Diesel Locomotive Classes –
Meter Gauge & Narrow Gauge
Note: Information on broad gauge diesels can be found here.
Meter Gauge Diesel Locomotives
Note: Class names for mainline diesels are according to the old classification scheme, unless otherwise mentioned. See the general loco page for an explanation of the new scheme.
YDM–1Originally class 'DY', these were among the first MG main-line diesels, and were survivors from the second batch of North British diesel locos supplied in 1955. Some may still have been working into the end of the 1990s [12/99]. They were originally used by WR for goods haulage on lines where water supply for steam locos was problematic. Later transferred to SCR. CLW replaced the engines on these with Maybach engines around 1975 (1974-1976 according to Hughes). WR phased these locos out in the 1990s.
- Builders: North British Locomotive
- Engine: Paxman V12 RPHXL II, 625/580hp replaced by Mak/CLW L6 6M 282 A(K), 700hp
- Transmission: Voith hydraulic with Cardan shaft drive to bogies
YDM–2
Locos used on originally on SCR and later also on SR. A few remained [1999] at the Egmore and Tambaram sheds. Until recently [1997?] they were hauling local trains around Kumbakonam. [1/04] A couple of them have been spotted on the Tirunelveli - Quilon line. [3/04] 2(??) of them are at Chengalpattu.
- Builders: CLW
- Engine: Mak/CLW L6 6M 282 A(K), 700hp
- Transmission: Voith hydraulic
YDM–3, YDM–5
GM (EMD) designs, model GA12. The main difference is the addition of 10t of weight to the YDM-5. In 1998, Ahmedabad had the last 2 YDM-3's (#6073, #6074) and the last YDM-5 (#6098). All are now [7/00] said to be out of service.
- Builders: GM-EMD
- Engine: EMD 12-567C, 1390/1260hp
- Transmission: Electric
YDM–4, YDM–4A
Co-Co diesel electrics originally from Alco (1961-1964), later manufactured by DLW (1968-1993). The initial batch of 55 from Alco were used for evaluation and comparison with a similar batch of General Motors locos. The Alcos were chosen as the preferred MG main-line diesel locos. Alco model is DL535A. Originally manufactured with only vacuum brakes and dynamic braking, no air brakes. Rated at 1350/1200hp. Max. speed 100km/h. YDM-4A are identical to YDM-4, except that they were supplied by MLW (1964) -- the Canadian batch consisting of about 99 locos. Some of the MLW locos do not have the 'A' suffix in the class designation.
Ahmedabad was the main centre for these locos. A few were hauling local trains in the Secunderabad-Bodhan section in 1997, and are reported [8/00] to be working around Mysore, Villupuram, etc. Some from the Guntakal shed are still [7/02] hauling trains on the Pakala-Guntakal-Bellary route. Some are thought to be at Gandhidham after gauge conversion left Gandhidham - Palanpur an isolated MG line.
DLW has exported some (15 each) of these to Tanzania and Vietnam (1976-1985), and to Bangladesh (2000?). The ones for Bangladesh were classed YDM-4BR and had dual cabs, a change achieved without modifying the length of the loco. This variant turned out later to have major cooling problems.
Malaysian railways (KTM) acquired 39 used YDM-4's from IR in 1996. It is not clear if they were leased or sold. Of these, 14 were returned to India by 1999. In Malaysia they retained their IR road numbers (between 6352 and 6725).
- Builders: Alco, MLW, DLW
- Engine: Alco 251B-6 (Alco/MLW), Alco 251D-6 (DLW); 6 cyl., 4-stroke, inline
- Transmission: Electric (DC-DC, in contrast to most other locos that were AC-DC).
- Axle load: 12t. Bogies: Co-Co trimount.
- Fuel capacity: 3000l
See the section on transfers and exports for information on YDM-4's sent to other countries.
Narrow Gauge Diesel Locomotives
ZDM–1Built by Jung , these were the original class DZ on NR (Kalka-Shimla Railway). Identical to NDM-1 (see below), but with 2'6" gauge. Four of these were regauged to 2'0" gauge and converted to NDM-1 units later when the ZDM-3 locos became available (1972-1982). The fifth, NR #704, is at Pragati Maidan in New Delhi, where it used to haul a short train of aluminium-bodied coaches on a 1.5km figure-8 track at the exhibition centre. All-India numbers #543-547 were allotted but never displayed on the locos. They are almost always referred to by their NR/KSR numbers #700-704. Axle load 7.5t.
ZDM–2
25 of these 650/700hp B-B units were supplied in 1964 and 1965. [2/03] Used mainly on the Nainpur-Gondia section.
- Builders: Maschinenbau Kiel
- Engine: Maybach V8 MD435
- Transmission: Voith hydraulic
ZDM–3
40 of these B-B 700hp units were built from 1970 through 1982. Later, 10 ZDM-4 units (see below) were converted to ZDM-3 class by removing one axle from each bogie (Numbers remained unchanged). They are fittec with a Mak/CLW 6M 282 A(K) engine and Suri hydromechanical transmission.
ZDM–4
Built by CLW, they are a modification of the ZDM-3 design with an extra axle to reduce axle loading (1-B-B-1 bogies). However, this led to excess slip and the locos were all converted back to ZDM-3 class by removing an axle from each bogie. (Numbers unchanged.)
ZDM–4A
A variant of the ZDM-4 design. This loco worked on the Barsi Light Railway. These 1-B-B-1 locos have a 700hp power-pack. In 1996, one went to Nepal Jayanagar Janakpur Rly.
- Builders: CLW
- Engine: Mak/CLW 6M 282 A(K)
- Transmission: Voith hydraulic
ZDM–5This model is notable as being one of the most powerful narrow gauge diesel locos currently in use anywhere. Four of these were sent to the Jayanagar Janakpur railway in Nepal in 1994.
- Builders: CLW
- Engine: KCL KTA-1150L
- Transmission: Voith hydraulic
NDM–1
Articulated loco with two prime movers; both engines were used for travelling uphill, and one for downhill, on the Neral-Matheran line. Originally intended for the Kalka-Shimla Rly. (and classed ZDM-1) and regauged when ZDM-3's were obtained for that line. The two engines shared a common hydraulic transmission with dog clutches. The single cab was suspended between the two power units like a Garratt.
The first one, #500, was ZDM-1 #543 (NR #700), regauged as an experiment. Three more ZDM-1 locos (504-506, ex-ZDM-1 #544-546, NR #701-703) were also regauged later. Three (#501-503) were supplied with original gauge 2'0".
- Builders: Jung
- Engine: (Two engines) MWM TRHS 518S, 145/128hp
- Transmission: Twin Voith hydraulic
NDM–5
Used on CR's Gwalior NG lines, these are a variant of the ZDM-5 design. Eleven were built between 1987 and 1989. Equipped with dual brakes.
- Builders: CLW
- Engine: KCL KTA-1150L, 450hp
- Transmission:Voith hydraulic
NDM–6This loco is used on the Neral-Matheran narrow-gauge route. A new batch of NDM-6 locos intended for the Matheran Light Railway have instead been allocated to work on the Darjeeling Himalayan Railway (this was announced 4/99, and the locos may begin work on the DHR in 1999 or 2000). [11/99] Update: It is believed that 6 of these locos have been ordered (numbers 600-605), of which 4 are destined for Matheran, and two for the DHR. As of [9/04], two (#604 'Maverick' and #605 'Buccaneer') were at the DHR, and #600, #602, and #603 were known to be at Neral; the whereabouts of #601 were unclear, but it is also probably at Neral.
The locos are 2-axle air-braked units and about 17.5 tonnes each. The engine is a Kirloskar-Cummins engine with 335hp continuous output. The transmission is hydraulic. Note: SAN (the manufacturers) in their documentation describe these as '0-B-0', which is plainly incorrect as these are 4-wheeled locos.
- Builders: Suri and Nayar (SAN) Engg. and Loco Co., Bangalore
- Builders' model number: DL 400 L2r2zU2
- Engine: Kirloskar-Cummins NTA 855L, 6 cylinders
- Transmission: Suri and Nayar Voith hydraulic, model L2r2zU2 with 2-stage reduction in final drive gearbox.
- Wheel diameter: 700mm
- Max. speed: 30km/h
- Weight: 17.2t
More diesels (BG) on the this page. Also have a look at the electric locomotives section.