NEW RAILWAY SIGNALS

Dominion, Volume 15, Issue 56, 30 November 1921, Page 9

NEW RAILWAY SIGNALS

AUTOMATIC SYSTEM FOB THE WELLINGTON-HUTT LINE. Signal appliances which are now being erected along tho railway lino between Wellington and Upper Hutt aie of a class new in this country, and are operated electrically, without human intervention. With this system, a Hue can bo fitted with signals at short intervals, and it is possible to have a train on each section of lino between adjacent signals. On oaech post is a small electric motor, geared to the signal arm, and the method of operation is that when tho lino is clear for traffic the apparatus receives current, and the motor brings the signal arm to the "clear” position. If a train enters the section controlled by a signal, the current, which is carried by the rails, is switched off from the relay controlling the motor by traversing the wheels and axles of the train, and the signal promptly falls to the "stop' position. At the same time the signal next behind the advancing train, which was previously at "stop,” is operated by a different set of electrical connections, and moves to an intermediate position which, warns the driver of a following train, that he is to proceed with caution. Any mishap which prevents current reaching the signal motor, such as a break in a rail, or the failure of any of the electrical apparatus, will cause tho eigmal to fall to the "stop” position. The "clear" position can thus only be given when there is no train on the section of line, and when the apparatus is all working properly. An important difference between the present signals and the new ones is the introduction of the third "cautionary ’ position. The manual signal arms point horizontally for "stop," and are dropped to an angle of forty-five degrees for "proceed.” The new signal will be horizontal for "stop,” and will rise to on angle of forty-five degrees for "caution," and to a vertical position when the line is clear. The night signals are also varied; Red now signifies stop, and green clear. With tho new installation the same colours will be retained. with the same meaning!. For "caution” a yellow light will show. The coloured glass used for these yellow lights has been specially made so that the light which passes cannot be mistaken for either green or icd, even by people with bad colour perception. The coloured glasses are attached to the signal arm, so that they come in front of a fixed white light, as in the older signal apparatus.