November 1, 1920 



THE INDIA RUBBER WORLD 



89 



Chairman Hale: — The efficiency of solid tires as far as ab- 

 sorbency is concerned depends entirely upon the formula used in 

 compounding the rubber. It is possible to have a wide range in 

 the efficiency of the rubber stock. There seems to be a very posi- 

 tive indication ot a very satisfactory saving of gasoline in the use 

 of the pneumatic as compared with solid tires. 



Mr. Foljambe: — In regard to the tendency toward or away 

 from pr.eumatic tires when we get good roads, it seems that the 

 tendency toward pneumatic tires will be increased under those con- 

 ■ditions. With good roads, speeding is the next thing desired. 

 Even on gcod roads the desired speed cannot be attained with 

 a. solid tire. There never will be a time when all roads will be 

 improved. Even with a highly-improved highway system the 

 truck must occasionally leave the hard surface, which again re- 

 ■quires some kind of tire other than a solid one. 



Chairman Hai-e : — The speed at which the pneumatic-tired 

 trucks shall be operated must be controlled entirely by the safety 

 at which they can be operated. We have found that 25 to 30 

 m.p.h. is satisfactory ; it is very similar to passenger-car speed. 



There has been considerable talk to the effect that the pneumatic- 

 tire equipment for trucks would completely supersede solid-tire 

 •equipment, with the claim that the pneumatic tire rides so much 

 -easier that the truck chassis will stand up better than it would 

 in the case of the solid tires. No doubt this is true in the country 

 when driving at high speeds, but it has been my experience that 

 Tieavy trucks in crowded city traffic on short hauls last prac- 

 tically indefinitely when run on solid tires, because the nature 

 of the service and the traffic conditions prevent the truck from 

 running fast enough to develop any serious vibration. I feel 

 that there will always be a large field for solid tires for heavy 

 trucks in city work. 



H. B. Knap: — On trucks in general it appears that solid tires 

 -will be used in cities for short-haul hard-road low-speed work. 

 Pneumatic tires will be used for high-speed long-haul conditions 

 and for soft-road rough-country conditions. In other words, the 

 added expense per mile of the p?ieumatic tire must be offset chiefly 

 by making more trips per year, either by virtue of higher per- 

 missible speeds or by being able to negotiate soft roads and 

 ■ground where solid-tire equipment cannot operate. 



Mr. Darrow : — The question of solid and pneumatic tires can 

 be argued only on two counts. The first is reliability. We can 

 •expect 7,000 miles and over from pneumatic tires. During the 

 life of each tire we can expect to remove it once from necessity, 

 and perhaps other times for treatment. With average mileage 

 and care we must remove one tire per month. 



The second point is cost. The first-class improved highway of 

 ■ concrete, with a deep foundation, costs $40,000 per mile. Mr. 

 Seiberling mentioned that there are 200,000 miles of more-or-less 

 improved highways in the United States. This runs up to $8,- 

 •000,000,000. If we ever get highways of that character, the ele- 

 ment of depreciation on roads must be included in the cost of 

 pneumatic tires. 



In regard to unit load, there is a limit to the weight that can 

 be carried on solid tires per inch of tire width. As a matter 

 of fact, this is not the right way to measure it ; it should be 

 -pounds per square inch of contact area. With pneumatic tires, 

 the load per each square inch of contact area is equal to the in- 

 flation pressure. As to the cushioning, a solid tire deflects about 

 f^-inch. A pneumatic tire deflects ^-inch or more. We have 

 only one-quarter the impact with one-half the load, per square 

 inch. Those things have a bearing on the maintenance of the 

 foundation of the road. The road is the expensive part. We 

 must keep in mind that solid tires will injure the foundation of 

 the road and that the investment involved in keeping the roads in 

 repair is tremendous. 



To sum up and connect three things together, in a pneumatic- 

 -tired truck we have a saving in the truck itself, an increased effi- 



ciency and a large saving in roads. Taking into consideration 

 only the initial tire cost and mileage delivered, we cannot show 

 that pneumatic tires are more economical but, considering these 

 other things, there is no question that pneumatic tires excel solid 

 ones. 



Joseph Schaeffer :-^Considering the future prospects of large- 

 size pneumatic tires, it appears that the weight will prove the main 

 limiting factor. A driver and his helper can handle a tire with 

 rim below 200 pounds, so that the 40 by 8-inch tire would still be 

 practical, wdiile the 48 by 12-inch tire, weighing with rim about 

 500 pounds, can hardly be handled by one or two men without 

 involving undue efl'ort. In exceptional cases the very large sizes 

 may be justified and establish a field of usefulness, but for gen- 

 eral adoption they appear to be too heavy and too expensive 



THE NEW YORK ELECTRICAL SHOW 



THE annual New York Electrical Show was held Octoljcr 6-16, 

 inclusive, at Grand Central Palace. The displays made by 

 an unusually large list of exhibitors were of much popular in- 

 terest since many of them featured household electric appliances 

 of every sort, in which rubber in some form is used. No house- 

 keeper, it would seem, can aflFord to do without some of the lalxir- 

 saving electrical machines, such as those for washing, ironing, 

 cooking, and cleaning. A few only of the typical exhibits need 

 be referred to here. 



The Habirshaw Electric Cable Co., Inc., exhibited detailed 

 plans showing how a home should be wired and where outlets 

 should be placed. The exhibit also included samples of all the 

 types of wires, c4bles and cords essential for the full utilization 

 of the many domestic appliances which relieve household work 

 of drudgery. 



Western Electric Co. showed a complete assortment of elec- 

 trical appliances for the home. Five essential machines of more 

 than ordinary importance were shown, namely, the clothes washer, 

 vacuum sweeper, dish washer, portable sewing machine, and 

 ironer. 



The Westinghouse Electric & Manufacturing Co. A general 

 display of electric household heating devices for laundry, kitchen 

 and nursery was augmented by an exhibit of a number of motor- 

 driven appliances using small Westinghouse motors. This in- 

 cludes machines for washing, ironing, vacuum cleaning and dish 

 washing. In another section the same company showed a complete 

 motion picture equipment using a Westinghouse motor-generator 

 set to transform from alternating to direct current, a studio light- 

 control outfit for motion picture work and an outfit for charging 

 vehicle^batteries. 



The Elasticap Co. demonstrated the value and convenience of 

 Elasticaps, molded rubber caps, for the positive insuLition of end 

 splices of electric wires. They do away with the usual and often 

 unreliable rubber tape method, meet all requirements of the fire 

 underwriters, and are approved by the Underwriters' Laboratories, 

 Inc. The Elasticap was illustrated and described in The India 

 Rubber World, March 1, 1920, page 366. 



The General Electric Co. in its main exhibit show-ed in actual 

 operation many of the latest devices and apparatus for the utiliza- 

 tion of the heat of electric energy. Of special interest were the 

 following : electric arc welding equipment, automatically making 

 perfect welds without attendance; electric furnace, heat-treating 

 steel parts and tempering in an electrically heated oil oven for 

 japanning and baking foundry cores ; besides various other in- 

 dustrial heat applications, electric vehicle charging, and better 

 lighting equipment of industrial establishments emphasized by 

 an exhibit of four miniature models of machine shops. The re- 

 sults of research work in the insulating material field made an 

 unusual display. 



