Midland class 3
London, Midland & Scottish class 3P
For the increased weight of express trains at the turn of the century, Johnson developed the class 3 with the 4-4-0 wheel arrangement. It was the first locomotive on the Midland Railway to have a Belpaire firebox, which increased its heating surface and therefore also power. Between 1900 and 1905, 80 were built, of which the last 15 received a slightly larger boiler.
Between 1913 and 1926, 73 of the locomotives received a new standard boiler with superheater. The remaining seven remained in use without superheaters until 1925 or 1926. Number 714 was destroyed in the Charfield accident in October 1928, in which 16 people died and 41 were injured. The decommissioning of the remaining ones began in 1935 and was not completed until 1953, when the last ones had already been taken over by the British Railways.
Technical data
General
- Built
- 1900-1905
- Manufacturers
- Derby
- Wheel arrangement
- 4-4-0 (American)
- Gauge
- 1,435 mm (Standard gauge)
Dimensions and weights
- Wheelbase
- 6.83 m
- Total wheelbase
- 14.43 m
- Service mass
- 52.7 t
- Adhesion mass
- 35.2 t
- Total mass
- 105.9 t
- Rigid wheelbase
- 2.90 m
- Axle load
- 18.6 t
- Water capacity
- 20,456 l
- Fuel capacity
- 4.1 t (coal)
Boiler
- Grate area
- 2.323 m²
- Firebox surface
- 13.471 m²
- Tube heating surface
- 127.649 m²
- Evaporative heating surface
- 141.12 m²
- Total heating surface
- 141.1 m²
Power plant
- Driver diameter
- 2,057 mm
- Boiler pressure
- 12.4 bar
- Expansion type
- simple expansion
- Cylinders
- two, 495 x 660 mm
Power
- Power source
- steam
- Estimated power
- 634 kW (862 PS)
- Starting effort
- 83.1 kN
Calculated values
- Factor of adhesion
- 1 : 4.15
- Optimal speed
- 47 km/h
- Power-to-weight ratio
- 12.0 kW/t
- Heating Surface Equivalent
- 208.5 m²
- Cylinder volume/HSE
- 1 : 1,220.70
- Adhesive weight/Total
- 1 : 1.50
- Tractive force/Heating surface
- 1 : 12.29
- Grate area/Heating surface
- 1 : 60.75
- Firebox/Tube surface
- 1 : 9.48