As a part of the IRS program, the class XT was a small tank locomotive for passenger service on broad gauge branch lines. It had two driving axles with wheels of 51 inches or 1,295 mm and a flexible trailing axle that was mounted in Timken roller bearings. Another modern feature was the Caprotti valve gear. The cylinders measured twelve inches in diameter and had a stroke of 22 inches. To make better use of poor coal, a wide firebox was hidden between the water tanks. With full supplies, the maximum axle load was 14 tons. A total of 77 locomotives were built from 1929, at least partially in the Ajmer workshops.