The Battle of the Atlantic
The Battle of the Atlantic was aimed at severing Britain's lifelines. The only country that faced Germany at the beginning of the war was Britain, and being an island it was entirely dependent on raw materials and supplies that from overseas mainly from America and the Commonwealth countries. Even after the entry of the Soviet Union and the United States into the war against Germany, Britain continued to serve as the main base for the fighting in North Africa and Europe, and for providing assistance to the Soviet Union. Due to its geo-strategic location and its crucial role among the Allies, maritime transport to and from Britain was vital during the entire war for its survival and for the development of the Allied war effort.
The successful German experience of submarine warfare in World War I, which almost defeated Britain in that war, transformed the submarines as a main weapon of the Germans in World War II as well. This was so especially since the German navy was inferior to its British rival and the investment in building a strong fleet of this kind seemed less promising in terms of cost / benefit time and space compared with submarine investment. In fact, Nazi Germany succeeded in setting up a modern and formidable weapon in World War II, which almost succeeded in defeating Britain. At the head of the German navy's submarine arm was Admiral Karl Doenitz (Hitler's successor as the Fuhrer of Germany after the he committed suicide towards the end of the war).
During the war, the Germans built 1,162 submarines, of which 830 were operational. At no time during the war did the Germans have more than 240 operational submarines (and usually only a few score). This arm managed to sink 5,150 Allied ships during the war, with a displacement of 21 million tons.
The three main factors that enabled the Allies to deal with the German submarines and eventually even to win against them were: Intelligence - in fact the ability to decipher the German messages that were encoded in the Enigma code transmitters, the radar installed in Allied ships and aircraft, which detected the submarines from afar and the usage of the Air Force in the war at sea. Furthermore the American capability to build ships during the entire war was a decisive counter to the capability of the German submarines to sink Allied shipping..
The Battle of the Atlantic is divided into six main stages:
Stage I: From September 1939 until the fall of France.
Stage 2: From June 1940 to the "lend-lease"" agreement.
Stage 3: From April 1941 to Pearl Harbor.(7th of December 1941)
Stage 4: From January 1942 until the sinking of Convoy PQ 17
Stage 5: From July 1942 until the withdrawal of the German submarines.
Stage 6: June 1943 to May 1945.
The war against the submarines.
The reasons for the success of the war against the submarines are:
1. Significant improvement in the organization of the convoys and their escort by American warships.
2. The use of advanced radar(and distance and direction measurement) techniques based on a very short wave length made it easier for long-range reconnaissance aircraft to locate and attack German submarines using aerial depth-charges .
3. British Intelligence by using the Enigma machine was able to decipher the German submarine transmissions, at sea, enabling them to monitor their movements, especially regarding the time of their return to base. Despite the large number of submarines destroyed, the German navy did not believe until the end of the war that their code had been deciphered.
According to post-war studies, Allied forces destroyed 781 of the 1,154 submarines operating in the German Navy during the war. About 30,000 officers and sailors of the German Navy submarine fleet were killed. The submarines sank about 2,780 ships of all types, most of them merchant navy, totaling about 14 million tons. The submarines' greatest successes were in 1942 when about 6 million tons were sunk.
The submarine offensive continued until the end of the war, but from the summer of 1943they were no longer a threat to the Allied fleet, and the Battle of the Atlantic had been decide
Stage 1: From September 1939 until the fall of France
At this stage the Germans had 57 operational submarines . The first sinking of passenger and merchant ships took place. The British operated the convoy system for the first time and the Western Approaches Command was set up for inter-arm coordination of the Battle of the Atlantic under the command of Admiral Max Horton. At the end of this period the Germans captured a British submarine and copied its torpedoes.
Stage 2: From June 1940 to the "Lend Lease" agreement.
During this period, the Germans had 21 operational submarines and transferred to using the "wolf pack" method. The British allocated 375 warships to escort and guard the convoys. After the fall of France, the Germans began to operate submarines from well-protected pens in French ports. On 17 August, Hitler declared a total naval blockade of Britain. On two days in October, six submarines operating as a "wolf pack" formation destroyed 36 of the 79 ships that had sailed in two convoys. October was the most effective of the submarines, each submarine sinking an average of 60,000 tons of British ships. On March 11, 1941, the US Congress approved the Lend Lease agreement with Britain and the shipping lanes of the North Atlantic became all the more important.
Stage 3: From April 1941 to Pearl Harbor.
The Germans had already built 249 submarines at this stage, 35 of them operational. The "Ultra" operation of the British succeeded in cracking the code of the German "Enigma" machine and, as a result, British Intelligence succeeded in tracking the location and activities of the German submarines and thus could organize itself accordingly. At this stage, the US navy began to be involved in escorting convoys in the western Atlantic,. The British Navy captured the German U-110 submarine with its Enigma encryption machine. The Canadian Navy also began escorting the convoys. In August, the first convoy sailed from England, to the Russian port of Murmansk- The Atlantic routes became vital not only to Britain but also to Russia. An American ship was sunk by a German submarine. The US began building aircraft carriers specifically to escort convoys, Liberty merchant ships and long-range anti-submarine B-24 bombers armed with 24 depth charges each.
Stage 4: From January 1942 until the sinking of convoy PQ 17.
The German submarine fleet increased to 331, of which 140 were operational. 98% of the convoy escorts in the Atlantic were British and Canadian. In January-March, the German submarines again achieved a new record by sinking 216 ships on the east coast of the United States, most of them tankers. This was the first wave of the submarine attack on the United States, and five long-range German submarines sank 25 ships in one day. The Germans changed the encryption method of the Enigma machine and their radio transmissions could no longer be decoded until October. The first German supply submarines of the "Milk Cow" type began to be employed.. Together with the supply ships from Bermuda**, they extended the stay at sea of long-range submarines of the 9 type to 8 weeks and of the smaller 7 type to 4 weeks.
In May, the US finally decided to switch to the convoy system and to adopt blackout along the East Coast. June was the worst month of the war. German submarines sank a total of 834,196 tons, which was the first month that the rate of shipbuilding exceeded the rate of sinking. In this month 23 ships of convoy PQ 17 were sunk on their way to Murmansk (out of 36 ships).
Stage 5: From July 1942 until the retreat of the German submarines.
At this stage, the Germans had 393 submarines, 212 of which were operational (on April 1 they reached a peak of 240 operational submarines). The Allies equipped long-range anti-submarine aircraft with 10-cm radar. The last two submarines operating on the east coast of the United States were recalled so as to concentrate force in the North Atlantic. On August 22, Brazil declared war on Germany after its ships were attacked. The Allied forces reduced anti-submarine activities in much of the Atlantic to concentrate forces to protect the convoys carrying the Allied Expeditionary Force that was scheduled to land in North Africa– " Operation Torch ".- In January 1943, Convoy 7 lost seven out of nine tankers with 100,000 tons of fuel destined for North Africa. At the Casablanca Conference the subject of submarine warfare received top priority.
The President of the United States allocated another 250 aircraft to combat submarines in the Atlantic, bypassing the Commander of the US Navy. The Germans lost 43 submarines in May, twice as much as their capacity to rebuild, and sank only 34 Allied ships. Admiral Doenitz ordered all submarines to withdraw from the North Atlantic. Forty-five months of fighting were over.
Stage 6: June 1943 to May 1945
Doenitz tried new technologies and failed. The Allies operated magnetic detectors and launched an aerial offensive on the submarine production facilities. Submarines with modern snorkels and electric engines were put into operation. But it was too little and too late.