West of India Portuguese Railway Articulated Locomotives in India

Class Details by Steve Llanso of Sweat House Media

Class Mallets (Locobase 20106)

Data from "Mallet Locomotives for the West of India Portuguese Railway", Locomotive Magazine, Volume 19 (15 November 1913), pp. 252-253. See also Administration Report on the Railways of India (corrected up to 31 March 1918) (Calcutta [sic], India: Superintendent of Government Printing, 1918), pp. 94-95; and "English tale in Goa's Portuguese story", The Times of India (7 May 2013), found online at [], last accessed 6 November 2016.

At the same time as their deliveries of 0-6-6-0 Mallets to the Burma Railways (Locobase 20108), NBL turned out these three very similar articulateds for the British-owned railway operating in Portugal's Goa colony on India's west coast. Like many British locomotives, these engines had Belpaire fireboxes. Using balanced slide valves on all four cylinders, however, was unusual. The only differences from the BR locomotives were the smaller tender fuel capacity (because of the shorter distance) and a slight weight increase.

As the LM report noted, operating on this steep, winding line imposed demands "a very severe nature". Specs from the railway called for the engine's ability to pull 230 tons (234 metric tons) up the 1 in 40 (2 1/2%) at an average speed of 10 mph (16 kph). The first 41 miles of the line connecting Mormugao Harbour with Sonaulim [Sanvorden] opened on 17 January 1987 and 10.1 miles more to the Portuguese border at Castlerock started operations on 2 March 1888 and linked the port to the much larger Madras and Southern Mahratta Railway system. As built, the line used 60- and 62-lb/yard (30- and 31 kg/metre) rail over a ruling grade of 1 in 100 until it reached the Ghat

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID20106
RailroadWest of India Portuguese Railway
Number in Class3
Road Numbers
Number Built3
BuilderNorth British
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m) 8.25 / 2.51
Engine Wheelbase (ft / m)24.25 / 7.39
Ratio of driving wheelbase to overall engine wheelbase 0.34
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)134,400 / 60,963
Engine Weight (lbs / kg)134,400 / 60,963
Tender Loaded Weight (lbs / kg)53,088 / 24,080
Total Engine and Tender Weight (lbs / kg)187,488 / 85,043
Tender Water Capacity (gals / ML)2400 / 9.09
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 4.40 / 4
Minimum weight of rail (calculated) (lb/yd / kg/m)37 / 18.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)39 / 991
Boiler Pressure (psi / kPa)180 / 12.40
High Pressure Cylinders (dia x stroke) (in / mm)15.5" x 20" / 394x508
Low Pressure Cylinders (dia x stroke) (in / mm)24" x 20" / 610x508
Tractive Effort (lbs / kg)26,604 / 12067.39
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.05
Heating Ability
Tubes (number - dia) (in / mm)178 - 2" / 0
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)15
Firebox Area (sq ft / m2)115 / 10.68
Grate Area (sq ft / m2)33 / 3.07
Evaporative Heating Surface (sq ft / m2)1513 / 140.56
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1513 / 140.56
Evaporative Heating Surface/Cylinder Volume346.39
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation5940
Same as above plus superheater percentage5940
Same as above but substitute firebox area for grate area20,700
Power L12333
Power MT229.62

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