsig, Henschel, Humboldt
Year(s) of manufacture	1902–1909
Retired	1927
Wheel arrangement	4-4-0
Axle arrangement	2’B h2
Type	S 24.16
Track gauge	1,435 mm (4 ft 8 ^1⁄2 in)
Length over buffers	18,210 mm
Service weight	50.2 t
Adhesive weight	31.9 t
Axle load	16.0 t
Top speed	100 km/h
Indicated Power	736 kW
Driving wheel diameter	1,980 mm
Leading wheel diameter	1,000 mm
Valve gear	Walschaerts (Heusinger, outside)
No. of cylinders	2
Cylinder bore	540 mm
Piston stroke	600 mm
Boiler Overpressure	12 bar
No. of heating tubes	115
No. of smoke tubes	18
Heating tube length	4,300 mm
Grate area	2.32 m^2
Radiative heating area	10.65 m^2
Evaporative heating area	117.70 m^2
Tender	pr 3 T 153/15 pr 2’2’ T 16
Water capacity	13.0/15.0/16.0 m^3
Data for production series

Not until the teething troubles had been resolved was the S 4 put into series production in 1902 in Borsig, from 1906 also in Henschel and Humboldt.[1] Unlike the prototypes the production engines were developed independently of the S 3, and 104 examples were built in the years to 1909 when procurement was halted in favour of the Prussian S 6. Up to 1906 a smokebox superheater was installed; afterwards smoke tube superheaters were used.[1]

The S 4's star waned even before the First World War, so that within a few years most of the engines had disappeared from the tracks. The remainder were employed on passenger train or even goods train duties.

In 1923 the Deutsche Reichsbahn recorded 44 S 4's in its provisional renumbering plan as 13 501-544. But by 1925 only four of them were left. These were given running numbers 13 501–504 in 1925[1] and were retired by 1927.

After the First World War, six locomotives were given to the Polish State Railways (PKP), where they were classified as Pd2 class, numbers 1 to 6.[1] During the Second World War five S 4s came into the Reichsbahn holdings from Poland as 13 401–405.[1] Two of them were eventually given back to Poland in 1955 by the DR.

The locomotives were equipped with tenders of Prussian classes pr 2’2’ T 16, pr 3 T 13 and pr 3 T 15.

See also

• Prussian state railways
• List of DRG locomotives and railcars
• List of Prussian locomotives and railcars

References

1. Rauter and Scheingraber (1991), pp. 84-90.

Literature

• Rauter, Herbert; Scheingraber, Günther (1991). Preußen-Report. Band 2: Die Schnellzuglokomotiven der Gattung S 1 - S 11 (in German). Hermann Merker Verlag. ISBN 3-922404-16-2.