Film and Television: Starting from the Journey to Guandong

Chapter 134

During the First World War, the German army twice dispatched submarines in an attempt to break into Scapa Flow, but they were both discovered and sunk by the British army.

This time, Dönitz was determined to break through the Kirk Strait, which was unexpected by the British army, to achieve a surprise victory.

He summoned Captain Prien, the captain of the U-47 submarine, who was famous for his superb skills in the German submarine force, and ordered him to secretly conduct a feasibility study on breaking through Scapa Flow. Prien believed that as long as the navigation is accurate and the operation is correct, , it is possible to cross the shipwreck barrier and enter Scapa Flow.

After careful preparation, Prien commanded the U-10 submarine to set off from Kiel on October 8, and quietly arrived at the eastern waters of the Auckland Islands at 47:13 on the th. He then dived and sat on the seabed to give the crew a rest, which was very necessary. , The mental state of submarine soldiers is always one of the important factors that determine the outcome of a battle.

At 19:15, the submarine surfaced and began to break into Kirk Strait.

Prien shut down the diesel engine and used only the electric engine to provide power. With his superb driving skills, he overcame the difficulty of the rapid water flow and bypassed the sunken ship and the steel cables connected in series. He successfully arrived at 10:14 on October . Breaking into Scapa Flow.

However, Prien did not find any warships at the main anchorage in the southwest of Scapa Flow. It turned out that during the voyage of U-47, the main force of the British fleet had left the port and went to sea.

Prien had no choice but to sail east again, and finally found two battleships and several destroyers on the west side of Mainland. At 2:3000, Prien fired a salvo at the two battleships from a distance of 2 meters from the bow launch tube. Three torpedoes.

One of the torpedoes hit the battleship "Royal Oak". After Prien fired the first torpedo, he quickly turned the steering wheel, fired another torpedo from the tail torpedo tube, but missed, and then evacuated towards Kirk Strait at full speed.

The British army did not expect to be attacked by a German submarine. When the battleship "Royal Oak" was hit by a mine, some people thought that the warship had exploded, and some thought that it had been attacked by an air raid. The base command headquarters sounded the air raid alarm. The warships took air defense measures, but the captain of the "Royal Oak", Captain Ben, and several major officers only made a cursory inspection and did not take any remedial measures.

Prien discovered the situation of the British army from the periscope. Prien, who was brave and skilled, simply returned again, reloaded the first torpedo tube with torpedoes, and carried out the second attack.

At 47:2200, U-833 aimed at the "Royal Oak" at a distance of meters and fired three torpedoes. Two torpedoes hit the starboard side, the engine room was blown through, and a big explosion was caused. The "Royal Oak" tilted sharply to the right. It capsized and sank at :, killing people on board, including Rear Admiral Bugrov, commander of the Second Battleship Squadron.

U-47 quickly sailed towards Kirk Strait and evacuated Scapa Flow along the same route.

Returning to Wilhelmshaven on October 10, he was warmly welcomed by Navy Commander-in-Chief Raeder and Dönitz.

Prien was awarded the Iron Cross First Class and became a hero who would be saluted by the people wherever he went. The rest of the crew were awarded the Iron Cross Second Class. All the officers and soldiers who participated in the war were also received by Uncle Xi, and Dönitz was also received by Brigadier General was promoted to Major General.

Although the German submarines did not achieve impressive results in the Atlantic in the early stages of the war, the victory in the sinking of the "Brave" and the sneak attack on Scapa Flow made the German high command gradually realize the huge role of submarines and gradually began to pay attention to the construction of the submarine force. , and began to step up the production of submarines.

After the "Athena" was sunk on September 9, Britain believed that Germany had begun unrestricted submarine warfare, and immediately eliminated all hesitations. From September 3, it began to implement escorts that were quite effective in World War I. The transport fleet system was established. By October, the escort transport fleet system was established on the main routes between Britain and other allied countries.

In fact, Uncle Xi had always had illusions about making peace with Britain in the early days of the war, so Dönitz was strictly prohibited from conducting unrestricted submarine warfare, and the rules for capturing merchant ships must be strictly enforced during the operation to break diplomatic relations.

The British escort transport fleet system is derived from the principle of mathematical probability theory, which is also a major contribution of mathematicians in war. According to the analysis of probability theory, merchant ships encountering submarines at sea are random. With a certain number of ships, the larger the formation size, The smaller the number, the more batches there will be. If there are more batches, the probability of encountering submarines will increase;

And because the number of submarines is limited, every time they encounter a fleet, they can only attack the same merchant ships due to the limitations of the ammunition they carry. In other words, the larger the fleet is, the more likely each ship will be sunk even if it encounters a submarine. The smaller.

Based on the above two laws, the larger the fleet size, the smaller the probability of each ship being sunk. Taking 100 ships as an example, if organized into five fleets, the probability of each ship being sunk is 25%;

If organized into a team, the probability of each ship being sunk is 1%, a full 24 times difference!

The escort transport fleet system is led by the British Admiralty. All ships are divided into slow transport fleets for transporting supplies (speed below 7.5 knots), fast transport fleets for transporting supplies (speed between 9 and 10 knots) and troops for transporting troops. There are three types of transport fleets.

Escort transport fleets on fixed routes are usually coded using the first English letter of the starting point. For example, the fleet from Halifax to the UK is codenamed HX. Each fixed route has a sailing schedule for the escort transport fleet. surface.

早期的护航运输船队通常由40至60艘船组成，排成9路或12路纵队，船与船之间距离约为550米，纵队之间间隔约为900米，形成正面宽约4至 4.5海里，侧翼宽约1.5至2海里的长方形队形。

This can reduce the chance of being attacked by submarines on the flanks of the transport fleet. Secondly, it can prevent the formation from being too long and the rear ships are busy chasing the ships in front. Thirdly, it can reduce the risk of ships colliding with each other. Moreover, such a formation is the most effective Facilitates visual communication between ships.

Four escort warships are arranged at the four corners of the fleet, forming a box-shaped warning circle, and the remaining warships are located in the sector directly in front of the fleet.

Initially, the British army used battleships or cruisers as escort warships. When the threat from German surface ships was eliminated, battleships or cruisers were no longer used as escorts.

Because in the face of submarine threats, using precious battleships or cruisers to escort transport ships is not worth the gain.

Some people have a negative attitude towards the convoy fleet system, believing that a large number of ships must stay at the port after loading or unloading cargo, waiting to form a convoy with other ships, which wastes time and reduces the ship's carrying capacity. .

But facts speak louder than words. The implementation of the escort transport fleet system greatly reduced ship losses. In the four months after the outbreak of the war, only 5756 of the 12 ships included in the escort transport fleet were sunk. Moreover, 12 of these 5 ships were sunk while falling behind.

During the same period, 102 ships sailing alone were sunk.

During this stage, Britain lost a total of 114 transport ships, totaling 42.3 tons.

In the early days of the war, the British anti-submarine measures had almost no other effective measures except the escort transport fleet system.

The offensive anti-submarine tactics of the aircraft carrier formation were aborted due to the sinking of the "Brave"; the MKⅠ radar equipped with the anti-submarine aircraft had poor performance and could only detect submarines sailing on the water surface 5000 meters away.

When visibility is good, a submarine can even spot an aircraft first through visual observation!

Moreover, due to the poor performance of the bombs used by anti-submarine aircraft, after being thrown at the submarine, they would bounce off the water and explode in the air, causing more damage to the aircraft than to the submarine!

Two planes were shot down by their own bombs.

In addition, the number of anti-submarine aircraft was seriously insufficient, so the British had to adopt "scarecrow" tactics, that is, requisitioning a large number of unarmed aircraft from civilian flying clubs and flying along the coast to force German submarines to dive and discover the sunken transport ships in time. This backwardness The tactics were actually used until after the fall of France in May 1940.

In order for anti-submarine aircraft to truly play a role in combat, not only the bombs must be modified, but bomb sights and new detectors must also be installed. It will take at least a year to complete these tasks.

In order to make up for the shortage of escort ships, the United Kingdom began to step up the construction of light frigates. This kind of frigate has a displacement of less than 2000 tons and is equipped with artillery, depth bombs and sonar. With the support of armed trawlers and other small ships, it is a kind of ship that can operate at close range. A ship capable of effectively conducting anti-submarine warfare in coastal waters.

In the first stage from September 1939 to May 9, due to various reasons, the German army mainly adopted single-boat operations. Dönitz still started to conduct tentative experiments in group operations in accordance with the pre-war assumptions.

The first time was in mid-October 1939. Six submarines were dispatched. As a result, one of them hit a mine and sank in the English Channel, and two were sunk while attacking the escort transport convoy. Therefore, the cluster combat experiment was unsuccessful.

At the same time, submarines were organized to mine a large area in the waters near the British coast. The mines they laid sank 12 ships and injured 6, and the tonnage of the ships lost reached 12 tons.

In mid-November 1939, Dönitz once again dispatched four submarines to conduct swarm operations. The U-11 submarine discovered the KS-4 escort transport fleet, although it was repeatedly suppressed and driven away by British escort warships and seaplanes. , but still maintained contact with the fleet and guided the other three submarines to come.

However, due to various reasons, the group attack could not be achieved, and the submarine only attacked the straggler ships.

Although the swarm attack tactics failed to work as expected, the German submarines mostly used single boats to carry out positional ambushes or mobile ambushes in British ports and coastal routes, or carried out hunting operations in the possible routes of the escort transport fleet or in the vast sea area, and still achieved considerable success. results.

9月击沉41艘同盟国及中立国的船只计15.3万吨，10月击沉27艘计 13.5万吨，11月击沉21艘计5.2万吨，12月击沉25艘计8.1万吨，被潜艇击沉的船只占损失船只总数的51.7%。

The reason for the decline in performance in November and December was that the submarines that went out after the outbreak of the war gradually returned to the base to replenish supplies. Due to the small number of German submarines and the distance between the base and the combat sea area, the number of submarines operating in the Atlantic was greatly reduced, usually only 11 to 12 3 ships, never more than 5 ships.

By the end of 1939, the German army had lost a total of 9 submarines, accounting for almost one-sixth of its total number of submarines.

What pleased Dönitz the most was that various restrictions on diplomatic operations were gradually lifted, and on September 9, he was allowed to attack ships ordered to stop sailing but still using radio alarms;

9月24日获准可以攻击法国船只；9月30日可以攻击任何在北海航行的船只；10月2日从英法沿岸至西经15度海域航行的所有船只均可以予以攻击；

10月17日获准攻击除客轮以外的任何敌方船只；10月19日从英法沿岸至西经20度海域航行的船只只要实行灯火管制均可予以攻击；

On November 11th, all restrictions were finally lifted and submarine warfare without any restrictions began! ——At this point, Dönitz can finally let go and do something big!

In November 1939, the United States finally gradually realized the brutal nature of Nazi Germany and began to change its neutral stance of prohibiting the sale of weapons or loans to both warring parties. Congress passed an amendment to the Neutrality Act, allowing the principle of "self-transportation in cash transactions" Weapons for sale.

That is to say, countries purchasing weapons must pay in cash and transport them on their own ships. On paper, this is fair to both parties. In fact, because the German navy is very weak and unable to protect its own ships, this amendment It is clearly leaning towards the UK.

Entering 1940, there was still no breakthrough in the German submarine war. In January, 1 merchant ships were sunk, totaling 40 tons, and in February, 11.1 ships were sunk, totaling 2 tons.

In February, Dönitz organized the third test of swarm operations and sent five submarines to the North Atlantic. As a result, U-2 discovered two French escort transport fleets, but the other two submarines in the group were too far away. Far from arriving in time, they only attacked ships that had fallen behind because they had fallen behind, and the third attempt at a swarm attack failed again.

On March 3, the German High Command issued an order prohibiting submarines from carrying out diplomatic-breaking operations and using all of them for the upcoming Norwegian campaign. According to this order, the German army committed 4 submarines to the Norwegian campaign, accounting for 31 of its total submarines. %.

For this reason, Dönitz not only withdrew the training submarines from the submarine school, but also shortened the trial time of the two newly launched submarines. Except for a few submarines undergoing maintenance, almost all of them participated in the war.

But what made Dönitz dumbfounded was that during the battle, the submarine force was given the task of detecting and covering the activities of the own fleet. This was simply a huge misunderstanding in the use of submarines, and therefore the loss of four submarines was in vain.

The only gain was the discovery of huge flaws in the G7 torpedo during combat. It conducted 36 torpedo attacks with no success, and was called a "useless torpedo" by officers and soldiers of the submarine force.

It is conceivable that if this problem is not discovered in time, the submarine will definitely suffer heavy losses when attacking a fleet with a strong escort force in the future. From this perspective, the Norwegian Campaign was a major loss for the German submarine force. reward.

In late April, Dönitz established a Torpedo Investigation Committee to investigate problems with torpedoes.

Believing that there was a large amount of iron ore on the seabed in Norwegian waters, which would cause deviations in magnetic fuses, Dönitz ordered a ban on the use of magnetic fuses.

Before this, only less powerful trigger fuses could be used. In the past, attacks that could be solved with only one torpedo would require at least two, which greatly increased the speed at which submarines consumed torpedoes in combat.

Therefore, the combat time was greatly shortened. Many submarines watched the British transport fleet shuttle back and forth on their way back without torpedoes to use.

After the Battle of Norway ended in May, some submarines were in urgent need of overhaul, and several submarines were assigned to submarine schools as training submarines. The newly launched submarines still need trial sea trials and training. The German army only has 5 submarines that can be put into the Atlantic to carry out the task of breaking the war. There are no more than 30 submarines actually fighting on the front line of the Atlantic every day.

In view of this situation, Dönitz had no choice but to temporarily shelve the swarm attack tactic and wait until a sufficient number of submarines were available before implementing it. Now he proposed the "economic use principle", that is, sending submarines to the sea areas where the British escort force is weakest as much as possible. Strive to achieve the highest sinking tonnage for each submarine.

In the war room of the submarine force headquarters in Wilhelmshaven, Dönitz displayed the sinking situation on a large chart, conducted careful research and analysis, and directed submarine operations accordingly.

By June 1940, German submarines had sunk a total of 6 ships with a total tonnage of approximately 242 tons.

These losses were still affordable for Britain, because the tonnage of new ships built during the same period fully made up for the losses.

Moreover, the overall situation of British anti-submarine warfare was not bad, sinking 24 German submarines and gradually driving German submarines out of coastal waters.

In the second phase of the Battle of the Atlantic that began in June 1940, as Germany successively occupied France and Norway, the originally extremely unfavorable maritime situation suddenly changed. The German Navy quickly established submarine bases in ports along the coasts of Norway and France.

Especially starting from the ports of Lorient, Brest, Saint-Nazaire, La Rochelle and Bordeaux in the Bay of Biscay, submarines can directly enter the Atlantic Ocean, which is a much shorter voyage than starting from bases in Germany. 800 kilometers, even a 250-ton small submarine can enter the Atlantic Ocean.

Large submarines can even reach the mid-Atlantic sea area, and after the submarines have consumed the ammunition, fuel and materials they carry, they no longer need to travel long distances back to their home bases for resupply, and can sail to the nearby Bay of Biscay port for replenishment and supplies. Overhaul.

Therefore, Dönitz attached great importance to the construction of these bases. He personally came to various ports in the Bay of Biscay to supervise the construction projects, and also moved the submarine force's headquarters to Lorient, France.

With the commissioning of submarine supply ships in July, submarines can be replenished with fuel, torpedoes and food at sea, which has greatly increased the submarine's on-going rate and cruising time for front-line activities.

Before July, an average of at least 7 submarines were needed to ensure that one submarine was cruising at sea. After July, this ratio dropped to 2.35:1. Therefore, although the total number of German submarines decreased from 7 at the beginning of the war to 1.84, in the Atlantic Ocean However, the number of submarines performing combat patrols has doubled, with an average of 1 to 57 submarines operating at sea every day. These submarines are dispersedly deployed in the waters west of the British Isles, waiting on the routes of the British transport fleet, and will attack ships sailing alone once they are discovered;

If an escort transport convoy is discovered, it will be reported immediately to the submarine force headquarters in Lorient, and efforts will be made to maintain contact with the convoy and report the convoy's new voyage, speed and position at any time. Dönitz will quickly direct the activities in nearby waters. The submarines gathered in the waters where the fleet was located.

Then start a cluster attack at night, end the attack before dawn, use the daytime to rush to the next attack position, organize the attack again after nightfall, and repeat the attack night after night until the fleet reaches its destination.

During the same period, due to the air threat of the German Air Force, the British changed the route of the escort convoy from Canada to the North Channel between Ireland and Scotland. This resulted in frequent congestion at the entrance of the North Channel and the waters west of Scotland. With a large number of ships, it became the most ideal hunting area for German submarines.

In addition, because many destroyers were sunk and damaged in the Battle of Norway and the Dunkirk evacuation, the British Navy had to retain a large number of destroyers to deal with possible German invasion, so the number of British escort warships was reduced a lot, which gave Excellent opportunity for German submarines.

Moreover, after several months of combat, German submarines have accumulated rich experience in breaking through the warnings of British escort warships, and they have also received favorable cooperation from the German Air Force and Italian submarines.

Beginning in mid-July, Dönitz finally had enough submarines to begin implementing a swarm attack tactic known as the "wolf pack tactic."

During this period, both single-boat and group operations achieved great results. The summer and autumn of 1940 were also called the first "golden period" of German submarines.

6月德军潜艇击沉58艘，28.4万吨；7月击沉38艘，19.6万吨；8月56艘，26.8万吨；9月57艘，29.5万吨，10月63艘，35.2万吨。英国的船只损失直线上升！

Starting in July, the UK expanded its escort range in both directions from the starting point of the route. Transport fleets bound for Canada and the United States from the UK were escorted by British Navy escort warships to 7 degrees west longitude. By October, it was expanded to 17 degrees west longitude. Spend.

However, there is no escort in the middle section of the Atlantic route. This area is also the area where German submarine activities are most rampant. It was not until the waters near Newfoundland that the Canadian Navy came to respond.

In August, the British Army's Type VII airborne anti-submarine bomb began to be put into actual combat. It was developed on the basis of a 8 kilogram cylindrical anti-submarine bomb. The bomb has a circular fairing on the head and a tail fin on the tail, which can maintain a stable attitude in the air. Using a hydraulic fuse, it will only explode under the action of water pressure after falling into the water and reaching a predetermined depth. It will not cause damage to the aircraft and is much more powerful than old-fashioned bombs.

At the same time, the British army also developed an airborne AS-VII radar, which can detect submarines on the water surface at a longer distance.

However, these equipment did not achieve obvious results in actual combat. Scientists from the British military industry conducted careful analysis and research and found that the water pressure fuze of the depth bomb was too large and often exploded under the submarine, so they quickly changed it to a shallow fixed-depth fuze.

British scientists also discovered that in visual situations, submarines are usually the first to spot aircraft, because the black paint of British military aircraft is a very obvious black spot against the light background of the sky.

According to the fact that the bellies of seabirds are generally white, the British Air Force conducted a comparative test with white-painted aircraft and black-painted aircraft. Sure enough, the white-painted aircraft was found 30% further away than the black aircraft. Based on this, the British Air Force quickly Paint the lower parts of all anti-submarine aircraft white. - But it will take time for these measures to take effect.

On August 8, Mr. Hope ordered the implementation of a comprehensive naval blockade against the United Kingdom. Submarines have the right to sink any ship entering the blockaded waters. Neutral ships are also legal targets as long as they enter the blockaded waters.

In this way, the restricted hands and feet of the submarine force were completely liberated. Submarine captains began to show their talents and actively participated in the "tonnage race". A large number of famous ace captains emerged, such as Captain Prien of U-47, U — No. 99 Captain Krest Schmer, U-100 Captain Schepke, U-46 Captain Indoras, U-101 Captain Froenhan, especially the first three The captain is known as the three trump cards.

在这一黄金时期里典型的战斗有9月间SC—2护航运输队和HX—72护航运输船队，10月间SC—7、HX—79和OB—229护航运输船队的护航战。

As early as August 8, the Cryptozoological Section of the Intelligence Division of the German Navy, code-named Organization B, deciphered the British military's coded telegrams regarding the route of the SC-30 transport fleet and the sea area where it would rendezvous with escorting warships.

根据这一情报，德军调集U—47、U—65、U—101和U—124共4艘潜艇前往攻击。

On September 9, U-6 discovered the transport convoy, but was driven away by the British escort warship before it could report its position. It was not until after midnight that U-65 discovered the convoy again and guided U-65 Come.

U-47 took advantage of the cover of night and adopted surface attack tactics to continuously attack the fleet, sinking three transport ships in one go.

During the day on September 9, British seaplanes and warships tried their best to drive away the German submarines. This ensured the safety of the fleet that night.

9月8日夜间，U—47和U—65号潜艇再次成功突破了护航军舰的警戒，实施了攻击，U—47又取得了击沉1艘运输船的战绩。

In the early morning of September 9, the U-9 and U-28 submarines operating in nearby waters also arrived and joined the attack. U-99 sank a transport ship. After daybreak, the submarines that besieged the fleet were driven away.

In this escort battle, the British escort ships relied on visual observation and sonar detection, and were unable to detect German submarines in time and accurately. They were unable to organize night surface attacks by German submarines on the fleet, resulting in the loss of 5 transport ships, totaling more than 2 people. Ton.

9月20日U—47发现了从加拿大开往英国的HX—72运输船队，该船队编有41艘运输船、1艘驱逐舰和4艘护卫舰。

At this time, U-47 only had one torpedo left, so it was unable to attack, so it had to track the fleet and summon nearby submarines to come as soon as possible.

U-99, which was the first to arrive after dark, attacked the convoy and damaged three transport ships. One of them eventually sank due to excessive injuries, and the remaining two were sunk by other submarines after falling behind due to injuries.

Before dawn, U-48 also attacked and sank a transport ship.

After nightfall on September 9, the U-21 submarine broke into the middle of the fleet. Captain Shepke gave full play to his superb driving skills and conducted a continuous four-hour attack, sinking 100 transport ships in a row and escorting them. The warship was helpless and had no choice.

In the early morning of September 9, two British destroyers arrived to strengthen the escort force and drove away the U-22 submarine that was trying to attack. This ended the fleet's nightmare voyage.

In this escort battle, the German submarines, especially the U-100, performed well and sank a total of 12 transport ships, totaling 7.7 tons.

In October, the German army assembled as many as 10 submarines in the waters near the North Channel and actively launched operations to break diplomatic ties.

In the early morning of October 10, U-17 discovered the SC-48 fleet bound for the United Kingdom from Canada. The fleet consisted of 7 transport ships and 30 frigates. The captain, Major Blacklout, decisively attacked and sank it. 5 transport ships were purchased and the speed, course, number of ships and other information of the fleet were reported to the Submarine Command.

After dawn, U-48 was discovered by a British seaplane and was immediately attacked by depth charges.

The seaplanes and guided destroyers conducted continuous depth charge attacks on the sea area where the submarine was located. Although the submarine was not damaged, it was forced to submerge for a long time and lost contact with the fleet.

This made Dönitz, who was busy mobilizing troops and generals, very anxious. Fortunately, U-38 arrived in time and rediscovered the fleet. This allowed Dönitz to quickly mobilize U-46, U-99, and U-100. , U-101 and U-123 submarines formed a patrol line in front of the fleet route, setting up a net and waiting.

On the evening of the 17th, U-38 was the first to attack and damaged a transport ship. However, U-1 was quickly driven away by the escorting warships.

After dusk on the 18th, the fleet broke into the submarine patrol line and was besieged by the above-mentioned five submarines. The formation of the fleet was completely disrupted. The German submarines took the opportunity to go on a killing spree, sinking 5 transport ships and damaging 19 transport ships. 5 ships, among which U-99 achieved the most brilliant results, sinking 6 ships and damaging 1 ship. After daybreak, U-99, U-101 and U-123 all used up all the torpedoes they carried and returned.

On the night of the 19th, the other two escort fleets HX-79 and OB-229 also passed through this sea area and were also violently attacked by German submarines. The HX-79 fleet lost 12 ships and the OB-229 fleet lost 2 ships. Most of the ships and submarines participating in the war used up the torpedoes they carried and returned one after another.

A total of 35 merchant ships were sunk in these three escort transport fleets, with a loss of 16 tons.

Between July and October 1940, during the golden age of German submarines, the Germans sank 7 British and neutral transport ships at the cost of 10 submarines, with a total tonnage of 6 million tons.

Faced with such heavy losses, Prime Minister Churchill had no choice but to ask for help from Roosevelt. In August, Rothover secretly sent a military delegation headed by General Graham to the United Kingdom to hold talks with the United Kingdom and formulate a plan for the U.K. Plans to enter into post-war cooperation with the British Navy in the Atlantic.

The United Kingdom also provided the experience and intelligence gained in naval warfare over the past year, as well as advanced technologies such as radar, to the U.S. for free.

On the basis of these talks, the U.S. Chief of Staff held secret negotiations in Washington from January to March 1941 and signed the "ABC-1" agreement, which stipulated that the U.S. would be responsible for escorting convoys in the North Atlantic regardless of whether it participated in the war or not. main responsibility.

At the same time, after many negotiations, the United Kingdom and Britain reached an agreement on September 1940, 9. The United Kingdom transferred its naval and air forces in the Bahamas, Jamaica Islands, Antigua, Saint Lucia, Trinidad, and British Guiana. Ninety-nine-year rights to use the base.

At the same time, the Argentine and Bermuda island bases in Newfoundland will be provided to the U.S. for free in exchange for U.S.'s 50 old destroyers that have overaged their service.

This agreement has changed the neutral status of the United States and caused great dissatisfaction in Germany. Uncle Greek immediately ordered the lifting of the final restrictions on submarine attacks on the United States' merchant ships, and even came up with the idea of ​​seizing certain islands in the mid-Atlantic. However, Germany still Try to avoid direct conflicts with U.S. troops, and at the same time strictly order naval ships not to attack U.S. ships.

On September 9, Roosevelt issued an order to establish a neutral sea zone, or "safe sea zone" along the coast of the American continent. The U.S. Atlantic Fleet would organize patrols in the neutral sea zone and provide escort for sailing ships. At the same time, he announced that all participating parties in the neutral sea zone would be expelled. Combat ships.

In fact, the U.S. Navy, which claimed to strictly observe neutrality, informed the British Navy of the location of German merchant ships sailing in the sea area from the beginning.

Entering November, the glorious era of German submarines has finally come to an end. Due to long-term operations at sea, a large number of submarines are in urgent need of overhaul and maintenance. Therefore, the number of submarines that can go to sea has been greatly reduced. On average, only 11 submarines are hunting in the Atlantic every day!

Moreover, the bad weather in the Atlantic also seriously affected submarine operations, resulting in only 11 ships, totaling 32 tons, sunk by German submarines in November.

In December, due to the British victory in the Air Battle of Britain, the possibility of Germany invading the British Isles was greatly reduced. A large number of destroyers that the British Navy had kept on the mainland for anti-landing preparations were transferred to Atlantic escort operations. German submarines were forced to gradually move towards The escort force is weak and the ocean transfer is carried out to find fighter planes.

However, as it develops to the ocean, the probability of discovering the escort transport fleet gradually decreases. Therefore, only 37 transport ships were sunk in the whole month, totaling 21.3 tons.

On December 12, the Coastal Aviation Force of the British Air Force was placed under the command of the Navy in order to organize sea and air coordination more effectively and further strengthen the air escort force.

During the same period, Dönitz also deeply felt that the submarine lacked strong reconnaissance support and was difficult to expand its results. He submitted a memorandum to the Naval Command requesting that the submarine force be equipped with an air reconnaissance force.

With the strong support of Navy Commander Marshal Redl and the Chief of Operations of the German High Command, Admiral Jodl, a group of long-range reconnaissance aircraft was obtained in January 1941 after many setbacks. However, this move offended those who regarded the Air Force as a taboo. Air Force Commander-in-Chief Göring.

Moreover, due to the lack of special training for pilots, maritime reconnaissance capabilities and coordination with submarines are very poor. In addition, the range of the reconnaissance aircraft is too small, which is far from meeting the needs, and the effect is minimal.

On December 12, Uncle Qiu sent a letter to Rossifer. This letter was called the most important letter in his life by Uncle Qiu in his memoirs!

The letter introduced the difficult situation faced by the United Kingdom and the heavy losses it suffered, and proposed to the United Kingdom that the United Kingdom's navy escort the British fleet, expand the neutral sea zone controlled by the United Kingdom's navy, and use the country's shipbuilding industry to supplement British ships. losses, and a series of requests for the provision of large amounts of military supplies, including aircraft.

Finally, it was made clear that the UK is currently unable to pay for the above-mentioned aid, and specifically requested not to insist on the principle of cash payment.

As an outstanding and far-sighted politician, Rothover certainly knew the importance of the British War of Resistance to the U.K., and how urgent it was to assist Britain!

However, it was difficult to achieve due to the constraints of isolationism that was still very active in the country at that time and the restrictions of the Neutrality Act.

After careful consideration, he delivered his famous "fireside chat" on December 12: "If your neighbor's house is on fire and he comes to borrow a hose from you, can you say that the hose is worth ten dollars? Please pay ten dollars first? No!" No! We will just say, take it and use it, and then give it back to me after you’re done with it!”

This metaphor vividly illustrated the situation at that time and also set off a big discussion in the U.S. about aid to the United Kingdom. Three months later, on March 1941, 3, Congress passed the Lend-Lease Act, which provided the British with a loan in the form of a lease. , China and other countries at war with the Axis powers provided war materials.

Throughout 1940, German submarines sank a total of 471 transport ships, with a total tonnage of approximately 218.6 million tons, and lost 31 submarines.

In January 1941, Britain began to equip escort warships with HF/DF high-frequency direction finders. This device can intercept radio waves between German submarines or between submarines and bases, thereby accurately measuring the location of the submarine emitting radio waves.

Also equipped are improved AS radars, which greatly facilitate the detection of submarine traces. After the German submarine discovers the fleet, as long as it sends a report, its position will be measured by a high-frequency direction finder;

Implementing nighttime surface attack tactics will be detected by new radar;

Sneaking underwater, it is difficult to escape the search of sonar, so it is difficult to guarantee its own safety and concealment during submarine operations.

Moreover, the British army began to equip reconnaissance aircraft with radars so that they could expand the reconnaissance range as much as possible. It was precisely because of the increase in the number and improvement of the performance of the British long-range reconnaissance aircraft that German submarine activities were greatly suppressed.

In January, German submarines sank 1 ships worth 21 tons.

In February, the U.S. announced that the safe sea area for naval escort was expanded from 2 degrees west longitude to 60 degrees west longitude.

The U.S. Naval Operations Department began to formulate an escort plan and assumed the escort mission from Aginsha, Newfoundland to Iceland.

At the same time, the German army began to implement improved submarine tactics, that is, 6 to 8 or even more submarines were deployed at intervals of to kilometers in the sea areas where the escort transport fleet may pass, forming a submarine patrol line or submarine curtain. As long as any one of the submarines detects the fleet, it will immediately report it to the Submarine Command, which will then organize nearby submarines to launch continuous nighttime surface attacks.

Dönitz summarized the principle idea of ​​this tactic as concentrating the maximum number of submarines at the necessary time and place.

This is the famous "wolf pack tactic". With the use of this tactic, the record in February increased slightly, reaching 2 transport ships sunk, totaling 37 tons. But compared with the past golden age, the results have still declined.

Therefore, Dönitz mobilized the most elite submarines to the northwest waters of Britain in March, attempting to launch a large-scale operation to break diplomatic relations and create greater glory.

(End of this chapter)