AS THE WORLD REMEMBERS the bravery and sacrifices made by the Allied soldiers and airborne troops who took part in the D-Day landings 70 years ago today, BT recalls the technology that made the invasion possible.
BT, then the Post Office and a public organisation, was instrumental in laying a telecoms network along the south coast of the UK and then over the Channel and on into Europe as the Allied forces marched towards victory.
BT head of heritage and archives David Hay explained, "Preparations for the Normandy invasion required the laying of a new network of hundreds of miles of cable as well as the installation of switchboards, telephones and teleprinters at numerous points along the south coast of England.
"Once the invasion was under way, new cross-Channel cables were laid and, by VE-Day, Post Office engineers had made direct communication possible by telephone or teleprinter to all allied forces in north-west Europe."
These efforts even earned the praise of General Eisenhower, supreme commander of allied forces in Europe, who wrote:
"The build up of the necessary forces for the current operations has involved the construction of a vast network of communications radiating from key centers of vital importance in the United Kingdom. The greater part of this work has been undertaken by the engineers and staff of the General Post Office."
As well as this vital work, the Post Office also played an instrumental role in helping the Allied forces gather knowledge of the Nazi's plans, thanks to the Colossus computer.
It was developed by telecoms research engineer Tommy Flowers, working at the Dollis Hill research station, now BT's Adastral Park research laboratories. The computer first sprang to life on 5 February 1944 when it was let loose on messages that had been sent by German units and encrypted using the Lorenz machine.
The Colossus could read 5,000 characters a second, far in advance of anything else available at that time, and this meant it could take just four hours for it to find the first key in a code, the most important part in any code-breaking.
By the end of the war, it is estimated that Colossus had deciphered 63 million characters of German messages, helping shorten the war and save countless lives. Despite this, its existence was kept secret for 30 years after the war. µ