Burma Railways Articulated Locomotives in Burma


Class Details by Steve Llanso of Sweat House Media

Class Modified Fairlie (Locobase 6374)

Data from [] (a page of the ca. 1920 Vulcan Foundry catalogue). See also "Meter-Gage [sic] Fairlie Engines for the Burma Railway Company," Scientific American Supplement, No. 1389 (16 August 1902) , pp. 22256-22258.

In the same website's [], two of the locomotives are shown as works #1775-1777. This was a sizable narrow-gauge articulated with considerable power. Although built as tank engines, the Burma Fairlies always drew their water from trailing tenders except when shunting (switching).

The boilers were fitted back to back and each had its own Belpaire firebox, which eliminated the narrow passage to one side of common firebox that was a feature of the original Fairlie design. Instead, the driver stood amidships working a single reversing gear handle and each of two firemen fueled his firebox through a firehole in the corner. Inside the firebox were thirty-two Drummond cross water tubes that contributed 64 sq ft (5.95 sq m) to each firebox's heating surface area.


Class N (Locobase 20108)

Data from "0-6-6-0 Mallet Articulated Compound Locomotive", Railway and Locomotive Engineering, Volume 24, No 10 (October 1911), p. 418; and [],4200476, last accessed 18 October 2011. See also "Hill Lines of India" (1935), archived on Mike's Railway History site at [], last accessed 4 July 2021. ,

Works numbers were 19117-19120 in 1911, 20077-20080 in 1913, 21079-21082 in 1915, and 22701-22705 in 1921.

This all-adhesion Mallet design came in four batches in the teens. All seventeen had Belpaire fireboxes and balanced slide valves supplying both HP and LP cylinders.

According to Hill , "these engines dealt with the bulk of the traffic, goods, passenger, and mixed, on this [the Lashio branch] and the Southern Shan States branch-assisted by a sturdy 2-6-2 tank for pushing work-until the introduction of the 2-8-0 + 0-8-2 Beyer-Garratt."

Somehow, Glasgow's Beardmore & Co, Ltd got the 1924 contract to add five more. These superheated Ns class locomotives appear in Locobase 11046.


Class Ns (Locobase 11046)

Data from [],4200476, last accessed 6 November 2016. See also "Articulated Locomotive Tests in India and Burma", Railway Engineer, Volume 46, No.11 (November 1925), pp. 399-402. Works numbers wer 264-268 in 1924.

Locobase 20108 describes the four batches of this all-adhesion Mallet design delivered in the 'teens and early twenties. Somehow, Glasgow's Beardmore & Co, Ltd got the 1924 contract to add five more. These were superheated and were the model for the BR's upgrade of the earlier 17. The only signficant difference was a slightly greater weight for the 1923 engines.

Principal Dimensions by Steve Llanso of Sweat House Media

ClassModified FairlieNNs
Locobase ID6374 20108 11046
RailroadBurma RailwaysBurma RailwaysBurma Railways
CountryBurmaBurmaBurma
Whyte0-6+6-00-6-6-00-6-6-0
Number in Class51722
Road Numbers209-213342-345, 381-384, 1-4, 11-1516-20
GaugeMetreMetreMetre
Number Built5175
BuilderVulcan FoundryNorth BritishBeardmore
Year190019111923
Valve GearWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m) 7.58 / 2.31 8.25 / 2.51 8.25 / 2.51
Engine Wheelbase (ft / m)35.62 / 10.8624.25 / 7.3924.25 / 7.39
Ratio of driving wheelbase to overall engine wheelbase 0.21 0.34 0.34
Overall Wheelbase (engine & tender) (ft / m)35.62 / 10.8648.58 / 14.8148.58 / 14.81
Axle Loading (Maximum Weight per Axle) (lbs / kg)22,624 / 10,262
Weight on Drivers (lbs / kg)135,520 / 61,471130,368 / 59,134135,520 / 61,471
Engine Weight (lbs / kg)135,520 / 61,471130,368 / 59,134135,520 / 61,471
Tender Loaded Weight (lbs / kg)70,112 / 31,802215,824 / 97,896
Total Engine and Tender Weight (lbs / kg)135,520 / 61,471200,480 / 90,936351,344 / 159,367
Tender Water Capacity (gals / ML)600 / 2.272400 / 9.092568 / 9.73
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 2.80 / 3 6.60 / 612.10 / 11
Minimum weight of rail (calculated) (lb/yd / kg/m)38 / 1936 / 1838 / 19
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)39 / 99139 / 99139 / 991
Boiler Pressure (psi / kPa)160 / 11180 / 12.40180 / 12.40
High Pressure Cylinders (dia x stroke) (in / mm)14" x 20" / 356x508 (4)15.5" x 20" / 394x50816" x 20" / 406x508
Low Pressure Cylinders (dia x stroke) (in / mm)24.25" x 20" / 616x50824.25" x 20" / 616x508
Tractive Effort (lbs / kg)27,339 / 12400.7826,766 / 12140.8727,988 / 12695.16
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.96 4.87 4.84
Heating Ability
Tubes (number - dia) (in / mm)304 - 1.8" / 46178 - 2" / 5197 - 2" / 51
Flues (number - dia) (in / mm)15 - 5.25" / 133
Flue/Tube length (ft / m)8 / 2.4415 / 4.5715 / 4.57
Firebox Area (sq ft / m2)266 / 24.71115 / 10.68
Grate Area (sq ft / m2)26 / 2.4233 / 3.0733 / 3.07
Evaporative Heating Surface (sq ft / m2)1398 / 129.881513 / 140.561071 / 99.50
Superheating Surface (sq ft / m2)309 / 28.71
Combined Heating Surface (sq ft / m2)1398 / 129.881513 / 140.561380 / 128.21
Evaporative Heating Surface/Cylinder Volume196.16346.39230.11
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation416059405940
Same as above plus superheater percentage416059407247
Same as above but substitute firebox area for grate area42,56020,700
Power L139812285
Power MT388.57231.85

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