Indian locomotive class WAP-7
|Builder||Chittaranjan Locomotive Works, West Bengal, India|
|Gauge||5 ft 6 in (1,676 mm)|
|25 kV, 50 Hz overhead AC with pantograph|
|Top speed||Test Run:180 km/h (112 mph), Operational: 140 km/h (87 mph)|
|Power output||6,350 hp (4,735 kW)|
|Locale||Northern Railways, South-Central RailwayEastern Railway South East Central Railway|
WAP 7 is a moderate speed high power locomotive developed by Chittaranjan Locomotive Works by modifying the gear ratio of existing WAG 9 class. It is capable of hauling trains at speeds ranging between 140 and 180 km per hour and is now largely used by Northern Railways (NR), South Central Railways (SCR), Southern Railways (SR), Eastern Railways (ER), South East Central Railway (SECR), Central Railways (CR), West Central Railways (WCR). As of November 2013, there are 180 locomotives in service.
Similarity with WAG 9
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 160 km/h (IR restricts it to 140 km/hr), the WAP-7 has the highest acceleration figures while hauling mail/express trains. The WAP-7 can also haul loads of 24-26 passenger coaches (1430–1550t) at 140 km/h per hour. It is also known to haul 18 heavyweight Air Conditioned coaches (1120t) in 1:40 inclines single-handedly. At a trial conducted by Indian Railways, it clocked a speed of 184 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 Hyderabad - New Delhi, H.Nizamuddin-Thiruvananthapuram, H.Nizamuddin-Chennai, H.Nizamuddin-Bangalore, New Delhi-Sealdah and the New Delhi - Mumbai Rajdhani Express and Nizamuddin-Ernakulam Duronto Express.
WAP-7 locomotive can deliver 6000 HP with regenerative braking being one of its salient features. The regenerative braking is deployed on down gradients conserving energy to the tune of 30-35 percent. It has an inbuilt microprocessor based fault diagnostic system to make trouble shooting easier. Another feature of this locomotive is that it eliminates the need to have separate EOG sets for air-conditioning in long distance trains hence providing significant amount of savings on maintenance and running costs. This technology, called HOG or "Head On Generation", transfers electric power from the loco's pantograph to the coaches instead of "End on Generation" in which a Power Car equipped with diesel generator capable of generating adequate power of 3-phase 50-cycle 415V/750V AC (called as hotel load) is provided at either end of the train rake to supply power.
A 24-coach (1500t) passenger rake can be accelerated to 110 km/h in 180 seconds (over 3.7 km) by a WAP-7; to 120 km/h in 235 sec. (5.3 km); 130 km/h in 302 sec. (7.9 km); 140 km/h in 390 sec. (9.1 km); 150 km/h in 490 sec. (11.1 km); and to 160 km/h in 610 sec. (13.1 km).
|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.)|
|Wheel diameter||1092mm new, 1016mm wor n|
|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|
|Pantograph locked down height||4255mm|
The current locomotive sheds which house this locomotive are:
- Ghaziabad (Code:GZB)
- Lallaguda (Code:LGD)
- Ajni (Code:AJNI)
- Howrah (Code:HWH)
- Bhilai (Code:BIA)
- Royapuram (Code:RPM)
- Tughlakabad (Code:TKD)
- Arakkonam Jn. (Code:AJJ)
- Gomoh (Code: GOMO)
Trains hauled by WAP-7
- Sealdah - New Delhi Duronto Express (Howrah WAP-7)
- Howrah Rajdhani Express (Howrah WAP-7)
- Secunderabad Rajdhani Express (Lallaguda WAP-7)
- Secunderabad Hazrat Nizamuddin Duronto Express (Lallaguda WAP-7)
- Hyderabad - New Delhi Andhra Pradesh Express (Lallaguda WAP-7)
- Hyderabad - Hazrat Nizamuddin Dakshin Express (Lallaguda WAP-7)
- Hyderabad - Chennai Charminar Express (Lallaguda WAP-7)
- Secunderabad - Visakhapatnam AC Duronto Express (Lallaguda WAP-7)
- Hyderabad - Visakhapatnam Godavari Express (Lallaguda WAP-7)
- Secunderabad - Visakhapatnam GaribRath Express (Lallaguda WAP-7)
- Secunderabad - Vijayawada Satavahana SF Express (Lallaguda WAP-7)
- Secunderabad - Kakinada Gowthami SF Express (Lallaguda WAP-7)
- Secunderabad - Sirpur Kaghaznagar Telangana Express (Lallaguda WAP-7)
- Chennai Central - Coimbatore - Chennai Central Intercity express (Train 12679 / 12680) (WAP-7)
- Chennai Central - Trivandrum- Chennai Central Superfast Mail (12623/12624) (RPM WAP 7)
- Chennai Central - Trivandrum - Chennai Central Superfast Express (12696/12695) (WAP 7)
- Chennai - Alappuzha-Chennai express (16041/16042) hauled by WAP 7 (Royapuram)
- Chennai Central - Coimbatore - Chennai Central Duronto express (Train 12243 / 12244) (WAP-7)
- Kerala Sampark Kranti Express (Ghaziabad WAP-7)
- Kochuveli Amritsar S/F Express (Ghaziabad WAP-7)
- Dadar Amritsar Express (Ghaziabad WAP-7)
- Sealdah Rajdhani Express (Ghaziabad WAP-7)
- Chennai Rajdhani Express (Ghaziabad / Lallaguda WAP-7)
- Thiruvananthapuram Rajdhani Express (Ghaziabad WAP-7)
- Bangalore Rajdhani Express (Lallaguda WAP-7)
- Bangalore - New Delhi Karnataka Express (Ghaziabad WAP-7) as of July 2013
- Bilaspur Rajdhani Express (Ajni WAP-7)
- Ranchi Rajdhani Express (Ghaziabad WAP-7)
- Hazrat Nizamuddin - Ernakulam Duronto Express (Ghaziabad WAP-7)
- Hazrat Nizamuddin - Chennai Duronto Express (Ghaziabad/Lallaguda WAP-7)
- Hazrat Nizamuddin Pune Duronto Express (Ghaziabad WAP-7)
- Bandra Terminus Hazrat Nizamuddin Yuva Express (Ghaziabad WAP-7)
- Yeshvantapur Delhi Sarai Rohilla AC Duronto Express (Ghaziabad / Lallaguda WAP-7)
- Howrah - New Delhi Yuva Express (Ghaziabad WAP-7)
- Chennai Central Hazrat Nizamuddin Garib Rath Express (Ghaziabad WAP-7)
- Allahabad New Delhi Duronto Express (Ghaziabad WAP-7)
- Himalayan Queen Express (Ghaziabad WAP-7)
- Vijayawada - Visakhapatnam Ratnachal SF Express (Lallaguda WAP-7)
- Adilabad - Tirupati Krishna Express (Lallaguda WAP-7)
- Tirupati - Hazrat Nizamuddin AP Sampak Kranti SF Express (Lallaguda WAP-7)
- Bihar Sampark Kranti Superfast Express (Darbhanga - New Delhi) (Ghaziabad WAP-7)
- Taj Express (Ghaziabad WAP-7)
- Chhattisgarh Express (Ajni WAP-7)
- Amarkantak Super Fast Express (Ghaziabad WAP-7)
- Sewagram Express (Ajni WAP-7)
- Goa Express (Ghaziabad WAP-7)
- Bhopal Express (Tuglakabad WAP-7)
- Agra - Jhansi Passenger (Ghaziabad WAP-7)
- Chennai Bangalore Mail (Lallaguda WAP-7)
- Chennai Bangalore Express (Lallaguda WAP-7)
- Chennai Bangalore Brindavan Express (Lallaguda WAP-7)
- Bangalore Chennai Shatabdi Express (Lallaguda WAP-7)
- Coalfield Express (Howrah WAP-7)
- Hazrat Nizamuddin - Patna Garib Rath Express (Ghaziabad WAP-7)
- Kalka Mail (Howrah WAP-7)
- Howrah - Dhanbad Double Decker Express (Howrah WAP 7)
- Paschim Express (Ghaziabad WAP-7)
- Indore - Hazrat Nizamuddin Intercity Express (Tuglakabad WAP-7)
- Pune Nagpur Garib Rath Express (Ajni WAP-7)
- Nagpur-Pune Superfast (Ajni WAP-7)
- Nagpur Duronto express (Ajni WAP-7)
- New-Delhi Prayag Raj Express (GZB WAP-7)
- Tirupati-Secunderabad padmavati express (Lallaguda WAP-7)
- Howrah New Delhi Poorva Express (GZB WAP 7)
- Purushottam Express (Ghaziabad WAP 7)
- Kalinga Utkal Express (Tughlakabad WAP 7)
- Chhattisgarh Sampark Kranti Superfast Express
- Grand Trunk Express (12615) hauled by WAP 7 (Royapuram)
- Tamil Nadu Express (12622) hauled by WAP 7 (Royapuram)
- Chennai - Bangalore AC Double Decker Express (22625/22626) (RPM/LGD WAP - 7)
- howrah-secunderabad falaknuma express (LGD WAP-7)
- Gorakhpur Lokmanya Tilak Terminus Superfast Express (Ajni WAP-7)
- NDLS-PNBE Rajdhani Express(Ghaziabad/Howrah WAP-7)
Accidents and incidents
Kalka Mail which derailed on 10 July 2011 was being hauled by a WAP-7 locomotive.
Malfunction of the undergear of the locomotive could also be a reason. The driver of the Kalka Mail said he saw the engine shaking. 
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.
- http://www.rdso.indianrailways.gov.in/works/uploads/File/13_10_09.pdf. Missing or empty
- "New energy-efficient loco introduced for high speed train". Economic Times. 9 Feb 2012. Retrieved 25 Aug 2012.
- "Southern Railway inducts fast locomotive". The Hindu. 18 Oct 2012.
- "Train had WAP-7 engine, ‘black box’ may reveal cause". Zee News. 9 Aug 2010. Retrieved 25 Aug 2012.
- "Recent Developments". Chittaranjan Loco works. Retrieved 25 Aug 2012.
- "Development of Electric locomotive with Head On Generation (HOG) facility". Indian Railways.
- "Recent Developments". IRFCA.
- "Train had WAP-7 engine, ‘black box’ may reveal cause". The Indian express. 12 July 2011. Retrieved 14 July 2011.
- "Engine failure behind Kalka Mail tragedy". IBN Live. 13 July 2011. Retrieved 14 July 2011.
|Wikimedia Commons has media related to Indian locomotive class WAP7.|
- IRFCA-Indian Railways Fan Club
- CLW Railways India
- Notes on electric locos from IRFCA-Indian Railways Fan Club
- IR WAP-7 @ Trainspo