Indian locomotive class WDP-4

{{Short description|Indian Railways passenger class diesel locomotive}} {{more citations needed|date=October 2015}} {{Infobox locomotive | name = WDP-4 | powertype = Diesel–electric | image = KJM WDP4D.jpg | caption = KJM based WDP-4D hauling Chamrajnagar - Tumakuru Passenger. | builder = EMD & BLW | serialnumber = | buildmodel = GT46PAC (2000–2007) GT46PACe (2007–2012) JT46PACe (2010–2017) | builddate = (EMD) 2000–2001 (DLW) 2003–2017 | totalproduction = WDP-4: '''100''' WDP-4B: '''86''' WDP-4D: '''525''' | Britishclass = Bo1-1Bo, later Co-Co | uicclass = (Bo1)(1Bo), later Co'Co' | gauge = {{track gauge|5ft6in|lk=on}} | trucks = high adhesion HTSC (High Tensile Steel Cast) | wheeldiameter = {{convert|1092|mm|in|abbr=on|lk=in}} | axleload = '''WDP-4''' : {{convert|19.5|t|LT ST|abbr=on|lk=in}} '''WDP4B''' : {{convert|20.2|t|LT ST|abbr=on|lk=in}} '''WDP4D''' : {{convert|20.5|t|LT ST|abbr=on|lk=in}} | locoweight = '''WDP4''' : {{convert|115.8|t|LT ST|abbr=on|lk=in}} '''WDP4B''' : {{convert|117|t|LT ST|abbr=on|lk=in}} '''WDP4D''' : {{convert|123|t|LT ST|abbr=on|lk=in}} | fueltype = Diesel fuel | fuelcap = {{convert|5,000 - 6,100|L|impgal USgal|abbr=on|lk=in}} | primemover = EMD 16-710G3B | rpmrange = 200 - 954 rpm | rpmrange low = 200 rpm | rpmrange idle = 269 rpm | rpmrange max = 954 rpm | enginetype = 2-stroke V16 diesel | displacement = {{convert|186.16|L|cuin|abbr=on}} | aspiration = turbocharged | alternator = '''WDP4 / WDP4B''' : GM TA-17 (main) with CA-6B (companion) '''WDP4D''' : EMD TA-17 (main) with C6AB (companion) or BHEL TA 9901 (main) with AA 9201 (companion) | tractionmotors = '''WDP4''' : Siemens 1TB2622-0TB02 '''WDP4B''' : Siemens 1TB2622-0TA02 or EMD A 2916-8 '''WDP4D''' : Siemens 1TB2525-0TA02 or EMD A 2916-8 | t/m amps cont = 1250 Amps DC | cylindercount = 16 | transmission = AC Electric | gear ratio = 17:77 | poweroutput = <div> *{{convert|4,000|hp|kW|-1|abbr=on}} (WDP4) *{{convert|4,500|hp|kW|-1|abbr=on}} (WDP4B) *{{convert|4,500|hp|kW|-1|abbr=on}} (WDP4D) </div> | tractiveeffort = '''WDP-4''' : {{convert|27550|kgf|kN|abbr=on}} '''WDP-4B''' : {{convert|40775|kgf|kN|abbr=on}} '''WDP-4D''' : {{convert|43788|kgf|kN|abbr=on}} | maxspeed = '''WDP-4''' : Service : {{convert|160|km/h|mph|abbr=on}} Testing : {{convert|180|km/h|mph|abbr=on}} '''WDP-4B''' : {{convert|130|km/h|mph|abbr=on}} '''WDP-4D''' : {{convert|135|km/h|mph|abbr=on}} | locobrakes = Air, Handbrake, Blended (not in WDP4), Dynamic brake | trainbrakes = Graduated Release Twin Pipe Air Brakes (IRAB-1 Compatible) | operator = Indian Railways SNTF(Algeria) - as EMD GT-'''36''' HCW, with just minor modifications in the body design, along with down-rating the power output to 3,600 HP (2.7 MW) using a 16-645 '''F 3B''', as the number GT-"36" | fleetnumbers = '''20000 - 20103''', '''40001 - 40608''' | locale = India | notes = Unless specified otherwise, data is obtained from RDSO diagram books, given in references. }}

The '''Indian locomotive class WDP-4 (EMD GT46PAC)''' is a passenger-hauling diesel–electric locomotive with AC electric transmission designed by General Motors Electro-Motive Division and built by both GM-EMD and under license by Banaras Locomotive Works (BLW) of Varanasi, India for Indian Railways as the classes WDP4, WDP4B and WDP4D.<ref>{{Cite web |url=http://www.dlw.indianrailways.gov.in/view_section.jsp?lang=0&id=0,295,329,389,391 |title=Welcome to DLW Official Website |access-date=2014-12-09 |archive-date=2014-12-14 |archive-url=https://web.archive.org/web/20141214113303/http://www.dlw.indianrailways.gov.in/view_section.jsp?lang=0&id=0,295,329,389,391 |url-status=dead }}</ref> The GT46PAC is a passenger version of the previous Indian Railways EMD GT46MAC ('''WDG-4''') freight locomotive. The locomotive has a 16-cylinder 710G3B diesel engine and is one of the fastest diesel–electric locomotives in service in Indian Railways.<ref>{{Cite web|url = http://www.dlw.indianrailways.gov.in/view_section.jsp?lang=0&id=0,295,329,389,391|title = Details from production Factory}}</ref>

== Variants == === WDP-4 === The WDP-4 was the loco originally designed by GM EMD and 10 of them were dispatched to India by June 2001. Later on Banaras Locomotive Works, Varanasi started building them initially using knocked-down kits and later indigenously. Starting 2003, the locomotives were produced in large numbers by BLW. The locomotive features self diagnostics control using EM2000 onboard microprocessor which was a new technology for Indian Railways back then.

Unlike the Co-Co wheel arrangement featured on most locomotives, including its freight hauling variant, WDG-4, this loco has a Bo1-1Bo wheel arrangement meaning that it has two powered and one unpowered axle per bogie. This was done to reduce the weight of the loco to make it suitable for passenger operations and also to reduce maintenance.<ref>{{Cite book|url=https://rdso.indianrailways.gov.in/works/uploads/File/Introduction%20handbook%20on%20General%20Motor%20Diesel%20Locomotives.pdf|title=Introduction Handbook on GM Locomotive|publisher=IR CAMTECH|year=2006}}</ref>

==== Visibility Issue ==== The use of the locomotive with the long hood forward configuration has been criticised with respect to the driver's visibility as it is affected due to the protruding radiator section at the hood-end. This criticism has been rejected by the Railways.<ref>{{Cite web|title=Railway claims engine design not faulty|url=https://www.news18.com/news/india/ffgfx-report-rail-pro-reax-341832.html|date=2010-06-15|website=News18|access-date=2020-05-15}}</ref> However, in response, the cab profile of some WDP-4s were widened with a ''Piggy-face'' profile, to increase the field of view from the control cab and the WDP-4B variant was also produced with the same widened cab profile.

=== WDP-4B === This was the first attempt of the Railways to improve upon the successful WDP-4 locomotive. The Bo1-1Bo was found inadequate for hauling 24 coach passenger trains due to the reduced tractive effort. As a result, DLW, reconfigured the chassis to be Co-Co instead. This led to better adhesion with the rails to provide better acceleration with heavy trains. Moreover, the original EMD 710 engine was tweaked to produce an output of 4,500 HP instead of the original 4,000 HP. this Up-rated engine was designated as EMD 16N-710G3B-EC, with an RPM of 910 at Notch-8. This locomotive came to be known as the "GT46PACe". One more important change added to this loco was the inclusion of Blended Brake System. This was added to maximise the use of Dynamic brakes by the loco-pilot and therefore minimise the wear and tear on the fixed brake rigging of the coaches and the locomotive. The addition of blended brake is responsible for the subclass to be designated with a 'B'. Some more features are the widened ''piggy-face'' cab profile to aid visibility, change in the Traction Motor blower by installing a higher power motor and increase in the axle load to {{Convert|20.2|t|LT ST|abbr=}}. The locomotive also has a self-load test feature that allows it to test the net output of the engine. In Siemens and EMD systems, the loco has been provided with 2 traction inverters (TCC-1 and TCC-2, for the respective bogies) while in the Medha system, it has 6 traction inverters, one for each traction motor.<ref>{{Cite book|url=https://rdso.indianrailways.gov.in/works/uploads/File/WDP4B%20(MP-MISC-293-OCT-2014).pdf|title=RDSO diagram book for WDP-4B|publisher=Railway Design and Standards Organisation|year=2014|pages=5}}</ref>

=== WDP-4D === The final alterations to the GT46PAC came in the form of the WDP-4D. The locomotive is the most distinctively identifiable of the three thanks to the addition of a second cab at the long hood end of the locomotive. Due to the heat generated from the radiator at the second cab end of the locomotive, DLW had to install air conditioning to protect both the electrical components and the loco-pilot from the high temperatures.

The existing features from WDP-4B have been carried forward to this class and it exclusively features the widened cab profile. Since it is a Dual Cab now, it is called as "JT46PACe". The loco features a completely different desk control stand, provided by Medha with digital display screens allowing for remote fault diagnostics.

Many locos also have GSM-R based transmission antennae to transmit critical loco info for use by maintenance and signalling staff. It features electro-pneumatic microprocessor based control adapted from the WDP-4B and brake system equipment of KNORR/NYAB CCB type.

This loco again with Dual-Cab, but with More Power and Better Fuel Consumption and State-of-the-Art features compared to ALCo DL560C, along with an Air Conditioned Hood Cab, became a very efficient replacement of WDP-3A (ALCO DL560C) alias "Toaster".<ref>{{Cite book|url=https://rdso.indianrailways.gov.in/works/uploads/File/WDP4D%20(MP-Misc-316)%20(Rev-00)%20SEPT-2016%20(WDP4D%204500%20HP).pdf|title=WDP4D diagram book|publisher=Railway Design and Standards Organisation|year=2016|pages=12}}</ref>

==Builders== The first set of 10 locos starting from road number 20000 to 20009 were manufactured by the Electro Motive Diesel (EMD) of (General Motors) while road numbers 20011 upwards have been manufactured by Banaras Locomotive Works (DLW) of Varanasi in collaboration with GM (General motors). Siemens and Medha are part of this group providing a large number of components of the electronics on board this loco such as the control stand and traction inverters.<ref>{{Cite web|url = http://www.dlw.indianrailways.gov.in/view_section.jsp?lang=0&id=0,295,329,389,391|title = DLW site}}</ref> Additional components are acquired through tenders and a bidding process.

== Locomotive sheds == {| class="wikitable" |+ ! rowspan="2" style="background:Orange;"|Zone ! rowspan="2" style="background:Orange;"|Name ! rowspan="2" style="background:Orange;"|Shed Code ! colspan="3" style="background:Orange;"|Quantity |- ! style="background:Orange;"|WDP-4/4B/4D |- | rowspan="2" |Central Railway |Pune |PADX |26 |- |Kalyan |KYDX |12 |- |Eastern Railway |Howrah |HWHD |18 |- | rowspan="3" |Northern Railway |Ludhiana |LDHD |77 |- |Lucknow | AMVD |28 |- |Tughlakabad |TKDD |59 |- |North Central Railway |Jhansi |JHSD |8 |- |North Eastern Railway |Izzatnagar |IZND |11 |- | rowspan="2" |Northeast Frontier Railway |Guwahati |NGCD |72 |- |Siliguri |SGUD |63 |- |North Western Railway |Bhagat Ki Kothi | BGKD | 93 |- | rowspan="1" |Southern Railway |Ponmalai Goldenrock |GOCD |48 |- | rowspan="1" |South Coast Railway |Gooty |GYD |18 |- | rowspan="2" |South Central Railway |Moula Ali |MLYD |12 |- |Kazipet || KZJD |5 |- | rowspan="2" |South Western Railway |Krishnarajapuram |KJMD |103 |- |Hubballi |UBLD |31 |- |Western Railway |Sabarmati |SBTD |22 |- | rowspan="1" |West Central Railway || Itarsi || ETD | 4 |- | colspan="3" |'''Total Locomotives Active as of May 2026'''<ref>{{Cite web|title=Diesel loco availability targets|url=https://elocos.railnet.gov.in/Holding/Dsl_Mar'2026.pdf|access-date=2026-03-04}}</ref> | colspan="3" |710 |}

==Trains Hauled By WDP-4== {{update section|date=March 2026}} * Poorna Express (both ICF and LHB rakes) * Vivek Express (both ICF and LHB rakes) * Rajdhani Express (LHB rake) * Shatabdi Express (LHB rakes) ** Mysuru to MGR Chennai Central and Fro 12008/07 (between Mysuru Junction and KSR Bengaluru stations) - both ICF and LHB rakes, 2003–2018 ** Howrah to New Jalpaiguri and Fro 12041/42 (End to End) - only LHB rake, 2012–2020 ** Pune to Secunderabad and Fro 12025/26 (End to End) - only LHB rake, 2011-2017 * Humsafar Express (LHB rake) * Duronto Express (LHB rake) * AC Express (LHB rake) * Yesvantpur-Barmer AC Express (ICF Rajdhani rake) * Yesvantpur-Hassan Intercity Express (both ICF and LHB rakes) * Kanchanjunga Express (both ICF and LHB rakes) * Manwar Sangam Express (ICF rake) * Vishwamanava Express (ICF rake) * Karnataka Express (ICF rake) * Yesvantpur-Harihar Intercity Express (LHB rake) * Wainganga Express (both ICF and LHB rakes) * Marusagar Express (ICF rake) * Hampi Express (ICF rake) * Tippu Express (ICF rake) * Konark Express (ICF rake) * Kaziranga Express (ICF rake) * Chalukya Express (ICF rake) * Garib Rath Express (ICF rake) * Double Decker Express (LHB rake) * Jan Shatabdi Express (both ICF and LHB rakes) * Mahamana Express (ICF rake) * Jan Sadharan Express (ICF rake) *Tutari Express

==WDAP-5 Dual Mode Locomotive== {{Main|Indian locomotive class WDAP-5}}Indian Railway was planning for a dual mode locomotive from 2015. In 2019 Banaras Locomotive Works Varanasi, RDSO and CLW together have got the successes of producing a new class of dual mode locomotive named WDAP-5 which can run on both diesel and electric. The design of the locomotive is based on WDP-4D and the bogies were taken from WDG-5. It has been designed for a speed capable of 135kmph. It will produce 4500Hp in diesel mode and 5500Hp in electric mode. The fuel tank capacity is 3000 liters which is half of the WDP-4's due to weight saving. Only 1 unit has been produced until now{{When|date=September 2024}} and it is in trial with RDSO. It will pull all passenger trains equipped with LHB coaches just like WAP-7 in yet later after a speed trials{{As of?|date=September 2024}}

== Gallery == <gallery widths="150" heights="150" class="center"> File:Palnadu Express at James Street 01.jpg|WDP4 No. 20032 File:WDP4 20014 (SGUJ) NFR at NGC yard 2.jpg|WDP4 No. 20014 File:WDP4 20094.jpg|WDP4 No. 20094 File:EMD GT46PAC - Indian Railways.jpg|WDP4 No. 20006 File:WDP4B 40042 at Jabalpur.jpg|WDP4B No. 40042 File:The WDP-4B class Locomotive of Indian Railways.jpg|WDP4B No. 40068 File:WDP-4B -20047.JPG|WDP4 No. 20047 File:The Indian Railways’ production unit, Diesel Locomotive Works, Varanasi, produces world’s first ever 5500 HP Diesel Locomotive.jpg|WDP4D No. 40122 File:CAB-1 front view - Flickr - Dr. Santulan Mahanta.jpg|WDP4D No. 40086 </gallery>

==References== {{reflist}}

==External links== {{commons category|EMD GT46PAC locomotives}} *[http://www.emdiesels.com/emdweb/international/gt46pac.jsp EMD specification] {{Webarchive|url=https://web.archive.org/web/20110927140646/http://www.emdiesels.com/emdweb/international/gt46pac.jsp |date=2011-09-27 }} *[http://www.emdiesels.com/emdweb/international/indianews/autocarWDG4091009.pdf Autocar India has a detailed profile of the WDG-4 locomotive.] *[http://www.irfca.org/faq/faq-loco2d.html#loco Diesel loco specification at IRFCA website] *[http://www.rdso.indianrailways.gov.in/works/uploads/File/Spec-Twin-Cab-4500HP-publish%2025-Aug-11.pdf Detailed Specifications for the WDP4D] *[http://www.rdso.indianrailways.gov.in/works/uploads/File/Spec-4500HP-2400.43_rev_04_corrted_final_%2026.09.pdf Detailed Specifications for the WDP4B] *[http://trainweb.org/railworld/WDG5/EMD%20TMs.pdf Traction Motor Specifications and Model Numbers]

{{DEFAULTSORT:WDP-4}} Category:A1A-A1A locomotives GT46PAC P-4 Category:5 ft 6 in gauge locomotives GT46PAC Category:C-C locomotives Category:Co-Co locomotives Category:Railway locomotives introduced in 2000 Category:Banaras Locomotive Works locomotives Category:Passenger locomotives