The YL was an IRS design for mixed traffic on metre gauge. It appeared in the early fifties and was a successor of the 2-6-2 class YF of the twenties. It still had a low axle load of only eight tons for a wide route availability. The boiler was mounted high on a pedestal and had a Belpaire firebox. Of the total production of 264 locomotives, 151 were built by Henschel. 63 came from Hitachi, 40 from MÁVAG and 10 from Robert Stephenson and Hawthorns.
130 were operated by the North Eastern Railway and 74 by the Western Railway. Smaller numbers came to the Southern, Northern and Central Railway. The last ones were withdrawn in 1976 and 5001 is still on static display at Gorakhpur. 5000 and 5010 are also existing, but are stored in poor condition.