Vosper 46ft FireFloat Mk2

The hull of the 46ft FireFloats, often referred to to as Crash Boats, was of hard chine type, built of double-skin mahogany on birch plywood framing. Bulkheads divided the craft into five compartments: fore peak, fore cabin and wheelhouse, sick bay, engine room, cockpit and after peak. The main engines were twin Rover Meteorite petrol units, developing 375 hp each at 2,400rpm. The units were marinized versions of the Meteorite engines developed for miltary transport. Each engine had eight cylinders of 5.5" bore and 6" stroke, in two banks of four set at 60 degrees, the capacity being, 1,099 cubic ins. The compression ratio was 6-1. Mathway hydraulically operated reverse gearboxes were employed, with direct drive, and the engines were controlled from the wheelhouse. Both engines rotated anti-clockwise. Three-bladed propellers of 19.5" diameter and 17" pitch were used, and with the engines running at 2,400rpm a speed of 28 knots was attained.

Fire fighting was carried out by two 3.5" hand-operated monitors which were suitable for foam or water, each being fitted with a hinged 1" nozzle for use with water. The pumping engine was a Ford V-8, which drove a rotary vane pump manufactured by Sun Enginering (Richmond) Ltd and designed to deliver 2,250-2,500gpm of foam at 1,800rpm or 500-600gpm of water at 500rpm. The same pump, connected to a suction hose, was employed for salvage pumping, the water discharged through the monitors. A spring-loaded towing hook was fitted abaft the engine room casing and was designed for towing a flying boat and had an overload release of 10,000lb. Rescue equipment carried included breaking in tools, line throwing rockets, a crash ladder, stretchers and a portable deck davit with winch.