Prussian P 4

4 ft 8+1⁄2 in)Coupled dia.1,750 mmCarrying wheel diameter1,000 mmWheelbase:​ • Overall7,400 mmLength:
​ • Over beams16,411 mmAxle load15.5 tAdhesive weight31.0 tEmpty weight44.6 tService weight49.1 tWater cap.15.0 m³Boiler:
​No. of heating tubes141No. of smoke tubes1 fire tubeBoiler pressure12 barHeating surface:​ • Firebox2.32 m² • Radiative8.9 m² • Tubes76.2 m² • Evaporative85.1 m²Superheater:
​ • Heating area21.0 m²Cylinders2Cylinder size460 mmPiston stroke600 mm

Performance figures
Maximum speed	90 km/h
Indicated power	675 kW (900 PS)

Career
Retired	1921

The Prussian P 4 was a derivative of the P 4.1 (Hanover variant) and the second superheated steam locomotive in the world.

Design

The engine was based on that of the Class P 4.1 that had Hanomag had produced in large numbers since 1892. It had slightly larger wheels and, due to its new design, significantly fewer heating tubes. The superheater and the steam engine were entirely independent designs.

Service and preservation

In 1898 a one-off was delivered by Hanomag to the Prussian state railways. The economy of the superheated system was soon proven in 1899 by the engine during trial runs from Kassel. Apart from a short stay at Halle the engine was assigned to Kassel as Cassel 131 and, from 1906, as P 4 Cassel 1846. In 1921, after the First World War, the engine was mothballed, along with many other machines of similar class. With its sectioned boiler the P 4 stood for a long time in the Transport and Construction Museums, part of Museum of the Present at Hamburger Bahnhof in Berlin^{[clarification needed]}.

See also

• Prussian state railways
• List of Prussian locomotives and railbuses
• List of preserved steam locomotives in Germany

References

Express train locomotivesPassenger and express train locomotivesGoods train locomotivesTank locomotivesNarrow gauge locomotivesElectric locomotivesRailbuses