THE CLEANSING OF MODERN STREETS.
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How The Up-to-date Motor Washing Machine Effects the Cleansing of Road Surfaces in Cities and Towns.
WITH THE advent of large numbers of heavy transport vehicles in recent years, the nature and construction of the streets in towns have undergone a complete change. This has been necessitated by the terrific wear and tear imposed upon them by the rapid passage of these vehicles, particularly those shod with solid tyres.
With the co-operation of firms specializing in this class of work, highway surveyors and engineers began experimenting with different materials to produce a type of road that would stand up reasonably well under the strain imposed upon it. One of the things that have evolved after various trials is the asphalt-surfaced road, which is now used to a large extent. Although somewhat -expensive in construction, it has been found to give very good results in prolonged use.
Owing to the enormous increase in traffic, particular attention has to be paid to the cleansing of these roads, especially when the surface is wet, the deposit thereon being churned into a mixture with the consistency of grease. The surface, being smooth, soon becomes more or less like a skating rink, involving skidding and consequent accidents. Extensive building operations being carried out in many places also contribute to this cause, clay being dropped from the wheele of vehicles engaged on this work.
Using Water as a Sweeping Medium:
The continuous drizzle experienced during the winter months aCce,ntuates this state of affairs, the fall of rain being insufficient to wash the grease away. It is, therefore, clear that measures have to be taken to remove this unpleasant deposit, in the interests of cleanliness and public safety. Intensive swilling with water has been found the best method of attaining this end, either by means of hosepipea connected to hydrants at the side of the street, or by the use of motor vehicles—a method which is rapidly gaining favour with municipal authorities. The former ease entails a good deal of labour, with consequent expense, and can only be carried out when the streets are clear of traffic—usually in the early hours of the morning. With the use of motor vehicles, a eertain amount of. washing can be done during the day, whilst only two men are required instead of a gang, resulting in lower working costs.
The outfit consists of as large a,tank as possible, mounted on a lorry chassis, on which also is arranged a pump driven from the engine and fitted with suitable delivery nozzles. The tank is mounted on longitudinal steel bearers, evenly distributing the load over the whole of the chassis. This practice eliminates the occurrence of rivet leaks due to straining, which are common on machines of this type where the hearers are placed across the chassis.
A filling bend, connected with a suitable length of hose for attaching to the hydrants, is placed at the centre of the tank, at the rear end, enabling the machine to fill from either side of the street without turning round. A detachable strainer is incorporated in this bend to prevent stones; which may come through with the water, from choking the delivery nozzles. This is very necessary, particularly where sea-water is used, a surprising amount of stones and shells coming through the hydrants.
The pump, constructed throughout of gunmetal, is mounted on an extension of the sub-frame in front of the radiator. A cone clutch engaging with a small flywheel on the front end of the crankshaft provides the drive, giving maximum efficiency, no gears or chains whatever being used. .A lever in the drivers cab operates the clutch, which is a distinct advantage, as it-enables the pump to be put in and out of action while the machine is in motion..
The washing heads are arranged in front of the dumb-irons, the delivery nozzles 'being in the shape of a fan, situated as near, the ground as possible. In this way full pressure of the water is brought.. upon the roadway, thoroughly loosening and removing the deposit. An important feature is that the nozzles can be independently -turned in any direction,when
• in operation. When the centre of the road has been cleansed, the machine4goes along the side with the nozzles turned sideways, sweeping the grease into the gutter. A
pressure of 80 lb. per sq. in. is delivered upon the road when washing, showing the eincae. ney of the pump. A length of delivery hose can be attached to the pump for washing down places where it is not easy to rnanceuvre the machine, such as yards, courts, etc. The pump is also capable of filling the tank from natural sources, at the rate of 203 gallons per minute.
If required, the washing nozzles can be quickly detached, a pair of heads for watering mirposes taking their place. The latter practice is not in much use to-day, gutter flushing only being done, a gravity-fed pipe for which is situated on the near side of the vehicle.
A special means of fixing allows quick interchangeability of the tank with a body, giving the machine a greater sphere of usefulness. Many councils will not consider the purchase of such a machine unless it can be used for several purposes, chiefly on the score of economy.