SECRET CENTRE

New Zealand Herald, Volume LXXVIII, Issue 23995, 19 June 1941, Page 6

SECRET CENTRE

DEFENCE OF BRITAIN

COMMUNICATIONS NETWORK ARMY SIGNALS SYSTEM LONDON. May 14 Every applicable contrivance of modern science is being used to give military communications in this country a supple strength capable of withstanding the assaults on them which, in the light of what happened in France would be one of the earliest phases of any attempted invasion, says a special correspondent in the Times. I have just visited the signals station at G.H.Q., the nerve centre of an astonishing network that has been established since Dunkirk, through which the General Staff could get into immediate touch with almost any unit of the Home Forces, cutting out if need be the normal link with the various Commands. Underground Labyrinth The underground labyrinth of G.H.Q., with its mysterious galleries, red lights, and general air of secrecy, is a little reminiscent of the control rooms of a Maginot fortress. The signals station is clearly one of its most vital parts for the link it must maintain between the operations room and field formations. So many means of communication have been devised that the chances of all being put out of action, I was assured, are remote. Military communications to some extent use Post Office circuits from which direct private linos are maintained by Army specialists, many of whom were Post Office technicians of high skill. The usual means of transmitting and receiving messages is by teleprinter. M any of these machines, in direct communication with the Commands, are installed in the teleprinter room, where an hourly check is made on a switchboard —more frequently in periods of heavy air raids —to ensure that each line is working. Part for Actual Battle Then the station has its own telephone exchange, controlled by women operators from the Post Office, with more private lines to the Commands, the war rooms of the Cabinet, the Admiralty and War Office, the Ministries, and so on. One section of the switchboard, labelled significantly "combined operations panel," is set apart for actual battle, and to this only a limited number of officers of the General Staff would have access. Many lines are reserved for the Commands of the Koj*al Air Force: Every precaution is taken against the use of the telephone for the transmission of false messages. Should the telephone system with each of its alternative routes break down entirely, there is a reserve system of wireless transmission. As a general rule all wireless messages from so far back are sent in cipher—only forward formations would use wireless en

dair—and some of the most interest- ; ing moments of my visit were spent 111 the cipher room, with all its cryptic devices. Here the idea was dispelled that the use of cipher necessarily involves delay, j for an almost uncanny •electrical j machine exists by which messages may ' be enciphered or deciphered with the speed of an ordinary transmitter. All i tlie operator does is to put in a message j in plain language and it comes out in ; cipher ready for despatch, and the same I operation is carried out the other way j round.

Finally, if all else failed, there is a small army of despatch riders at general headquarters, who normally maintain a service of letter delivery; but a good deal would have to happen before it came to that