The Street Washer as a Defence Unit
Page 48
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AT the Cleansing Conference, held at Portsmouth last June, attention was drawn to the possibilities of utilizing cleansing vehicles as important units in the defence scheme in the event of war. It was shown that various types of vehicle, in general use by municipalities throughout the country, could quickly be converted from their peace-time work to the important function of decontamination and the dispersal of poison. gases.
On Monday last, Scammell Lorries, Ltd., Watford, demonstrated to Government and municipal officials its new municipal street washer, which is equipped with auxiliary apparatus for dispersing poison gas, also with fire; fighting appliances. The machine is a development of the concern's wellknown 1,250-gallon street washer, which is used in conjunction with the Scammell mechanical horse.
The tank is of frameless construction, and, when it is likely to be used in conjunction with disinfecting agents or neutralizing solutions, special coatings for the inside of the tank are available. Salient features of the street-watering apparatus include two sprinkler heads, one on each side of the vehicle, these being connected to a valve, which allows either the top or the bottom, or the whole, of the sprinkler orifice to 'be used at will ; a total effective spray width of 90 ft. is obtainable.
Four street-washing jets are mounted obliquely under the tank, and are arranged to wash towards the near-side kerb. Separate shut-off cocks allow for individual control. Behind and parallel to the street-washing jets are five squeegees. In addition, a reel housing 60 ft. of rubber hose is also a standard fitment.
The pumping unit comprises a fourcylindered petrol engine, which. is c 10 coupled to a 3-in. by 2-in, single-stage volute pump. The pump is capable of delivering 220 gallons per minute, and pressures up to 120 lb. per sq. in. are obtainable.
Poison-gas dispersion jets are fitted to the sewer-flushing point on each side of the machine, and, with four jets, a fantail of water is obtained, which completely surrounds the vehicle, it being possible to disinfect an area 70 ft. wide by 35 ft. high. This corresponds to a capacity of 1,054,044 cubic yds. with one tank full when the vehicle is travelling at 12 m.p.h.
' At the demonstration on Monday last the effectiveness of the machine when engaged on its peace-time occupation of street washing was shown. Then followed the procedure to be adopted in decontaminating streets following a gas attack. After sprinkling, the roads are washed under low pressure and, where chloride of lime or bleach has been applied, the squeegees, used in conjunction with the washing jets, are an effective means for cleaning the street surface. The third sequence is the flushing of the chemicals through the gullies and, whilst this would normally be undertaken by connecting up to hydrants, the value of the Scammell machine, in cases where the water main has been broken, was clearly shown.
For dispersing non-persistent gases, the use of overhead sprays is recont mended, and the four fishtails, which are interchangeable with the standard washing jets, provide, as previously mentioned, a fan-shaped sheet of water.
The first-aid hose is also of value in decontamination service, for washing the-sides and window sills of buildings. etc. Used in conjunction with a portable foam-making branch, it can also deal with chemical or petrol and oil fires. Thus, the machine, in addition to its normal duties, can become a useful mobile fire-fighter.
To conclude the demonstration on Monclay last, the efficiency of the machine, when used as a fire-fighter, was put to the test. A pit, 30*ft. in diameter, was filled with 200 gallons of oil and ignited. The street washer was coupled to a No. 2 Pyrene foammaking branch, and the conflagration extinguished in under a quarter of a minute.