| WAP-7 | |
|---|---|
| WAP-7 numbered 30255 hauls train number 18237 Chattisgarh Express | |
| Power type | Electric |
| Builder | Chittaranjan Locomotive Works, West Bengal, India |
| Gauge | 5 ft 6 in (1,676 mm) |
| Current collection method |
50 kV, 50 Hz overhead AC with pantograph |
| Top speed | Test Run:177 km/h (110 mph), Operational: 140 km/h (87 mph) |
| Power output | 6,350 hp (4,735 kW) |
| Career | Indian Railways |
| Locale | Northern Railways, South-Central Railway. |
WAP 7 is a high speed locomotive indigenously developed by Chittaranjan Locomotive Works. It is capable of hauling trains at speeds ranging between 140 and 160 km per hour and is now largely used by Northern Railways (NR), South Central Railways (SCR), South Western Railway (SWR) and Southern Railways (SR).
Contents |
The current locomotive sheds which house this locomotive are:
The WAP-7 is actually a modified version of the WAG 9 freight locomotive with modified gear ratios and is set to replace the fleet of WAP 4's, the most widely used passenger locomotive today. The process will be a very slow one however, with WAP-4s still being produced and the production of WAP-7's increasing at a slow pace.
With a maximum speed rating of 180 km/h (IR restricts it to 145 km/hr), the WAP-7 boasts of the most phenomenal acceleration figures while hauling mail/express trains. The WAP-7 can also haul loads of 24-26 passenger coaches (1430-1550t) at 110+ km/h per hour. It is also known to haul 16 heavyweight Air Conditioned coaches (1120t) in 1:40 inclines single-handedly. At a trial conducted by Indian Railways, it clocked a speed of 177 km/h. It is the most successful passenger locomotive in the Indian Railways portfolio after the WAP-4. It is used to haul premium trains like the Rajdhani Express and the Shatabdi Express apart from other regular mail/express trains. It also regularly hauls other trains like the Nizamuddin-Chennai, Nizamuddin-Bangalore, New Delhi-Sealdah and the New Delhi - Mumbai Rajdhani Expresses.
Currently a 6000 hp version with IGBT traction is under development by Chittaranjan Locomotive Works.
The most unique feature of this locomotive is that it eliminates the need to have separate DG sets for air-conditioning in long distance trains hence providing huge savings on maintenance and running costs. This technology is called HOG or "Head On Generation" where the loco transfers electric power from its pantograph to the coaches.
A 24-coach (1500t) passenger rake can be accelerated to 110 km/h in 240 seconds (over 4.7 km) by a WAP-7; to 120 km/h in 304 sec. (6.7 km); and to 130 km/h in 394 sec. (9.9 km). Around 100 of these locomotives have been put to service as of early 2011.
The locomotive is expected to in use in the Mumbai area of Western Railway by the end of December 2011 or the start of January 2012 and in the Mumbai area of Central Railway by January 2013.
| Manufacturers | Chittaranjan Locomotive Works |
| Traction Motors | 6FRA 6068 3-phase squirrel-cage induction motors (850 kW, 2180V, 1283/2484 rpm, *270/310A; Weight- 2100 kg, forced-air ventilation, axle-hung, nose-suspended; Torque 6330/7140Nm. *95% efficiency.) |
| Gear Ratio | 72:20 |
| Axle load | 20.5t |
| Power | 6350 HP |
| Wheel diameter | 1092mm new, 1016mm worn |
| Wheelbase | 15700mm |
| Bogies | Co-Co, Fabricated Flexicoil Mark IV bogies; bogie wheelbase 18500mm + 18500mm |
| Unsprung mass per axle | 3.984t |
| Length over buffers | 20562mm |
| Length over headstocks | 19280mm |
| Body width | 3152mmn |
| Cab length | 2434mm |
| Pantograph locked down height | 4255mm |
Kalka Mail which derailed on 10 July 2011 was being hauled by a WAP-7 locomotive.[2]
Malfunction of the undergear of the locomotive could also be a reason. The driver of the Kalka Mail said he saw the engine shaking. [3]
A post-accident diagnostic revealed that the first axle (leading) of the locomotive registered a jerk and the fourth axle (trailing bogie) showed loss of contact of the wheel with the track.
The locomotive in question (30221) has been re-railed and is undergoing fault diagnostics and repairs.
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