Great Western Railway class 7200
These 2-8-2T tank locomotives were created by the addition of a trailing axle to 2-8-0T locomotives, alongside a four-feet extension of the frames to increase the capacity of the coal bunker. They were intended for heavy short distance coal trains in South Wales. Starting in 1934, 40 were rebuilt from the class 5205. 14 more were created from the class 4200 which also got cylinders with a diameter of 19 instead of 18.5 inches. These 14 and four of the first batch had “Coal Scuttle” bunkers which increased the water capacity from 2,400 to 2,700 gallons, while decreasing the coal capaity from six to five tons.
Although these locomotives were too long for some sidings, they fulfilled their job in heavy coal traffic. Some were used in ore and stone traffic in England, but the introduction of more powerful goods locomotives brought them back to South Wales after World War II. British Railways assigned them to power class 8F. They still survived until the sixties, with withdrawals between 1962 and 1965. Three have been rescued from the scrapyard on Barry Island. Numbers 7200 and 7202 are currently under restoration. The third one is 7229 that is still waiting for its restoration to start.
Technical data
General
- Built
- 1934-1939
- Manufacturers
- Swindon
- Wheel arrangement
- 2-8-2T (Mikado)
- Gauge
- 1,435 mm (Standard gauge)
Dimensions and weights
- Length
- 13.67 m
- Wheelbase
- 10.74 m
- Rigid wheelbase
- 6.10 m
- Service weight
- 94.1 t
- Adhesive weight
- 73.9 t
- Axle load
- 19 t
- Water capacity
- 10,910 l
- Fuel capacity
- 6.1 t (coal)
Boiler
- Grate area
- 1.91 m²
- Firebox surface
- 11.958 m²
- Tube heating surface
- 125.386 m²
- Evaporative heating surface
- 137.344 m²
- Superheater surface
- 17.818 m²
- Total heating surface
- 155.2 m²
Power plant
- Driver diameter
- 1,410 mm
- Boiler pressure
- 13.8 bar
- Cylinders
- two, 483 x 762 mm
Power
- Estimated power
- 783 kW (1,065 PS)
Calculated values
- Optimal speed
- 32 km/h
- Power-to-weight ratio
- 8.3 kW/t
- Heating Surface Equivalent
- 232.8 m²
- Cylinder volume/HSE
- 1 : 1,197.63
- Adhesive weight/Total
- 1 : 1.27
- Grate area/Heating surface
- 1 : 81.24
- Firebox/Tube surface
- 1 : 10.49
- Total/Superheater
- 1 : 7.71