STEEL CAR INDUSTRY, The. The building of steel railroad cars is recognized as one of the most prominent of our industries. European countries were pioneers in the use of iron cars, and as early as 1861 we find records of cars with iron bodies being built in France, while in India, iron was substituted for •wood at an early date, as the latter material was par ticularily susceptible to the attacks of ants and other insects, which condition necessitated the use or iron or steel in the construction of equip ment for use on the railroads of that country. In other foreign countries the selection of iron for this purpose was undoubtedly governed largely by the comparative cost of iron and wood, which in many instances favored the use of the former material, and also for the reason that climatic conditions in many of these countries are such that wooden cars rapidly dis integrated. To the American engineer, how ever, should be given the credit of foreseeing the possibilities of steel in car construction, not solely from a constructive standpoint, but as a scientific solution of the problem of economical transportation. The successful operation of a railway is dependent on the relative cost of transportation, and the use of steel in car con struction has made it possible to decrease to the minimum the percentage of dead weight to that of paying load. The progress made in the proper appreciation of the stresses to which the different parts of a car are subjected has re sulted in great improvements, providing ample strength for the duties imposed on the several parts, eliminating superfluous material where it may be done without detriment to the car as a whole, thus producing, in steel, cars of minimum weight and maximum strength. This favorable comparison of percentage of dead weight to paying load is much more evident in the higher capacity cars, where the full benefit of the dif ference in strength between wood and metal may be realized.
-The capacity of freight cars in this country has been continually on the increase, and con stant efforts are being made to reduce the rela tive proportion between weight of car and weight of Fading. Up to 1876 the average
ft eight car had a carrying capacity of 20,000 pounds, while the ratio of paying load to total weight of car and lading was about 47 per cent. In 1880 the capacity had been increased to 40,000 pounds, and the ratio of paying load to 60 per cent; in 1883 to 50,000 pounds and 65 per cent; in 1889 to 60,000 pounds and 66 per cent ; in 1895 to 80,000 pounds and 68 per cent; and in 1903 to 100,000 to 110,000 pounds and 75 to 79 per cent, respectively.
In the catalogue of all-steel cars manufac tured in 1918, the largest load capacity is that of the 120-ton gondola car. It is 50 feet in length, 9 feet 8 inches in width and with walls 7 feet 4 inches high above the floor level. This car weighs about 74,000 pounds and with its full load represents a total weight of 314,000 pounds — the paying load approximately 77 per cent. The standard all-steel 50-ton box (freight) car varies in weight from 43,100 pounds to 52,600 pounds. It ranges in inside length from 36 feet to 40 feet; from 8 feet 6 inches to 9 feet in inside width, and from 8 feet 4 inches to 9 feet 2 inches in inside height. The higher weight car carries a paying load of 70 per cent of the total weight; the heavier car a paying load of about 66 per cent. Hopper cars for coal carry 100 tons upon a car weight of 60,000 pounds to 75,300 pounds, the paying load thus ranging from 77 to 73 per cent of the total rolling weight. The 100-ton flat car and the 110-ton well-hole car, weighing respectively 90,000 pounds and 92,000 pounds, have still lower paying efficiency. However, when durability is considered, the heavy cars are more economical in the long run, and with their far greater burden serve to roll up the record of ton-miles • with far greater rapidity than the light car of smaller burden. The modern all-steel passenger coaches range in weight from 116,000 to 146,000 pounds, and the dining-cars, the heaviest of all standard coaches, reach 175,000 pounds.