Indian locomotive class WAP-7 explained

WAP-7
Powertype:Electric
Builder:
Builddate:1999 - present
Totalproduction:1728 as of August 2024
Bogies:Co-Co, Fabricated Flexicoil Mark IV bogies; bogie wheelbase 1850abbr=onNaNabbr=on + 1850abbr=onNaNabbr=on
Wheeldiameter:1092abbr=onNaNabbr=on new, 1016abbr=onNaNabbr=on worn
Wheelbase:15700abbr=onNaNabbr=on
Over Bufferbeams:20562abbr=onNaNabbr=on
Width:3152abbr=onNaNabbr=on
Height:5235abbr=onNaNabbr=on
Length:20.62abbr=onNaNabbr=on
Pantodown:4255abbr=onNaNabbr=on
Axleload:WAP 7
20.5t[1]

WAP 7HS18.08t[2]

Locoweight:123t[3]
Powersupply:3-phase 2180 V 50 Hz
Electricsystem:25 kV 50 Hz AC Overhead
Collectionmethod:Pantograph
Tractionmotors:6FRA 6068 3-phase squirrel-cage induction motors
850kW, 2180 V, 1283/2484 rpm, 270/310A;
Weight-2100kg (4,600lb), forced-air ventilation, axle-hung, nose-suspended;
Torque 6330Nm7140Nm
~88% efficiency.
Transmission:Electric
Gear Ratio:WAP 7
72:20
WAP 7HS
70:22
Locobrakes:Air and regenerative
Trainbrakes:Air
Maxspeed:140km/h (WAP-7)
160km/h (WAP-7HS)
Potential speed: 180km/h(WAP-7HS)155km/h (WAP-7)
Poweroutput:Max Power : 6350HP
Continuous: 61202NaN2
Tractiveeffort:Starting : 322.4kN
Continuous : 228kN at 71 km/h
Operator:Indian Railways
Fleetnumbers:
  • 30201+ CLW
  • 37001+ BLW
  • 39000+ PLW
Firstrundate:19 May 2000
Locale:All over India

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. 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 1676 WAP-7 have been built, with more units being built at CLW, Banaras Locomotive Works (BLW) and Patiala Locomotive Works (PLW).

The WAP-7 is the most successful locomotives of Indian Railways serving passenger trains for over 23 years. 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 6125HP, 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 110km/h140km/h.

History

It is now largely used by Northern Railways (NR), South Central Railways (SCR), Central Railways (CR), South East Central Railways (SECR), South Eastern Railways (SER), West Central Railways (WCR), Eastern Railways (ER), Western Railways (WR), North Central Railways (NCR), South Western Railways (SWR), Southern Railways (SR), East Central Railways (ECR), East Coast Railways (ECoR), North Eastern Railways (NER), North Western Railways (NWR), Northeast Frontier Railways (NFR)among other zones. 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.[4]

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 180km/h, and is capable of hauling a 24-car train at 160km/h as opposed to the 140km/h 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 stayed restricted to 130km/h.

Head-on Generation (HOG)

A main feature of Majority locomotives of this class is that they eliminate the need to have separate End on Generation (EOG) sets or DG (Diesel Generator) sets for supplying power to the train resulting in significant 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 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.[5] [6] [7]

Locomotive sheds

Zone! rowspan="2" style="background: skyblue;"
NameShed CodeQuantityIntroduction
HOGNon HOG
AQE6532010
KalyanKYNE6952019
PunePADX 3912023
HWHE892012
SealdahSDAD 20102020
GMOE462000
BarauniBJUE 62021
SamastipurSPJD462022
East Coast RailwayWATE6452016
GZBE119392000
LDHE 3142022
North Central RailwayKanpurCNBE842019
North Eastern RailwayGondaGDDX172021
IzzatnagarIZND62023
GorakhpurGKPL52024
Northeast Frontier RailwaySiliguriSGUD62024
North Western RailwayBhagat Ki KothiBGKD302023
EDE762017
RPME104102011
LGDE116332008
VijayawadaBZAE592021
South Eastern RailwayTatanagarTATE 622017
BondamundaBNDL162018
SantragachiSRCE222017
BIAE1122012
KrishnarajapuramKJMD582019
HubliUBLD52024
BRCE1252016
ValsadBLEE452024
TKDE62212013
ItarsiETE892018
Total1592134
Total Locomotives Active as of August 2024[8] 1726

See also

Notes and References

  1. Web site: [IRFCA] Indian Railways FAQ - AC Electric Locomotives .
  2. Web site: What are the specifications of WAP 7 HS? .
  3. Web site: [IRFCA] Indian Railways FAQ - AC Electric Locomotives .
  4. Web site: Brief History of DLW. Ministry of Railways, Government of India. 30 December 2017.
  5. Web site: Train had WAP-7 engine, 'black box' may reveal cause. Zee News. 9 Aug 2010. 25 Aug 2012.
  6. Web site: Recent Developments . . 25 Aug 2012.
  7. Web site: Development of Electric locomotive with Head On Generation (HOG) facility . Indian Railways.
  8. Web site: e-Locos.