23
means, has this been done? At junctions where the signals and points are worked on the interlocking system, so long as the signals are at “all-right,” it is impossible for the signalman to move his points while a train is passing them; but if the signals are put to “danger” before the train is quite past the junction points, they are at liberty to be shifted, so far as the interlocking gear is concerned. Opinions differ very much (as I have remarked) as to whether facing points can be moved from the signal-box during the time that a train is passing them, so as to alter the course of some part of it after the signals have been put to “danger,” but I have not the slightest hesitation myself in saying that it can be done. It does not altogether depend upon the distance the wheels are from each other upon the carriages, or the space that there is between the wheels of one carriage and the wheels of that following it; it is the amount of strain that the signalman is able to put upon the thin end of the point with his lever. This is very great, and constitutes all the danger there is in placing the signals at “danger” before the train has passed through the points. The rod leading from the lever is attached to the weakest part of the points, viz., about two feet from the thin ends. The length of facing points is from sixteen feet downwards; the space between the wheels upon the different classes of vehicles runs from fourteen feet downwards; and the distance between the wheels of one vehicle and those of the next one following it—measuring from that part where they rest upon the rails—is from twelve feet downwards, but this distance is increased according to the strain upon the drawbar, which depends upon the length and weight of the train in motion. The thin end of a pair of facing points can be jerked far enough open, while a train is passing over at great speed, for the wheels of any carriage to strike them on the reverse side, as soon as the wheels of the previous carriage have travelled about two-thirds the length of the points. Thus it will be seen, that in any of the above-named distances between the wheels upon a vehicle, or between the wheels of one vehicle and those of that following it, if the signals are placed at
