WDP 3A

The WDP 3A is a class of diesel-electric locomotive of Indian Railways. They were manufactured from 1998 to 2001 at Diesel Locomotive Works Varanasi. The WDP-3A was IR's attempt to create a High speed diesel locomotive. The WDP 3A were earlier classified as WDP 2. These Locomotives have air brakes only and the gear ratio is 64:19. They are the Fastest ALCo based locomotives in India with a Top speed of 160 Km/h, making them some of the fastest locomotives in active service in India.

History
Designed during 1998 as a High Speed Diesel Electric Locomotive, WDP 3A are 3100hp dedicated passenger diesel locomotives. They have Twin cabs similar to WAP locomotives. Prime Mover used is ALCo 251C, 4 stroke Turbo Supercharged V16. Turbo Supercharger are of ABB/GE make.All Locomotives feature an electronic governor to control the engine's power output. They Are essentially Heavily Modified WDM 3 with Better Bogies and in a streamlined shell.

44 were Produced by DLW, and more were expected but the arrival of much powerful WDP 4 ultimately put an end on WDP 3A's production.

The first one WDP 3A #15501, was rolled out in October 1998. Initially They were Exclusively used on SR (with Trivandrum Rajdhani) ,some other SR sections(Chennai Egmore - Kanyakumari) and NR.

Rated top speed is 160km/h (in both directions). Two-stage suspension with Flexicoil Mark IV fabricated bogies. All Units are Air-braked.

These Locomotives were earlier Known as WDP 2, and were Later classified as WDP 3A in accordance to new Nomenclature.

Service History
They entered service soon after they were manufactured. During Initial Mainline runs, A Replacement Locomotive was provided in case the WDP 3A failed during journey. They proved themselves useful In SR, Hauling Premium Trains like TVC Rajdhani through Kokan railway at speeds upto 130 km/h. As Locomotives of TVC rajdhani, WDP 3A ran form Kota to vadodra non stop at speeds upto 120 km/h.

They remained exclusive Links to TVC Rajdhani until Their age started to hamper them and were rapidly Replaced by WDP 4Ds and ultimately Electric Locomotives.

They were also Exclusive links to Tejas Express and ran through Konkan railway at speeds of 120 km/h but were removed from job given their Age.

Most of the remaining Units have been Rebuilt and are expected to remain operational for around 10 more years. They are now only used for Passenger and Intercity Services, Expresses being rare.

Given the design of the Locomotive, One driving cab is right in front of the radiator causing that Cab to heat up to uncomfortable levels during Operation. This trait prompted Loco Pilots to nickname it "Toaster".