This is a list of
narrow-gaugelocomotives that have been or are being operated by
Indian Railways. All railways except the heritage ones are closed or under conversion/are converted to the nation-wide standard
5 ft 6 in (1,676 mm) gauge, under
Project Unigauge. So narrow-gauge locomotives are operating only on the heritage routes as of 2021.
ZDM-1: This locomotive was built by
Arnold Jung Lokomotivfabrik. These were called the class DZ on NR (
Kalka–Shimla Railway). This was a narrow-gauge locomotive with
2 ft 6 in (762 mm) wide gauge. It was identical to NDM-1 class with
2 ft (610 mm). Only four of these locos were regauged to 2 ft (610 mm) gauge and converted to NDM-1 units. The ZDM-3 locos were available in (1972–1982). The fifth loco NR #704, was used at
Pragati Maidan in
New Delhi, where it was used to haul a short train with the name
Pragati Express with aluminium-bodied coaches on a 1.5 km figure-8 track at an exhibition centre specially during IITF. Loco numbers were not written on the body of the loco.
ZDM-2: This was a narrow-gauge locomotive with 2 ft 6 in (762 mm) wide gauge. These loco were mainly used in Nainpur–Gondia section narrow-gauge route. All the locomotives are retired/withdrawn from service.
ZDM-3: This is a narrow-gauge locomotive with 2 ft 6 in (762 mm) wide gauge of Indian Railways. These locomotives can be found on the routes of Kalka–Shimla route and
Kangra Valley route.
ZDM-4: These locomotives were built by
Chittaranjan Locomotive Works and they were the modified version of ZDM-3 class with an extra axle to reduce axle load (1-B-B-1 bogies). But this extra axle caused
wheel slip. These locomotives can be found on routes like Kangra Valley and were found earlier on the Nagpur narrow-gauge routes and Raipur narrow-gauge routes. This is a narrow-gauge locomotive with 2 ft 6 in (762 mm) wide gauge.
ZDM-4A: This was a variant of the ZDM-4 loco. This loco was used in
Barsi Light Railway. These 1-B-B-1 locos had a 700 horsepower power-pack. In 1996 one of these was sent to Nepal
Janakpur–Jaynagar railway line.
ZDM-5: This locomotive was one of the powerful narrow-gauge locomotives of the world. These locomotives were operated on routes like Pratapnagar narrow-gauge and Dhaulpur narrow-gauge routes. Four locos of this class were sent to work on Janakpur–Jaynagar railway in Nepal in 1994. All the locomotives are retired/withdrawn from service. This was a narrow-gauge locomotive with 2 ft 6 in (762 mm) wide gauge.
NDM-1: This is a articulated locomotive with two prime movers. But in case of uphill travel it uses both its engines and in case of downhill it uses one engine on
Neral–Matheran line. It was originally intended to be used in Kalka–Shimla route. This is a narrow-gauge locomotive with 2 ft (610 mm) wide gauge. When Kalka–Shimla route was regauged ZDM-3 was obtained for that route.
NDM-5: These locomotives were used on Central Railways Gwalior narrow-gauge route. These locomotives were based on another narrow-gauge locomotive called ZDM-5. It had been equipped with dual brake system. All the locomotives are retired/withdrawn from service. This was a narrow-gauge locomotive with 2 ft (610 mm) wide gauge.
NDM-6: This locomotive was originally intended for
Matheran Hill Railway but for some reason it was then allocated to
Darjeeling Himalayan Railway. Only six of these locomotives have been made and all are in service on Darjeeling Himalayan Railway. This is a narrow-gauge locomotive with 2 ft (610 mm) gauge.
NBM-1: This locomotives were used on Central Railways Gwalior narrow-gauge route. These were the battery electric locomotives which are similar to
YAM-1 locomotives. Only three units were built in 1987. All the locomotives are retired/withdrawn from service. This was a narrow-gauge locomotive with 2 ft (610 mm) wide gauge.