Abstract: A wheel slip control for DC series wound traction motor vehicles such as railway locomotives in which each traction motor drives an axle and connected wheel set. The control utilizes motor field shunting, also known as field weakening, for providing wheel slip control. Each traction motor has its field shunted by a small percentage, such as 10%, during normal motoring operation. In the event that slipping of a wheel set is sensed by the control system, the motor powering the slipping wheel set is controlled by opening the shunting circuit, causing the motor's armature current and power to be dramatically reduced, thus stopping the wheel slip and allowing the shunting of the fields to be reapplied. This permits the continuous application of a higher aggregate amount of power over previous wheel slip correction methods and apparatus.