Rio Grande do Sul 2-6-6-2 Locomotives in Brazil


Class Details by Steve Llanso of Sweat House Media

Class 621 (Locobase 20094)

Data from "Compound Articulated Locomotive, Brazil Railway", Locomotive Magazine, Volume 19 (15 September 1913) , p. 207. See also "Locomotivas Henschel & Sohn G.m.b.H v Kassel

Locomotiva 2-6-0 + 6-2-0 da VFRGS* Viatpo FTrrea do Rio Grande do Sul", at the Centro Oeste Brasil website at [], last accessed 14 August 2016. Works numbers were 20356-20365 in 1913.

The data indicate that these Mallets were indeed delivered as saturated-boiler locomotives, although they may have added superheaters later.


Class 631 (Locobase 4432)

Data from illustration at narrowmind.railfan.net. See also DeGolyer, Vol 72, pp. 128+. The complete list of Baldwin works numbers created by Connelly and supplied by Allen Stanley in July 2007 from his extensive Rail Data Exchange gives the works numbers as 58160-58161.

Meter Prairie Mallets that differed from most in being built as simple-expansion locomotives. The boiler's relatively small size in relation to the cylinders and the large grate suggest that this was primarily a helper engine and that it used relatively low-calorie coal. Firebox heating surface included 17 sq ft (1.6 sq m) of arch tubes. All four cylinders were served by 8" (203 mm) piston valves.


Class 701/705 (Locobase 20449)

Data from , archived at [], last accessed 27 October 2018. See also "2-6+6-2" on the Locomotivas da RVPSC website at [], last accessed 27 October 2018. Works numbers were 11033-11034 in January 1912.

Henschel joined the metre-gauge supplier list compiled by the Brazil Railway Company with a repeat of the Baldwin design used in the four delivered in 1909-1910 (Locobase 3608). Built on outside frames, the long, lean profile was topped by a generator, safety valve stand, rear sand dome, steam dome directly over the HP cylinders, bell, forward sand dome, short stack, and large headlight. Its wood-burning firebox was carried by the rearmost driving axle and trailing truck. These two axles were equalized.

The two Mallets' operational environment lay in the Sao Francisco mountains on the Nereu Ramos a Rio Vermelho leg. This was a challenging stretch that featured a 2% ruling grade on heavier 36 kg/metre (72 lb/yard) rail that had recently been installed.

Unfortunately for the Rio Grande's expectations, the pair proved too heavy for the railway and the shops. But the Sorocabana, which was quite satisfied with the Baldwin Mallets, accepted the two engines and renumbered them 705-706.

Principal Dimensions by Steve Llanso of Middle Run Media

Class621631701/705
Locobase ID20094 4432 20449
RailroadRio Grande do SulRio Grande do SulRio Grande do Sul
CountryBrazilBrazilBrazil
Whyte2-6-6-22-6-6-22-6-6-2
Number in Class422
Road Numbers621-630631-632701-702/750-751
GaugeMetremetreMetre
Number Built422
BuilderHenschel & SohnBaldwinHenschel & Sohn
Year191319241912
Valve GearWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m) 8.04 / 2.45 7.50 / 2.2910 / 3.05
Engine Wheelbase (ft / m)36.09 / 1135.75 / 10.9042.75 / 13.03
Ratio of driving wheelbase to overall engine wheelbase 0.22 0.21 0.23
Overall Wheelbase (engine & tender) (ft / m)63.16 / 19.2560.62 / 18.4866.33 / 20.22
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)134,173 / 60,860132,540 / 60,119161,100 / 73,074
Engine Weight (lbs / kg)159,493 / 72,345166,590 / 75,564189,800 / 86,092
Tender Loaded Weight (lbs / kg)105,822 / 48,000104,000 / 47,17490,200 / 40,914
Total Engine and Tender Weight (lbs / kg)265,315 / 120,345270,590 / 122,738280,000 / 127,006
Tender Water Capacity (gals / ML)4000 / 15.154500 / 17.05
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)5 / 516.50 / 15
Minimum weight of rail (calculated) (lb/yd / kg/m)37 / 18.5037 / 18.5045 / 22.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)42 / 106742 / 106747 / 1194
Boiler Pressure (psi / kPa)200.20 / 13.80170 / 11.70204.50 / 14.10
High Pressure Cylinders (dia x stroke) (in / mm)15.98" x 20" / 406x50816" x 22" / 406x559 (4)17" x 22" / 432x559
Low Pressure Cylinders (dia x stroke) (in / mm)25" x 20" / 635x50826.5" x 22" / 673x559
Tractive Effort (lbs / kg)29,381 / 13327.0138,754 / 17578.5433,318 / 15112.81
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.57 3.42 4.84
Heating Ability
Tubes (number - dia) (in / mm)200 - 2.008" / 51121 - 2" / 51194 - 2.25" / 57
Flues (number - dia) (in / mm)24 - 5.375" / 137
Flue/Tube length (ft / m)17.06 / 5.2016 / 4.8821 / 6.40
Firebox Area (sq ft / m2)109.79 / 10.20165 / 15.33154 / 13.19
Grate Area (sq ft / m2)53.82 / 553.70 / 4.9941.60 / 3.86
Evaporative Heating Surface (sq ft / m2)1881 / 174.751711 / 158.962528 / 234.86
Superheating Surface (sq ft / m2)432 / 40.13
Combined Heating Surface (sq ft / m2)1881 / 174.752143 / 199.092528 / 234.86
Evaporative Heating Surface/Cylinder Volume405.16167.10437.40
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation10,77591298507
Same as above plus superheater percentage10,77510,9558507
Same as above but substitute firebox area for grate area21,98033,66031,493
Power L1299774663762
Power MT295.47745.12308.89

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