THE LATEST IN SIGNALLING.

Otago Daily Times, Issue 20287, 21 December 1927, Page 6

THE LATEST IN SIGNALLING.

INT E RESTING EXPERIMENTS. The rerrfarkablc progress which the British railways have made in signalling during recent years is due hot so much to the desire to secure a greater degree of safety as to the recognition of tho fact that improved methods enable traffic to be handled more expeditiously, with (lie result that tho capacity of anv given section, of lino can be increased. In this connection it is interesting to record the Institute of Railway Signal Engineers has decided to admit to its membership anyone engaged in railway operation who represents a practical realisation of the necessity of traffic officers having a knowledge of signalling methods (says the Observer). One of the most striking recent innovations is the so-called “colour-light” signal, in .which tho customary semaphore arm is eliminated, the lights being kept burning throughout the 21 horn's. This type of signal, which has a much more penetrating effect in fog than the orthodox pattern, is used on the London and North-Eastern s Wemblov line, and has been _ standardised on (he Southern’s newly-electrified sections, where one signal gives as many ns four indications to tho driver by moans of a corresponding number of lamps, Ihe latest development in this direction is to be found at the York road terminus at Belfast, one of the Irish sections of the fondon. Midland, am] Scottish, whore an elaborate new installation lias just been finished. . , , A notable feature of this Irish installation is that the colour light signal is also used for the control of shunting movements In place of the former semaphores, the whole of the signalling is now by means of red, green, and white Edits. The shunting signals arc so designed (bat while there is "a white and green light for each track, only one red or “danger” light is required for a number of lines. Tho economy of the system is further illustrated by the fart that in one -instance a bridge earryin"- eight signals has been replaced by a single group of lights, controlling four tracks. This has been made possible by (be use of what is known as the route '■ rbratnr.'' '--bir-h mv-v'drs any one «<gnnl nr set of signals for as many tracks ns desirable, but indicates the bne for which (he cie-nal is sot bv means of a frame displaying Ihe number of the platform for which the road :« clear. Anv desired mmhpr of cur’ll iWl’Vnfions r, no no rombinH with one signal. (bn= eliminating the forest of semaphore arms otherwise necessary at la i-gp s( at inns. The mule indicator, of winch one of the earliest installations was at Paddington, is not new. but its ,-ornlrnation on so -arm a scale with colour light signals is a notable development.