Indian locomotive class YDM-4
The class YDM-4 is Indian Railways' workhorse diesel locomotive. The first units were imported fully built from the American Locomotive Company (Alco) in 1961. Since 1968, it has been manufactured in India by the Banaras Locomotive Works (BLW), Varanasi. The model name stands for metre gauge (Y), diesel (D), mixed traffic (M) engine. The YDM-4 has been the most successful diesel locomotive in the metre gauge operation of Indian Railways.
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The YDM-4A is a variant of the YDM-4 supplied by MLW . Originally equipped with vacuum brakes. Some were later equipped with dual brakes, particularly those working in the Northeast Frontier Railway were retrofitted with dual brake system by Lumding shed. The YDM-4 locos have a maximum speed of 100 km/h (62 mph),[1] restricted to 85 km/h (53 mph).[2]
History
In the mid 1950s Indian Railways began introducing diesel locomotives to its metre gauge system. Metre gauge, though rare gauge today, used to be a dominant gauge that time. After the introduction of YDM-1 locomotives by North British, Indian Railway thought for more powerful ones and hence General Motors Electro-Motive Division (EMD) and the American Locomotive Company (ALCO) submitted designs of YDM-3/YDM-5 (12-567C) and YDM-4 respectively for new diesel locomotives. Each company supplied 30 locomotives in 1961. While YDM-3 was 13 ton lighter than the YDM-4, Indian Railways opted for the ALCo design because of the heavier axle load and technology agreement that would allow these locomotives to be manufactured in India. After Banaras Locomotive Works (BLW) completed construction of its factory in Varanasi, production of the locomotives began in India. Initial 30 YDM-4 locomotives supplied by American Locomotive Company (ALCo) in 1961 had the road numbers in #6020 to #6049 range. Another batch of 8 locomotives followed the route to India soon which had the road numbers in #6105-6112 range. YDM-4 #6113-6129 were built perhaps in 1964. Siliguri Diesel Locoshed was the first DLS to home YDM-4 locomotives in 1962. The very first YDM4 numbered as #6020 was allotted to New Guwahati Diesel Loco Shed which was an outbase of Siliguri DLS on 30/10/1962. The loco, however is assumed to be scrapped due to overage.
YDM4 numbered in #6130 to #6198 range were built by Montreal Locomotive Works (MLW) in 1964 under the license of ALCo and were classified as YDM-4A. All the YDM-4 delivered till then were presumably based at three premier DLS across India namely Siliguri (SGUJ), Golden Rock (GOC) and Sabarmati (SBI).
The First YDM-4 built by Banaras Locomotive Works (BLW) Varanasi was #6199 christened as Hubli. This loco rolled out from DLW in 1968 and was dedicated to the nation by the then Deputy Prime Minister of India, Morarji Desai. DLW built at first locos in the range #6199 to #6258.
Another batch of YDM-4A were dispatched from MLW in 1969 in the range #6259 to #6288.
From 1969 till 1993 DLW produced YDM-4 locomotives for Indian Railways in the number range #6289 to #6769. Last YDM-4 was based at Rangapara North outbase of Siliguri DLS but later on transferred to Myanmar (Burma) Railways and possibly renumbered as DF1332.[3]
Locomotive sheds
| Zone | Name | Shed Code | Quantity |
|---|---|---|---|
| North Eastern Railway | Izzatnagar | IZN | 24 |
| North Western Railway | Phulera | FL | 8 |
| Southern Railway | Golden Rock | GOC | 5 |
| Western Railway | Sabarmati | SBI | 12 |
| Diesel Loco Shed, Mhow | MHW | 8 | |
| Total Locomotives Active as of 01-07-2020[4] | 57 | ||
Technical specifications[5]
| Manufacturers | Alco, MLW, DLW |
| Engine | Alco 251-D, Inline-6, 1,400 hp (1,000 kW) (1,300 hp or 970 kW site rating) with Alco turbocharged engine. 1,100 rpm max, 400 rpm idle; 228 mm × 267 mm (8.98 in × 10.51 in) bore x stroke; compression ratio 12.5:1. |
| Transmission | Electric, DC-DC (DC Generator and DC Traction motor) |
| Traction motors | GE for original Alco and MLW models, BHEL for DLW |
| Axle load | 12.0 t (11.8 long tons; 13.2 short tons) |
| total weight | 72.0 t (70.9 long tons; 79.4 short tons) ALCo and DLW, 67.0 t (65.9 long tons; 73.9 short tons) MLW |
| Bogies | Alco design cast frame trimount (Co-Co) bogies with asymmetrical arrangement of traction motors |
| Starting TE | 18.94 t (18.64 long tons; 20.88 short tons) |
| Continuous TE | 16.05 t (15.80 long tons; 17.69 short tons) |
References
- "YDM–4, YDM–4A". Indian Railways Fan Club. Retrieved March 29, 2016.
- RDSO (19 August 1967). "YDM4 Loco Max Operating Speed 85 kmph" (PDF). Research Designs and Standards Organisation (RDSO). Retrieved March 29, 2016.
- "YDM4 - About".
- "Railway Website Mechanical Department". Retrieved 16 May 2020.
- "[IRFCA] Indian Railways FAQ: Locomotives -- Specific classes : AC Electric". www.irfca.org.
