PRESENTATION OUTLINE
WAP-4 is a common electric locomotive used in India. It is capable of hauling 26 coaches at a speed of 140 km/h.
The locomotive was developed, after a previous class WAP-1 was found inadequate to haul the longer, heavier express trains (24 - 26 coaches) that were becoming the mainstay of the Indian Railways network. It was introduced in 1994, with a similar bodyshell to the WAP-1 class, but with Hitachi traction motors developing 5000 hp (5350 hp starting).
Electricals are traditional DC loco type tap changers, driving 6 traction motors arranged in Co-Co fashion. This locomotive has proved to be highly successful, with over 800 units in service and more being produced. Newer examples have been fitted with Microprocessor Controlled diagnostics, Static Converter units (instead of arnos) and roof mounted Dynamic (Rheostatic) Brakes.
The locomotive can be seen in service across the electrified network of Indian Railways and are homed at 14 sheds (depots).
WAP 5 is the name of a class of electric locomotive used by Indian Railways. The first 10 locomotives were imported from ABB in Switzerland in 1995. They are supposed to be a variant of the Swiss Lok 2000 (Design Concept) and German DB Class 120 (mechanical chassis). Chittaranjan Locomotive Works (CLW) started production in 2000. It was designed to haul 18-coach passenger trains at 200 km/h (124 mph). It is the first 3-phase locomotive in India.
All locos in the class have been converted to WAP-4. This class was really a variant of the WAP-4 design. One or two prototypes were built early from existing WAP-1 or WAP-4 locos without renumbering. WAP-4 #22212 (formerly a WAP-1) was the first to be converted to a WAP-6; it was provided with Flexicoil bogies and other upgrades. Later this particular loco was later converted back to a WAP-4 (and even refitted with the standard WAP-4 bogies). Curiously, it spent a long time with both class codes WAP-4 and WAP-6 on it. Later, more WAP-1 locos were regeared and provided with high-adhesion fabricated bogies (Flexicoil Mark IV) which are somewhat similar to the Alco Hi-Adhesion bogies. About 16 (perhaps more) of these were built (All in the number series 22400-22416.) Of railfan interest is the fact that some of them reveal their origins in the form of the old WAP-4 class code being still evident -- often a '6' is crudely repainted over the '4' which is still visible.
They were intended for service at 160km/h but failed trials and were restricted to a top speed of 105km/h. They were then used for less prestigious trains such as the Amritsar Exp., Doon Exp., or Janata Expresses.
WAP 7 is a moderate speed high power locomotive developed by Chittaranjan Locomotive Works by modifying the gear ratio of existing WAG 9 class. It is capable of hauling trains at speeds ranging between 140 and 180 km per hour and is now largely used by Northern Railways (NR), South Central Railways (SCR), Southern Railways (SR), Eastern Railways (ER), South East Central Railway (SECR), Central Railways (CR), West Central Railways (WCR). As of November 2013, there are 180 locomotives in service.
