Second special mention:
January 30 2023: 90th anniversary of Hitler becoming chancellor. An obscure moment, but an important one.
Early skirmishes (September 1939 – May 1940)
In 1939, the Kriegsmarine lacked the strength to challenge the combined British Royal Navy and French Navy (Marine Nationale) for command of the sea. Instead, German naval strategy relied on commerce raiding using capital ships, armed merchant cruisers, submarines and aircraft. Many German warships were already at sea when war was declared, including most of the available U-boats and the “pocket battleships” (Panzerschiffe) Deutschland and Admiral Graf Spee which had sortied into the Atlantic in August. These ships immediately attacked British and French shipping. U-30 sank the liner SS Athenia within hours of the declaration of war—in breach of her orders not to sink passenger ships. The U-boat fleet, which was to dominate so much of the Battle of the Atlantic, was small at the beginning of the war; many of the 57 available U-boats were the small and short-range Type IIs, useful primarily for minelaying and operations in British coastal waters. Much of the early German anti-shipping activity involved minelaying by destroyers, aircraft and U-boats off British ports.
With the outbreak of war, the British and French immediately began a blockade of Germany, although this had little immediate effect on German industry. The Royal Navy quickly introduced a convoy system for the protection of trade that gradually extended out from the British Isles, eventually reaching as far as Panama, Bombay and Singapore. Convoys allowed the Royal Navy to concentrate its escorts near the one place the U-boats were guaranteed to be found, the convoys. Each convoy consisted of between 30 and 70 mostly unarmed merchant ships.
Some British naval officials, particularly the First Lord of the Admiralty, Winston Churchill, sought a more ‘offensive’ strategy. The Royal Navy formed anti-submarine hunting groups based on aircraft carriers to patrol the shipping lanes in the Western Approaches and hunt for German U-boats. This strategy was deeply flawed because a U-boat, with its tiny silhouette, was always likely to spot the surface warships and submerge long before it was sighted. The carrier aircraft were little help; although they could spot submarines on the surface, at this stage of the war they had no adequate weapons to attack them, and any submarine found by an aircraft was long gone by the time surface warships arrived. The hunting group strategy proved a disaster within days. On September 14, 1939, Britain’s most modern carrier, HMS Ark Royal, narrowly avoided being sunk when three torpedoes from U-39 exploded prematurely. U-39 was forced to surface and scuttle by the escorting destroyers, becoming the first U-boat loss of the war. The British failed to learn the lesson from this encounter: another carrier, HMS Courageous, was sunk three days later by U-29.
Escort destroyers hunting for U-boats continued to be a prominent, but misguided, technique of British anti-submarine strategy for the first year of the war. U-boats nearly always proved elusive, and the convoys, denuded of cover, were put at even greater risk.
German success in sinking Courageous was surpassed a month later when Günther Prien in U-47 penetrated the British base at Scapa Flow and sank the old battleship HMS Royal Oak at anchor,[20] immediately becoming a hero in Germany.
In the South Atlantic, British forces were stretched by the cruise of Admiral Graf Spee, which sank nine merchant ships of 50,000 GRT in the South Atlantic and Indian Oceans during the first three months of war. The British and French formed a series of hunting groups including three battlecruisers, three aircraft carriers, and 15 cruisers to seek the raider and her sister Deutschland, which was operating in the North Atlantic. These hunting groups had no success until Admiral Graf Spee was caught off the mouth of the River Plate by an inferior British force. After suffering damage in the subsequent action, she took shelter in neutral Montevideo harbour and was scuttled on December 17, 1939.
After this initial burst of activity, the Atlantic campaign quieted down. Admiral Karl Dönitz, commander of the U-boat fleet, had planned a maximum submarine effort for the first month of the war, with almost all the available U-boats out on patrol in September. That level of deployment could not be sustained; the boats needed to return to harbour to refuel, re-arm, re-stock supplies, and refit. The harsh winter of 1939–40, which froze over many of the Baltic ports, seriously hampered the German offensive by trapping several new U-boats in the ice. Hitler’s plans to invade Norway and Denmark in the spring of 1940 led to the withdrawal of the fleet’s surface warships and most of the ocean-going U-boats for fleet operations in Operation Weserübung.
The resulting Norwegian campaign revealed serious flaws in the magnetic influence pistol (firing mechanism) of the U-boats’ principal weapon, the torpedo. Although the narrow fjords gave U-boats little room for manoeuvre, the concentration of British warships, troopships and supply ships provided countless opportunities for the U-boats to attack. Time and again, U-boat captains tracked British targets and fired, only to watch the ships sail on unharmed as the torpedoes exploded prematurely (due to the influence pistol), or hit and failed to explode (because of a faulty contact pistol), or ran beneath the target without exploding (due to the influence feature or depth control not working correctly).[21] Not a single British warship was sunk by a U-boat in more than 20 attacks. As the news spread through the U-boat fleet, it began to undermine morale. The director in charge of torpedo development continued to claim it was the crews’ fault.[22] In early 1941 the problems were determined to be due to differences in the earth’s magnetic fields at high latitudes[23][page needed] and a slow leakage of high-pressure air from the submarine into the torpedo’s depth regulation gear. These problems were solved by about March 1941, making the torpedo a formidable weapon.[24]
I have yet to ask any questions concerning one of the most important campaigns of World War II. The Battle of the Atlantic has been raging for one year now. Who has the advantage at this time and why and if you wish, please explain what you do at this time if you are the Axis or Allies?
The Battle of the Atlantic was a lengthy and extremely complex conflict in which the advantage shifted repeatedly from one side to the other, as a result the interplay of a very large number of factors – strategy, tactics, technology, intelligence, weather and so forth. In my opinion, the fundamental question to consider isn’t “Which side had the advantage at such-and-such a date?” (because the answer will be different depending on what date is chosen); rather, the question is: could either side have done something at any point in the war that would have significantly changed the ultimate outcome of the Second World War? My guess is: perhaps, but probably not.
For the Allies, a fundamental improvement in the outcome of WWII would, in my opinion, mean “defeating Germany a year or more earlier than was actually the case.” I’m not sure that getting a definitive upper hand on the U-boats in mid-1942 rather than (as was actually the case) mid-1943 would have accomplished this. It would have accelerated the pre-invasion buildup of Allied forces (both men and materiel) in the UK, but it would not have affected such factors as the training of the troops, the development of specialized equipment, the overall planning process (which was massive and detailed), nor would it have helped the Americans and the British resolve the strategic disagreements over which the were at loggerheads for two years. It should also be noted that Germany had suffered major losses on the Eastern Front in the year prior to D-Day; if the Allies had invaded France in mid-1943 rather than mid-1944, they would have faced an enemy who was much stronger overall (though not on the Western Front specifically) than he was in mid-1944.
For the Axis, a fundamental improvement in the outcome of WWII would have meant starving Britain into surrender. Germany could certainly have made things a lot more difficult for Britain if it had played its cards differently in the Battle of the Atlantic, and it’s true that the economic strangulation of Britain was theoretically the most plausible way for Germany to defeat it…but to achieve this, or even to have a reasonable hope of doing so, Germany would have had to do more than just tinker with a few details. Its entire naval strategy – including its naval construction program – would have had to be focused on U-boat warfare, and this would have had to be the case right from the start of the war (or even earlier) rather than having to wait for Donitz to replace Raeder as head of the Kriegsmarine in 1943. It would also have required much better inter-service cooperation with the Luftwaffe, and possibly even the development of a full-blown Kriegsmarine naval air service – a concept that didn’t fly (no pun intended) with Hermann Georing, who wanted to control anything in Germany that had wings.
Germany lost 23 U Boats in the whole of 1940. They lost almost twice that in May 1943 alone.
In 1940 2.2m GRT at allied shipping was sunk by G subs (if my mental maths are accurate!). In 1943 the total sunk was not much higher.
If these changes were part of the allies winning the Battle of the Atlantic, then they were either losing or drawing before then.
In which case the allies only had the advantage if their change of fortunes was a probability.
PS Intended to total the GRT getting through, but lost patience with this touch screen device!
I voted advantage Axis. As others have explained, the Allies didn’t have very good methods of detecting u-boats–at least not after the first year of the war. However, that changed as the war progressed. The Germans did not anticipate the Allies miniaturizing radar to the point where it could be equipped on board an aircraft. (Even though they later duplicated that feat.) When the British began using such aircraft against u-boats, it fundamentally altered the equation in the Atlantic.
During the last year of the war, the Germans were taking steps to reclaim the edge in the war of the Atlantic.
One of those steps involved torpedoes. A standard-issue WWII era torpedo involved a diesel engine, as well as fuel and compressed air so that the engine could work. The compressed air took up plenty of space. Early in the war, Germany’s torpedoes were based on this model. But there are problems with diesel-powered torpedoes. They are noisy, and can be detected by enemy ships. As they burn diesel fuel, they leave a telltale trail of bubbles in the water. If this trail is observed from the air, it alerts the target ship a torpedo is coming, and guides planes back to the sub which launched the torpedo in the first place. Something better was needed–or at least desired.
The Japanese dealt with these problems by providing their torpedoes with compressed oxygen, not compressed air. Separating the oxygen out from the rest of the air was very difficult, and the Japanese closely guarded their secret of how to do it. A diesel engine requires only 1/5 as much compressed oxygen to burn a given quantity of diesel fuel as it would compressed air. Due to the enormous space savings gained by using compressed oxygen, Japanese “Long Lance” torpedoes had about triple the range of anyone else’s. Also, the air bubble trail they left was much less pronounced than typical for a WWII-era torpedo. This was particularly important for the South Pacific at night, because the presence of luminescent algae meant that those bubble trails glowed in the dark!
The Germans dealt with the torpedo problem in a different way. As the war progressed, they began making use of battery-powered electric torpedoes. At first these torpedoes represented a very serious trade-off. Their range was much shorter than a standard-issue diesel torpedo’s. On the other hand, the electric torpedoes left no bubble trail, and were very, very quiet. They were therefore a mixed blessing–at least until the Germans began to improve their range. Later in the war, Germany’s electric torpedoes had about the same range as standard-issue diesel torpedoes. (Japan’s torpedoes, of course, had a much longer range than anyone else’s.)
Good torpedoes were useful, but not alone enough to swing the Battle of the Atlantic back in Germany’s favor. What it needed was a submarine much harder for the British to detect than the submarines it had. In addition, the submarine in question needed a long range, and it needed to be mass produceable in large quantities. The Type XXI u-boat was all these things and more.
The Type XXI was fast. Its hydrodynamic shape allowed it to actually travel faster underwater than it could on the surface. It had a very advanced (for the time) electronics suite and sonar system. Its electric torpedoes had a range comparable to most diesel-powered torpedoes of the era. Its hull was coated in a layer of rubber, making it very difficult to detect via radar or sonar. It had a very large complement of batteries–batteries which allowed it to remain submersed for 2 - 3 days at a time. When it did finally have to emerge, it didn’t need to come all the way to the surface. Instead, it would go most of the way to the surface, then raise its snorkel. With the snorkel above the surface it could run its diesel engines. (Necessary to recharge its batteries.) This submarine was much, much quieter than almost any other sub of WWII. The Type XXI u-boat and associated models were by far the most advanced submarines of the war. In many ways they had more in common with nuclear submarines of the postwar era than with their WWII contemporaries.
Albert Speer began producing this type of submarine in large quantities in 1944. These subs were built in sections to make them easier to mass produce. However, there were some initial glitches in the production process, slowing things down. Also, a submarine this sophisticated required a relatively long working up period. No Type XXIs saw action before the war ended. Had the war lasted another six months, the story would have been very different. :o
A sister ship–the Type XXIII–was put into service, in limited numbers, before the war ended. The Type XXIII was very similar to the Type XXI in most ways, except much smaller and with a shorter range. The Type XXIII could hold only two torpedoes (compared to twelve for the XXI). The Type XXIII was intended for use in coastal waters. Type XXIIIs sank or damaged five Allied ships; and the Allies did not sink or damage any Type XXIIIs. The rather one-sided track record of the Type XXIII reinforces the suspicion that it would have been very, very difficult for the Allies to detect or destroy the Type XXIs.
From the OP: please explain what you do at this time if you are the Axis or Allies?
Am I allowed to use 20/20 hindsight? If I am, my choice would be to accelerate the development and production of the Type XXI as quickly as possible. Had the Type XXI appeared in the Atlantic in large numbers in 1943, it could have decisively tipped the Battle of the Atlantic in Germany’s favor.