Roylecraft Amphibious Jet Bus

The Roylecraft Amphibious Jet Bus is a 12-metre amphibious passenger vehicle developed by Covelink Marine Ltd of Staindrop, County Durham, England. It was the result of a programme begun in 1987 by David Royle. He listed the requirements for a fast, efficient and safe amphibian, studied why earlier designs had performed poorly, and then built and tested prototypes in the workshops of his specialist vehicle company. Four prototypes followed: 1988-1990, 1990-1992, 1993-1997 and 1998-2000. The company acknowledged funding from NESTA, the National Endowment for Science, Technology and the Arts, for its high-speed amphibian development.

Design

The Roylecraft vehicles combined automotive and marine design. They had retractable wheels, waterjet propulsion and their own steering systems. Covelink chose waterjets because the lack of exposed propellers makes rescue work safer and allows a shallow draught. Hulls were aluminium for strength, light weight and corrosion resistance, though GRP or composites could be used in volume production. Standard hulls kept costs down, a low-wash design reduced bank erosion on inland waters, and raw-water and air-cooled heat exchangers allowed use in hot climates. The controls were laid out for single-handed operation by a driver with some marine experience.

Jet Bus

Factory production of the Jet Bus began in 2002, with four under construction, intended for rivers and canals (Category A waters). Road and marine certification was still being sought in the UK. The bus is 11.6 m long and 2.51 m wide, has a diesel engine driving four wheels, and seats 28 passengers. Quoted speeds are 60 mph (97 km/h) on land and 15 mph (24 km/h) on water. A Series II for Category B and C waters, with a similar specification, was planned for 2004.

Proposed uses

Covelink listed a wide range of possible roles, including flood rescue, ship's lifeboat or shore boat, island and river ferries, cruise-ship excursions, sightseeing, police, customs and anti-smuggling patrols, oil-pollution control, airport rescue, water ambulance, hydrographic survey, and military use as a DUKW replacement.