The Australians at War Film Archive

Naval Service - Northwest Europe

The term Battle of the Atlantic does not adequately describe the full extent of the struggle for the sea lanes. U-Boats and surface raiders extended their operations into the Indian ocean to the south as well as the North and Arctic Seas, although the Atlantic was the major area in which losses were sustained by both sides. It was in effect a global strategy into which Australian merchant seamen and naval personnel were drawn. For example, on 18 June 1940 the SS Niagara, which sailed regularly to Vancouver from Australia and New Zealand, was blown up by a German mine in the Hauraki Gulf, New Zealand. The German commerce raider Kormoran's sinking of the HMAS Sydney near Carnarvon, WA, stands as the most striking example of the far-reaching arm of German naval strategy.
War in the Atlantic Ocean was essentially one of attrition and high drama. The battle for these vital sea lanes began as soon as war was declared and climaxed in mid 1943. From the point of view of the Allies, control of the Atlantic had three essential aims. The first was to set up a blockade and restrict German supplies and naval activity. The second was to provide adequate protection to ensure Britain's survival. The third was protection of troopships and convoys of vital supplies and munitions for reopening of the "Second Front".
German submarines (U-Boats) and surface raiders successfully penetrated Allied defences during the first years of the war, striking at the eastern and western Atlantic convoy routes. Convoys sailing through the Suez and Mediterranean routes to Britain had to endure the threat of the attack in the Atlantic during the last leg of their journey.
From the outset Allied losses were heavy. By December 1940, British shipping losses for the year amounted to in excess of two million tons, over five hundred ships. While the German U-Boats accounted for nearly two thirds of these - mines, bombers and the surface raiders (such as the Graf Spee) contributed significantly.
The German U-Boats were the main menace. A lack of pre-war rebuilding left the Royal Navy lacking in some classes of ships at the outbreak of war and convoys suffered through a lack of escorts. This was exacerbated by the need to guard the Mediterranean and protect troop convoys and military forces, such as the British and Dominion troops operating in North Africa, Greece and Crete.
The Admiralty initially responded to the U-Boat threat by forming two hunting groups led by aircraft carriers. The sinking of the carrier Courageous and near miss by torpedoes fired at the Ark Royal saw that plan quickly abandoned, although escort carriers were developed after 1941. The establishment of a submarine tracking room in which all information about the U-Boats was collected proved successful. Manned night and day this tracking room utilized various kinds of intelligence and for sustained periods was able to plot the likely whereabouts of the enemy and thus inform convoys of any imminent danger allowing them to detour where necessary. By 1943, through the combination of the room's expert forecasting and better counter-offensive measures at sea, more U-Boat losses were inflicted than could be sustained and Donitz temporarily withdrew from the Atlantic. However, grievous losses were inflicted upon Allied shipping before this victory. In 1941 nearly 1300 ships were lost to all causes and this increased to over 1600 in 1942, a fact which moved Churchill to describe the U-Boat threat as 'our worst evil'.
The capitulation of France in 1940 meant U-Boat bases on the Atlantic coast and German bombers could strike at the sea lanes bombing shipping as well as laying mines. E-boats (patrol boats), too, were used for hit and run raids. Each phase, however, prompted inventive counter-measures. Armed with 'asdic' (a submarine detection device for use against submerged vessels) and depth charges, the Royal Navy considered itself initially reasonably well armed. However, the Germans countered by laying magnetic mines and also adopting the tactic of fighting on the surface where the U-Boats proved quite difficult to spot with their low silhouettes. Their diesel engines could also outrun most escort vessels unless they were forced to submerge. The method of attacking in 'wolf packs' was also adopted.
The British countered by beginning to fit radar detection equipment to their ships for use against U-Boats, which led to a long technological duel between the Allied and German navies. They developed a magnetic sweep that could explode the mines prematurely and a degaussing mantle was also constructed that allowed ships to pass over mines without triggering the firing gear. These of course took time and many losses were incurred.
An initial problem was the vast distances over which the convoys had to travel without escort. Fifteen hundred mile gaps and more were not uncommon and these journeys were highly anxious times for merchant ships and convoys which were vulnerable to raiders and U-Boats. Until the air gap was closed in the North Atlantic in 1943, the U-Boats could operate with relative immunity beyond the range of Allied planes.
Long-range spotter planes were used by the Germans to locate convoys or single ships and these were reported to the U-Boats. To counter this, CAM-ships (catapult-aircraft merchants) were introduced from which a single fighter would be launched to combat the spotter plane. Later, MAC ships were devised (merchant-aircraft-carrier), usually tankers, over which was laid a full flight deck that could accommodate up to six fighters thus overcoming the previous deficiency of the pilots having to ditch in the sea on return.
America's entry into the war saw an intensification of U-Boat construction and American convoys lost heavily in the first four months of 1942 as the US Navy was not yet geared to providing adequate protection. This began to improve and as the combined operations of the US Coast Guard, Navy and Air Force intensified the U-Boats, too, began to suffer heavily and by late 1942 had shifted their focus to the calmer waters of the Caribbean. However, US forces were unable to provide the long-range surface escorts and this role fell chiefly to the British and Canadians.
Early 1943 promised little different in the battle of the oceans with shipping losses in the first quarter as appalling as previous tallies. The screw was beginning to turn tightly. Fortunately, as the Allies began to drive through Northern Africa, American ships began to be freed up for the protection of the convoys. Improved depth charges, spotlights and radar coupled with quicker escorts, the closing of the airgap and renewed access to German naval codes, suddenly saw the German wolf packs exposed. German losses of 41 U-Boats in May, 1943 proved decisive. German successes, however, had come perilously close to tipping the scale in their favour. Tens of thousands of Allied sailors lost their lives in the Battle of the Atlantic.