Ambi at 11:49, 21 February 2026

2026-02-21T11:49:25Z

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{{Short description|Indian Railway shunter class diesel locomotive}}
{{More footnotes needed|date=July 2019}}
{{Infobox locomotive
| name = WDS-6
| powertype = Diesel
| image = Tughlakabad-based WDS-6 locomotive at Anand Vihar Terminal.jpg
| alt =
| caption = A Tughlakabad-based WDS-6 at Anand Vihar Terminal
| builder = [[Banaras Locomotive Works|BLW]], Central Railway Loco Workshop, Parel
| ordernumber =
| serialnumber =
| buildmodel =
| builddate = 1975+
| totalproduction = '''WDS-6:''' 300 <br />'''WDS-6AD:''' 111<ref name = "BLW - WDS6ADT-1350">{{cite web |last= |first= |date= |title=WDS6ADT-1350 - Shunting Locomotive |url=https://blw.indianrailways.gov.in/uploads/WDS6ADT.pdf |website= |location= |publisher=[[Banaras Locomotive Works|BLW]] |access-date=14 January 2026}}</ref>
| rebuilder = Parel Workshops
| rebuilddate =
| numberrebuilt =
| Britishclass = [[Co-Co locomotives|Co-Co]]
| uicclass = [[Co′Co′]]
| gauge = {{RailGauge|1676mm|lk=on}}
| trucks =
| bogies = ALCO Asymmetric cast frame trimount
| wheeldiameter = {{convert|1092|mm|ftin|0|abbr=on}}
| trailingdiameter =
| minimumcurve =
| wheelbase = {{convert|12.834|m|ftin|abbr=on|frac=8}}
| length = {{convert|16.088|m|ftin|abbr=on|frac=8}}
| width = {{convert|2.864|m|ftin|abbr=on|frac=8}}
| height = {{convert|4.185|m|ftin|abbr=on|frac=8}}
| axleload = {{convert|21000|kg|abbr=on}}
| weightondrivers =
| locoweight = {{convert|113000|kg|abbr=on}}
| fueltype = [[Diesel fuel|Diesel]]
| fuelcap = {{convert|3000|L|abbr=on}}
| lubecap = {{convert|530|L|abbr=on}}, {{convert|630|L|abbr=on}} DLW
| coolantcap =
| watercap = {{convert|22|L|abbr=on}}, {{convert|28|L|abbr=on}} DLW
| sandcap =
| consumption =
| watercons =
| primemover = [[ALCO 251|ALCO 251-D]]
| rpmrange = 400-1100
| enginetype = [[Straight-six engine|Inline, 6-cylinder]], [[Diesel engine|diesel]]
| aspiration = [[Turbo-supercharger|Turbo-supercharged]]
| displacement = 267 mm
| alternator =
| generator = DC
| tractionmotors = 6 DC
| cylindercount = 6
| cylindersize =
| transmission = [[Diesel–electric transmission]]
| multipleworking = 2
| maxspeed = {{convert|71|km/h|0|abbr=on}}
| poweroutput = Max:{{convert|1400|HP|abbr=on}}<br>Site rated:{{convert|1300|HP|abbr=on}}
| tractiveeffort = {{convert|34.0|t|0|abbr=on}} maximum {{convert|16.050|t|0|abbr=on}} continuous
| factorofadhesion =
| trainheating =
| locobrakes = 28LV-1, Air brake for Locomotive using SA-9 brake handle
| locobrakeforce =
| trainbrakes = Originally [[Vacuum brake|vacuum]], or [[Railway air brake|air]], but some modified to [[Vacuum brake#Dual brakes|dual]]
| safety =
| operator = [[Indian Railways]]
| operatorclass =
| powerclass =
| numinclass =
| fleetnumbers =
| officialname =
| nicknames =
| axleloadclass =
| locale = All over Indian Railways, and also leased and sold to some private- and public-sector industrial concerns<ref name = "SAIL - MAINTENANCE OF WDS-6 LOCOMOTIVES>{{cite web |last= |first= |date= |title=METHOD OF PERIODIC MAINTENANCE OF WDS-6 LOCOMOTIVES IN STEEL PLANTS |url=https://www.sail.co.in/sites/default/files/ipss/2020-06/3-02-008-18_0.pdf |website= |location= |publisher=[[Steel Authority of India|SAIL]] |access-date=14 January 2026}}</ref>
| deliverydate =
| firstrundate =
| lastrundate =
| retiredate =
| withdrawndate =
| preservedunits =
| restoredate =
| scrapdate =
| currentowner = Indian Railways, Private industries
| disposition = Active
}}

The Indian locomotive class '''WDS-6''' is a [[diesel–electric locomotive]] used by the [[Indian Railways]] mainly for shunting and also for performing departmental duties. The model name stands for [[5 ft 6 in gauge railway|broad gauge]] (W), '''D'''iesel (D), '''S'''hunting (S) engine, '''6'''th generation (6). As of April 2022, 375 units of this class are currently in use all over India.

==History==
This class was designed in 1975 to address the need for a powerful shunting locomotive with the ability to haul 20- to 24-coach rakes. The previous [[WDS-4]] class was found to be grossly underpowered for this kind of operation. A WDS-6 locomotive basically consists of a [[YDM-4]] powerpack (a 6-cylinder, 4-stroke, inline, turbo-supercharged [[American Locomotive Company|ALCo]] engine) mounted on a [[Indian locomotive class WDM-2|WDM-2]] body frame.
Beginning in 1975, these were initially manufactured solely by [[Banaras Locomotive Works|BLW, Varanasi]], but later, the Parel Workshop started building them using CKD (completely-knocked-down) kits provided by DLW.
WDS-6 units can be easily recognized by their low short hoods (with two cab windows above these) and flat-ended cabs on the long-hood end. Many of them were sold and transferred to private industrial concerns and public sector undertakings (PSUs) in huge numbers, but still display their IR road numbers.

== Locomotive sheds ==
Total Locomotives active as of March 2025 : 270

== Liveries ==
Generally, these locomotives are seen with the typical yellow livery with green/red stripes.

== Technical specifications ==
The technical specifications of WDS-6 are as follows:<ref>{{Cite web|url=https://www.irfca.org/faq/faq-loco2d.html|title=[IRFCA] Indian Railways FAQ: Locomotives -- Specific classes : AC Electric|website=www.irfca.org}}</ref>
{| class="wikitable"
|Manufacturers
|DLW, Parel Workshop
|-
|Engine
|[[American Locomotive Company|Alco]] 251-D, [[Straight-six engine|Inline-6]], {{convert|1,400|hp|abbr=on|lk=on}} ({{convert|1,300|hp|abbr=on|disp=or}} site rating) with Alco turbocharged engine. 1,100 rpm max, 400 rpm idle; {{convert|228|x|267|mm|in|2|abbr=on}} bore x stroke; compression ratio 12.5:1.
|-
|Transmission
|Electric, DC-DC (DC Generator and DC Traction motor)
|-
|[[Traction motor]]s
|GE for original Alco and MLW models, BHEL for DLW
|-
|-
|[[Axle load]]
|{{convert|21|t|abbr=on}}
|-
|total weight
|{{convert|113|t|abbr=on}}
|-
|[[Bogie]]s
|Alco design cast frame trimount ([[Co-Co engine|Co-Co]]) bogies
|-
|Starting TE
|{{convert|34|t|abbr=on}}, at adhesion 27%
|-
|Length over [[buffer beam]]s
|{{convert|17,370|mm|ftin|abbr=on|frac=8}}
|-
|Distance between [[bogie]]s
|{{convert|10,516|mm|ftin|abbr=on|frac=8}}
|}

==Gallery==
<gallery>
File:WDS-6AD locomotive used in Indian Railways.jpg|A WDS-6AD locomotive in the outer area of [[Saharanpur Junction railway station|Saharanpur Junction]]
File:A Tondiarpet-based WDS6 locomotive at Chennai Central Station.jpg|A [[Tondiarpet|Tondiarpet-based]] WDS6 locomotive at [[Chennai Central railway station|Chennai Central Station]]
File:Tughlakabad-based WDS-6 locomotive at Anand Vihar Terminal.jpg|A [[Tughlakabad railway station|Tughlakabad-based]] WDS-6 locomotive at [[Anand Vihar Terminal railway station|Anand Vihar Terminal]]
File:SHUNTING DUTY OF WDS-6AD AT NAGPUR JUNCTION.jpg|A [[Kurla railway station|Kurla-based]] WDS-6AD locomotive performing [[Shunting (rail)|shunting duty]] at [[Nagpur Junction railway station|Nagpur Junction]]
</gallery>

==See also==
* {{section link|Rail transport in India|History}}
* [[Locomotives of India]]
* [[Rail transport in India]]
* [[YDM-4|Indian locomotive class YDM-4]]

===Bibliography===
{{refbegin}}
*{{Hughes-IndianLocos4}}
{{refend}}

==References==
{{reflist}}

==External links==
* [https://rdso.indianrailways.gov.in/works/uploads/File/WDS6.PDF RDSO document for WDS-6] ([https://web.archive.org/web/20190701124918/https://rdso.indianrailways.gov.in/works/uploads/File/WDS6.PDF Archived copy])
* https://www.irfca.org/faq/faq-loco2d.html
* https://www.irfca.org/faq/faq-specs.html#WDS-6
* https://www.irfca.org/apps/locos/list
{{commons category|Indian locomotive class WDS6}}

{{Broad gauge locomotives of India |state=open}}
{{DEFAULTSORT:WDS-6}}
[[Category:Diesel–electric locomotives of India|S-6]]
[[Category:Co-Co locomotives]]
[[Category:Banaras Locomotive Works locomotives]]
[[Category:Railway locomotives introduced in 1975]]
[[Category:5 ft 6 in gauge locomotives]]
[[Category:Shunting locomotives]]

Indian locomotive class WDS-6 - Revision history

Ambi at 11:49, 21 February 2026