Motor Fire Apparatus—Electrically Propelled
This is a subject upon which it is somewhat difficult to write with any degree of intelligence at this time, because my experience with electrically driven apparatus has been brief, and limited to only one make of vehicle. The Springfied department has two pieces of electrically driven apparatus in service. These are a combination hose and chemical car and aerial ladder truck. Both have been in service only about five months; hence a determination of their efficiency in the long run is not easy. Subsequent development, however, may prove that our early experience with electrically driven apparatus is typical of its ultimate efficiency in service. My belief is that it will. It is not my purpose to consider in this paper a comparison of electrical and gasoline apparatus, or to submit an opinion as to which is superior for the needs of a lire department except as it may be necessary to point out the merits of the electric vehicle. I need not say that its superiority over the old horse drawn type is very great. The Springfield department has in service both electric and gasoline cars, and we arc well pleased with the work done by each tyne. Springfield has the distinction of being the first city in the United States to make a thorough service application of the electric vehicle in fire department operation. Following is a description of the 85-foot aerial hook ancl ladder truck in service in our department. It differs from the combination car only in that it has a tiller wheel for guidance of the two rear wheels The truck was built by the Seagrave Manufacturing Company, of Columbus, Ohio, and the wheels with the motors are the product of the Couple Gear Freight Wheel Company, of Grand Rapids, Mich. Kach wheel is made up with a motor of the direct current, series railway type, of 3 horsepower capacity, normal rating. The motor is a pancake bi polar type, enclosed within two steel disks, which replace the spokes of the ordinary artillery type of wheel. The back field casting connects through a steering knuckle to the rigid axle, thus supporting the wheel, with the motor armature being at all times horizontal. The armature has a shaft running through it, on each end of which is a wick oiled bearing which is part of the field casting. Terminating this shaft are two beveled pinions; one pinion engages in the circular beveled rack, which is a part of the outer disk of the wheel, while the other pinion engages in a similar rack which forms part of the inner disk. Tile armature shaft is set at an agle so that each pinion engages only one rack. This construction gives tlie wheel the name “Couple-Gear,” since the forces act as a couple to turn the wheel around the motor, the forces being applied practically at its rim. The armature shaft is bored out, and serves as a bearing for the pinoin shafts, which are connected together by an “evener” device which compels the same amount of power to be transmitted by each pinion. This device is simply a differential coupling, and is believed to be responsible for the satisfactory operation of the wheel; first, because it removes practically all sliding friction on the gear teeth, thereby increasing greatly the life of the pinions; and sec ond. because it insures the transmission of equal amounts of power to each side of the wheel, thereby increasing the efficiency and maintaining a true “couple.” The efficiency of transmission as given by the “U. S. Bureau of Standards” is 97 1/2per cent, of the power of the motor. Around the circumference of the disks and bolted securely to these and the gear racks, is a band on which are placed the tires This forms a dust and water proof shell enclosing the motor. The outside disk has two circular hand holes for oiling and inspection. The brakes are of the contracting type of large diameter, one on each of the four wheels. These are operated from the driver’s scat by means of two foot pedals, one pedal controlling the front wheels, the other controlling the rear vvhee’s. The driver’s seat is located immediately in the rear of right front wheel. These front wheels tic steers by means of the regular type of hand wheel. The rear wheels are controlled by the tillerman in the same manner as in the horse drawn apparatus. The controller is a street railway type, giving five speeds forward and five speeds reverse, without the use of resistance, so that any one of the five speeds may be used without loss of power. A Sangamo ampere-hour meter which gives the exact amount of charge in the battery, and eliminates any chance of error as to the amount of power remaining in the battery. The battery is an 80-cell, 17-platc National battery, giving 225 ampere-hour capacity at 160 volts; is of the latest type of bolted connection, high bridge jars, which makes it readily accessible, and avoids the troublesome operation of cleaning. Wheel base, 26 feet 6 inches. Total length of vehicle, 54 feet, with running boards on each side sufficient to carry twenty men and equipment. The tires are 40×4 inches dual, side flange. The truck has a guaranteed maximum speed of twenty miles an hour on a level roadway, and on a test run made a half mile in one minute seventeen seconds, corresponding to a speed of 23.4 miles an hour. It has ascended a twelve per cent, grade at a speed of eight miles an hour. The weight of the truck, including its full complement of men, is ten tons, and it will run about fifteen miles at full speed on a single charge. The combination car is provided with a forty-gallon chemical tank and 200 feet of chemical hose, besides one thousand feet of two and one-half inch hose, and weighs about seven tons as driven to fires. Its speed guarantee is thirty miles an hour, and its battery equipment is the same as that of the ladder truck. On a twelve per cent, grade this piece of apparatus has a speed of twelve miles an hour. Both pieces of apparatus are supplied with energy through a motor generator set. Flexible cables with plug connections convey the energy to the battery-charging plugs on the apparatus. The charging equipment occupies a space five feet long by three feet wide. A voltmeter and ammeter are installed, and the apparatus can be disconnected within one or two seconds in case an alarm is received during the charging period. There are perhaps half a dozen points which recommend the electrically driven apparatus. These I have noticed during the time our truck and combination have been in service. They may he set down as follows: (a) Immediate action at all times and in any temperature, (b) Any or all speds are practicable; no loss of power at any speed, (c) Economy, (d) Cleanliness, (e) No damage to building or contents by smoke, (f) Less danger by fire. By immediate action I mean this. In the event of a fire alarm being sounded, the driver of the electric apparatus has hut to jump into his seat, throw over a lever, and be off to the blaze. He does not have to crank his car before starting, and he is never bothered by hot or cold weather; they have no effect upon electrically propelled apparatus; for this reason alone “juice” cars have a decided advantage. Like a trolley car. the electric truck of the Springfield department has five speeds ahead and five backward. The operator may use any of the speeds at any time, and there is never any loss of power resulting. The question of economy which I have spoken of is a most important one. and it appears to me from our five months’ experience with the electric truck and combination that this method of propulsion affords the minimum of expense in maintenance at least. The item of repairs is hardly worth mentioning. The only parts of the truck and combination to get seriously out of order are the batteries. The life of these I shall consider later under the head of costs. The electric piece of apparatus has no engine, no carburetor, no magneto, no spark plugs, no transmission—in fact, nothing but the batteries to bother its owners. I have spoken of the cleanliness of the electric truck. This appears to me to he an important consideration in favor of the type. There is no dripping of oil to the floor. You have not to he continually scrubbing the station floors to keep them free from oil and the grease and dirt which arc hound to accrue from its presence. The annaratus is more easily kept clean. I have noticed, and probably those of you who have had experience with gasoline cars have also, that stations housing gasoline apparatus become blackened by smoke over and around the doors and in the immediate vicinity of the apparatus. This, I suppose, is caused by the smoke which issues from the cars going to and returning from fires and trying out the engine. Electric apparatus does not bring about such conditions. There can be do damage from lire in electric apparatus. There is nothing about them to burn, no gasoline or oil to catch fire—an item which is worth considering. While it is not likely that our gasoline cars will ca.ch fire any oftener or as often as private gasoline cars, still at the same time there is the possibility, which is absolutely precluded in the use of electric apparatus. Coming now to the important item of cost of elec rie cars, we find that they are highly desirable from this point of view. Our electric apparatus was put in service in March of this year, and the following figures show approximately the expense of maintenance since that time. These figures have to do wholly with the cost of recharging the batteries of two pieces of apparatus, the principal item in the maintenance bill: April, $74.78; May, $“77: June, $11.91; July, $0.21; total, $29.70, or $14.85 for each piece of apparatus—an average per mon;h of $371 for each piece of apparatus. A large share of the recharging expense is due not to fire service, but to exhibition runs and experience getting for the men who operate the apparatus. After the truck has been in service longer, and the men have become more accustomed to it, so that practice can make them more capable in running it, the expense of recharging the batteries will be smaller. Supposing even that we spend $-1 a month on our batteries, the yearly cost of recharging the batteries would not be over $50. Another expense which is hardly worth mentioning is that of keeping the battery plates covered with water, on account of evaporation. For this we use distilled water. Enough for our use costs about $1 a year, or should, if the expense for the first five months is to be taken as any criterion. Electrolyte for use only when a battery jar is broken is another slight expense. This is a combination of one part chamically pure acid to two parts distilled water. We are about to install, at a cost of $25, a plant for distilled water, which will enable us to produce distilled water at a cost of two cents a gallon, a saving of about eight cents on each gallon. A broken battery jar costs about $3 to replace, but this we have not had to do since the truck went into service. We have heard the criticism that the batteries would not last long enough to make them practicable. In my opinion this criticism is unfounded, although I am willing to let the batteries themselves decide that question. My belief , that the batteries will prove to he well worth their original cost is founded on the fact that after fourteen months, the space of time which has elapsed since their manufacture, they show not the slightest sign of deterioration. The truck is the first of its kind ever made. That fact called for a great deal of experimenting by the manufacturer to meet contract requirements. The batteries were shipped to the Seagrave Company in Columbus, Ohio, in June, 1910, Fourteen months have elapsed since that time, and those same batteries are in service, without the least indication being given that they are not in the best possible condition for service. They have been examined by an expert, who found them in perfect order. It is my belief that the batteries will have a lifq. of at least four years. The cost of replacing them is $400 or $500. The initial cost of our truck was $10 000; that of the combination about $6,000. We have secured an electric tractor for one of our old horse drawn aerial ladder trucks, which has been fitted to the truck and is now in the paint shop. On a test run the tractor wi‘h the truck showed a speed corresponding to twentyseven miles an hour on a level roadway; on a twelve per cent, grade thirteen to fifteen miles an hour. The necessary tools to care for electrical apparatus are few and inexpensive, consisting of a hydrometer and tube to test the density of the solution; thermometer to test the temperature, and a small portable voltmeter to test the voltage, at a cost not exceeding seven dollars.
Kansas City, Mo., firemen are secure in their places, and will not be required to take a civil service examination, for the present, at least. A temporary injunction to that effect has been granted by Judee James H. Slover, of the Circuit Court. While the examination already has been held, the court ruled that the old men cannot be disturbed in their places at least until the case is heard on its merits. John Mahoney was nominal plaintiff in the suit, in which practically all of the 300 Kansas City firemen joined.
Read at recent convention of Massachusetts Firemen’s Association,