Buenos Ayres Great Southern 4-8-0 Locomotives in Argentina

Class Details by Steve Llanso of Sweat House Media

Class Class 15B (Locobase 2457)

Some data from Carlos Alberto Fernandez Priotti in Bryan Attewell ([] Steam Locomotive simulator program (April 2000), supplemented by "Thirty '15B' Class 4-8-0 for the Buenos Ayres [sic] Great Southern Railway", Vulcan Magazine, archived at [], last accessed 7 July 2007. See also ee also D[ennis] Rock Carling, 4-8-0 Tender Locomotives (New York: Drake Publishers Inc, 1972), p. 72 and serial #197 in table XI, pp. 106-107.Works numbers were 5628-5657

A repeat order of 4-8-0s similar, but lighter, than the Class 15A that had been delivered to the Buenos Aires Great Southern before World War II (Locobase 4309). The Spanish-language website members.es.tripod.de/rielsud/locoayer.html (December 2001) said the 15Bs had completely redesigned steam passages (although they retained the characteristic Belpaire boilers).

The first six had names: General Peron, Eva Peron, Coronel J F Castro, 24 de Febrero, 1 de Marzo, 4 de Junio.

1958-1959's reworking of these engines used Andre Chapelon's design, said Carling. It produced a long list of modification at moderate cost ("about a seventh of that of a general overhaul"). Jacking up the boiler pressure to the limits of the design was only one change. Small tube alterations meant fewer gases through the flues. Fuel combustion was now completed in the firebox, thanks to an improved oil burner. Valve chests received new liners and valves and pistons had new rings and the steam circuit benefited from better exhaust passage design and a single Kylchap exhaust. Valve gear used a new combination lever.

Greater power required frame strengthening, "especially the cross bracing". Driving axle horns now used automatically adjusted wedges and mechanical lubricators served bearing, valves, and pistons, Carling added.

For the same fuel consumption, power increased between 26% to 40%. When using the same power as before, consumption dropped 16% to 40%. Average fuel consumption when hauling 1,500-2,000 tons came out as 30% lower.

"So much had the performance improved, " Carling concluded, "that they took over duties from larger and more recently built 4-8-0s, such as haulage of fast perishable traffic, despite their smaller wheels."

Principal Dimensions by Steve Llanso of Sweat House Media

ClassClass 15B
Locobase ID2457
RailroadBuenos Ayres Great Southern
Number in Class30
Road Numbers1561-1590
Number Built30
BuilderVulcan Foundry
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)18.50 / 5.64
Engine Wheelbase (ft / m)29.75 / 9.07
Ratio of driving wheelbase to overall engine wheelbase 0.62
Overall Wheelbase (engine & tender) (ft / m)69.60 / 21.21
Axle Loading (Maximum Weight per Axle) (lbs / kg)35,280 / 16,003
Weight on Drivers (lbs / kg)139,552 / 63,300
Engine Weight (lbs / kg)181,688 / 82,412
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)
Tender Water Capacity (gals / ML)7200 / 27.27
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)2887 / 10,927
Minimum weight of rail (calculated) (lb/yd / kg/m)58 / 29
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)68 / 1727
Boiler Pressure (psi / kPa)225 / 15.50
High Pressure Cylinders (dia x stroke) (in / mm)19.5" x 28" / 495x711
Tractive Effort (lbs / kg)29,945 / 13582.84
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.66
Heating Ability
Tubes (number - dia) (in / mm)134 - 2.125" / 54
Flues (number - dia) (in / mm)27 - 5.5" / 140
Flue/Tube length (ft / m)14 / 4.27
Firebox Area (sq ft / m2)190 / 17.66
Grate Area (sq ft / m2)32.60 / 3.03
Evaporative Heating Surface (sq ft / m2)1752 / 162.83
Superheating Surface (sq ft / m2)348 / 32.34
Combined Heating Surface (sq ft / m2)2100 / 195.17
Evaporative Heating Surface/Cylinder Volume181.02
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation7335
Same as above plus superheater percentage8582
Same as above but substitute firebox area for grate area50,018
Power L115,371
Power MT971.31

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