Prussian P 7
Although the decision-makers at the Prussian State Railways were not great fans of four-cylinder compounds, they could not ignore the good experiences in France with the de Glehn locomotives. In this design, the second driving axle was driven by the outside high-pressure cylinders and the first by the inside low-pressure cylinders. Eighteen passenger locomotives with a 4-6-0 wheel arrangement were ordered in order to gain experience from regular operations and to consider the procurement of larger numbers of de Glehn locomotives.
Since the Elsässische Maschinenbau-Gesellschaft in Grafenstaden had already manufactured the Baden IV e and the Elsass-Lorraine P 5, the locomotives were also ordered there and designated P 7. The locomotives were used on the lines from Hagen via Cologne to Trier and between Frankfurt and Bebra. Apparently, the boiler did not always provide enough steam for the cylinders, what in view of the more expensive maintenance meant that no further P 7 were purchased. Five were handed over to the Belgian State Railways and the rest were decommissioned in the First World War.
Technical data
General
- Built
- 1899-1902
- Manufacturers
- Grafenstaden
- Wheel arrangement
- 4-6-0 (Ten-wheeler)
- Gauge
- 1,435 mm (Standard gauge)
Dimensions and weights
- Length
- 18.05 m
- Length loco
- 10.60 m
- Empty mass
- 54.7 t
- Service mass
- 61.8 t
- Adhesion mass
- 44.5 t
- Axle load
- 15.1 t
- Water capacity
- 16,000 l
- Fuel capacity
- 6 t (coal)
Boiler
- Grate area
- 2.4 m²
- Firebox surface
- 11.3 m²
- Tube heating surface
- 128.2 m²
- Evaporative heating surface
- 139.5 m²
- Total heating surface
- 139.5 m²
Power plant
- Driver diameter
- 1,750 mm
- Boiler pressure
- 14 bar
- Expansion type
- compound
- Cylinders
- four, HP: 350 x 640 mm and LP: 550 x 640 mm
Power
- Power source
- steam
- Estimated power
- 650 kW (884 PS)
- Top speed
- 90 km/h
- Starting effort
- 75.9 kN
- Starting effort simple
- 91.1 kN
Calculated values
- Factor of adhesion
- 1 : 5.75
- Optimal speed
- 53 km/h
- Power-to-weight ratio
- 10.5 kW/t
- Heating Surface Equivalent
- 196.0 m²
- Cylinder volume/HSE
- 1 : 1,404.10
- Adhesive weight/Total
- 1 : 1.39
- Tractive force/Heating surface
- 1 : 11.36
- Grate area/Heating surface
- 1 : 58.13
- Firebox/Tube surface
- 1 : 11.35