First Standard Dual purpose Fire-engine
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EAST HAM'S is the first fire brigade to receive one of the new dual-purpose fire-engines designed and built to comply with the specification set down by the Design and Development Committee of the Central Fire Brigade's Advisory Council.
Fully equipped with hire-fighting gear and a crew of six men, it weighs approximately 8 tons and is capable of a speed of 60 m.p.h. From a standing start, and passing through, the gears, 30 m.p.h, can be reached in 30 secs. The power unit is a Rolls-Royce eightcylindered type B.80 petrol engine, (1.n/eloping 150 b.h.p. at 3,000 r.p.m.
The ignition coils and petrol-pumps are duplicated, one of the latter being mechanical and the other of the doubleacting electric type, .To ensure immediate starting under all weather conditions, the sump oil is maintained in a fluid condition by an immersion heater.
Special high-resistance ignition cables are used in place of the normal hightension leads, which removes the need for separate suppressor equipment on the ignition. Suppressors are, however, fitted to the other electrically operated components.
Engine Cooling System
Incorporated in the engine-cooling circuit is a heat exchanger built into the bottom radiator tank, connected to the main pump and requiring no manual control. During a long spell of pumping with the vehicle stationary, water from the pump is conveyed to the exchanger and back to the pump. The engine-cooling water,. which circulates only round the engine, is maintained at the correct temperature by a thermostat and the heat exchanger.
By adopting this closedcircuit arrangemenh. 'anti-freeze can be 'used, and no water is run to waste round the appliance.
In the design of the body and cab, special attention has been given to driver's visibility and to making the exterior free of projections, All controls, door handles, etc., have been kept B22 within the body lines, and the pump controls and connections, which are in duplicate, are arranged in recesses formed on each side of the body. Various items of fire-fighting equipment are carried in side lockers, of which there are a number on each side.
Provision has been made to carry two hook ladders 'in addition to either a 35-ft. extension ladder or a wheeled escape. Both vertical and lateral adjustment of the escape trunnion-bar are provided so that the mounting position can be varied to accommodate most types of escape now in use. The locking gear for securing the head of the escape is operated from the crew's compartment.
So that the fire officer may keep in contact with headquarters, radio transmitting and receiving apparatus will be carried. Other items of equipment for which accommodation is provided are three sets of breathing apparatus, with replacement gas cylinders.
Within the body structure is a 100gallon water tank which feeds two 1-in.-bore hoses, each of a total length of 180 ft. The hose-reel pump, driven off the power take-off of the main gearbox, is capable of delivering 25 g.p.m. at a pressure of 100 lb. per sq. in.
The main pump, also driven from a power take-off from the gearbox, is of the Dennis two-stage centrifugal type, and when operating from a 10-ft. lift through 16 ft. of 5L--in. smooth-bore hose, can deliver 760 g.e.m. at 100 lb. per sq. in.. pressure, or 650 g.p.m. at a pressure of 160 lb. per sq. in.
The approximate delivery on a 24-fi.deep lift through 32 ft. of 51-in. smooth-bore hose is 400 g.p.m, at a pressure of 100 lb. per sq. in.; the priming time on a 24-ft. lift is 20 secs.
The foundation of the body and cab is ,a hardwood frame, the panelling throughout being in light alloy sheet. The crew is accommodated entirely under eover.
Special Equipment
There are two fire bells. One is operated electrically, and is under the control of the officer or the driver, and the secondis hand-operated from the officer's seat. Amongst the special fittings are twin amber flashing lights, a portable searchlight with 30 ft. of cable, and a spot light which can be worked from the officer's seat. The spot light is used principally for the identification of road signs and hydrant points.
The appliance has Girling-Lockheed servo brakes, which have shown 75 per cent. efficiency. From a speed of 30 m.p.h. the machine can be brought to rest in a distance of 40 ft.
The finish of ate appliance is in fireengine red, with all the polished parts chromium plated. The lettering, of course, is in accordance with the authority's name and crest.
These dual-purpose outfits are being provided by the Home Office for purchase by local authorities in accordance • with Clause 22 of the Fire Service Act. Dennis Brothers (Guildford), Ltd., Guildford, Surrey, was the builder, and the design was evolved by this company in conjunction with the Ministry of Works. The contract covers 70 vehicles of a similar type.