New Fire-engine with 100-ft. Turntable Ladder
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QPECIALIZ1NG in. appliances for the fire services; Merry-weather and Sons, Ltd., Greenwich, London, S.E.10, has now introduced a new form of chassis solely for use with the 100-ft. turntable ladder.
Known as the Merryweather-A.E.C., the chassis basically consists of a modified' A.E.C. Regent Mark II double-decker bus chassis, employing a Meadbi,vs; six-cylindered, 120 b.h.p. petrol:. engine. At present the standard 145-ftt. 3-im, chassis frame is being used with certain modifications, but later rrtodelS will be assembled on frames designed with a. shorter wheelbase:
Power is =unmated through a fourspeed constant-mesh gearbox, modified to enable a twin-drnie power take-oft to be driven off the primary shaft. Mime to the turntable gear and fire pump ia through open propeller shafts frosm the twin, drive.
The turntable equipment, is a masterpiece of engineering; and is made to be foolproof to the smallest detail. P'ower input to the. turntable is through twospeed high and low gearing, which is controlled: by means or clutches actuated by the operator.. From this gearing the power is taken through three double-acting clutches which control the extension, elevation and traverse of the ladder. The four clutches operating the gear are controlled by levers which are based on the principle of thedeadrnanis handle:
An accelerator pedal,, which is coupled to. the engine, providesthe speed variationsrequired by the turn, table equipment. Unlike all rtevious models, the new equipment is arranged' so that the operator travels around on the tabletogether with the controls. The ladder may be elevated, extended' and traversed, at the same time, thus affording rapid operation: In a space of 30 secs. theladder can he fully extended to 100 ft., the fire manbeing carried up as the ladder opens. .During trials on the equipment, the ladder was raised with a load of 715 lb. in 30' sees, and maintained at an angle of 75 degrees from the horizontal. Fabricated from 16.S.W.G. steel, the ladder, an all-welded unit, weighs 2: tons. The fabricated ladder is foundto. have an inherent strength which exceeds that of light alloys.
Foolproof arrangements incorporated irr the design of the turntable equipment ensure that no damage is involved by overloading, and. that the ladder is not at an angle which would be likely, to make the chassis unstable. Refinements includean automatic compensating gear, which corrects the ladder angleshould the chassisbe on a steep camber, telephone and. loudspeaker equipment at the bottom and top of the ladder, and quick-release wide-span outrigger brackets.
Brink Acceleration
On test, the vehicle accelerated from 0to 40 m.p.h. in 30 secs, and reached a maximum speed' of 48-50 m.pth. The total cha§sis weight, together with all equipment, is 9f tons. The test was observedby chiefs of fire' services, both of this country. • and from overseas. Their appreciation. is. shown by the orders for this chassis which. have been received from South America, Scandinavia and the Colonies.
Although the company is busy on theturntable chassis, there is considerable activity on. fire tenders based on four and sis-wheeled chassis. For use in South American oilfields, these vehicles are fitted with a. 1,000-gallon water tank, foam drums and chemical appliances. A particular feature of this chassis is that thefire-pump drive is taken: froma power take-off from therear axle.