K. MECHANICS AND ENGINEERING. 393 



ROLLING RAILWAY AXLES. 



A. communication was recently made to the British Asso- 

 ciation upon a method for shaping railway axles by rolling 

 pressure instead of by hammering, the result being accom- 

 plished in two minutes instead of half an hour, as required 

 by the usual method, the axle at the same time being not 

 only superior in quality, but more uniform in size, and of 

 course capable of being jn'oduced more cheaply. The ma- 

 chine consists of three rollers, regulated so as gradually to 

 press more closely together, thus reducing the diameter of 

 the bar, and extending its length until shaped to the size re- 

 quired. Axles of any length can be rolled in this manner 

 with collars at any part. The rollers are geared to revolve 

 in all the same direction, their friction imparting motion to 

 the axle. It was thought by the author of the communica- 

 tion that the rolling process would tend to obviate those flaws 

 in axles which so frequently cause disasters on railways. 

 5 A.October, 1870,441. 



TESTING OF RAILWAY AXLES. 



In view of the results of a recent accident in England, 

 caused by the breaking of a railway car axle from the un- 

 soundness of the material, by which eighteen persons lost their 

 lives, Sir Joseph Whitworth, the eminent English mechani- 

 cian, urges the great importance of the use of every possible 

 means for detecting the unsoundness of the iron used in axles 

 of railway carriages. As the best method for this purpose, he 

 advises the drilling of a hole through the centre of its axis for 

 its entire length, thus opening to inspection and examination 

 that part of the material which, in the case of ordinary man- 

 ufacture, is most subject to flaws. The hole should be about 

 one inch in diameter, and with suitable mechanical arrange- 

 ments might be drilled at an average cost of about thirty- 

 seven cents per axle. With the outside turned and the inside 

 thus exposed to view, a serious flaw in the axle, which is only 

 about four and a half inches in diameter, could hardly escape 

 discovery. This plan will also diminish the tendency of the 

 axle to get heated, by removing the material near the neu- 

 tral axis, and, under the circumstances, would reduce the in- 

 ternal strain, and thus render the axle safe. 3 A, Aug. 5, 103. 



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