Indian locomotive class YDM-1

The Indian locomotive class YDM-1 is a class of diesel-Hydraulic locomotive that was developed in 1954 by North British Locomotive Company (NBL) for Indian Railways. Its class designation denotes a metre gauge (Y) diesel (D) mixed traffic (M) locomotive of the 1st generation (1). They entered service in 1955. A total of 20 YDM-1 locomotives was built between 1954 and 1956, which made them among the first metre-gauge main-line diesels.

Indian locomotive class YDM-1
A YDM-1 class locomotive no 6002 preserved at National Rail Museum, New Delhi
Type and origin Power type Diesel Designer North British Locomotive Company (NBL) Builder North British Locomotive Company (NBL) Order number PR/4574/S/4910/52 Build date 1954–1956 Total produced 20 Rebuilder CLW Rebuild date 1974–1976 Number rebuilt 20
Specifications Configuration: ​  • AAR B'-B'  • UIC B-B  • Commonwealth Bo-Bo Gauge 1,000 mm (3 ft 3+3⁄8 in) metre gauge Wheel diameter 804 mm (31.65 in) Wheelbase 2,134 mm (84.02 in) ​  • Engine 1 Length: ​  • Over couplers 12.020 m (39 ft 5+1⁄4 in)  • Over body 10.630 m (34 ft 10+1⁄2 in) Width 2,743 mm (9 ft 0 in) Height 3,421 mm (11 ft 2+5⁄8 in) Axle load 11,000 kg (24,000 lb) Loco weight 43,680 kg (96,300 lb) Fuel type Diesel Fuel capacity 3,724 L (819 imp gal; 984 US gal) Lubricant cap. 200 L (44 imp gal; 53 US gal) Coolant cap. 204 L (45 imp gal; 54 US gal) Sandbox cap. 0.35 L (0.077 imp gal; 0.092 US gal) Power supply 110 V DC supply Prime mover Earlier Paxman V12 RPHXL II, 625/580hp replaced by Mak/CLW L6 6M 282 A(K), 700hp RPM: ​  • RPM low idle 525  • RPM idle 525  • Maximum RPM 1250 Engine type 12RPHXL/II Aspiration Turbo-supercharged Alternator Boom Wade N5 Generator C.A.V D3-9 Head end power 110 V DC Cylinders 12 Transmission Voith hydraulic with Cardan shaft drive to bogies MU working 2 Loco brake Air brake, hand brakes, Train brakes Vacuum brake Compressor 494 L (109 imp gal; 131 US gal) Exhauster 852 L (187 imp gal; 225 US gal)
Performance figures Maximum speed 83 km/h (52 mph) Power output Earlier Paxman V12 RPHXL II 580 hp (430 kW) replaced by Mak/CLW L6 6M 282 A(K) 700 hp (520 kW) Tractive effort: ​  • Starting 10.320 t (10 long tons; 11 short tons)  • Continuous 08.230 t (8 long tons; 9 short tons)
Career Operators Indian Railways Class Earlier 'DY' class Numbers 6000-6019 Locale Western Railway zone First run 1955-56 Last run 1995 Retired 1995 Withdrawn 1990s Preserved 3(6002, 6008, 6015) Scrapped 2000s Current owner NRM, ICF resume Disposition All except 3 scrapped

The YDM-1 served both passenger and freight trains for over 46 years. As of January 2020, all 20 locomotives have been withdrawn from service with 3 locomotives being preserved at various location around India.

History

These locomotives originally called 'DY' class was imported from North British Locomotive Company (NBL) to haul goods and passenger rakes in Western Railways particularly around Gandhidham due to of scarcity of water for steam locomotives. These are among the first Metre Gauge main-line diesels locomotives of India.

The YDM-1 class locomotives are the survivors from the second batch of North British diesel locos supplied in 1955. They were homed at a specifically made Diesel shed in Gandhidham. CLW replaced the engines on these with Maybach engines around 1975. Western Railways phased these locos out in the end of the 1990s (December 1999) from mainline service and from shunting duties in Ajmer on 15 February 2001. YDM-1 6002 came at NRM from Wankaner in August 2003 after renovation at Ajmer Loco Workshop.

Specification

A YDM-1 hauling an inspection special

Original No	No 3001 to 3020
Maker's Name & No	North British; Locomotive Co. Glasgow, UK, 27507
Builders	North British Locomotive
Engine	Paxman V12 RPHXL II, 625/580 hp replaced by Mak/CLW L6 6M 282 A(K), 700 hp
Transmission	Voith hydraulic with Cardan shaft drive to bogies
Year Built	1954
Gear Box	David Brown, UK
Wheel Arrangement	B-B
Hauling Power	10,977 kg
Tare Weight	42 Tonnes
Gauge	1 Metre
Cost	Rs. 4,85,209/- (Capital Head)
Remarks	Fitted with Automatic, Vacuum & Air Brake System
First Trip	From Gandhi Dham to Palanpur
Last Service	worked for Kandla Port and Naliya etc.

Preserved Examples

A total of three YDM-1 locomotives have been preserved all over India.^[1][2]

Class	Manufacturer	Loco Number	Previous shed	Name	Livery	Location	ref
YDM-1	NBL	6002	Gandhidham		Orange with twin black stripes	plinthed at National Railway Museum, Delhi (NRM)	[3]
YDM-1R	NBL	6008	Gandhidham		Light blue/red/dark blue	Preserved at Regional Rail Museum, Chennai.	[4]
YDM-1	NBL	6012	Gandhidham		Navy blue with yellow stripe	Preserved at Regional Rail Museum, Chennai.	[5]

Former shed

• Gandhidham (GIM): All the locomotives of this class has been withdrawn from service.

See also

• Rail transport in India § History
• Indian Railways
• Locomotives of India
• Rail transport in India