The reference for locomotives and railcars


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Buenos Aires Great Southern classes 12A, 12B and 12D
Argentina | 1907 | 61 produced

Beginning in 1907, the Buenos Aires Great Southern received a series 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

Variant12A12B12B superheated12D
ManufacturerBeyer, Peacock & Co., North BritishVulcan FoundryBAGSBeyer, Peacock & Co.
Axle config4-6-0 (Ten-wheeler) 
Gauge5 ft 6 in (Indian broad gauge)
Dimensions and Weights
Wheelbase25 ft 11 in26 ft 1 1/2 in
Fixed wheelbase12 ft 8 in14 ft 3 in
Service weight145,824 lbs154,560 lbs156,632 lbs150,584 lbs
Adhesive weight98,560 lbs103,040 lbs109,424 lbs111,384 lbs
Total weight247,150 lbs257,600 lbs266,952 lbs251,938 lbs
Axle load32,855 lbs34,347 lbs36,475 lbs37,240 lbs
Water capacity4,203 us gal4,804 us gal4,203 us gal
Fuel capacity15,680 lbs (coal)
Power sourcesteam
Estimated power800 hp (597 kW)850 hp (634 kW)1,200 hp (895 kW)950 hp (708 kW)
Optimal speed34 mph27 mph44 mph25 mph
Starting effort15,001 lbf19,754 lbf17,559 lbf23,770 lbf
with start valve18,001 lbf23,705 lbf21,071 lbf
Power Plant
Driver diameter72 in
Boiler pressure200 psi225 psi200 psi160 psi
Expansion typecompoundsimple
Cylinderstwo, HP: 27 1/2 x 26 in
and LP: 19 x 26 in
four, HP: 14 x 26 in
and LP: 23 x 26 in
two, 22 x 26 in
Grate area25 sq ft28 sq ft25 sq ft
Firebox area139 sq ft136 sq ft135 sq ft
Tube heating area1,495 sq ft1,677 sq ft1,241 sq ft1,205 sq ft
Evaporative heating area1,634 sq ft1,813 sq ft1,377 sq ft1,340 sq ft
Superheater area324 sq ft310 sq ft
Total heating area1,634 sq ft1,813 sq ft1,701 sq ft1,650 sq ft
Calculated Values
steam locomotive
last changed: 03/2023

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