. Railroad construction, theory and practice; a text-book for the use of students in colleges and technical schools, and a hand-book for the use of engineers in field and office . merit of cheapness with adaptability to the circum-stances of very light traffic operated at slow speed when a con-siderable element of danger may be tolerated for the sake ofeconomy. The rails from A to 5 (see Fig. 135*) are not fastened * The student should at once appreciate that in Fig. 135, as well as innearly all the remaining figures in this chapter, it becomes necessary touse excessively large frog angles, sh
. Railroad construction, theory and practice; a text-book for the use of students in colleges and technical schools, and a hand-book for the use of engineers in field and office . merit of cheapness with adaptability to the circum-stances of very light traffic operated at slow speed when a con-siderable element of danger may be tolerated for the sake ofeconomy. The rails from A to 5 (see Fig. 135*) are not fastened * The student should at once appreciate that in Fig. 135, as well as innearly all the remaining figures in this chapter, it becomes necessary touse excessively large frog angles, short radii, and a very wide gauge inorder to illustrate the desired principles with figures which are sufficientlysmall for the page. In fact, the proportions used in the figures are suchthat serious mechanical difficulties would be encountered if they wereused. These difficulties are here ignored because they can be neglectedin the proportions used ia practice, 338 RAILEOAD CONSTRUCTION. §299. to the ties; they are fastened to each other by tie-rods whichkeep them at the proper gauge; at and back of B they aresecurely spiked to the ties, and at A they are kept in place by. Fia. 135. - Stub Switch. the connecting bar (C) fastened to the switch-stand. One greatobjection to the switch is that, in its usual form, when operatedas a trailing switch, a derailment is inevitable if the switch ismisplaced. The very least damage resulting from such a derail-ment must include the bending or breaking of the tie-rods of theswitch-rail. Several devices have been invented to obviate thisobjection, some of which succeed very well mechanically, al-though their added cost precludes any economy in the total costof the switch. Another objection to the switch is the loosenessof construction which makes the switches objectionable at highspeeds. The gap of the rails at the head-block is always con-siderable, and is sometimes as much as two inches. A driving-
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Keywords: ., bookauthorwebbwalt, bookcentury1900, bookdecade1920, bookyear1922
