Vehicles and Transfer Facilities
The work of a sweeper falls into two main parts:
(i) sweeping, and transferring wastes to receptacle, and
(ii) transporting full receptacle to a transfer point where it can be emptied.
In terms of sweeping, while the first activity is productive, the second is unproductive because it represents loss of sweeping time. The aim, therefore, should be to reduce to the minimum the proportion of time spent on transport.
This can be achieved in two ways: (i) minimizing the distance over which the collected wastes have to be transported, and
(ii) providing the maximum size of receptacle for swept wastes.
Various activities involved in the first approach are described as under: An essential feature of the organization for street sweeping is the provision of a transfer facility within reasonable distance of each beat. The ideal arrangement is for this to be located in the district depot where it is under continuous supervision. It can take many different forms, but it must not be a dump on the ground, which would be unhygienic and costly in manpower for reloading.
The following are systems in common use, and the capacities are based on 40 sweepers each of whom brings in 0.5 m3/day, a total for the district of 20 m3/day:
(i) a side-loaded trailer of 7 m3, exchanged three times a day, and (ii) a steel skip of 4 m3 exchanged five times/day by a skiphoist vehicle.
There is an alternative to the provision of transfer facilities for sweepers: this is to arrange for every sweeper to be visited about four times a day by a vehicle into which his full bins are emptied. The system requires very careful routing and the observance of precise timetables by sweepers and vehicles to ensure rendezvous without tedious searches. It has the advantage that the sweeper is able to devote the whole of his time to sweeping, but it does not eliminate the need for the other depot facilities such as welfare and handcart parking.
The second one which has been seriously neglected in many cities and towns. Often sweepers are given baskets for the transport of street wastes, as a result of which they spend most of their day walking to empty the basket instead of sweeping. The best solution is a handcart, the gross weight of which may be as much as 50 to 60 kg in level areas and less in hilly areas.
The handcart design should avoid the need to empty the cart on to the ground at the transfer place, because this would create the unnecessary task of shovelling wastes into another vehicle at the time when the wastes is to be delivered to the disposal site. A better method is to equip the handcart with a number of portable receptacles that can be lifted off and emptied by one man into a transfer facility serving a number of sweepers.
The desirable features of a handcart for use by a single sweeper are as follows:
(i) frame of light tubular steel, or angle, supporting a platform on which are placed two or more portable bins,
(ii) wheels of large diameter, with rubber tyres, preferably pneumatic, ball or roller bearings, (iii) the portable bins should have a capacity of 30-40 litres each, according to the density of the wastes, (iv) brackets should be mounted on the frame of the handcart to carry three brooms and a shovel.
11.5.5 Hand-Carts/Tricycles
Each sweeper engaged in street sweeping should be given a handcart having 4 to 6 containers or a tricycle having 8 or more containers of 30 to 40 liters
capacity each as illustrated below, for ease of handling. These containers should be detachable to facilitate the direct transfer of street sweepings and household waste from the container into the communal waste storage bins. Such containers should lockable with a chain arrangement. The handcart should have at least 3 wheels ball bearings so that it can be used efficiently. A typical sketch of six-bin handcart arrangement is shown in Fig. 11.3.
A detailed drawing of a new Handcart (M.S. Wheel Barrow) is shown in Fig. 11.4 and their specifications are given in Table 11.3.
A detailed sketch of Polyethylene Container to be used in the Handcart (M.S. Wheel Barrow) for collection and transportation is shown in Fig. 11.5.
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