Indian locomotive class WAP-7

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

2016–present (BLW)

2017–present (PLW)
Total produced2193 as of March 2026
Specifications
Gauge5 ft 6 in (1,676 mm)
BogiesCo-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
Wheelbase15,700 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 loadWAP 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)

WAP 7AD

20.5 t (20.2 long tons; 22.6 short tons)[1]
Loco weight123 t (121 long tons; 136 short tons)[1]
Power supply3-phase 2180 V 50 Hz
Electric system/s25 kV 50 Hz AC Overhead
Current pickupPantograph
Traction motors6FRA 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
WAP 7AD
175:20
Loco brakeAir and regenerative
Train brakesAir
Performance figures
Maximum speed140 km/h (87 mph) (WAP-7)

160 km/h (99 mph) (WAP-7HS) 180 km/h (110 mph) (WAP-7AD)

Potential speed: 200 km/h (120 mph) (WAP-7AD) 180 km/h (110 mph) (WAP-7HS)

155 km/h (96 mph) (WAP-7)
Power outputMax Power : 6,350 hp (4,740 kW)
Continuous: 6,120 hp (4,563.68 kW)
Tractive effortStarting: 322.4 kN (72,500 lbf)
Continuous: 228 kN (51,000 lbf) at 71 km/h
Career
OperatorsIndian Railways
Numbers
  • 30201-30829 CLW
  • 37001-37999 & 45000+ BLW
  • 39000+ PLW
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. WAP-7 locomotives are 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. In February 2017, Banaras Locomotive Works built their first WAP 7 class locomotive.[2]

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 if any others have been built, and the single completed WAP-7HS has remained restricted to 130 km/h (81 mph) operation.

In 2025, a variant of the WAP-7, designated the WAP-7AD, was introduced with an aerodynamic design. The WAP-7AD has a maximum 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-7AD for Amrit Bharat Express & other Express trains. The first WAP-7AD 37873 entered service on September, 2025 hauling 12284 Ernakulam Duronto express. A pair of WAP-7AD, painted with Amrit Bharat livery are currently parked at ICF, Chennai waiting for rake and route allotment.

A Tughlakabad based WAP-7AD #37873 at Thrissur.
A Sealdah based WAP-7 #39207 pulling Uttar Banga Express.

Head-on Generation (HOG)

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.[3][4][5]

Train Services

earlier this locomotive pull passenger with ICF coaches now in 2020s 100% was LHB coaches

Locomotive sheds

Zone Shed Name Code Quantity Introduction
Central Railway Ajni AQE 73 2010
Kalyan KYNE 82 2019
Pune PADX 68 2023
Eastern Railway Howrah HWHE 100 2012
Sealdah SDAD 46 2020
East Central Railway Gomoh GMOE 47 2000
Barauni BJUE 6 2021
Samastipur SPJD 59 2022
East Coast Railway Visakhapatnam WATE 90 2016
Northern Railway Ghaziabad GZBE 162 2000
Ludhiana LDHE 41 2022
North Central Railway Kanpur CNBE 103 2019
North Eastern Railway Gonda GDDE 20 2021
Gorakhpur GKPL 18 2024
Izzatnagar IZNE 6 2024
Northeast Frontier Railway Siliguri SGUD 43 2024
New Guwahati NGCD 28 2026
North Western Railway Bhagat Ki Kothi BGKD 78 2023
Southern Railway Erode EDE 97 2017
Royapuram RPME 126 2011
South Central Railway Lallaguda LGDE 157 2008
Vijayawada BZAE 82 2021
South Eastern Railway Tatanagar TATE 54 2017
Bondamunda BNDL 19 2018
Santragachi SRCE 52 2017
South East Central Railway Bhilai BIAE 26 2012
South Western Railway Krishnarajapuram KJMD 91 2019
Hubballi UBLD 29 2024
Western Railway Vadodara BRCE 140 2016
Valsad BLEE 74 2024
West Central Railway Tughlakabad TKDE 87 2013
Itarsi ETE 95 2018
Total active locomotives as of March 2026[6] 2199

See also

References

  1. ^ a b c "[IRFCA] Indian Railways FAQ - AC Electric Locomotives".
  2. ^ "Brief History of DLW". Ministry of Railways, Government of India. Archived from the original on 2 April 2019. Retrieved 30 December 2017.
  3. ^ "Train had WAP-7 engine, 'black box' may reveal cause". The Indian Express. 9 August 2010. Retrieved 25 August 2012.
  4. ^ "Recent Developments". Chittaranjan Locomotive Works. Archived from the original on 10 May 2012. Retrieved 25 August 2012.
  5. ^ 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.
  6. ^ "e-Locos".