Buenos Aires Great Southern classes 12A, 12B and 12D
Argentina 1907 61 produced
Beginning in 1907, the Buenos Aires Great Southern received some batches of Ten-Wheelers with different cylinder configurations from British manufacturers. The first was the class 12A with a two-cylinder compound engine, which was built a total of 32 times by Beyer, Peacock and North British and was later converted to simple expansion and superheated. Also in 1907, nine class 12B locomotives were built by the Vulcan Foundry, using four cylinder compound engines, three of which were superheated in 1924. In 1914 Beyer, Peacock built 20 class 12D locomotives, which had a simple two-cylinder engine and a superheater.
Technical data
General
| Property | 12A | 12B | 12B superheated | 12D |
|---|---|---|---|---|
| Built | 1907 | 1924 | 1914 | |
| Manufacturers | Beyer, Peacock & Co., North British | Vulcan Foundry | BAGS | Beyer, Peacock & Co. |
| Wheel arrangement | 4-6-0 (Ten-wheeler) | |||
| Gauge | 1,676 mm (Indian broad gauge) | |||
Dimensions and weights
| Property | 12A | 12B | 12B superheated | 12D |
|---|---|---|---|---|
| Wheelbase | 7.90 m | 7.96 m | ||
| Service mass | 66.1 t | 70.1 t | 71 t | 68.3 t |
| Adhesion mass | 44.7 t | 46.7 t | 49.6 t | 50.5 t |
| Total mass | 112.1 t | 116.8 t | 121.1 t | 114.3 t |
| Rigid wheelbase | 3.86 m | 4.34 m | ||
| Axle load | 14.9 t | 15.6 t | 16.5 t | 16.9 t |
| Water capacity | 15,910 l | 18,185 l | 15,910 l | |
| Fuel capacity | 7.1 t (coal) | |||
Boiler
| Property | 12A | 12B | 12B superheated | 12D |
|---|---|---|---|---|
| Grate area | 2.323 m² | 2.601 m² | 2.323 m² | |
| Firebox surface | 12.914 m² | 12.635 m² | 12.542 m² | |
| Tube heating surface | 138.89 m² | 155.799 m² | 115.293 m² | 111.948 m² |
| Evaporative heating surface | 151.804 m² | 168.433 m² | 127.928 m² | 124.49 m² |
| Total heating surface | 151.8 m² | 168.4 m² | 158.0 m² | 153.3 m² |
| Superheater surface | 30.101 m² | 28.8 m² | ||
Power plant
| Property | 12A | 12B | 12B superheated | 12D |
|---|---|---|---|---|
| Driver diameter | 1,829 mm | |||
| Boiler pressure | 13.8 bar | 15.5 bar | 13.8 bar | 11 bar |
| Expansion type | compound | simple expansion | ||
| Cylinders | two, HP: 698 x 660 mm and LP: 483 x 660 mm | four, HP: 356 x 660 mm and LP: 584 x 660 mm | two, 559 x 660 mm | |
Power
| Property | 12A | 12B | 12B superheated | 12D |
|---|---|---|---|---|
| Power source | steam | |||
| Estimated power | 597 kW (812 PS) | 634 kW (862 PS) | 895 kW (1,217 PS) | 708 kW (963 PS) |
| Starting effort | 66.7 kN | 87.9 kN | 78.1 kN | 105.7 kN |
| Starting effort simple | 80.1 kN | 105.4 kN | 93.7 kN | |
Calculated values
| Property | 12A | 12B | 12B superheated | 12D |
|---|---|---|---|---|
| Factor of adhesion | 1 : 6.57 | 1 : 5.22 | 1 : 6.23 | 1 : 4.69 |
| Optimal speed | 55 km/h | 43 km/h | 71 km/h | 40 km/h |
| Power-to-weight ratio | 9.0 kW/t | 12.6 kW/t | 10.4 kW/t | |
| Heating Surface Equivalent | 216.4 m² | 231.6 m² | 251.3 m² | 244.8 m² |
| Cylinder volume/HSE | 1 : 1,448.72 | 1 : 1,330.66 | 1 : 1,226.37 | 1 : 1,323.21 |
| Adhesive weight/Total | 1 : 1.48 | 1 : 1.50 | 1 : 1.43 | 1 : 1.35 |
| Tractive force/Heating surface | 1 : 9.18 | 1 : 10.90 | 1 : 10.32 | 1 : 14.41 |
| Grate area/Heating surface | 1 : 65.35 | 1 : 64.76 | 1 : 60.76 | 1 : 65.99 |
| Firebox/Tube surface | 1 : 10.75 | 1 : 12.33 | 1 : 9.12 | 1 : 8.93 |
| Total/Superheater | 1 : 4.25 | 1 : 4.32 | ||
