The class YD was a metre-gauge goods locomotive developed in accordance with the Indian Railway Standard (IRS) rules. Its direct basis were ten Mikados built in 1927 by the Vulcan Foundry for the Assam Bengal Railway which were later designated YD/1. The boiler was closely related to that of the YC Pacific, but shorter.
Assam Bengal Railway No. 211, built by Vulcan Foundry
flickr/Historical Railway Images 
Up to 1953, at least 270 were built by manufacturers from Britain, Germany, Czechoslovakia, India and Japan. The 25 locomotives produced in Japan had been built by Nippon Sharyo for Pakistan in 1952 and were oil-fired. Some had also come to Myanmar, of which a few were still in service after 2010. Generally, there are still many which were preserved. 