The XD was one of several standard designs introduced for the railways of India in the twenties. Being a Mikado type goods locomotive, it was to be lighter than the XE. In the result, it had an axle load of 17 tons and drivers with a diameter of 5 ft 1 1/2 in or 1,562 mm. The cylinders measured 22.5 inches in diameter and 28 inches in stroke. Operating at a boiler pressure of 180 psi, it developed a starting tractive effort of 35,265 pounds.
From a total of 194 built between 1928 and 1948, North British contributed the most with 132. 41 came from Vulcan Foundry and eleven from Armstrong Whitworth. Additionally, Škoda from Czechoslovakia built ten. Two similar classes came from North America. The AWD was built by Baldwin and the CWD by the Canadian Locomotive Company and Montreal Locomotive Works.