556 



THE INDIA RUBBER WORLD 



concerned is judged by the number of trips per day, the advan- 

 tage seems to lie with pneumatic equipment, provided the runs 

 are long enough and not restricted by such factors as traffic con- 

 gestion and delays at terminals. 



As I suggested before, there are certain conditions under which 

 trucks on pneumatics can make trips when those on solids cannot 

 be operated. Hence, their earning capacity is just so much 

 greater. It has been noted that trucks on pneumatics not only 

 notjoliatc the unpavcrl roadways mmx- easily but do less damage 



Pneumatic Tires Ari 



P.^RTMENT ON TRUCKS WhiCH TaRRV ^ 



Spot Enemy Aircraft. The Delicate 

 Makes 2Mecessary the Greatest 



than those on solids, and hence are looked upon with more 

 favor by the farmers they serve. 



RELATIVE EFFECTS ON OPERATION COSTS. 



When we come to consider the relative effects of solids and 

 pneumatics on the cost of operation and up-keep we find a wide 

 variety of opinions, but very few conclusions based on accurate 

 cost records. 



Let us examine briefly the items which should be included in 

 such costs, and see how they are affected by solid and pneumatic 

 tires. The following items are usually not affected by tire 

 equipment : interest on investment ; insurance ; taxes and license : 

 garage ; supervision ; wages of drivers and wages of helper. 1 he 

 following, however, may vary according to the type of tires used : 

 depreciation ; gasoline ; oil ; tires ; repairs due to wear and tear 

 and accident. 



Taking them up in the order given, there are, so far as 1 

 know, no dependable figures covering depreciation on which !■■ 

 make comparisons, as no trucks have been run long enough on 

 pneumatics to determine their effect on the ultimate life of tlu- 

 truck. As to the relative consumption of gasoline and oil, very 

 few reliable figures are available, but the best-informed operators 

 are inclined to feel there is little if any saving in these items, 

 particularly on short hauls. On long hauls, however, the ad- 

 vantage seems to lie in favor of pneumatics. 



When it comes to tires there is no question. The cost of 

 pneumatics averages from two to three times that of solids. 

 This is due to the higher initial cost of the equipment and the 

 spare tires, their greater susceptibility to abuse and accident, and 

 their lower average mileage. 



So far as the cost of repairs to the truck is concerned, com- 

 parative data of a reliable nature cannot be obtained. The evi- 

 dence indicates, however, that, except for the engine, the cost 

 of repairs will be considerably less on pneumatics than on solids, 

 due to the reduced vibration. And if the engine is not run at 

 excessively high speed or continually overworked it will prove 

 less subject to damage on pneumatics. 



Summing up the factors affecting the saving of time and money. 

 I have come to the conclusion that no general claims in favor of 

 incumatic equipment on trucks as a whole coming in the debata- 



ble lield can be substantiated, and that the work to be done by 

 each specific installation must be analyzed carefully before either 

 t\ pe of tires can be safely considered the more economical. 

 THE QUESTION OF SERVICE. 



Having reviewed the engineering features and the practical 

 operating features, let us now see what the operator faces in so 

 far as tire service is concerned. As the nature and extent of 

 service of the maintenance and renewal of solid tires are well 

 known, it seems unnecessary to comment on them except to say 

 that years of study and competition have developed this end of 

 the business to a high degree of perfection, so that the operator 

 can depend upon many well-equipped service stations for instant 

 attention, either in the day or night. 



The manufacture of heavy-duty pneumatic tires of six-inch 

 section and larger, is, however, a relatively new development. 

 Less than a third of the manufacturers of passenger-car tires 

 have started actively to make heavy-duty pneumatic truck tires, 

 fur they realize that the job of building a tire which will stand 

 u|) under the use and abuse to which it is subjected nowadays 

 is not easy. Moreover, the task is not finished when the tire 

 comes out of the heater. It must be sold to the dealer, who, in 

 turn, must not only stand behind 'the tire, but place himself in 

 position to give the truck operator service. This means he 

 must install a high-pressure air-pump, repair material and molds 

 for vulcanizing and in most cases a service car for emergency 

 calls, as it must be remembered the tire is apt to fall away from 

 its base and it cannot be driven home flat. 



It may be said, without fear of contradiction, that the tire 

 companies themselves are not as yet prepared to give really 

 efficient service in all parts of the country. In fact, even in the 

 principal cities this phase of the business has not been fully 

 developed. In the smaller towns there are almost no air tanks 

 or pumps to keep tires properly inflated. Pumps on trucks them- 

 s<:lves are reported as not always dependalile, sometimes re- 



iG I^ACToRs: Traction 

 WITH Cost Subordinati 

 Protection of Mercha 



Y Kind of Road Surface, or off Tt 

 •BED WITH Cost Subordinated, or Whe 

 from Road Shock Is Essential. 



hour 



secure the desired 



quiring from 15 minutes to half 

 pressure in a tire. 



PNEUMATICS DIFFICULT TO REPAIR. 



By far the most serious and difficult phase of giving^ service 

 with heavy-duty pneumatics, and that which causes the most 

 concern to truck operators, is connected with the repair. In 

 fact, the chief complaint in regard to pneumatic truck tires, 

 aside from their high initial cost, is that they are subject to 

 injuries, cuts and damage generally of such a nature that they 

 cannot be repaired except at the factory where they are made, 

 or in a few cities at a factory branch, and often they are dam- 

 aged beyond all repair. This is not only expensive, but fre- 

 quently necessitates the purchase of more than one set of spares 

 should the first set be injured while the others are being re- 



