The Indian locomotive class WAP-7 is a class of 25 kV AC

electric locomotive An electric locomotive is a locomotive powered by electricity from overhead lines, a third rail or on-board energy storage such as a Battery (electricity), battery or a supercapacitor. Locomotives with on-board fuelled prime mover (locomotive), ...

s that was developed in 1999 by

Chittaranjan Locomotive Works Chittaranjan Locomotive Works (CLW) is an electric locomotive manufacturer based in India. The works are located at Chittaranjan in the Asansol Sadar subdivision of West Bengal, with an ancillary unit in Dankuni. The main unit is 32 km fr ...

(CLW) for

Indian Railways Indian Railways is a state-owned enterprise that is organised as a departmental undertaking of the Ministry of Railways (India), Ministry of Railways of the Government of India and operates India's national railway system. , it manages the fou ...

. The model name stands for broad gauge (W), AC Current (A), Passenger traffic (P) locomotive, 7th generation (7). They entered service in 2000. A total of 1909 WAP-7 have been built, with more units being built at CLW,

Banaras Locomotive Works The Banaras Locomotive Works (BLW), formerly Diesel Locomotive Works (DLW), is a production unit of Indian Railways situated in Varanasi, Uttar Pradesh. DLW was renamed BLW in 2020. History Founded in 1956 as the ''DLW'', it manufactures locom ...

(BLW) and

Patiala Locomotive Works Patiala Locomotive Works (PLW) (formerly Diesel Loco Modernization Works (DMW)) is a production unit of the Indian Railways located at Patiala in the Indian state of Punjab. It was set up in the year 1981 as "Diesel Component Works" (DCW) to m ...

(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 The Indian locomotive class WAG-9 is a class of 25 kV AC electric locomotives that was developed in 1995 by ABB for Indian Railways. The model name stands for broad gauge (W), AC Current (A), Goods traffic (G), 9th generation (9) locomotiv ...

freight locomotive with a modified

gear ratio A gear train or gear set is a machine element of a mechanical system formed by mounting two or more gears on a frame such that the teeth of the gears engage. Gear teeth are designed to ensure the Pitch circle diameter (gears), pitch circles of e ...

to pull lighter loads at higher speeds. With an output of 6,125 hp, it is the most powerful passenger locomotive in the

fleet, and the most numerous passenger locomotive in India. The WAP-7 is capable of hauling 24 coach trains at speeds . It also capable of hauling 26 coaches 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 A screw is an externally helical threaded fastener capable of being tightened or released by a twisting force ( torque) to the head. The most common uses of screws are to hold objects together and there are many forms for a variety of mater ...

and centre-buffer coupling. In February 2017,

built their first WAP 7 class locomotive. 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 , and is capable of hauling a 24-car train at as opposed to the 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 operation.

Head-on Generation (HOG)

Indian Electric Locomotive WAP-7 ED - 39231

Many locomotives of this class are fitted with

head-on generation In rail transport, head-end power (HEP), also known as electric train supply (ETS), is the electrical power distribution system on a passenger train. The power source, usually a locomotive (or a generator car) at the front or 'head' of a train, ...

(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 A pantograph (, from their original use for copying writing) is a Linkage (mechanical), mechanical linkage connected in a manner based on parallelograms so that the movement of one pen, in tracing an image, produces identical movements in a se ...

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 In rail transport, head-end power (HEP), also known as electric train supply (ETS), is the electrical power distribution system on a passenger train. The power source, usually a locomotive (or a generator car) at the front or 'head' of a train, ...

') is provided at either end of the train rake to supply power.

Locomotive sheds

References

External links

{{DEFAULTSORT:WAP-7 5 ft 6 in gauge locomotives 25 kV AC locomotives Co-Co locomotives Electric locomotives of India Banaras Locomotive Works locomotives Chittaranjan Locomotive Works locomotives Railway locomotives introduced in 1999

History

Head-on Generation (HOG)

Locomotive sheds

See also

References

External links