Electrics Don't Loaf, says Hovis O VER all other forms of
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transport, the battery-electric has one distinct advantage—that, owing to its reliability and freedom from breakdown, it is'available for work more days in the year than any other type. That is the opinion of Captain C. F. Roberts, M.C., M.I.T.A., transport manager of Hovis, Ltd., and figures are available to substantiate it.
This company has been operating electric vehicles since 1912, and its fleet now includes a Garrett 6-tonner, a Walker tractor and five Walker 5-tonners, the Edison shown in an accompanying picture being no longer in service. The batteries employed are of D.P. and Edison make, both leadacid and alkali types being used.
Experience has shown that whilst the life of the lead type is 4-3 years, batteries of the nickel-iron type last 8-9 years. Neither retains its full capacity throughout the whole period, but the falling-off can be minimized by care in
charging and servicing. Lower consumption and less need for maintenance are characteristics of the acid battery. The alkali equipment requires more frequent additions of distilled water and renewal of electrolyte, which is
rather expensive. Also, its internal resistance is higher. On the other hand, it will stand more overcharge and requires less attention as distinct from maintenance.
Some of the older vehicles operated by Hovis, Ltd., serve to demonstrate the undesirability of inaccessible batteries. This is a fault that has been remedied by makers of modern machines, and it is an important point, because inaccessibility leads to neglect. Charging of the Iiovis fleet is carried out by two motor-generator sets. One was supplied by the Lancashire Dynamo and Cryptv Co., Ltd., and delivers current at 70-130 volts and 300 amps. The other is a product of the Macfarlane Engineering Co., Ltd., and supplies current at the same voltages up to 385 amps. Both are run from the 440-volt mains A.C. supply. These sets are used in parallel at Abe commencement of charging, one being cut out at about half-time.
As mentioned earlier, we were shown by Captain Roberts a record of the time two vehicles—an electric and a petrol—were held off the road as a result of repairs necessary and paint ing, over a period of six years. The figure for the electric was 69 days and for the petrol 114 days. When the "standing charges and the cost of running a replacement vehicle are considered, the saving for which the electric was responsible is material.
Over a period of four months some interesting comparative figures were given us for the two types. In both cases the anileage was 2,840, and the total load 1,444 tons. The average cost per mile for the electric was 10.7d. and for the petrol 14.47d., which in terms of average cost per ton are equivalent to 21,07d. and 28.52d, respectively. The two machines to which these figures apply were both 6-tonners. They were carrying three loads per day and making from one to 20 deliveries per load.
Reverting to the charging plant, Captain Roberts remarked that there was no need nowadays to lay down expensive equipment. The introduction of the rectifier has removed this obstacle to further development. Reviewing the attractions of the battery-electric he enumerated thg following points :—That it uses homeproduced fuel, is silent, clean and odourless, has excellent acceleration, does not consume fuel while standing. covers three to four times the distance of a petrol vehicle on a set of tyres and incorporates many fewer working parts, of which none, in the driving components, reciprocates.
With regard to the actual operation of the Hovis fleet of battery-electrics, they run, in the main, within a radius of 20-25 miles of the mill in the London area. With the batteries in good condition 45 miles is possible on one charge, whilst by giving the storage equipment a boost during the lunch hour 15 miles may be added to the vehicle's range.
In connection with the peak-load system, the view was expressed that it reduced the charging time and, therefore, made impracticable a long 'charge at a low rate, which was conducive to long battery life, Finally, Captain Roberts expressed the view that the selection of batteries was of the utmost importance for successful and economical service. Low first cost should not be placed too highly. It paid to have good quality batteries every time.