Indian locomotive class WAM-4
The Indian locomotive class WAM-4 is a class of 25 kV AC electric locomotives that was developed in the 1970 by Chittaranjan Locomotive Works for Indian Railways. The model name stands for broad gauge, AC Current, Mixed traffic engine, 4th generation. They entered service in March 1971. A total of 500 WAM-4 were built at CLW between 1970 and 1983, which made them the most numerous class of mainline electric locomotive till its successor the WAG-5.
The WAM-4 is one of the most successful locomotives of Indian Railways having served both passenger and freight trains for over 50 years. This class provided the basic design for a number of other locomotives like WCAM-1, WAG-5A, WCG-2, and some WAP models. However, with the advent of new 3-phase locomotives like WAP-5 and WAP-7, the WAM-4 locomotives were relegated to hauling smaller passenger trains and now the aging fleet the WAM-4 locomotives are being rapidly scrapped and have been fully withdrawn from mainline duties.
History
The history of WAM-4 begins in early 1970s with the aim of addressing the shortcomings of the previous WAM-1/2 and WAG 1, WAG-2, WAG-3, WAG-4 classes and remove steam locomotives from IR by a target date of 1990. The WAM-1s were not great successes as some of their advanced features were unsuitable for Indian conditions.so the designers at RDSO and CLW decided to use the following
- Instead of the Bo-Bo bogies of WAM-1/2, ALCO asymmetric Trimount bogies of the WDM-2 were provided for better traction and power.
- Silicon rectifiers with speed control by three series-parallel motor combinations and weak field operation.
- Auxiliaries from Westinghouse and Kirloskar, S F India and Northey
- Air brakes for loco and vacuum train brakes fitted as original equipment with Rheostatic braking also provided
- MU operation made possible up to 4 units possible.
Variants
This loco class has been seen in many variations, as a lot of workshops and sheds have carried out their own enhancements or modifications to the basic loco design. Although the code indicates a mixed-use loco, most WAM-4's ended up hauling passenger trains.Variants include
- WAM4B or G: Freight only
- WAM4D or DB: Dual Braked
- WAM4E: Air Brake only
- WAM4H: Hitachi Traction Motors instead of Alstom
- WAM4P: Passenger only
- WAM4/2S3P: 2 Traction Motors in Series, 3 in Parallel
- WAM4/6P: 6 traction motors permanently in parallel
- WAM4/6PE: Air braked, 6 Traction Motors perm. in parallel
- WAM4/6PDBHS: 6 Traction Motors permanently in parallel, Dual Brakes, High Speed
- WAM-4P D: Passenger only
- WAM-4P DB 6P and WAM-4 6P D: These are for superfast trains
- WAM-4P DB 3P and WAM-4 2S-3P: some superfasts, passengers
The WAM-4 locomotives were later reconfigured to have all motors always in parallel or with the three series-connected pairs in parallel. Some WAM-4 locomotives from CLW are thought to have had the 2S 3P configuration right from the start. The 2S 3P configuration was better for the mixed traffic loads especially as it allowed the locomotives to start hauling larger loads without stalling. With increasing use of the WAM-4 locomotives for passenger traffic the all-parallel configuration was deemed more desirable since it allowed higher speeds and higher acceleration.
Livery
This loco has the widest variety of liveries, with each loco shed having its own liveryMost of the WAM-4 locomotives now have their MU capability disabled as RDSO disapproves of these locomotives running MU'd over 100 km/h.
Named locomotives
A few WAM-4 locomotives have been named by Indian RailwaysClass | Loco Number | Name | Loco Shed | Current status | ref |
WAM-4 | 20401 | Rajatabha | Bhillai | Condemned | |
WAM-4 | 20420 | Sukh Sagar Naveen | Vijayawada | Scrapped | |
WAM-4 | 20615 | Surubhi | Aasansol | Condemned in November 2011 | |
WAM-4 | 21320 | Garuda | Arakkonam | Plinthed at Rail Soudha, SWR HQ, Hubli | |
WAM-4 | 21380 | Navchetna | Asansol | In Inferior service | |
WAM-4 | 21399 | Anant | Bhusawal | The last WAM-4 ever built. No longer in holdings - assumed withdrawn/scrapped January 2019 |
Preserved Examples
A few WAM-4 locomotives have been preserved by Indian Railways at various location around IndiaClass | Loco Number | Previous shed | Name | LIvery | Location | ref |
WAM-4 | 20400 | BIA | BIA cream/orange with blue stripe | Used at Electric Loco Training Center, Uslapur . Reumbered ELTC-120 | ||
WAM-4 | 20472 | Ghaziabad | Restricted to shunting/departmental duties only. Earmarked for preservation: I.R. Heritage Website | |||
WAM-4 | 20484 | Bhusawal | BSL cream/orange with orange lining | Loco now preserved at CLW loco park | ||
WAM-4 | 20601 | Jhansi | Maroon with [cream band | Earmarked for preservation: I.R. Heritage Website | ||
WAM-4 | 21320 | Arakkonam | Garuda | Red/dark grey/light grey with white line | Plinthed at Rail Soudha, SWR HQ, Hubli | |
WAG-5/WAM-4B | 21101 | Tatanagar | Brown/Black with Yellow stripe | Plinthed outside TATA |
Locomotive sheds
Former sheds
- Vadodara
- Visakhapatnam
- Itarsi
- Arrakonam
- Mughalsarai
- Vijaywada
- Bhusawal
- Valsad
- Howrah
- Jhansi
- Tughlakabad
- Tatanagar
- Bhilai
Technical specificationshttp://www.irfca.org/faq/faq-loco2e.html#loco Indian AC electric loco information