North Western Railways - Kalka Simla Kitson-Meyer Locomotives in India

Class TD (Locobase 3267)

Data from Wiener (1930). See also Robert Tufnell, The Illustrated Encyclopedia of Railway Locomotives (London: Quarto Publishing Ltd, 1986); and Lionel Wiener, "Les Locomotives Articulees Actuelles," Revue General des Chemins de Fer, Volume 49 (July 1929), pp. 6-8.

The Kalka-Simla branch was, as can be seen, quite narrow gauge. It also twisted (220 120-ft/36.6 sq m radius curves), climbed (4,727 ft in 60 miles on an average 3% grade), and tunnelled (103 over its length). Up this route the railroad wanted engines to pull 160 tons at 10 mph.

The Kitson-Meyer articulated layout, with its two swiveling engine units, provided the needed flexibility and power, says Tufnell. Some of the individual features of the design included bogies that tilted 2 1/2 in, and cylinders that all exhausted into the front stack which lengthened exhaust piping, but improved drafting. Clearly proper draft was important, as these engines had their cylinders at the extreme ends of the driver sets. A cutaway in Wiener shows the deep firebox sloping down toward the front and a wide gap between the front edge of the firebox and the front driver set.

Soon after they entered service, the railroad realized that they were too much for the traffic levels on the branch and they were redeployed to support the Kangra Valley hydroelectric project until they were retired in 1939.