To further exploit the possibilities of steel in car construction the Carnegie Steel Com pany in 1896 had 'built at the Keystone Bridge Works three all-steel cars, one of these being a steel-flat car and two self-clearing hopper cars, in which the floors are inclined from the ends downward toward the centre and at the bot tom of these inclines doors being provided, which, when opened, permit the load to dis charge by gravity. These cars were exhibited at the conventions of the Master Car Builders and Master Mechanics' associations, held at Saratoga in Tune 1896, and elicited the interest of car builders and railroad men throughout the country. Rolled plates and shapes, which could be purchased in the open market and all of which constituted the product of the Car negie mills, were used in the construction of these cars.
Previous to this time the Schoen Pressed Steel Company, of Pittsburgh, Pa., had for a number of years been manufacturing various parts of cars by pressing plates into special shapes. This company was the first to Intro duce a design of an all-steel self-clearing hopper bottom coal car built entirely from pressed shapes, these being built under patents issued to C. T. Schoen and J. M. Hansen. The prompt and extended adoption of the all-steel car is undoubtedly due to the aggressive policy pur sued by this company and its successor in the introduction of its product. The designs for these cars were placed before railroad engineers shortly after the exhibit of the cars built at the Keystone Bridge Works for the Carnegie Steel Company. The Carnegie Steel Company, own ing and operating the Pittsburgh, Bessemer and Lake Erie Railroad, extending from Pittsburgh to Lake Erie, decided to place in service on this road enough cars to thoroughly demon strate the possibilities of cars built of steel, and early in 1897 placed with the Schoen Pressed Steel Company an order for 600 self-clearing steel hopper cars of 100,000 pounds capacity, it being specified that 400 of these cars were to be of the structural design originally prepared by the Carnegie Company's engineers, and 200 to be of the pressed steel design advocated by C. T. Schoen. At the time of the placing of this order, it may be interesting to note that there was no industrial establishment in the country specially equipped for the construction of steel cars and the Schoen Pressed Steel Company was not able to turn out one com plete car per day. Upon being awarded this order, however, those interested in the Schoen Pressed Steel Company, of which C.. T. Schoen was the executive head, immediately arranged for the extension of its plant and carried on the work of enlargement simultaneously with the construction of the cars, with the result that the entire order for 600 cars were com pleted in nine months, the first car having been completed in June 1897.
Following the order of cars for the Pitts burgh, Bessemer and Lake Erie Railroad, the Pittsburgh and Western Railroad placed with the Schoen Pressed Steel Company an order for 450 pressed steel self-clearing hopper can of 100,000 pounds capacity. These two orders marked an epoch in car construction and rail way freight transportation and the steel car industry was firmly established, and has since grown with phenomenal rapidity. As already stated, the cars for the Pittsburgh, Bessemer and Lake Erie Railroad were of two different designs, one employing rolled sections and the other pressed shapes. As both were along radi cally different lines from previous designs of either wood or metal cars a general description of both types may prove, of interest.
The cars designed by the Carnegie Steel Company were what is known as the hopper bottom type of car, the cubical capacity being about 1,400 cubic feet. The centre sills con sisted of two 15-inch I beams, and the side sills were 12-inch channels with their flanges placed inward. No intermediate sills were used. The plates forming th•. sides of the car extended to the bottom of the side sill channels, and were riveted to the web of same. This latter form of construction was employed on the first sample car, but on later cars was modified by omitting the channel side sills and riveting an angle along the lower edge of the side plates, a second angle being riveted to the plates about 18 inches higher up, both angles extending the full length of the car. The body bolster was of a built-up latticed girder type, and the floor of the car was made up of inclined steel plates and a cross-hood placed at the centre of the car. This car weighed about 37,150 pounds. The car made of pressed steel was similar in general appearance to the above described car, but differed materially in the details of con struction. The centre sills were made of plate, pressed to channel form, being 17 inches deep at the centre and tapering to 10 inches deep at the bolsters. The side sills were of similar con struction, and the side plates were flanged at both top and bottom, the bottom flanges being riveted to the top flanges of the side sills. The body bolsters also were of pressed steel, being trough-shaped in form. This car weighed about 34,350 pounds.