Experiences in Five Important Areas
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first essay. "Collection of Refuse with Petrol TElicles," is by Mr. R. C. Thomson, Wallasey. He says the cleansing service would appreciate more help from the public, and to speak about cleansing transport without referring to refuse receptacles is putting the cart before the horse. There is a firm of partners operating an immense business—the local authorities and the vehicle manufacturers.
Almost dustless loading is now employed, but it will not be possible to make it perfect until the householder takes an intelligent interest in the subject; people will over-fill special dustbins. When propaganda effects a reduction in the bulk and weight, the application of dustless loading will be generally introduced.
The householder demands that his dustbin be emptied regularly at a definite time. Nothing upsets house refuse collection so Much as irregularity.
There is no advantage in setting out a list of reasons why petrol vehicles may be considered better or worse than any other type in this service. There is a definite place for the petrol vehicle under certain conditions which are remote from those concerning the operation of electric or horsed vehicles. The petrol vehicle has no limit to its working capacity, and it has no rival in its adaptability and mobility.
The standard chassis, with a special body, on good roads will give a minimum life of five years up to a maximum of eight, but, if used for work for which it was never designed, then the user may be disappointed. The petrol vehicle specially designed for house and shop refuse collection will give a more sustained performance and higher efficiency; the life should be a minimum of eight years.
Chassis are designed to take loads of 7 to 18 cable yds., ranging from if ton to 5 tons. All chassis are built for low loading, the wheels having 27-in. by 6-in. pneuniatics. A 10-cubic-yd. body will carry two tons, with an unladen weight slightly over three tons and £50 tax. Is it not possible for makers to reduce the weight to slightly under three tons? This would save £15 per annum, or, in eight years, a total of £120.
The petrol engine stands up well on continual stopping and starting, and an engine may be replaced in two hours. Particular attention should be paid to petrol consumption. The average return of a 10-cubic-yd. vehicle is 6 m.p.g. on collection and 12-14 m.p.g. on long runs. If the engine be stopped and started after every second or fourth house, the figure is probably 9 m.p.g., but the starter battery will have a short life.
Drivers' cabs deserve more consideration; they should be fully enclosed. The author would like more standardization in refuse bodies. A difficulty with the tractor type is that it is not so suitable for tip work. In the North, for narrow passages, 2-ton 7-cubic-yd. vehicles are successful. The 15-cubic-yd. vehicle has possibilities for getting through a large part of the district in a day. The mechanical horse, with 18-cubic-yd. trailer, is eminently satisfactory where it B36 is not possible to have a relay system, where the refuse is bulky and the roads good.
The author is satisfied that there is one type which is a great improvement upon any other, subject to the following conditions :—(1) Disposal at works or controlled tip; (2) collection districts within a one-mile to four-mile area; (3) relay system for two vehicles in each district; (4) straightforward refuse collecting. It is of 10 cubic yds. capacity and has rear-barrier loading.
Mr. W. H. Andrews, in his essay on the "Collection of Refuse with Electric Vehicles," says the impression is prevalent that electric-vehicle traction is in its infancy, but it has progressed past its embryo stage and is exceptionally efficient. Vehicles nearly 20 years old are giving satisfaction. In January, 1933, the Institute gave the numbers of cleansing vehicles as follow —Petrol, 1,669; oilers, 26; steam, 126; electric, 534; petrol tractors, 50; steam tractors, 40. Total, 2,408.
In refuse collection the ratio is at least two petrol to one electric, which is a matter for surprise and disappointment. There are indications that the advantages of the electric are being realized. It is silent, emits no noxious gases, runs on home-produced "fuel," and compares favourably in price. The fire risks are negligible and road accidents less. Reasons for the reliability of electrics are that all moving parts rotate,. gearing is almost eliminated, transmission wear is negligible and, when stationary, all working parts are at rest.
The author quotes some costs from The Commercial Motor dated March 9, 1934, showing costs slightly in favour, of electrics, which pay lower tax than the petrol vehicle.
Lead-plate and nickel-iron batteries give satisfactory service, but it is advisable to standardize on one type, because of the different treatment required by each. At Birmingham the average life of lead batteries is over three years, and one of the largest makers in the country gives the average life of its batteries as 39.6 months.
Where current is generated at incineration plants, the cost averages id. per unit; elsewhere it can usually be purchased at Id. per unit, when the average cost for the 3-tonner should not exceed 1.5d. per mile.
The makers of electrics have been enterprising; the vehicles may have dustless loading, barrier loading, selfpacking and moving-floor bodies. The author admits the superiority of the internal-combustion engine for certain sections of cleansing, and uses them for such work as cesspool emptying, manure and stores delivery, and the disposal of clinker.
The cleansing superintendent of Liverpool, Mr. 'I'. A. Short, deals with the "Collection of Refuse with the Container System." He is an advocate of horsed vehicles for house-to-house collection, but recognizes the value of power vehicles for conveying the collected refuse for diaposal. He claims that the most economical results can be obtained by using each type of machine in the capacity for which it is best suited. This is exemplified by the container system. It is a matter of opinion whether the hygienic value of entirely dustless loading justifies the extra cost, compared with the semi-dustless variety, such as the canopy container. If is not always possible to synchronize loading with the journey to and from disposal, but this should be the aim; the relay vehicle should arrive back to the collectors when the paired conveyance is loaded. The arrangement of three vehicles serving two gangs is the most economical, and large-capacity vehicles most suitable.
Disposal for incineration is costly, for vehicles usually wait to discharge. Horse-drawn vehicles at destructor and tip impede quicker-moving motors; the horse on tip work is decidedly inferior to the motor. The ordinary motor with low loading has small wheels, militating against speed and manceuvring at tips. Insufficient clearance may cause embedding in soft ground, and it cannot always discharge its load in the position required. This objection cannot be advanced against the container system, as the motor has large wheels and excellent manceuvring power The costs per ton for conveyance to controlled tips in Liverpool for the year ended March 31, 1933, were: Horse, 2s. 1.19d.; motor, Is. 4.19d.; container system, Is. 2.85d. The Liverpool fleet consists of seven petrol, 15 oil-engined vehicles and 90 containers; two of these vehicles are held in reserve.
Mr. C. Boden deals with Stepney's experience of largecapacity vehicles with moving floors. A vehicle was designed with a drop platform at the rear, giving a loading line of 4 ft. 2 ins., the platform being a few inches higher than the kerb, enabling collectors to step from the footway on to the platform. The depth below the loading line is 3 ft. 4 ins., and the capacity 15 cubic yds. Inside is a wooden barrier suspended by an enclosed 3-in, track, and an apron is fixed to the barrier, being connected by links riveted in the apron and drags on the floor.
In loading, the collector empties refuse over the rear door into a compartment bounded by the movable barrier and door; loading continues until this is full. The collector then winds the floor (with the barrier) forward, taking with it the refuse and leaving space at the back to receive more refuse.
Refuse in the first section tended to slip, owing to the floor angle of 15 degrees, but five drags, each 7 ins. long, were fixed to the floor at right-angles. The reverse process to loading applies to discharging. The rear door, suspended by spring tension front the top of the body, can be raised. The average weight of refuse collected by moving-floor vehicles is 3 tons 2 cwt. per load, without compression.
Compression can be' achieved by operating the floor in the reverse direction partly laden, the movable,barrier compressing the refuse against the rear door. By compression, the carrying capacity would increase 25 per cent.
The author is convinced that, in a hand-propelled floor, it is essential that loading and unloading should be conducted by handles at the front, for otherwise, when discharging against a wind, the operator might be covered with refuse. The cost of maintaining floors compares favourably with end-tipping gears.
It is obvious that, with modern, lighter refuse, some method of increasing the weight per cubic yd. must be introduced. Even the introduction of cartons to replace milk bottles preeents its problem.
The use of the rollei shutter offers certain advantages in regard to loading space, but these are somewhat discounted because dustmen will enter the body to pack and tread the load. Some form of mechanical packing device is necessary. High-angle tipping and archimedeari screws are old and tried methods, but neither device exerts pressure to increase the density. Of recent years a step forward is the introduction of the Pactum, which has an action similar to that of a power-driven baling press. Experience with this packing arrangement showed 50 per cent. greater weight per cubic yd.
Moving-floor and barrier-type vehicles are rear loading if full use be made of the body space, but this slows the work, due to the restricted space, and with the barrier type the loaders must enter the vehicle. To compress effectively, the refuse must be placed under pressure and maintained in that condition.
The application of hydraulics to loading need have no terrors for the non-technical, the only difference between tipping gear and refuse compressor is that one elevates the body and the other 511s it. Both are rams, similar in design and operated from the same pump.