The Caterpillar 100 Ton Electric Drive Truck Ralph H. Kress Caterpillar Tractor Co. Earthmoving Industry Conference Central Illinois Section Peoria, Illinois April 5-6, 1966 660228 Downloaded from SAE International by University Of Newcastle, Friday, August 10, 2018660228 The Caterpillar 100 Ton Electric Drive Truck Ralph H. Kress Caterpillar Tractor Co. SEVERAL YEARS AGO, one of our top officials in Caterpillar coined a word out of a question sentence that has been a challenge to our refinement and research work. He asked "Is there a better way of doing it?" The first letter of each word in the sentence makes a word that pronounces rather easily, it is "Itabwodi." As we began design work on our new 100 ton truck, we kept "Itabwodi" prominent at all times. The desirable goal we were working toward was not con­ troversial. We simply wanted more productivity and better reliability than present haulers have. How to accomplish this, of course, does introduce many possible variations. Large capacity is always desirable, par­ ticularly as we look forward to the gigantic mining and con­ struction jobs that lie ahead. This large capacity must be measured in terms of greater productivity as it is quite ap­ parent that if a larger truck moves slower and maneuvers more awkwardly, it may not get any more work done than a smaller, less expensive unit. With these goals in mind, and appreciating the wisdom of our guide word Itabwodi," we realized that we must have a larger, more powerful engine than has been available for a vehicle in this country before, if we wanted to make a successful truck in the 100 ton class. This high horsepower development has been a long-range program with Cater­ pillar and we were fortunate to have a 1000 hp unit in the advanced concept design before we started our truck pro­ gram. With this basis, we then were assured that we could build a 100 ton truck that would have a power-weight-ratio equal to or better than any of the smaller vehicles presently available. This gave us the assurance that the productivity of our 100 ton truck would not only be greater in proportion to its increased capacity, but also equal to or better in ac­ celeration and hill climbing than any existing trucks of lesser capacity. Our next problem was to design a truck that could also be no more bulky, and, in some instances, less bulky than trucks of lesser capacity. As a guide line, we kept 15 ft overall width and 35 ft overall length and a turning circle of not more than 60 ft, as limiting dimensions to keep within established sizes of 50 - 65 ton trucks now in service. We also had to look for better materials to keep our over­ all weight to a minimum and our strength factors to a max­ imum to carry our expected payload, with maximum dur­ ability. Since the weight of the vehicle and the payload must be carried on rubber tires, we had to consider the di­ mensional size of these higher capacity tires, and also the number of tires it would take to carry our gross load. Our careful study indicated that we could make a more compact and more maneuverable vehicle by using eight 21:00 x 49 tires rather than six of any larger size. Concurrently, in designing this 100 ton truck, we also ABSTRACT Design features of the 100 ton electric drive truck de­ veloped by Caterpillar are discussed. Salient features of this vehicle are its power-weight ratio which is equal to or bet­ ter than many small vehicles, and its maneuverability which enables it to turn within a 52 ft SAE circle. Two additional items mentioned are the use of electric power for smooth shifting of the vehicle and oil-cooled friction brakes for control of the truck under any stopping or retarding require­ ment. Present testing indicates this vehicle will make a worth­ while contribution to the better handling of construction ma­ terial. Downloaded from SAE International by University Of Newcastle, Friday, August 10, 20182 designed