. The street railway review . been very materially reduced, and carefulinspection reveals these fractures; and when the fracture showsvery plainly and opens the axle is taken out. But many of themare not found, because of carelessness during inspection. Then ultimately the axle will break with the central action of the materialin perfect condition at the time of rupture; all the rest has beenhammered during service, so that it is all polished. But the fracturedocs not occur uniformly. Some of these rings are wide and othersare narrow. I have one axle in my office which has at least sixtysuch d
. The street railway review . been very materially reduced, and carefulinspection reveals these fractures; and when the fracture showsvery plainly and opens the axle is taken out. But many of themare not found, because of carelessness during inspection. Then ultimately the axle will break with the central action of the materialin perfect condition at the time of rupture; all the rest has beenhammered during service, so that it is all polished. But the fracturedocs not occur uniformly. Some of these rings are wide and othersare narrow. I have one axle in my office which has at least sixtysuch distinct rings, which shows that it broke on sixty aififerentoccasions. That is the way axles break. They do not breakbecause they are weak. They do riot break because the static loadsare too great. They simply break because of the enormous impactin crossing over frogs, and they break very gradually. Mr. E. D. Estrada in the same discussion submitted a sketch,Eig. 9, showing the end of a street railway axle broken on a Pitts-. SROKEN JOURNAL. burg road in the manner described by Mr. Henning. Tensile andchemical tests did not show anything which in Mr. Estradas opin-ion would warrant adverse criticism of the material. Most axles break in cold weather. They do not break because,as has some times been stated, the metal becomes weaker as thetemperature decreases, but because the roadbed is frozen hard andis more unyielding, thus causing a severer shock. Experimentsmade by Prof. R. C. Carpenter (Trans. A. S. M. E., vol. xvii., ), show that the tensile strength of iron and steel increases asthe temperature falls between the limits of -{■ 70° F. and — 60° F. Professor Dewar found that at very low temperatures iron andsteel became brittle, but the tensil strength was greatly iron which at -J- 59° F. had a resistance in tension of 34 tonsper sq. in., at — 292° F., had a resistance of tons; for a speci-men of steel the figures were tons and 60 tons
Size: 2784px × 898px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., book, bookcentury1800, bookdecade1890, booksubjectstreetrailroads
