The class XP locomotives entered service with the GIPR in 1937, as nos. 3100 and 3101. The class leader was named
King George, in honour of the then
King-Emperor of India, and the other class XP engine was named
Queen Elizabeth, after the then Queen-Empress. In November 1951, the GIPR was incorporated into the
Central Railway zone of the
Indian Railways. In the All-India renumbering of 1957, the two class XP locomotives were given the numbers 22599 and 22600, respectively. Both locomotives had been withdrawn from service by 1970. ==See also==