Arizona republican., 1919-07-27
EXPERT TELLS HOW AUTO TRA|LERS
 SOLVE HAuLACE PROBLEMS AND A|D
 IN REDUCING TRANSFORMATION COST

$. Light bulky articles. such as emp. ty boxes and barrels, bedding, willow furniture, etc, can be hauled most economically with trailers.
 '. Trailers may be left to be loaded and unloaded while the truck is deliv ering it's own load at another point or the tractor is hauling a loaded semi trailer Thus the idle time of the ex pensive motor vehicle and it's driver is greatly reduced I
 s. Standing time of the trailer is i'm material, as it's operating cost is all most nothing, since it does not involve waiting time of a driver, and interest on investment in the purchase price and other overhead expense is small.
 g. Maintenance and depreciation of trailers are, very low because there is no delicate mechanism to bR0Rk, get out of order or require overhauling or adjusting.
 Manufacturers Recommend Trailers
 So successful has been the operation of trailers with motor trucks, that leading manufacturers of motor trucks in the United States, after careful in vestigation of the advantages and economies of this method of hauling, are now making and listing short wheelbase models of their machines especially for use with trailers and semi traiIers. Other truck makers who have not yet put out such models recommend the use of trailers with their regular models. The special tractor models offered are designed with stronger rear frame member, stronger axles springs and wheels, and are provided with special attachment devices for connecting with the trailer One of these devices is a fifth wheel, mounted horizontally in the truck frame directly over the rear axle This carries the front end of the semi trailer and it's load and is constructed | to have a rocking motion so that the axle of the trailer can rise and fall with relation to the axles of the truck due to inequalities of the road. It also has springs to cushion the pull and thrust of the trailer When four whe eled trailers are to be used. the truck or tractor is provided with pil4tel hook or other device for coupling the spring drawbar of the trailer. In some cases draW-bar is bailt into the truck.
 While of simple construction, trail CTS are designed and built along motor | vehicle engineering lines and regular automobile or truck frames, axles, bearings, springs, wheels and tires are commonly employed. This gives them strength and durability and by con ecting the draw bar with the steering wheels, the trailer is made to follow | in the tracks of the rear wheels or the towing vehcle.
 Triple Truck Capacity
 In the summary already given of the ] chief advantages of the trailer, it was stated that by the use of trailers one truck can oo the work of two CT three This is not only because it can haul one or two additional loads, but be- cause the trailers can be left to be loaded and unloaded while the truck is delivering its own load, thus saving waiting time Where a tractor is used, i that does not carry any load itself, Il can be kept on the road practically all of the working hours of the day except for the few minutes required 10 couple : up to the trailers and to disconnect i them. ] he front end of u e semi trailer is provided with hinged sup ports 50 it may be left 5tlnding any ! where.
 i Tractor and semi trailer equipment is peculiar ly suitable for the lumber trade. in which the making up of loads by hand aften requires an hour or two. To save unloading time. many semi-trailers have rollers fitted across the body bed so that the whole load may Ee rolled off at tho rear as a unit in a very few minutes.
 Pole Trailers for Long Materials Telephone and telegraph poles, very long timbers or logs, derricks, iron ] beams. etc, are hauled on pole trail CTS with tractors or motor trucks. It would be impossible to load these on an ordinary truck. as the ends would trait on the ground or the weight at i the rear would raise the front end Of 1 the truck from the road. Moreover a 1 load two or three times the carrying ! capacity of the truck can be hauled in this way as only one third to one half the weight is sustained by the rear end or the truck. the remaining weight is being carried by the trailer axle and wheels. Thus a five ton truck or tractor hauls ten-ton or fifteen-ton 1 load.
 Less power is required to haul a given load on a trailer than on a truck, because. the trailer has no pow | CT plant or driving mechanism and therefore weighs only one quarter to one third as much as the truck. There
 is no loss of power in the trailer through friction in the transmission mechanism. For these reasons. it is customary to use a one-ton truck with a semi trailer of two to three tons capacity, tw0-ton truck With semi trailer of four, five or six tons capaci- ty and a five-ton truck with a semi trailer of ten to fifteen tons capacity.
 Forty Ton Casting Hauled l Because the weight is divided be- | tween the truck or tractor and the trailer. objects far too heavy to be moved by truck alone are handled in this way A recent example of this was the moving of a forty-ton marine engine cylinder on special trailer having a load capacity of 100000 \ pounds. This huge 40-ton casting was hauled twenty-three miles, from Los i Angeles to San Pedro. on the Pacific coast, in two hours and forty five min utes. To give the 612 ton motor truck sufficient traction. it carried an engine base weighing nearly seven