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Should ELECTRICS Be IGNORED?
Page 58
Page 69
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By Anthony Ellis
WHY has the battery-electric vehicle been neglected so long for house-to-house refuse cellection? Apart from a handful of cleansing authorities using electric vehicles, petrol and oil engines, which are not ideally suited for this type of operation, reign unchallenged.
In urban areas at least, where mileage to and from the start and finish of the collecting run is normally small, the battery-electric with its smooth acceleration, ease of driving, silence and cleanliness offers marked advantages.
Admittedly, the electric is inferior to internal-combustion-engined vehicles in performance, but in our congested cities where the average speed of traffic flow ranges from 8-12 m.p.h., there is little point in having refuse vehicles with top speeds of over 40 m.p.h. as is commonly the case. In congested areas, the 10-15 m.p.h. electric will not be far behind.
A more serious disadvantage is the limited range and consequent inflexibility of the electric. However, refuse collection is normally carried out on carefully observed schedules into which a 'batteryelectric with a range of 20-30 miles could be accommodated without undue difficulty.
Charging Tune
Intensive employment of electric vehicles presents problems, as about 12 hours out of each 24 must be allocated to battery charging. Thus, if a vehicle is to be used more than 12 hours a' day. it is necessary to have stand-by batteries. As traction batteries for a large electric vehicle may well cost £500, this can be an expensive provision.
Expense, of course, is one of the factors which has weighed most heavily against the electric vehicle. Initial capital cost, including batteries and charging equipment, is bound to be higher than that of comparable internal-combustionengined vehicles. Yet there is no doubt that the electric can recoup this extra capital during its long working life.
1324 Both Westminster City Council and the Royal 'Borough of Kensington have been using electric vehicles for refuse collection since the mid-30s. The Morrison units used by Kensington, most of which were acquired in 1937, have been taken out of service only during the past year, not because they were worn out but because of changing operational requirements.
At Westminster the original ElectricarScammell mechanical horses have now completed about 25 years' service. Replacements arc now being sought for them, largely because of the impossibility of obtaining certain spare parts, such as axles, for these chassis. The depreciation period for petroland oil-engined vehicles in the Westminster fleet is normally seven years. . .
Both authorities suggest that maintenance and running costs of their electric vehicles have been much lower than those for petroland oil-engined units in their fleets.
The batteries, which normally last longer than their four "ear' guaranteed life (Kensington expect them to 'remain efficient for seven years with careful maintenance) can be regarded as fuel purchased in advance and can be included in the fuel cost. It is reasonable to assume that the electric vehicle's overall running costs might be.30 per cent. 'less than those of a comparable oil-engined unit.
Chassis maintenance is reduced by the simplicity of the motor, the elimination of the clutch and gearbox, and the reduction of stress on the chassis and body arising from the low speed of the vehicle and the almost complete lack of vibration.
The motor, in particular, requires little attention and those fitted to the West:. minster Electricars are destined to be transferred to new vehicles when these are obtained.
Adding to the high initial cost of large battery-electric vehicles is the absence of ready-made designs. Westminster and Kensington have both been forced, in their search for replacement vehicles, to persuade individual manufacturers to produce special vehicles for them.
Kensington's relatively simple need for a tractor capable of hauling 9-ton gross train loads was met by the Karrier Bantam motive unit converted to electric traction by Smith's Delivery Vehicles, Ltd. No extensive chassis modifications were required, whilst the batteries were slung outside the chassis longitudinals between the back of the cab and the rear wheels.
Adequate Axle
Even the standard Karrier low-ratio rear axle proved adequate for the new model. Because the Karrier chassis is so suitable, the electric version costs less than £500 more than the petrol-engined model.
By using a relay system, Kensington employ the electric tractors solely for actual collection work. Apart from going out to the start of the collection route in the morning and returning to the depot at night, they do no extensive non-stop mileage.
The barrier-loading semi-trailers used with them are exchanged when full for an empty semi-trailer which has been brought into position by a petrol-engined tractor. The latter vehicle then takes the 1 laden semi-trailer to t1 e disposal point. Thus, the electric tr ctor's maximum (Continued on page 619) speed of 10 m.p.h. is entirely adequate and its range is conserved for the work to which it is most suited.
With simple barrier-loading semitrailers, there is no problem of supplying power for the operation of the body. However, Kensington also have a number of container-loading semi-trailers which incorporate hydraulic lifting mechanism. To avoid the complication of taking power. from the traction batteries to operate this mechanism, the semi-trailers carry their own batteries to power the electro-hydraulic gear.
Westminster use Eagle Compressmore semi-trailers with their electric tractors. These bodies require high power to operate the hydraulically actuated compression barrier. In this case, power for thesemi-trailers' eleetro-hydraulic system taken from the traction batteries on the tractor. These are larger than they would., otherwise be to provide extra capacity.
Unlike Kensington's, the Westminster vehicles carry out all phases of refuse collection, but mileage running to and from the disposal point is reduced by the capacity of the compression vehicles (26 cu. yd.) and the relatively compact area covered.
Intermittent Power Whilst it is feasible to supply extra capacity in the main batteries to operate a . refuse body which requires power intermittently, it would probably be impracticable to make similar provision for a continuously operating compression mechanism such as the Kuka and Haller rotary designs.If these bodies were fitted. to a battery-electric chassis they 'could be driven by small auxiliary engines.
Westminster have not confined their use of electric power to refuse collection only. This authority has what are thought to be the only electrically powered gully and street watering units in existence. The semi-trailers on which this equipment is fitted carry separate sets of batteries to power the electrohydraulic mechanism.
Pulled by electric tractors, these semitrailers can carry out their work in almost complete silence. This is regarded as essential as watering has to be carried out in the early morning in residential areas. This consideration applies also to refuse collection, early morning rounds being increasingly favoured to avoid daytime traffic congestion. Residents in the area covered by Westminster Cleansing Department are indeed fortunate and the authority's example could well be followed by others.
Westminster's requirements for new vehicles to replace their existing Scammells have proved more difficult to meet than the needs of Kensington. The tractors specified had to be capable of pulling gross-train weights of '15 tons,
albeit over; fairly level • terrain: No standard chassis appeared 'suitable for adaptation and it was recognized that a special model would have to be devised.
Seddon Prototype The only prototype obtained • so far, which was shoWn at the_ Institute of Public Cleansing Conference • in 1959, was produced by Seddon Diesel Vehicles, Ltd., who provided the chassis. and cab only. The electric motor -used ,was taken from one of the existing . ElectricarScarnmells and fitted to the vehicle in the cleansing department's workshops.
Although the attra'ctive Seddon design has not been ordered in quantity yet, it is an indication that specific demands for electricvehicles can be met without too
great difficulty. . • •
It is interesting that the isolated cases of demand for large battery-electric vehicles which have arisen in recent years have been met, in the first instance, by manufacturers of internal-combustion
engined vehicles. The electric-vehicle industry have not taken these opportunities to extend their activities—and who can blame them?
The localized structure of public cleansing in this country has led to the use of an extraordinary diversity of equipment. The total lack of standardization and excessive individuality apparent in this field make it extremely difficult. for anyone to assess a general
demand. .
Risk Unacceptable It would be an unacceptable risk for a manufacturer, well versed in constructing electric delivery vehicles for payloads up to 2 tons, to embark on developing a chassis suitable for refuse collection on the-strength of an order for a handful of prototypes.
However, it is encouraging that there are new electric vehicles available. Now that cleansing authorities who have changed to oil-engined vehicles have experienced greater capital outlay to improve long-term economy, it may be that when their new oil-engined vehicles reach the end of their useful life, they will be replaced by electric vehicles.
Meanwhile, developments in electrical storage methods could result in more compact, lighter batteries giving better performance and range to increase the attraction of the battery-electric. Even in the past year the Exide Ironclad battery with Gauntlet plate construction has come on the market. This battery, compared to conventional types, can save about 30 per cent. in space and weight.
Servalco Motor
A fillip for the battery-electric may be provided by the novel Servalco printedcircuit motor. This unit, which is more simple than conventional types and easier to manufacture, should be cheap. It has a relatively large diameter in proportion to its length and, as it is suitable for slowspeed operation, could be mounted within the wheels to simplify transmission requirements.
Whilst the Gauntlet battery is in use and the Servalco motor should be available shortly, fuel cells which, when fully developed, could provide a tremendous boost for the electric vehicle, are still in the early experimental stages. These units, which convert chemical energy direct into electrical energy at . a very high efficiency, are occupying research teams both in this country and the U.S.A.
It is thought that cells using hydrogen as a fuel may be available for special applications in five to 10 years, but that they will require a great deal more development before they are small and powerful enough to be used extensively in road transport.
These developments indicate that the evolution of the battery-electric vehicle is far from stagnating and, indeed, may make important advances within the
next decade. For public cleansing it should be, regarded as a serious and attractive competitor to other prime movers.