Motor Fire Apparatus Tire Equipment Analysis
THIS is an age of progress. No really progressive Manufacturer, Dealer, Consumer, Municipality, State or Country is willing to rest on laurels already gained. The mark to be obtained is ever set just ahead. The goal set once obtained is rapidly relegated to the rear and a new goal set farther ahead.
Perfection is very similar to the chasing of a rainbow’s end; it is ever just ahead and those striving to reach the goal are constantly required to strive steadily forward.
Were we to sit peacefully back as soon as a particular goal is obtained, it would be but a short time until we should be occupying a trailing position.
Municipalities and Fire Departments, at least really progressive ones, are never satisfied with results obtained. There is always a possibility that something better can be developed from past efforts and recently gained successes.
Manufacturers of Motor Vehicles and Rubber Tires are constantly endeavoring to improve their product, for in excellence of product is leading position secure.
Defects and weaknesses developed and brought to light are turned to advantage. Care is exercised that similar mistakes and weaknesses are not repeated. A general improvement of result is noticeable where this attitude prevails.
While Motor Fire Apparatus is rapidly developing from the infancy stage and is in reality a sturdy healthy youngster, just reaching the age of understanding, the tire equipment manufacturers are keeping pace with its development and growth.
The failures of the past have been carefully analyzed both for cause and effect. A better understanding of service conditions is the result of careful and painstaking analysis and Study.
New attitudes toward the ultimate consumer are appearing. There was a time in the past when the consumer’s interest was given but scant attention, now the consumer’s interests and needs are considered carefully in the production cf any article or idea. This is as it should be.
The bringing together ideas from both angles, the needs of the user and the ability of the Manufacturer to develop and produce an article to best meet these needs is a good thing for both. Neither knows the other fellow’s angle as well as his own without taking advantage of the opportunity of getting the other fellow’s viewpoint.
This brings about a new basis of business, new only because of its not having been generally practiced, and but recently recognized as the vital factor available but unused.
“That which is best for the user is always best for the producer.” Upon the demand of the consumer depends largely the success of any producer.
How many articles formerly marketed and sometime well known are now in oblivion because of their failure to meet existing and growing conditions, because the ever changing needs of the user were not carefully considered and a real, honest effort made to meet them, being satisfied with being able to “get by!“
This condition has been true in Fire Department equipment. Ability to “get by” was apparently the limit of effort. However, there were some who were not satisfied to drift along with the current, circling around in the eddies, spurting in rapids as often finding themselves away out of running in some sheltered cove without ability to work back into the real action or hopelessly wrecked on the rocks of the rapids through lack of steering ability, but those whose progress was steady, carefully planned and efficiently steered for a certain and definite goal. These invariably reached haven safely.
To succeed in supplying Fire Department equipment as well as in the successful management of a Fire Department, correct analysis of conditions and correct application of available material is absolutely necessary.
Fire Department officials should know as fully as possible what material is on the market suitable for their needs, under what conditions of operation it will give its best and most economical service, by a comparison of conditions recommended by the manufacturer with local conditions regarding which no one is or should be more familiar, very best results should be obtained.
First cost seldom appears as a factor with a wide awake, efficient official, rather the ultimate cost is the determining factor. This proves him to be farsighted and a careful student of conditions and results. Kconomical operation of his department means more than personal friendship with some merchant or his representative. It sifts down to a hard basis of business, Good Stewardship and Loyal Service.
Among the various makes of Fire Apparatus are eight separate and distinct types, each of which may vary from the others in construction according to the several manufacturers building them, each designed and built for specific service, to meet certain existing conditions, but seldom will the various makes of the same type deliver equal service under certain local conditions. Invariably one make will stand head and shoulders above other makes under the conditions of test.
This does not necessarily mean that other makes of the same type are not correctly designed or suited for that kind of service where operating conditions are more favorable or suitable.
Local conditions vary so much that they are frequently in a large measure a deciding factor of make and even type of apparatus necessary to deliver the desired service.
A heavy, high pumping capacity truck may be and often is required in closely built, high risk sections of cities, where water supply and pressures must be augmented to be efficient but would be unnecessary where high pressure systems are available or where road conditions would prevent its ready handling except under the most favorable conditions.
On the other hand, lighter construction, smaller capacity trucks will frequently prove to be more efficient where road conditions are for a large proportion of time unfavorable to the use of heavy types and where water pressure does not need a great deal of assistance to become effective.
Prope_____ly installed each of these constructions, makes or types are the maximum efficiency, but which cannot be determined by general application or the ignoring of existing local conditions.
This is equally true of each of the eight distinct types of apparatus designed for Fire Department use and is also true regarding the tire equipment used in this service.
In tires there are but three types available regardless of make, though each type varies somewhat in methods of construction in each factory. Generally speaking they are designed for corresponding service.
The three types are Pneumatic, Solid and Cushion.
Each has a distinct function and condition in which they give their best, most satisfactory and economical service.
The following basic facts have the greatest bearing on the proper selections of Fire Apparatus Tire equipment:
First—The types of Tires available.
Second—The type of Apparatus to be fitted.
Third—The road conditions.
Fourth—The operating conditions, speed, length and number of rims.
Fifth—Ultimate cost of operation.
In considering Pneumatic Tires for Fire Service it is first necessary to clear up an impression that seems to he rather prevalent, due possibly to experiences obtained and expressions voiced regarding the use of this type, during the early days of Motor Fire Trucks.
At that time Solid tires had not reached a very acceptable degree of perfection, also tbe first Motor Fire Apparatus was in reality a heavy, large Touring-CarChassis converted to Fire Department use and consisted of a hose car, a chemical car or a squad wagon type on which pneumatic tires were originally used.
For several years after the introduction of the Automobile Rubber Tire manufacturers’ engineers confined their research to the development of a pneumatic tire that would be highly resilient, enable the car to run at a higher speed, at the same time to withstand the effects of friction and generated heat so that a satisfactory mileage might be obtained.
At that time the principal troubles experienced with pneumatic tires were found to be, after a careful and thorough analysis, the result of excessive generated heat due to the rapid flexing of the side walls, more marked after long continuous runs at fairly high rates of speed, the tires giving less total mileage on long continuous runs than where runs were short and at infrequent intervals.
In the long continuous runs more heat was generated flue to the thickness of the sidewalls or flexing points than could be radiated in one complete revolution of the wheel.
After considerable experimenting manufacturers reduced the thickness of the sidewalls or flexing points to that point which enabled the tire to carry a recommended load with a small margin of safety.
The following statement may make the matter clearer:
No. 10 wire has greater tensile strength than No. 21 or fine wire, but is not as flexible; it cannot be bent as rapidly or for as long a period without generating excessive heat which will rupture the threads or fibres. When used under conditions for which it was designed either size will give satisfactory results, but not otherwise.
The simile applies to trucks and tires of every type equally as well.
The adoption of the light sidewall in pneumatic tire construction increased the popularity of the Passenger Car, or as it was known at that time “The Pleasure Car,” and gave the motor car industry greater impetus.
The inauguration of the Motor Fire Apparatus came about this period of the development, but owing to a lack of close co-operation between the manufacturers of Motor Fire Apparatus and Rubber Tires the development of correct tires for the service required was not given necessary attention.
Tires as manufactured for other purposes were used without any clear cut consideration of their fitness, with unsatisfactory results.
The general antagonistic attitude of the Fire Service to pneumatic tires can safely be said to have begun at this time.
Along about 1915 the first Pneumatic Tires for commercial trucks were developed and placed on the market after a careful investigation of the conditions of service this type of tire would necessarily encounter. Actual service has proven the idea to be practical but susceptible of further improvement and development.
Originally, cross woven fabric was used in the construction of pneumatic tires, but developments and improvements followed each other in rapid succession until a Cord construction, a fabric consisting of warp only, running in one direction, without a cross weave, was developed and put to practical use.
The introduction of this type of construction made a marked improvement in passenger car tires. The longer and generally all around better service obtained from Cord tires, heavier load carrying capacity because of added strength made this type of construction the logical one to use in Pneumatic Truck Tires.
Coincident with its use came the rapid increase in demand for this type of tire.
In building Pneumatic Truck Tires the engineers realized that the high speed and long continuous runs of the passenger car would not be required in Truck Service, therefore, the need of an easy flexing sidewall was not as necessary, but that a greater load carrying capacity would be advantageous, both the sidewalls and treads were built very much heavier. The correctness of this theory has been proven in actual use and practice, until now Pneumatic Tires for trucks up to tons capacity are a reality and in great demand in certain lines of service.
Solid tires as now used are a development of the rubber tires used on carriages of several decades ago with such changes necessary to meet growing condition. Their purpose was primarily to provide a cushion between the wheel and road surface, and provide better traction than could be obtained from a steel tire where driving power was applied direct to the wheels. Self-propelled vehicles operate at higher speed than horse drawn and vibration increases in direct proportion with the square of the speed. For example: a vehicle running at 12 miles per hour has four times as much vibration as when running at six miles per hour, and at 18 miles per hour has nine times the vibration it bad at six miles per hour.
Obviously then, rubber tires were not only sound deadeners and traction assurance, but furnished cushioning against that most destructive element—vibration.
It is also evident that solid tires must have a speed limit to correspond with their resiliency and cushioning ability so that speeds of 20 miles per hour and over taxed the cushioning of solid tires to and beyond their ability with the inevitable result of shortening life and durability.
Cushion tires are that type occupying the middle ground between Pneumatic and Solid tires. They have greater resiliency and cushioning power than solid tires, capable of being operated at a somewhat higher rate of speed without increase of vibration effects but do not have the durability.
They will not stand the speed of Pneumatic tires, they have neither their resiliency or traction possibility but they do eliminate the loss of service through puncture and blowout, so common when passenger car type pneumatic was commonly used in truck service.
Cushion tires, however, have a distinct field, namely, where a slightly higher rate of speed over solid tire possibility is advantageous and required and where road conditions are of such nature that pneumatic tires cannot be used without danger of premature ruin through cuts from hard sharp objects lying loosely about.
To obtain the best possible service from either of these three types they must be used under proper conditions, not overloaded, or run at excessive speed and must be given reasonable care.
It is often economical and advisable to apply an extra size tire, that the margin of safety, load carrying capacity may be increased to take care of even the occasional overload. Longer service and greater satisfaction will be the result.
THE APPARATUS TO BE FITTED
The eight types of Fire Apparatus are generally known by the following names; The Chief’s Car (a passenger car), The Chemical Truck, Hose Truck, Pumping Engine, Combination Hose and Chemical Truck, Combination Pump, Chemical and Hose Truck, Service or Ladder Truck, Tractor and Aerial Truck.
The service of each truck varies from that of each of the others. Each was designed to meet certain conditions. Not any one of these types can successfully meet all requirements, neither should any one type of tire be expected to do so.
Because of the varying service of the Apparatus types and Tire types, analysis is the best and only way to assure maximum service at minimum cost.
THE ROAD CONDITIONS
This phase is equally important in the selection of type of car as in choice of type of tire. Road conditions vary in every hamlet, village, town or city from both local and geographic conditions. Traction is affected or enhanced by road conditions.
One type of truck may give excellent results over one road condition and be an absolute failure economically over another because of loss of traction. Equally so one type of tire may give excellent traction over hard surface roads but fail in heavy sand or wet slippery clay.
It is advisable to be prepared for extreme conditions. The time of application is the best time to prepare for the emergency or unusual condition rather than wishing it had been done when the unexpected but possible condition advises.
Speed required, length and frequency of runs.
This phase sometimes neutralizes and sometimes exaggerates other conditions.
Where one type of car or tire would give maximum service in a restricted district where short runs at frequent intervals and at comparatively low speeds predominate, it would not give equally as good service where large areas must necessarily be covered over similar road conditions because of greater speed for longer periods.
ULTIMATE COST OF OPERATION
Initial cost should not be, and with the progressive efficient official is not the deciding factor in the purchase of either cars, trucks or tires.
Ultimate cost is a much better basis to use in making a selection. A low initial cost might and frequently does prove to be the most expensive in the end because it may be contributory to other items of expense such as mechanical repairs which could and would be eliminated by correct construction and quality at a higher initial cost, though sometimes a high initial cost or unnecessary quality might not be as economical because its full advantages cannot be fully used.
As a general outline of types of cars, road and operating conditions, the following is offered as a basic recommendation of type of tire equipment:
Chief’s Cars—Pneumatic Passenger Car Tires.
Chemical Trucks, Hose Trucks, Pumping Engines, Combination Chemical and Hose Trucks, Combination Pump, Chemical and Hose Trucks, Service or Ladder Trucks whose gross weight, loaded and ready for service including men, does not exceed 14,000 lbs. covering large areas over ordinary roads at from 25 to 35 miles per hour, occasionally through soft muddy roads or deep sand—“Pneumatic Truck Tires.”
Same types of trades over hard surfaced roads at a slightly lower rate of speed—Either Pneumatic Truck Tires or Cushion Tires.
Heavy Pumping Engines and Tractors, which seldom operate off pavement or hard surface roads, at low speeds—Either Cushion or Solid Tires.
Aerial Trucks—Usually solid tires though sometimes where conditions warrant Cushion or Pneumatic Truck Tires can be used on Tiller wheels.
The smaller cities and towns where ordinary dirt roads predominate or that have considerable deep loose sand, or heavy deep snow falls should adopt the lighter types of apparatus and will find the use of Pneumatic Truck Tires an assurance of ability to respond promptly to alarms regardless of road or weather conditions because of their superior traction. They do not cut into soft ground or snow because their wide surface makes a hard path for themselves under these adverse conditions.
A careful study and analysis of conditions by Fire Department and Municipal officials, Manufacturers agents, Tire Manufacturers and their representatives will do much to give the use of Motor Vehicles greater impetus than ever before.
There can be no hard and fast rule as to which type of tire, Pneumatic or Solid, is the proper equipment, to use as a standard by which all cities and Fire Departments shall be guided, for local conditions are the greatest determining factor.
Each city’s officials should avail themselves of all expert knowledge of transportation problems obtainable and Transportation Engineers of the Tire Manufacturers will gladly lend their aid so that all concerned may obtain that ultimate aim “Lowest Ultimate Cost” or in other words—Service.
The main idea and purpose in merchandising any article or product be it what it may, is Service.
This is what the cutsomer buys. The article bought and sold is simply a vehicle designed and manufactured to deliver the service bargained for.
This definition of business thoroughly understood and carried out will bring about better conditions in both Truck and Tire business.