Railway Signalling

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 189? Excerpt: ...if all the essential parts are properly working, that the switches are not only " home" but are lying for the right direction, that the points are plunged, and that the locking bar has been moved, then the signal can be lowered Fig. 320 represents Messrs. Dutton & Co.'s arrangement for working points, facing-point lock and bar, by one lever, which is illustrated here for the purpose of showing the detector. The arrangement illustrated is a lock for facing points on a single line of way, where trains run in one direction only. The points as seen in the illustration are lying for the right road, are bolted, and the signal is lowered. The rod a from the cabin is connected to the crank b to which is also attached the lock bar c (preventing the points being moved when a train is on them) and the plunger /which bolts the rods e e--one attached to each switch. In this apparatus the final movement of the rod (viz., that of plunging the rods from the switches) cannot be performed unless the points are properly over. One arm of the crank b does no work during the first movement of the crank until it engages in the escapement crank/ and to this are attached the switches. It will be seen from the illustration that the first operation is to raise the bar c and withdraw the plunger d and then move over the switches. In addition to the rods e e being plunged, they are separately detected at g. Fig. 321 shows an improved detector introduced by Messrs. Dutton & Co., having for its purpose the detection of the points, the plunger, and locking bar as is done by the Griffith's detector. need anything be said about the plunger not being able to bolt the points in case the connection between the switches failing, and so causing the divided stretcher rod to sepa...