In the early 1980s this transmission was developed for urban buses in the UK as the "Maxwell", with a four-speed gearbox. UK buses are mostly double-deckers with rear-mounted transverse engines. Their use also involves much stop-start driving, thus heavy clutch wear for conventional gearboxes. The advantage of this arrangement was its use of four clutches, all easily serviced from outside the engine assembly, without needing to remove the engine. The clutches were multi-plate oil-supplied wet clutches. The first gearboxes gained a reputation for unreliability and in 1985 the original developers, Brockhouse, licensed them to Avon Maxwell Transmissions. A developed version, with an enlarged oil pump, was available as a retrofit for most UK buses. An unusual feature of this gearbox was the ability to engage first and second gear simultaneously. This acted as a 50 hp hydraulic retarder.