Indian Midland 2-6-0 Locomotives in India

Class Details by Steve Llanso of Sweat House Media

Class F3 (Locobase 20021)

Data from "An Old Firm of Engine Builders", Railroad Gazette, Volume XXIX, No. 28 (9 July 1897), p. 488. See also "An East Indian Freight Locomotive," Locomotive Firemen's Magazine, Volume XXIII, no 2 (August 1897), p. 161, digesting from the Engineer of London. (Thanks to Abhijit Gore for his 2 January 2021 email noting the designation and road numbers.) Works numbers were 1489-1502 in 1896.

RG reports that the 166 was the 1,500th locomotive produced by the firm that began business as Charles Tayleur & Company, but was even then known as the Vulcan Foundry. The order was designed by the IM's George Barclay Bruce, CE.

A Mogul for India was quite appropriate, although in fact the wheel arrangement was not as common as in many other countries. Although apparently a 2-6-0, its front carrying axle rode in radial axle boxes rather than in a Bissel truck and the first and second driving axles were equalized. Also, like most British-built engines of the time, the 166 was driven by inside cylinders. The illustration of this class shows an odd shape to the smokebox that resembled a truncated cone in which the smokebox door end's diameter was noticeably smaller than the tubesheet end.

Four of the engines were delivered with a automatic rocking grate operated by a lever on the rear axle and taken in and out of gear by the fireman. (Locobase wonders if the apparatus withstood the operating environment's abuse.) An interesting economy concerned a substitute for the piping outlining panelling, lining and lettering. Instead of painting the lines, the builder riveted 1-2 in (25.4-50.8 mm) strips of polished zinc.

Gore's email pointed out that the IM merged with the Great Indian Peninsular Railway in 1904, but the only change was to add 1,000 to each road number.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID20021
RailroadIndian Midland
Number in Class14
Road Numbers166-179/1166-1179
Number Built14
BuilderVulcan Foundry
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)
Engine Wheelbase (ft / m)22.08 / 6.73
Ratio of driving wheelbase to overall engine wheelbase
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)87,300 / 39,599
Engine Weight (lbs / kg)107,520 / 48,770
Tender Loaded Weight (lbs / kg)75,600 / 34,292
Total Engine and Tender Weight (lbs / kg)183,120 / 83,062
Tender Water Capacity (gals / ML)2400 / 9.09
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 8.80 / 8
Minimum weight of rail (calculated) (lb/yd / kg/m)49 / 24.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)54 / 1372
Boiler Pressure (psi / kPa)180 / 12.40
High Pressure Cylinders (dia x stroke) (in / mm)18.5" x 26" / 470x660
Tractive Effort (lbs / kg)25,212 / 11435.98
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.46
Heating Ability
Tubes (number - dia) (in / mm)186 - 2" / 51
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)11.06 / 3.37
Firebox Area (sq ft / m2)103 / 9.57
Grate Area (sq ft / m2)21.25 / 1.97
Evaporative Heating Surface (sq ft / m2)1180 / 109.63
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1180 / 109.63
Evaporative Heating Surface/Cylinder Volume145.88
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation3825
Same as above plus superheater percentage3825
Same as above but substitute firebox area for grate area18,540
Power L13395
Power MT257.21

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