Wireless in the Submarine War
Submarine warfare played a major part in World War 1 and some historians consider it to have been just as important as the trench battles on the Eastern Front. In most cases the submariners war gained many more victories (and caused great losses) in a much quicker fashion than the trenches. The submarine war played its part in starving out Germany and bringing a halt to the war just by barricading trade and supply routes.
It is highly probable that without the use of submarines the war would have dragged on for many more years and possibly resulted the in complete destruction of Europe.
Critically if Germans had not used the submarine when it did in sinking the RMS Lusitania the war might have also taken a different course.
By 1915 Germany had declared the seas around the United Kingdom to be a war-zone, and the German embassy in the United States had even placed a newspaper advertisement warning people not to sail on the Lusitania. On the afternoon of 7th May, Lusitania was torpedoed by a German U-Boat, 11 miles (18 km) off the southern coast of Ireland and inside the declared 'zone of war'. A second internal explosion sent her to the bottom in 18 minutes.
Of the 1,959 passengers and crew aboard Lusitania at the time of the sinking, 1,195 lost their lives that afternoon in the waters of the Irish channel. Just as had been seen with Titanic, most of the casualties were from drowning or from hypothermia. In the hours after the sinking, acts of heroism amongst both the survivors of the sinking and the Irish rescuers who had heard word of Lusitania's wireless distress signals brought the survivor count to 764. By the following morning, news of the disaster had spread around the world. While most of those lost in the sinking were either British or Canadians, the loss of 128 Americans in the disaster, including American writer and publisher Elbert Hubbard, outraged public opinion in the United States.
Almost two years later, in January 1917 the German Government announced it would again conduct full unrestricted submarine warfare.
This announcement together with what became known as the 'Zimmermann Telegram' pushed US public opinion over the tipping point, and on 6th April 1917 the United States Congress followed President Wilson's request to declare war on Germany.
The Zimmermann Telegram was intercepted and decoded by the British cryptographers of Room 40. The telegram's message was a coded wireless telegram dispatched by the Foreign Secretary of the German Empire, Arthur Zimmermann, on 16th January 1917 to the German ambassador to Mexico, Heinrich von Eckardt.
The telegram instructed Ambassador Eckardt that if the U.S. appeared likely to enter the war, he was to approach the Mexican Government with a proposal for military alliance, with funding from Germany. Mexico was promised territories in Texas, New Mexico, and Arizona that had been lost to the United States starting in 1836 as parts of the former Republic of Texas, and in 1848 with the Mexican Cession. Eckardt was also instructed to urge Mexico to help broker an alliance between Germany and the Japanese Empire. Mexico, unable to match the U.S. military, ignored the proposal and after the U.S. entered the war, officially rejected it.
The Zimmermann Telegram's main purpose was to make the Mexican government declare war on the U.S., which would have tied down U.S. forces and slowed the export of U.S. arms. The German High Command believed they would be able to defeat the British and French on the Western Front, and strangle the UK by unrestricted submarine warfare, before American forces could train and arrive in Europe in sufficient numbers.
The sinking of the Lusitania and the wireless intercept of the Zimmerman Telegram brought America, along with her almost unlimited industrial capacity and military forces into the World War. Had they not joined the allied cause then the war would have been prolonged, the allies may even have lost or the war may well have continued to a inevitable stalemate.
The D class submarine was the Royal Navy's first class of submarines capable of operating significantly beyond coastal waters. They were also the first boats to be fitted with wireless transmitters. Before WW1 started, no fewer than 26 British submarines were fitted with W/T with a further two Commonwealth boats of the 'E' Class. In the bigger boats, the D and E Classes the overall aerial height was 35 feet, but in a small boats, the B, C and X Classes the aerial was 30 feet.
On the submarine deck were stowage position for each of the three support masts which had to drawn upright to make the wireless system operational. It must have been some task lowering these masts at the order 'open up for diving' and fortunately in WW1 anti-submarine aircraft patrols were rare. But in many circumstances the Skipper did accidentally dive with the aerial still fully rigged and taut as there were no set procedures or Standing Orders for wireless operation. The turbulence caused by such a large mass of wire aloft would have created some all telling noises plus the very obvious danger of anything snapping and ending up wrapping itself around the screws or hydroplanes.
Until 1916, German U-boats had to carry bulky long-wave radio equipment, which were limited to shorter-range (200–300 miles) radio links. As vacuum tube technology made possible longer-distance sending and receiving, German submarines shifted their attacks farther into the Atlantic. In January 1917 the German Government announced it would again conduct full unrestricted submarine warfare.
British submarines had spectacular successes in the Baltic and the Dardanelles but they were in these areas for only a short period of time. They played a vital role in the North Sea for the duration of the war and though they had less 'spectaculars', they made a huge impact on the outcome of the naval campaign. The most important role the submarines had was to assist the blockade of Germany's coastline.
Even in 1916, the Admiralty used the submarines in the North Sea for reporting information as opposed to attacking enemy ships. To force the German fleet into an open conflict, British submarines were used to report to the surface fleet when a German ship had left port giving its position, speed and direction. Such information was usually passed on by pigeon or wireless set. However, in order not to scare off the German fleet, British submarines were not allowed to attack a German ship in case this forced them to remain in harbour.
For a large part of the war, British submarines in the North Sea were used for observation purposes and then that information was passed on; they were also used to fill in mine fields swept by the German Navy. Ironically the mine became one of the submarines worst enemies with twenty British submarines lost to this weapon.
A new period of intelligence gathering followed the capture of the cruiser Magdeburg’s codebooks by the Russians in the Baltic. The Admiralty received one of the codebooks and was able to decipher all W/T messages from October, 1914 onwards. Room 40 was the hub of the transcription effort. In due course, cryptographers working here mastered the art of deciphering German W/T from throughout the war area. In this way, the Admiralty pieced together a highly accurate picture about Imperial submarines.
'As soon as a U-boat began to operate in our waters, her presence and her position were known, as a rule, first vaguely by wireless or other information, and then in some detail a day or two later when attacks were reported or when survivors from sunk ships had been landed and questioned.'
From the beginning of the war, the chain of direction finding (D/F) stations in Britain and, later, in the Mediterranean roughly determined the position of German warships whenever they used wireless transmissions (W/T).
The positioning was imprecise, accurate only within a 5 to 50 mile radius, but that was enough to give the Royal Navy a fix. Message traffic to U-boats from Germany (Nauen transmitter) or Austrian bases (Pola transmitter) were received simultaneously by all submarines at sea and the Royal Navy. The range of normal W/T by ocean-going submarines was several hundred miles. In the Atlantic, the boats rigged the wireless telegraphy mast on deck to be able to send and receive messages. Rigging antenna put the boat at risk in a diving emergency. As long as the submarine was in normal W/T range its position was sent every four hours. Returning from a cruise in the Atlantic a more fulsome report was delivered, including lists of ships sunk and other important news.
Although submarine commanders knew that D/F could roughly identify their position they never suspected any kind of a systematic deciphering of their message traffic by the Royal Navy. The Admiralty knew the numbers of submarines in service, their bases and tactical units, the deployment schedule, crew morale and how many new submarine orders had been placed. Unfortunately due to torturously slow intelligence dissemination, commanders at sea got little benefit. Often, twelve or more hours elapsed before destroyers arrived at a location where a U-boat had last been spotted.
Consequently, only a handful of submarines were sunk as direct consequence of deciphered W/T or D/F. Deciphering played a more important part in 1917/18 when it helped to redirect convoys from identified submarine positions.
Aircraft support was equally ineffective. Aircraft were slow, relatively scarce and had a limited range. Anti-submarine surface ships were equipped with an imprecise a passive noise detection device, the hydrophone. Depth charges first came into use in 1915/1916. In the first two war years, deck gunnery and ramming were the chief submarine killers. Admiral Beatty could not have been more succinct when he summed up the dilemma as 'looking for a needle in a bundle of hay, and, when you have found it, trying to strike it with another needle.'
Insiders were not blind to the system’s deficiencies. They were quite conscious that precious time was being lost in the process from deciphering to analysis to reaching the front, and that coordination between the army and navy never mind other intelligence branches, was severely wanting. Assigning blame reached a peak in the summer of 1916 when Room 40 deciphered German naval messages during the running Battle of Jutland a scant few minutes after they had been sent, but could not expeditiously pass them on to Admiral Jellicoe. It has been argued that the intelligence failure denied him the opportunity to annihilate the High Seas Fleet. The battle outcome was inconclusive. The Germans escaped. Reorganisation of Room 40 followed, but it was not before 1918 that the system worked to the satisfaction of its staff and the benefit of the Royal Navy.