AN APPLIANCE FOR WATERPROOFING ROADS.
Page 62
Page 63
If you've noticed an error in this article please click here to report it so we can fix it.
Details of a New F.W.D. Equipped for Spraying Bituminous Emulsion.
TODERN roads necessitate the employ.131..ment of the most up-to-date appliances, and the materials employed often involve the ass of m-achines built particularly to meet their characteristics: An example of this class is the F.W.D. tank wagon, equipped with spraying • apparatus and designed for Colfix (London), Ltd.
The road material which is to be employed in this vehicle is a form of bituminous emulsion, and special provision th made to avoid any risk of the fine spraying nozzles becoming choked.
The chassis is a standard-4-ton F.W.D., built by the Four Wheel Drive Lorry Co., Ltd., Buckingham Avenue, Trading Estate, Slough, and equipped with a four-cylindered engine of 41-in, bore and 5i-in. stroke, with Bosch magneto and Solex carburetter. An auxiliary gearbox, providing a fourth speed, is fitted between the engine and gearbox proper, and this gives road speeds of 22, 16, 8 and 4 m.p.h. at the normal engine speed of 1,300 r.p.m. From this box a roller-chain drive is taken to a Broom and Wade singleeylindered air compressor accommodated in a casing at the off side of the chassis, and provision is made for engaging and disengaging this drive from the cab as required.
A tank of approximately 1.000 gallons' capacity is mounted on the chassis and given a slight slope to the rear for draining purposes. Towards the rear of the off side of the chassis is mounted a 17-gollon water tank, which serves to supply cooling water for the air compressor, which gives pressures up to 35 lb. per sq. in. An air governor, or relief valve, prevents excessive pressures being generated.
Air is led into the top of the main tank, so that the contents are always under pressure, and it is intended that this pressure should be worked up while the vehicle is running along the road. This dome is provided with a fil c40 ter, through which the emulsion pastes when the tank is being filled, and, to prevent frothing, the filling pipe drops to within 3 ins, of the bottom of the tank. An air pipe can be taken to railway tanks, so that the contents can be blown into the tank of the vehicle.
At the rear of the vehicle is a main cock and a T-piece, having 15 nozzles, through which the emulsion is forced. This cock is controlled by levers Conveniently situated at each side of the chassis: In addition, there are two hose pipes, each 12 ft. long and with separate cocks, which., can be used for coating odd corners, hare patches, gateways, etc. When not in use, these pipes are carried in clips along the sides of the tank.
At the rear of the vehicle, . but forward of the T-piece, is a sheet-metal shield, and the end panels of this can be detached to •reduce the width of the vehicle. Also, when the vehicle is running and not spraying, the two pipes forming the horizontal portion of the Tpiece are detached from the centre pipe and carried in a box at the near side of the tank. Each nozzle is removed separately and carried in . an iron basket immersed in a container of paraffin. This is also carried, alongside the main tank. The paraffin effectively .prevents any gumming-up of the nozzle's.
The height of the 'contents in the tank is shown by a graduatd gauge glass mounted at the rear of the tank. Au ingenious arrangement of the speedometer drive is employed. The ideal spraying speed is, apparently, 1 m.p,b..„ and normal speedometers will_not register this speed; but it is equivalent to approximately 30 yards per minute, so a drive is taken off the engine through a small roller chain and an ordinary speedometer employed. The gearing is so arranged that, when the speedometer shows 30 m.p.h., this is equivalent to 30 yards per minute, but it is only required to record when spraying is actually taking place, and so the speedometer is driven in a similar manner to a tachometer, contact only being made when the main spraying cock is opened. At the end of the day, therefore, it is only necessary to multiply the miles recorded by a constant of 60 to give in yards the length of road sprayed. Several of . these machines are being built ; one for the same company for its Irish depot is arranged to load from barrels. For this purpose the inlet of the compressor has a three-way cock; and the tank calt be exhausted so that it can suck up the liquid, but to avoid the emulsion entering the pump a float is provided in the tank and a rubber cup on this shuts the inlet.
An improvement embodied since we viewed the machine is an air cock on the nozzle-carrying eross-tube to permit sir to be blown through the nozzles for cleaning them before the men lunch, so obviating clogging.