Cyclopedia of applied electricity : a general reference work on direct-current generators and motors, storage batteries, electrochemistry, welding, electric wiring, meters, electric lighting, electric railways, power stations, switchboards, power transmission, alternating-current machinery, telegraphy, etc. . ght at one time that a continuous rail would bean impossibility because of the contraction and expansion of the railunder heat and cold, which, it was thought, would tend to pull therails apart in cold weather and cause them to bend and buckle out of line in hot weather. Experi-ence has c
Cyclopedia of applied electricity : a general reference work on direct-current generators and motors, storage batteries, electrochemistry, welding, electric wiring, meters, electric lighting, electric railways, power stations, switchboards, power transmission, alternating-current machinery, telegraphy, etc. . ght at one time that a continuous rail would bean impossibility because of the contraction and expansion of the railunder heat and cold, which, it was thought, would tend to pull therails apart in cold weather and cause them to bend and buckle out of line in hot weather. Experi-ence has conclusively shown, how-ever, that contraction and expan-sion are not to be feared when thetrack is covered with paving ma-terial or dirt. The paving tendsto hold the track in line, and toprotect it from extremes of heatand cold. The reason that con-traction and expansion do notwork havoc^on track with weldedjoints is probably that the rails have enough elasticity to providefor the contraction and expansion without breaking. It is foundthat the best results are secured by welding rail joints during coolweather, so that the effect of contraction in the coldest weatherwill be minimum. In this case, of course, there will be considerableexpansion of the track in the hottest weather, but this does not cause. Fig. 228. Wolhaupter Joint 336 ELECTRIC RAILWAYS 239 serious bending of the rails; whereas occasionally, if the track iswelded in very hot weather, the contraction in winter will causethe joint to break. Cast-Welded Joints. The process of cast-welding joints con-sists in pouring very hot cast iron into a mould placed around theends of the rails. These moulds are of iron; and to prevent theirsticking to the joint when it is cast, they are painted inside witha mixture of linseed oil and graphite. Iron is usually poured sohot that, before it cools, the base of the rail in the center of the moltenjoint becomes partially melted, thus causing a true union of the steel
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Keywords: ., bookauthoramericantechnicalsoci, bookcentury1900, bookdecade1910
