The underframe is the locomotive's major structural element, comprising a combination of rolled and welded steel plate, topped by an aluminium-steel deck. It bore standard screw couplings and oleo-pneumatic buffers. The underframe also functioned as a mounting point for several pieces of equipment, such as the battery, air reservoirs, and weak field resistances. The traction motors are also fully suspended on rubber brushed mountings; connected to one another in parallel, these motors are fed power via an iron-cored choke to smooth out the supply. If required, any single motor (or pair of motors) can be isolated from the other units. Power from these motors was directed to the bogie-mounted wheels via an Alsthom-supplied drive attached to a universal link assembly. Weight was transferred to the bogies via transverse spring planks mounted to the base of the body support struts. The bogies incorporated a Metrolink swing link suspension system that provided favourable ride characteristics even when travelling at high speeds.