Emu Bay Railway Beyer-Garratt Locomotives in Australia
Class Details by Steve Llanso of Sweat House Media
Class 12 (Locobase 510)
Data from Gavin Hamilton's excellent compilation of Garratt data posted at [
] (6 September 2005); Emu Bay's locomotive diagram archived on Rail Tasmania's website at [], last accessed 18 September 2021; and "Emu Bay Railway-Design 1151", Beyer-Garrrat Patent Articulated Locomotives (Manchester, England: Beyer-Peacock & Company Limited, 1931), archived on flickr's Historical Railway Images at [], et seq, p. 55;. Works numbers were 6580-6582 in 1929
Double Mountain Garratts for a Cape-gauge railway. According to [], these Garratts did well, hauling heavy freights over a line with steep gradients until replaced by larger Australian Standard Garratts in the 1950s. Indeed, the specifications called for pulling 400 long tons up a 2.5% grade (1 in 40) while not overstressing 50 lb/yard (25 kg/metre) rail. In fact, one test saw one of the class move 496 tons from a standing start on the grade.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | 12 |
| Locobase ID | 510 |
| Railroad | Emu Bay Railway |
| Country | Australia |
| Whyte | 4-8-2+2-8-4 |
| Number in Class | 3 |
| Road Numbers | 12-14 |
| Gauge | 3'6" |
| Number Built | 3 |
| Builder | Beyer, Peacock |
| Year | 1929 |
| Valve Gear | Walschaert |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 16.34 / 4.98 |
| Engine Wheelbase (ft / m) | 49.33 / 15.04 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.33 |
| Overall Wheelbase (engine & tender) (ft / m) | 72 / 21.95 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | 23,520 / 10,669 |
| Weight on Drivers (lbs / kg) | 188,160 / 85,348 |
| Engine Weight (lbs / kg) | 297,136 / 134,779 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | |
| Tender Water Capacity (gals / ML) | 6300 / 23.86 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 6.60 / 6 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 39 / 19.50 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 43 / 1092 |
| Boiler Pressure (psi / kPa) | 184.20 / 1270 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 16.5" x 22" / 419x559 (4) |
| Tractive Effort (lbs / kg) | 43,617 / 19784.36 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.31 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 218 - 1.875" / 0 |
| Flues (number - dia) (in / mm) | 32 - 5.25" / 0 |
| Flue/Tube length (ft / m) | 12.37 |
| Firebox Area (sq ft / m2) | 174 / 16.16 |
| Grate Area (sq ft / m2) | 43.60 / 4.05 |
| Evaporative Heating Surface (sq ft / m2) | 2037 / 189.24 |
| Superheating Surface (sq ft / m2) | 380 / 35.30 |
| Combined Heating Surface (sq ft / m2) | 2417 / 224.54 |
| Evaporative Heating Surface/Cylinder Volume | 187.07 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 8031 |
| Same as above plus superheater percentage | 9316 |
| Same as above but substitute firebox area for grate area | 37,179 |
| Power L1 | 7670 |
| Power MT | 718.94 |