Page:Steamlocomotivec00ahrorich.djvu/50



Axles. As an example of a locomotive forging a simple straight axle may be taken to give an idea of the principles involved. Such axles are made from steel “blooms,” which may be described as long thick blocks of steel supplied from the steel works. An axle bloom is about 5 ft. long × 9½ ins. square, the corners being rounded or chamfered off. The end of the heated bloom is placed under the steam hammer and hammered into a circular form. The next operation is to form the journal portion and the collar of the shape shown in Fig. 10. To this end special blocks or dies of steel are machined out to the shape of the forging required. The bottom die fits into the anvil of the steam hammer, the top one being held by the forgeman. The axle is placed on the bottom die, and the hammer brought down upon the back of the top die, and by gradually turning the axle round, it is brought to the required shape. The middle of the axle is circular and is simply hammered