A restored relic of the country's first monorail - built under the rule of Maharaja Shri Bhupinder Singh of Patiala in 1907, PSMT is a unique system that runs on a single axial rail track and on one side is supported by huge wheels running on road surface. It is world's only operational locomotive hauled railway system, built using the Ewing system, where the monorail runs using balancing wheels. In 1909, four locomotives were built and delivered by Orenstein & Koppel of Berlin, Germany. These locos were an 0-3-0 adaptation of a standard O & K 0-6-0 design, with double-flanged wheels in the centre of each axle. The right-hand water tank was enlarged to shift some of the weight onto the 39-inch (990 mm) diameter road wheel. There were two outside cylinders of 5 inch bore & 14 inch stroke. The fire door was placed on the right side of the fire box rather than at the back. The middle rail wheel was flangeless to allow tight curves to be taken. This wheel was 50 cm (1 ft 8 in) in diameter. The other two double-flanged wheels were had groove depth of 2.15 centimetres (0.85 in). The locomotive wheelbase was 119 centimetres (3 ft 11 in).

Of the four locomotives built by the German company, one is exhibited at the railway workshop in Amritsar and the other two have been lost. NRM managed to acquire locomotive number 4 in the 1970s and it has been exhibited since then. It was regularly steamed and is now in perfect working condition to used for a heritage monorail ride for visitors every Wednesday and Friday.