The Upkeep of Electric Commercial Vehicles in New York.
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By Harold Whiting Slauson.
Owing to the much greater amount of power required to propel an electric vehicle over rough roads, this form of energy is best adapted for use in large cities where the streets are well paved, and where the grades are reduced to a minimum. Under such conditions, the electric van or delivery wagon attains a high degree of efficiency, and actual tests have demonstrated beyond a doubt the fact that the cost of its maintenance and repairs amounts to considerably less during a season than the corresponding expenditure for horse delivery. At the exhibition of the Association of Licensed Automobile Manufacturers, which was held during the third week in January, in New York, many of these electrically-propelled cars for delivery purposes were shown. All claims of the manufacturers as to the performance of their vehicles under different conditions have been fully substantiated by their users, and whatever figures and results are given in the succeeding paragraphs may be considered to be thoroughly reliable, and a sample of what is being done in New York in this field. Manufacturers have at last passed the stage where they deemed it advisable to make greater claims than their products were capable of fulfilling, and, in some cases investigated, the performance of the electric delivery vans has exceeded in efficiency and economy the highest expectations and promises of their makers.
The most popular type a electric van and truck seems to he that in
which the batteries are It:cated in a single set in a box suspended from the centre of the frame. In most of these, a single motor is used to drive both the rear wheels, by means of a double power reduction. In many cases, however, the motor shaft is connected directly to each of the rear wheels by double chains, thus using but a single power reduction. This method of drive is found to be very efficient, and it admits of greater flexibility than would be the case were a bevel gear and shaft employed. For the lighter vans, the single-tire whecls are used, but twin rear tires are employed on the heavy trucks to allow of a more even distribution of weight and a more uniform tractive effort.
With the batteries and motor located between the axles, this weight is evenly distributed between the front and rear wheels, and all parts of the operating mechanism and power plant are rendered accessible. In case the vehicle is in constant use, or provided there is no opportunity for charging during the night, two sets of batteries may be provided—one set to be charged while the other is in operation. The battery boxes are so arranged that the whole set of cells may be slid out as a unit on a platform, and the charged batteries replaced, at the expenditure of only two or three minutes of time. Automatic electrical connection is made when the batteries are installed in their place.
The controller which regulates the speed of the motor is generally placed under the driver's seat. Most of these controllers are of the continuoustorque type, which changes the speed of the motor by degrees without interrupting the power supply, thus giving a smooth and even acceleration without a jar or strain of ;triy
The batteries are of from 40 to to cells, and furnish current to the motors at a pressure 85 volts or more. The capacity of the batteries varies from 140 ampere-hours in the ordinary type of lead cell to 170 ampere. hours in those of the latest and most approved design.
Customary Performance.
Having glanced briefly over the general structural features and capacities of the electric power wagons, it will be interesting and advisable to examine the performance of these vehicles under actual working conditions, and thus to determine what practical service the average electric van or truck is capable of delivering. The number of miles which a loaded vehicle can travel on a single charge of the battery over ordinary city streets will vary between thirty and fifty, depending on the size of the van or truck, the manner in which it is handled, and the condition of the motor, controller, and running gear. It has been found by actual tests that the total cost for an electric truck of five tons capacity is about 4d. per ton-mile, assuming, of course, that the vehicle is loaded to full capacity on all trips. This cost consequently must be nearly doubled for general delivery purposes, as the return to
headquarters empty will consume nearly as much current as the outward-bound trip. Figuring on the same basis, the cost per too-mile for a three-ton truck is about 5d., whilst that for a one-ton delivery van reaches nearly tod. On the other hand, it must. be remembered that the smaller vaa is much cheaper to operate when running empty or only partially leaded than is the heavy truck under the same conditions.
Battery Maintenance.
As is to be expected in the case of an electric vehicle, it is in the batteries that the greatest amount of depreciation will be found, and, in the series of tests from which the figures of the preceding paragraph were taken, 15 months appeared to be the greatest length of tune that a set of lead cells could be used without renewal. At the end of that time, the positive plates had become practically useless and had to be renewed. The negative plates, however, were only about two-thirds gone, and, as the second set of positive plates will last but half as long as the first set, about 20 rronths is considered as the average length of life of an electric battery for commercial-vehicle purposes. Battery renewals vary in cost from .440 to 471oo per annum, according to size of vehicle.
It will be seen from the above that, during this 30 months, two sets of positive and one set of negative plates will have been used—one of the former, however, being the only renewal necessary throughout the available life of the battery. The arid and water must be renewed as evaperation and leakage lowers the level in the cells, but this is an operation which can be performed while the batteries are being charged and entails but little loss of time.
Horse or Motor.
A rather extensive test as to the respective merits of horse and motor delivery was recently conducted throughout an entire year by a large ice company in the vicinity of New York. I:s 6o hors's and 20 wagons
were replaced by to standard 3-ton electric trucks, at a total increase in investment of about too per cent. The annual operating expenses for the horse-delivery system, however, were about five times that of the motorwagon maintenance cost, owing, mainly, to the greater amount of territory covered by one electric vehicle, and the fewer number of drivers necessary in consequence. During the winter months while the demand for ice was not so great as in the sumnier time, the trucks could either be let out for other service, or could stand idle at no cost for upkeep. During slippery weather, the motorcar, with non-skid tires, is always far superior to the horse-drawn vehicle. During the twelve months, taking all things into consideration and including the interest on the investment at six per cent, in both cases, the operating expenses for the horse-delivery system were found.to be about 49,000, whilst that for the electric-van service was but slightly over L:4,000, or a saving of nearly ...5,000. This represents an annual saving of over 5o per cent. on the total investment and operating expenses of the two rival systems.
The Driver Question.
The operation of an electric vehicle is so simple that but little time is generally required for the average horse driver to become an expert chauffeur. In fact, it is stated on the authority of the manager of one of the large electric commercial-wagon concerns that horse-drivers are more careful, and they consequently will get a longer period of usefulness out of a delivery van than will a specially
trained chauffeur. " These men, from life-long habit, will slow down for obstacles in the road, and will drive around holes and depressions through which the ordinary chauffeur will dash at top speed," said the gentleman in question. "This carefulness on the part of the driver of an electric vehicle will add 25 per cent. to the length of life of the machine and, furthermore, good reliable men of this class can be obtained for considerably less wages than an expert who has been accustomed to automobiles all his life. This double saving in expense is an additional advantage that the electric power wagon has over its petrol brother."
On the other hand, the mechanism of a petrol wagon requires more expert handling than that of an electric vehicle, and, if the same efficiency is expected from both, a trained chauffeur will be required for the former. This means an increase in wages for the driver, and the consequent added item to the yearly cost of upkeep.
Probably the largest user of electric delivery vans in New York is the department store of Messrs. R. H. Macy and Company. This firm has used the electric van for the delivery of parcels to all parts of the city for the past six years, and at present has 30 oneton vehicles in operation. The first of these weighed 8,600 pounds and used lead batteries which would last, on the average, for about a year. These original yehkles, however, have since been replaced by more modern and improved vans, so that at present each one-ton wagon weighs but 3,700 pounds. This decrease in weight has been made possible, principally, by changes in the design of the battery, which is now made much lighter and gives good service for about 20 months. These batteries have a capacity of t68 ampere-hours, and they will run the vehicles about 40 miles on a single charge. It is claimed that the new batteries which have recently been perfected by Mr. Thomas A. Edison will deliver the same number of ampere-hours at onehalf the weight of the present cells hearing his name.
A Large User's Experience.
In the case of 'Messrs. Macy and Company, the 40 miles on a single charge of the batteries is ample for a full day's delivery of merchandise. This enables the exhausted batteries to be charged at night, without the necessity of removal from the van, and, as a complete power plant is operated in connection with this department store, as much current as is necessary is available at all times. A machine shop is also maintained
where all necessary repairs to the cars may be made,
Although the horse drivers are taught to operatethe delivery vans, none of them is allowed to touch a single part of the mechanism save the control and steering levers. In case a breakdown occurs while on the street, the driver immediately telephones for the emergency wagon, which hurries to the scene in charge of an expert repair man. If the breakdown is of too serious a nature. to be repaired on the street, the disabled machine is towed to the garage where all necessary tools and spare parts \\Ill be found at hand. This system eliminates the possibility of further damage being done to the mechanism through ignorance or inexperience on the part of the driver. In other words. the driver's business is to drive, and not to repair, this latter being left entirely in the hands of a different department.
In concluding an interview with the chief engineer of Messrs. Macy and Company, the writer asked " About what percentage of your vans
do you manage to keep in commission? You probably count on about ten per cent, being in the repair shop, di) You not? " " No," said Mr. Brennan, " we try to keep every one of the thirty machines working to full capacity every day—and we succeed pretty well. What small repairs are necessary can be made during the night, and it is seldom that we have a car which is not ready for its next morning's work." And this is really the wonderful part of the system— that practically too per cent, of the vans can be kept in commission throughout every business day, and their steady performance relied on without the necessity of holding two or three extra cars in reserve.
From these paragraphs, it will be seen that a first-class system of upkeep and repair will go a long way towards getting efficient results out of an electric delivery-van installation, and that high efficiency really depends more on the proper handling of the car than it does on the type of vehicle used. New York is certainly ahead in electric-truck work.