Great Northern (UK) No. 472 and 473
The Great Northern needed new locomotives to accommodate the growing freight traffic on the Metropolitan Line between King's Cross and the goods yards between Farringdon Street and Ludgate Hill. The particular challenges were gradients of up to 1 in 35, tight curves and several tunnels. Two locomotives were therefore ordered from Avonside in 1866, based on two others that had been built for the Vale of Neath Railway.
With four coupled axles they were exceptionally strong by British standards at the time. In order to be able to drive through the tight curves, the first and last axles could each be moved laterally by 5/8 inch and were reset by springs. Because of the tunnels they had a condenser. However, as they turned out to be too large for the Metropolitan Line, it is unclear how long they were actually used there in the time until they were scrapped in 1880.
Technical data
General
- Built
- 1866
- Manufacturers
- Avonside
- Wheel arrangement
- 0-8-0T (Eight-coupled)
- Gauge
- 1,435 mm (Standard gauge)
Dimensions and weights
- Wheelbase
- 4.83 m
- Service mass
- 56.9 t
- Adhesion mass
- 56.9 t
- Rigid wheelbase
- 1.65 m
- Axle load
- 14.2 t
Boiler
- Grate area
- 1.579 m²
- Firebox surface
- 9.29 m²
- Tube heating surface
- 134.719 m²
- Evaporative heating surface
- 144.009 m²
- Total heating surface
- 144.0 m²
Power plant
- Driver diameter
- 1,067 mm
- Boiler pressure
- 10.3 bar
- Expansion type
- simple expansion
- Cylinders
- two, 470 x 610 mm
Power
- Power source
- steam
- Estimated power
- 317 kW (431 PS)
- Starting effort
- 110.9 kN
Calculated values
- Factor of adhesion
- 1 : 5.03
- Optimal speed
- 18 km/h
- Power-to-weight ratio
- 5.6 kW/t
- Heating Surface Equivalent
- 190.5 m²
- Cylinder volume/HSE
- 1 : 1,110.13
- Adhesive weight/Total
- 1 : 1.00
- Tractive force/Heating surface
- 1 : 16.09
- Grate area/Heating surface
- 1 : 91.20
- Firebox/Tube surface
- 1 : 14.50