aluminium outer shell and interior walls with a timber layer sandwiched between. Access to the power compartment was achieved via a centrally-mounted door in the rear bulkhead behind the driver's position. The driver's position is outfitted with a pre-fabricated control unit that featured the majority of controls, gauges, indicators, and instrumentation required. Excellent external visibility was provided via relatively wide forward and side cabin windows; both wipers and electrically powered demisting apparatus were also installed upon the forward windows. Various measures for operator comfort were also included, such as an upholstered adjustable seat for the drive, numerous heating units, and a compact cooker for traincrews to prepare meals upon. 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. Operational history Upon the type's introduction, all AL2 locomotives were allocated to Longsight depot. During 1966, the final locomotive to be built, E3055, was destroyed by fire at Maw Green, leading to its withdrawal. The first locomotive built, E3046, was also destroyed by fire while north of Bletchley, on 7 January 1971, and similarly withdrawn early. Changes E3049 was the first to be refurbished with a silicon rectifier, replacing the mercury-arc rectifier; its refurbishment was completed during 1972. The rest of the class followed suit over the following years. Under the TOPS system, the type were reclassified as 'Class 82', while the individual locomotives were renumbered sequentially from 82001 to 82008. Withdrawal Following the introduction of newer electric locomotives, such as the British Rail Class 87, BR planners decided to withdraw the