The Indian locomotive class WAP-6 was a class of 25 kVACelectric locomotives that was developed in the mid-1990s by Chittaranjan Locomotive Works for Indian Railways. The model name stands for broad gauge (W), AC Current (A), Passenger traffic (P) locomotive, 6th generation (6). They entered service in April 1996. A total of 17 WAP-6 units were built at CLW between 1995 and 1998.
The WAP-6 were intended to be the faster variant of the successful WAP-4, but failed trials and were restricted to a top speed of 105 km/h. Now all units have been converted to WAP-4 specifications. All were homed at Asansol (ASN) shed but after conversion reallocated to Howrah (HWH) shed.
This class was a variant of the WAP-4 where Co-Co Flexicoil Mark 1 cast bogies of the usual WAP4 was replaced by Fabricated Flexicoil Mark IV bogies. All other specifications were same as WAP-4. WAP-1 unit no. 22212 was the first to be rebuilt into a WAP-6. It was provided with Flexicoil bogies and other upgrades. Then it was rebuilt into a WAP-4. Later, more WAP-1 units were re-geared and provided with high-adhesion fabricated bogies (Flexicoil Mark IV) which are somewhat similar to ALCO hi-adhesion bogies. They were intended to reach 140 km/h (87 mph) but failed to do so in trials and were restricted at 105 km/h (65 mph). Two units,i.e., 22406 and 22408 are upgraded with better wheel-sets. This class was an unsuccessful one. All have been converted back as WAP-4. About 16 of these were built (All in the number series 22400–22416.).[2]
Axle-hung, nose-suspended, force-ventilated, 3,485 kg (7,683 lb), 630 kW (840 hp), 750 V, 900 A, 895 RPM, parallel grouping, C class armature and field, temperature rise (Armature 60, filed 70 and commutator 85) in °C, coil resistance (armature 0.01284 ohms+10%, field 0.01184 ohms+10% and commutator 0.00907 ohms+10%, air gap main pole 6.35 kVA, air gap inter-pole 10 mm (0.3937 in)