When Britain entered World War I, one of its first acts was to order the cutting of German
submarine telegraph cables around the world. At the time, Britain dominated the worldwide telegraph network. The idea was to force German communication on to radio where it could be intercepted more easily. This would give British codebreakers a better chance of gaining useful information. Without telegraph connections, Germany could only directly communicate with locations outside Europe through its
high-power radio transmitter at Nauen. This included its African colonies and the United States. A few hours after war was declared at 11 p.m. on 4 August 1914,
Alert was sent out from
Dover on a planned mission to drag for, and cut, German cables in the English Channel. On board, and in charge of the operation, was Superintendent Bourdeaux. He was the only man on board who knew the purpose of the
Alerts secret mission as she set sail, and it was his job to ensure the correct cables were cut. There were five cables in the Channel linking Germany directly to France, Spain and the Azores, and indirectly to the rest of the world.
Alert was not accompanied by a
Royal Navy escort (none could be spared), which put her in danger of interception by German warships. Four cables were cut overnight, starting with the cable to Spain. In deteriorating weather,
Alert struggled with the fifth cable, losing many of the
grapples in her store to damage. A flotilla of unidentified destroyers was spotted approaching, but
Alert continued her work and succeeded in cutting the cable just as they arrived. The destroyers turned out to be French, and after interrogating
Alert and discovering she was cutting German cables, the French crew raised a cheer. Cutting the channel cables almost completely cut off telegraph connections to Germany. Many sources incorrectly report that the Channel cables were cut by . It has been established from archives that this is not the case and that CS
Alert was the ship responsible. One of the most serious consequences of the cable cutting for Germany was that Britain was able to intercept and decode the
Zimmermann telegram. This was an attempt by Germany to make a secret alliance with Mexico who stood to gain United States territory as a result. Without a secure telegraph connection of their own to the Americas, the Germans were allowed to use the US diplomatic telegraph link, which the US believed would assist peace efforts. Unfortunately for the Germans, this supposedly secure route went through Britain and was listened to by British intelligence. The British claimed they had intercepted the telegram in Mexico to avoid the embarrassment of admitting they were listening to American diplomatic traffic. The revelation of this German duplicity was partly responsible for the US later entering the war. == Post cable-ship history ==