Western Australian Government 4-6-4 Locomotives in Australia

Class Details by Steve Llanso of Sweat House Media

Class Ut (Locobase 7494)

Data from [], which reproduced an item from the January 1958 Railway Transportation.

The UT is a conversion of the Class U Pacific, a class originally built for operations in the Sudan (see Locobase 4486) and supplied to the WAGR in 1946-1947. For the latter, the locomotives were converted to oil-burning. The UT's boiler and running gear were essentially unchanged, the changes being concentrated in crafting a fixed oil-fuel bunker, side tanks that ran from cab to smokebox, and a 4-wheel trailing truck.

At the time of writing, the 1958 correspondent claimed that the engine accelerated "smartly" and kept suburban railcar schedules easily, including the taxing Perth to Fremantle, a 14-stop run over 11 miles covered in 34 minutes. Consumption when hauling a 4-car, 74-ton train amounted to 36 Imp gallons of water and 4.25 Imp gallons of oil per mile. Given that the goal was two round trips without refuelling or watering, the 50-mile water range was sufficient.

On the other hand, the rail heritage Museum of Western Australia ([], accessed 17 April 2007) notes that while "[t]he Ut locomotive was able to easily keep to the railcar schedule[,] [f]urther conversions were not undertaken due to the high running costs. The Ut was used intermittently until withdrawn in 1970"

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID7494
RailroadWestern Australian Government
Number in Class1
Road Numbers
Number Built
BuilderWestern Australia
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)
Engine Wheelbase (ft / m)
Ratio of driving wheelbase to overall engine wheelbase
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)101,920 / 46,230
Engine Weight (lbs / kg)178,752 / 81,081
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)178,752 / 81,081
Tender Water Capacity (gals / ML)2400 / 9.09
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)1200 / 4542
Minimum weight of rail (calculated) (lb/yd / kg/m)57 / 28.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)46 / 1168
Boiler Pressure (psi / kPa)184.20 / 12.70
High Pressure Cylinders (dia x stroke) (in / mm)18" x 24" / 457x610
Tractive Effort (lbs / kg)26,467 / 12005.24
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.85
Heating Ability
Tubes (number - dia) (in / mm)
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)
Firebox Area (sq ft / m2)142 / 13.20
Grate Area (sq ft / m2)26 / 2.42
Evaporative Heating Surface (sq ft / m2)1125 / 104.55
Superheating Surface (sq ft / m2)260 / 24.16
Combined Heating Surface (sq ft / m2)1385 / 128.71
Evaporative Heating Surface/Cylinder Volume159.15
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation4789
Same as above plus superheater percentage5699
Same as above but substitute firebox area for grate area31,126
Power L18341
Power MT541.27

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