Indian locomotive class WAP-7

Last updated

WAP-7
BZA WAP7.jpg
Vijayawada based WAP-7 at BZA ELS.
Type and origin
Power type Electric
Builder
Build date1999–2023 (CLW)

2016–present (BLW)

2017–present (PLW)
Total produced2021 as of August 2025
Specifications
Gauge 5 ft 6 in (1,676 mm)
Bogies Co-Co, Fabricated Flexicoil Mark IV bogies; bogie wheelbase 1,850 mm (72+78 in) + 1,850 mm (72+78 in)
Wheel diameter1,092 mm (43 in) new, 1,016 mm (40 in) worn
Wheelbase 15,700 mm (51 ft 6+18 in)
Length:
  Over beams20,562 mm (67 ft 5+12 in)
Width3,152 mm (10 ft 4+18 in)
Height:
  Pantograph4,255 mm (13 ft 11+12 in)
Axle load WAP 7

20.5 t (20.2 long tons; 22.6 short tons) [1]

WAP 7HS

18.08 t (17.79 long tons; 19.93 short tons) [2]
Loco weight123 t (121 long tons; 136 short tons) [1]
Power supply 3-phase 2180 V 50 Hz
Electric system/s 25 kV 50 Hz AC Overhead
Current pickup(s) Pantograph
Traction motors 6FRA 6068 3-phase squirrel-cage induction motors
850 kW (1,140 hp), 2180 V, 1283/2484 rpm, 270/310A;
Weight-2,100 kg (4,600 lb), forced-air ventilation, axle-hung, nose-suspended;
Torque 6,330–7,140 N⋅m (4,670–5,270 lbf⋅ft)
~88% efficiency.
TransmissionElectric
Gear ratioWAP 7
72:20
WAP 7HS
70:22
Loco brake Air and regenerative
Train brakes Air
Performance figures
Maximum speed140 km/h (87 mph) (WAP-7)

160 km/h (99 mph) (WAP-7HS)
Potential speed: 180 km/h (110 mph) (WAP-7HS)

155

Contents

 km/h (96 mph) (WAP-7)
Power outputMax Power : 6,350 hp (4,740 kW)
Continuous: 6,120 hp (4,563.68 kW)
Tractive effort Starting: 322.4 kN (72,500 lbf)
Continuous: 228 kN (51,000 lbf) at 71 km/h
Career
Operators Indian Railways
Numbers
LocaleAll over India
First run19 May 2000

The Indian locomotive class WAP-7 is a class of 25 kV AC electric locomotives that was developed in 1999 by Chittaranjan Locomotive Works (CLW) for Indian Railways. Its class designation denotes a broad gauge (W) alternating current (A) passenger (P) locomotive of the 7th generation (7). They entered service in 2000. A total of 1991 WAP-7 locomotives have been built, with more units being built at CLW, Banaras Locomotive Works (BLW) and Patiala Locomotive Works (PLW).

The WAP-7 has been serving passengers for Indian Railways since their introduction in 1999. It is a passenger variant of the WAG-9 freight locomotive with a modified gear ratio to pull lighter loads at higher speeds. With an output of 6,125 hp, it is the most powerful passenger locomotive in the Indian Railways fleet, and the most numerous passenger locomotive in India. The WAP-7 is capable of hauling 24 coach trains at speeds of 130 km/h.

History

The WAP-7 is largely used by most regional zones of Indian Railways. As of October 2021, all of these are fitted with H-type transition couplers which are compatible with both screw coupling and centre-buffer coupling.[ original research? ] In February 2017, Banaras Locomotive Works built their first WAP 7 class locomotive. [3]

In 2019, a variant of the WAP-7, designated the WAP-7HS, was introduced for higher speeds. The WAP-7HS has a max speed of 180 km/h (110 mph), and is capable of hauling a 24-car train at 160 km/h (99 mph) as opposed to the 140 km/h (87 mph) of the original. Indian Railways plans to use the WAP-7HS for Shatabdi, Rajdhani, and Duronto express trains. However, as of September 2022, it has not been confirmed[ according to whom? ] if any others have been built, and the single completed WAP-7HS has remained[ as of? ] restricted to 130 km/h (81 mph) operation.[ This paragraph needs citation(s) ]

Head-on Generation (HOG)

The HOG ports are equipped on right side upper and left side down on Erode based WAP-7 at White Field railway station Indian Electric Locomotive WAP-7 ED - 39231.jpg
The HOG ports are equipped on right side upper and left side down on Erode based WAP-7 at White Field railway station

Many locomotives of this class are fitted with head-on generation (HOG), eliminating the need to have separate End on Generation (EOG) sets or DG (Diesel Generator) sets for supplying power to the train and thus resulting in significant savings on maintenance and running costs. The HOG transfers electric power from the loco's pantograph to the coaches instead of EOG where a power car equipped with diesel generator capable of generating adequate power of 3-phase 50 Hz 415 V / 750 V AC (called 'head-end power') is provided at either end of the train rake to supply power. [4] [5] [6]

Locomotive sheds

ZoneShed NameCodeQuantityIntroduction
Central Railway Ajni AQE732010
Kalyan KYNE782019
Pune PADX552023
Eastern Railway Howrah HWHE932012
Sealdah SDAD402020
East Central Railway Gomoh GMOE462000
Barauni BJUE62021
Samastipur SPJD552022
East Coast Railway Visakhapatnam WATE902016
Northern Railway Ghaziabad GZBE1522000
Ludhiana LDHE442022
North Central Railway Kanpur CNBE952019
North Eastern Railway Gonda GDDX202021
Gorakhpur GKPL172024
Izzatnagar IZN62024
Northeast Frontier Railway Siliguri SGUD352024
North Western Railway Bhagat Ki Kothi BGKD642023
Southern Railway Erode EDE912017
Royapuram RPME1182011
South Central Railway Lallaguda LGDE1552008
Vijayawada BZAE772021
South Eastern Railway Tatanagar TATE552017
Bondamunda BNDL212018
Santragachi SRCE402017
South East Central Railway Bhilai BIAE262012
South Western Railway Krishnarajapuram KJMD772019
Hubballi UBLD152024
Western Railway Vadodara BRCE1532016
Valsad BLEE452024
West Central Railway Tughlakabad TKDE832013
Itarsi ETE932018
Total active locomotives as of August 2025 [7] 2018

See also

References

  1. 1 2 "[IRFCA] Indian Railways FAQ - AC Electric Locomotives".
  2. "What are the specifications of WAP 7 HS?". Quora . Retrieved 1 May 2025.[ unreliable source? ]
  3. "Brief History of DLW". Ministry of Railways, Government of India. Archived from the original on 2 April 2019. Retrieved 30 December 2017.
  4. "Train had WAP-7 engine, 'black box' may reveal cause". The Indian Express . 9 August 2010. Retrieved 25 August 2012.[ dead link ]
  5. "Recent Developments". Chittaranjan Locomotive Works. Archived from the original on 10 May 2012. Retrieved 25 August 2012.
  6. Development of Electric locomotive with Head On Generation (HOG) facility (PDF) (Technical report). Research Design and Standards Organisation. Archived from the original (PDF) on 19 February 2018. Retrieved 1 May 2025.
  7. "e-Locos".