WAG-12B

The WAG-12B represents a major advancement in Indian Railways' freight locomotive technology. Rated at approximately 12,000 horsepower (9,000 kW), it is among the most powerful electric freight locomotives operating on the Indian railway network.

The locomotive was developed as part of a partnership between Indian Railways and Alstom. Production is carried out through Madhepura Electric Locomotive Pvt. Ltd. at the locomotive manufacturing facility in Madhepura, Bihar.

Unlike conventional single-body locomotives, the WAG-12B uses a Bo-Bo + Bo-Bo twin-section architecture. This configuration provides eight powered axles and allows the locomotive to generate very high tractive effort for moving heavy freight trains.

The locomotive has a maximum sanctioned operating speed of 120 km/h. However, freight operations may normally take place at lower speeds depending on wagon configuration, route limits and operational requirements.

One of the locomotive's important technologies is regenerative braking. During braking, traction motors operate as generators and can return electrical energy to the overhead power system instead of wasting all of it as heat.

The WAG-12B is particularly suited to heavy freight operations and India's Dedicated Freight Corridors, where stronger locomotives can move larger loads while improving railway line capacity.

Its combination of enormous power, modern propulsion systems, improved braking and heavy-haul capability makes the WAG-12B one of the most significant freight locomotives introduced by Indian Railways.