Film and Television: Starting from the Journey to Guandong

Chapter 141

The birth of the T-class submarine is still not far away, and the K-class that the UK was previously proud of has continued to have problems.

Before the first stop, Britain and Germany were engaged in a fierce battleship race. Both sides competed to build battleships with larger displacement and larger main gun caliber to fill their fleets. In order to further enhance the decisive battle strength of the main battleship force, the British Navy fought Attention submarines.

In 1913, the British Navy proposed the concept of a large high-speed submarine, which would be incorporated into the battleship fleet and march together on the water.

During the decisive battle with the German "High Seas Fleet", it dived underwater and fired torpedoes at the German battleships. At this time, the torpedoes were likely to disrupt the strict formation of the "High Seas Fleet", and this submarine could also hunt down the slower and older battleships in the German fleet. and wounded stragglers.

At that time, the British Royal Navy's main submarine - Type E, had a speed of less than 16 knots and a range of only 3000 nautical miles. Of course, it was unable to perform the above tasks. To keep up with the speed of the battleship force, the submarine's surface speed must reach 20 knots. above.

In 1914, the British Royal Navy's two diesel-powered submarines "Swordfish" and "Nautilus" had just been completed. According to the design calculation data, they should be able to meet the indicators of high-speed submarines.

In 1915, two new submarines were tested, and their maximum speed did not exceed 18 knots, and they did not show the expected performance. The British Admiralty believed that diesel engines were no longer sufficient, and steam turbines with greater horsepower must be used.

At that time, Britain experimented with a 1-horsepower steam turbine for the first time on the S3750 submarine. This experiment was successful. The submarine's surface speed increased greatly, reaching 20 knots.

In the past, steam turbines were only used on large surface ships.

In September 1915, the British Admiralty ordered 9 K-class submarines at a high price of 34 pounds each.

The finally completed K-class submarine won the two championships of being the largest and fastest submarine in the world at that time.

On paper, the performance of K-class submarines is outstanding even in World War II.

The K-class submarine has a total length of 103 meters, a width of 8.08 meters, a draft of 6.38 meters, a surface displacement of 1980 tons, an underwater displacement of 2566 tons, and a total of 59 people on board.

The K-type submarine is three times larger than his grandfather E-type submarine. The tonnage jumped from 3 tons of the E-type submarine to 800 tons. It can carry a lot of fuel and other supplies, and the corresponding range is more than three times. The 2500 nautical miles has been increased to 3 nautical miles, allowing you to travel around the world with the battlecruiser.

High-speed surface navigation uses a 10500-horsepower steam turbine, and the maximum speed can reach 24 to 25 knots. This record was not broken until the emergence of nuclear submarines. Underwater navigation uses a 1400-horsepower motor for propulsion, and an 800-horsepower diesel engine is used for floating and submerging. In this way, the K-class submarine There are three power systems.

A total of 6 457mm torpedo tubes are equipped, 4 at the bow, 2 amidships, and 18 torpedoes.

Due to being too greedy for perfection, the K-class submarine has a serious center of gravity instability problem when diving.

Its maximum diving depth is 16 meters, which is much smaller than the length of the hull. Often when the bow of the boat dives to a depth of 16 meters, the stern of the boat is still sticking out on the water. It requires a lot of complexity to keep the stern of the boat flush with the bow. Fine adjustment measures.

The then-Crown Prince George VI was still serving in the Navy. He once participated in a dive test on the K4 submarine. However, the submarine lost control of its center of gravity during the dive and plunged to the bottom of the water. Fortunately, the test was conducted in an inland river where the water was not deep, and nothing serious happened. .

In order to solve the problem of unstable center of gravity, a large buoyancy tank was installed on the bow of the K-type submarine, and the bow was changed to a scissor bow to improve navigation performance. During the dive, the bow has strong buoyancy, which helps stabilize the center of gravity.

However, the large pontoons installed blocked the submarine's forward view, posing hidden dangers for future disasters.

Four more 4mm torpedo tubes were installed in the large pontoons, which increased the attack power of the K-type submarine to 457 10mm torpedo tubes. As a result, the K-type submarine became the submarine with the strongest torpedo firepower. Why it is said that torpedoes have the strongest firepower is because the British Navy also has a mixed-firepower submarine M-class, which is equipped with a battleship's giant cannon.

However, steam power has many shortcomings. When diving, the steam turbine must be shut down, the boiler must be extinguished, the chimney must be lowered and waterproof materials must be laid, and the exhaust fan for heat dissipation must be retracted into the hull. The entire process takes 10 minutes at the fastest. .

After surfacing, it has to operate in the opposite direction again, which makes the K-class submarine respond slowly to changes in the external environment. If the enemy's anti-submarine forces launch an attack at this moment, the K-class submarine will almost be a piece of fish on the chopping board.

Moreover, the chimney runs through the hull from the upper deck to the power compartment, making it impossible for the K-class submarine to form a perfect pressure-resistant structure.

The overly complex power system of the K-class submarine and the requirement to accompany the main fleet made it unlucky and accidents continued.

Its vaunted steam turbine was the source of the problem.

Due to the characteristics of the steam turbine itself, starting up and shutting down is not a simple matter. When starting up, it takes time to heat up the boiler, and when shutting down, all the steam inside needs to be evacuated to prevent steam from leaking into the interior of the submarine.

In order to maintain surface power when the main engine of the submarine is shut down and not waste precious electricity, the submarine has an auxiliary diesel engine that can provide limited power before preparing to dive or after surfacing and before the main engine starts. However, the submarine still consumes a lot of energy when diving. It takes a long time and takes 5 minutes. In wartime, 5 minutes is very fatal.

The operation of the steam turbine requires a lot of air and huge exhaust gas emissions, so the K-class has two large bendable chimneys, which need to be bent to avoid water intrusion when diving.

However, the huge smoke exhaust duct connected to the chimney weakened the bearing capacity of the submarine's pressure hull, and the watertight problem after the chimney was bent could not be solved well.

The K13 submarine sank in 1917. It is speculated that there was a watertight problem in the chimney, which caused seawater to pour into the submarine.

With a huge chimney, the amount of smoke emissions will certainly not be small. A K-class submarine sailing on the surface can be discovered very far away, and its too slow diving speed will lead to disaster.

Another problem is the view of the bridge. The bridge of the submarine itself is very low. After the large pontoon is installed on the bow, the view of the bridge is further blocked.

After its completion, the K-class submarine participated in some naval battles in World War I and launched torpedoes at enemy ships. Because the awareness of anti-submarine mine protection was improved at that time, many large surface ships installed mine nets on both sides, so the results were very few.

What really made the K-class submarine famous was a serious accident that occurred in 1918.

On January 1, the British Navy was ordered to perform combat missions in the North Sea. The fleet implemented a light blackout along the way. In that era when radio was not mature, the light blackout meant that communication at night became very difficult.

That night, the K-class submarines of the 12th and 13th squadrons served as the leader of the fleet. The other cruisers, battlecruisers and battleships lined up at the rear of the team. The entire fleet advanced rapidly at a speed of 20 knots.

When the fleet arrived at May Island, the leading submarine K14 discovered a small boat on the sea surface, so it made an emergency maneuver to avoid it. Its move directly prevented the K22 submarine behind it from avoiding it, and directly hit it. .

In this way, two large submarines were paralyzed on the main channel. Because of the backward lighting control and communication methods, the ships in the rear did not know about the accident ahead and continued to move forward according to the original position.

Soon a battlecruiser "Indomitable" passed by and hit the K14 solidly.

The sister ship K17 discovered the accident on the waterway, so she adjusted her course to prepare to rescue the K14. At this time, the flagship "Brave" of the submarine formation was moving forward according to the original route, and suddenly hit the K17 that changed its course. The submarine was Hit at the waist, it broke into two pieces and sank to the bottom of the sea.

The flagship "Brave" that discovered the accident immediately issued an order for an emergency stop. The K4 submarine that followed immediately stopped after receiving the order, and the K6 submarine behind it collided firmly, and the K4 submarine sank immediately.

The accident directly caused the sinking of two K-class submarines. Two submarines were seriously injured and one was slightly injured. In addition, the submarine's flagship "Valiant" and the battle cruiser "Indomitable" were also damaged. The entire combat mission had to be cancelled.

In the end, these K-class submarines did not show their majesty on the battlefield. Instead, they suffered from various failures that caused them to be sunk or damaged. They were eventually retired in the 20s. The only improved K26 was in service until the 30s and was under international treaties. Abolition under the restrictions.

Looking at it this way, neither the British nor the ugly submarines can be counted on.

Zhu Chuanren turned his attention to Italy again.

When it comes to Italy's military strength, it has always been strange.

In people's minds, Italy was a walk-on during World War II, and the Italian army was even worse at fighting, which simply brought shame to the great powers.

In fact, Italy was not weak at that time, and its overall strength was among the best in the world. It was just that it had been misunderstood for a long time.

To be honest, in terms of military strength alone, Italy is on the same level as Little Book.

First of all, Italy’s overall national strength is not bad.

As one of the established powers and one of the three giants of the Axis Powers, Italy's strength is naturally not bad.

Although there is still a certain gap between Italy and the top industrial powers such as the United States, the Soviet Union, and the United Kingdom, Italy was also one of the few industrial powers at the time. It was one of the few that could manufacture aircraft, tanks, automobiles, heavy artillery, and warships, including Aircraft carrier country.

Italy's industrial technology and industrialization level are even higher than Xiaoben. During the second stop, Neon imported a large amount of weapons and equipment, machine tools and other mechanical equipment from Italy.

For example, before the second stop, Neon imported dozens of BR-20s from Italy.

bombers, which shows Italy's industrial strength.

You know, China, as one of the top four allies, could not even build artillery and bicycles at that time, and there was a huge gap with Italy.

One of the most important reasons why Italy is criticized is that the performance of the Italian army is too poor.

In fact, this is a misunderstanding about the Italian army.

Italy has a well-equipped army and a navy and air force that are among the best in the world.

As one of the few modern industrial countries at that time, the Italian army was good in terms of weapons and equipment, training level, military philosophy and overall quality. It was a qualified modern army.

The Italian Army has various types of equipment such as tanks, heavy artillery, and anti-tank guns. The firepower and mechanization level of the Italian Army are one level higher than Neon.

After the retreat from Kiska Island, U.S. Commander Nimitz landed on the island and saw the airport that the Neon people had built for more than a year. He said: "Either I don't understand modern warfare, or I don't deserve to participate in modern warfare at all." ".

The United States and the United Kingdom have a very high opinion of the Italian army, and the Wooly Bears are even more troubled by the Italian army.

During the Ukrainian campaign, 26 Italian expeditionary forces swept across Ukraine and captured 10 woolly bears.

The Italian army can go head-to-head with the American and British armies, and it is a ruthless character that can go toe-to-toe with the furry bears who have been tempered by the flames of war.

On the other hand, in the later stage of the second station, the Neon Army was almost pressed to the ground and rubbed against the Mao Xiong. It can be said that the Italian Army is still very good. At least it has reached the basic level of European and American modern armies, and it is a team that can win. The modern army on the table is not a little bit better than neon.

In German terms, the neon army is still at the level of the one-stop era.

If Neon is thrown into the Soviet-German battlefield, its performance may not be better than that of Italy. It is difficult to say whether Neon's 38 large tanks and Azuki tanks can adapt to the modern combat on the Soviet-German battlefield.

In terms of navy and air force, Italy is not weak. The Italian Air Force is equipped with various types of fighter aircraft. The Italian MC205 fighter jet was one of the best fighter jets in World War II. The Fiat G55 was evaluated by the Germans as the best among the Axis powers. Good fighter.

In the Mediterranean and Soviet-German battlefields, the Italian Air Force fought against the air forces of the United Kingdom, France, the Soviet Union and other countries without falling behind. In the Soviet-German battlefield, the Italian Air Force even achieved a record of 15:88. The Allies did not dare to underestimate Italy. air force.

The Italians also planned to bomb the United States from a long distance, and their air force strength can be imagined.

If the Neon Air Force and Italy were duel, Italy would not necessarily lose, and the Italian navy should not be underestimated either.

1940年意大利海军拥有257艘各类舰艇，其中包括4艘3.5万吨级战列舰和7艘万吨级巡洋舰以及数量庞大的潜艇部队（有上百艘）和独特的蛙人作战部队。

The overall strength of the Italian Navy ranks fourth in the world and is a formidable maritime force.

At that time, except for the United States, Britain and Japan, no country's navy could defeat the Italian navy.

Therefore, Italy's strength at that time was not bad, but the Italians were not very enthusiastic about war, and their opponents were too strong, so the Italian army performed poorly.

Many people think that the Italian army is poor at fighting and lacks the will to fight, but in fact the Italians are terrible when they are violent.

In the Battle of Gubi Wells, because the British refused the Italians to surrender, the angry Italians ran to fight the British. As a result, the Italians defeated the well-equipped British 22nd Armored Brigade, which was shocking.

In the Battle of Stalingrad, the Italians were the first to break out of the heavy siege of woolly bears, and they did so by using bayonets. What's even more powerful is that the number of Italians who broke out was half as many as the Germans. .

The Greek Communist Party and the Italian Communist Party almost drove the German regular army out of Greece with their own strength. The Italian Communist Party guerrillas beat the Germans to tears in the Balkans and northern Italy.

After the second station, the new Italian army, with the Red guerrillas as its backbone, defeated the West German Bundeswehr in military exercises under the framework of NATO for decades.

After France withdrew from NATO military integration, the Italian army became the combat force of NATO's European allies.

Therefore, it is actually a false proposition that the Italian army is inferior. It is not that the Italian army is not good, but that the Italian army is unwilling to fight.

One by one, take the navy as an example. During the Second World War, Italy still had a powerful navy, allowing it to effectively dominate the Mediterranean in the early stages of the second world war.

Later, lack of fuel and completely wrong combat command led to the failure. Of course, its opponent was too powerful as the main reason.

When mentioning the Italian Navy, the first thing that may come to mind is its "clumsy" fight for the island of Malta with the UK's smaller naval and air forces. Later, when Uncle Xi saw that his teammate was really unable to help him, he sent his own troops to help.

However, in fact, the Italian Navy is not as useless as the army. Their appearance often causes headaches for the British Royal Navy, an established maritime power (mainly for diversion, of course).

The Royal Italian Navy in the second station is the fifth largest navy in the world, second only to Britain, the United States, Japan, and France. It is a formidable maritime combat force. Its purpose of existence is to launch aggression and attack.

The Italian navy's defense of the territory was also very important and could pose a serious threat to the Allies if they attempted an amphibious landing. Mainland Italy and the large islands of Sicily and Sardinia would be protected by the navy.

In addition, Italian territories in North Africa would also be looked after.

However, it was destined to suffer defeat at the hands of the Allies for several reasons.

Uncle Mo intended to use it to achieve his goals, but several factors combined to prevent the Italian Royal Navy from achieving victory for him in the Mediterranean.

In general, Italian warships are more advanced and faster than contemporaneous foreign navies, but in order to comply with the Treaty on the Limitation of Naval Arms, some other aspects must be sacrificed to improve weapons and speed.

Cruisers, in particular, have very thin armor and very short range.

Uncle Mo believed that since Italian ships would operate in the relatively calm waters of the Mediterranean, firepower and speed would be the qualities sought after.

These characteristics make these warships ideal for hit-and-run attacks, but also make them vulnerable to concentrated targeting and prolonged surface strikes.

Uncle Mo and his naval staff built many different types of warships and put them into service.

The most powerful warships of the Italian Navy were battleships.

Before the war began, four old World War I-era battleships were seized, fully restored to power and rebuilt.

They are: Cavor Conde, Cesar, Doria and Durio.

They were equipped with new cannons, new engines, new superstructures, new damage control and fire control systems, and the ability to launch reconnaissance aircraft with catapults.

When completed, they were superior to several French battleships in service at the time, but their gun performance still lagged behind the larger British battleships.

When Italy entered the war, two new 3.5-ton battleships, the Littorio class and Vittorio Veneto, had just been completed. The third Roma battleship was completed in 1943, and the Littorio class was highly praised. An excellent design, they were among the most powerful battleships ever designed and built in Italy.

Six of the seven battleships survived the war, and all but Count of Cavour were surrendered by the Allies. At the time, Count of Cavour was undergoing repairs and could not be used.

Before the second station, Italy had built a total of seven heavy cruisers, and their main weapons were eight 8-inch cannons. However, these heavy cruisers were brutally attacked in the naval battle and suffered heavy losses. Five of them were sunk or destroyed.

The other two, Gorizia and Bolzano, which had been severely damaged by the time of Italy's surrender in September 1943 and were being repaired, were captured by German forces and later destroyed.

King Vittorio Emanuele III of Italy, the diminutive king was the titular commander-in-chief of the Italian army.

However, since allowing Moto to establish a dictatorship in the early 20s, Vittorio Emanuele III has been little more than an incompetent figurehead in his own kingdom.

The king had only nominal power and little control over military affairs.

During the Second World War, the actual controller of the Italian navy and other armed forces was Uncle Mo.

He was allowed by the king to establish a dictatorship in Italy, a position that enabled him to exercise decisive power in all military matters.

Uncle Mo had planned to use his navy to attack the British and French navies.

Less than a month after Italy entered the war in June 1940, the collapse of France eliminated all threats from the French navy, leaving only one enemy left, the Royal Navy.

The British Empire at that time, including the Mediterranean theater, was protected only by scattered British naval power.

But despite this, the Italian navy was never able to effectively threaten and challenge the British army.

On July 1940, 07, a naval battle broke out at Cape Stillo between the British and Italian navies. In 09, the British army on the island of Malta was very small, with almost no air force, the navy was also weak, and the island lacked anti-aircraft guns. Prevention and control equipment.

The Italian navy and air force attacked a transport convoy escorted by a weak British fleet transferred by the British forces on the Island of Malta. As a result, the British ships were unscathed, but one battleship and two cruisers of the Italian navy were hit.

1940年11月11日，英国海军出动以“光辉”号航母为主的编队袭击了意大利驻塔兰托的意大利海军，造成 1艘战列舰被击沉， 3艘战列舰和1艘巡洋舰、1艘驱逐舰被重创。

In this surprise attack, almost half of the Italian Navy's main ships were lost, which can be said to be a serious loss of vitality. This naval battle fully demonstrated the threat to the island of Malta.

However, Mussolini had not yet realized the necessity of seizing the island of Malta. Of course, this would be even more disastrous for the German troops fighting in North Africa.

After more than a year of fighting, the British navy effectively faced off against the Italian and German armies.

However, the British army's victory was achieved by some weapons and equipment that Italy did not have, such as radar and naval air power on aircraft carriers. These equipment were of greatest value to the British army, but the Italian army turned a blind eye.

After several naval battles, Italy found they could not deal with the British navy.

Eventually, the Italian naval presence was converted into a diversion of much needed British naval forces elsewhere in the Allies.

Although this was not the goal of the Italian Navy in Mo's plan, the reality that the naval fleet still existed served its new purpose. The British had to maintain sufficient maritime power in the area at all times to prevent the Italians from launching a surprise attack with their navy at any time.

Italy did not have an aircraft carrier in service from the beginning to the end of World War II. This was fatal for World War II when sea and air control was more important. When the construction of the only aircraft carrier Aquila was nearly completed, Italy surrendered.

In any case, from June 1940 to September 6, the Royal Italian Navy at least performed bravely in every battle.

They suffered heavy losses, but also caused considerable losses to the British navy.

When Italy announced its surrender to the Allies, the naval fleet was ordered to attack the British island of Malta.

The Italians tried to convince their German allies that the fleet was attacking Allied landing forces.

However, the Germans suspected fraud and organized an air raid on the Italian air force squadron.

After a large number of Italian fleets set off from La Spezia, they were attacked by the Luftwaffe.

Admiral Bergamini's flagship Roma was hit by a radio-controlled glider bomb, blown in half, and subsequently sank, causing heavy casualties.

The battleship Italia was also hit, but the damage was not serious and she continued on. The Vittorio Veneto is intact.

The second Italian fleet, including the battleships Andrea Doria and Caio Durio, departed from the large naval base of Taranto in southern Italy.

The fleet reached Malta without incident. The battleship Giulio Cesar and a guard crew were anchored in Poland, left after encountering some difficulties, and also arrived safely in Malta.

The last battleship, the Cavalconti, was still under repair and could not move or escape, and was eventually captured by the German army.

For the Royal Italian Navy, the war was essentially over by this time, and Italy eventually rejoined the war as an Allied power.

Weird Italy has done a lot of bad things, such as the Leonardo da Vinci in the Navy.

Curio Bernardis was the most famous and important submarine designer during the Italian war. He was responsible for the design and construction of many types of Italian submarines, including the most powerful 6 "Marconi" class submarines, among which "Le Leonardo da Vinci is the third ship.

The submarine is designed to be a large fleet submarine operating in the Mediterranean region.

Single hull, maximum diving depth is 90 meters.

该艇于1938年9月19日在意大利蒙法尔科内的“亚德里亚海联合造船厂”开工建造，1939年9月16日下水。

After the boat was built, it was tested in the Mediterranean for several months.

In August 1940 the submarine was deployed to the Italian naval submarine base in the Bordeaux region of France.

This base is owned by the Italian Navy and is dedicated to placing submarines that can operate out of the Atlantic Ocean.

The Italian submarine is tasked with cruising in the Atlantic Ocean in waters south of Lisbon, Portugal.

Unlike the surface operations of the German Navy at that time, the Italian Navy required submarines to conduct underwater operations when encountering enemy ships.

Early torpedoes needed to submerge the torpedo tube in the water when launching. If necessary, the submarine could also float on the water to launch the torpedo.

A longer periscope is particularly important for submarines that must fight underwater at all times. Therefore, compared with German submarines of the same period, the control tower of Italian submarines is larger.

Since German submarines mostly attack targets on the water surface, in order to reduce the probability of being discovered, the appearance of the submarine is required to be as simple and low as possible so that the projection on the water surface can be minimized.

This means that compared with Germany at the time, Italian submarines were larger in shape and volume.

The key to the Italian Navy's operational principles that require submarines to attack underwater is concealment and the suddenness of the attack, so the speed of the submarine when engaging the enemy and retreating is not important.

The longer the Italian submarines' emergency dives took, the more vulnerable they were to air strikes on the surface.

Differences in usage tactics and structural design make Italian submarines and German submarines very different in performance, making it difficult for the two countries' submarines to be used in a coordinated manner.

Therefore, Italian submarines did not participate in the "wolf pack" operations of German submarines, but conducted operations alone on a route from Lisbon to the south of the country's east coast.

In order to adapt to the combat environment in the Atlantic, the Italians made some improvements to the submarine from 1941 to 1942: the size of the conning tower was reduced to reduce the probability of detection, and the periscope jacket was lowered to reduce the overall size of the ship.

As a result, these improvements were not successful in use, because the new improvements used many non-standard parts, which caused a lot of trouble for maintenance personnel and directly affected the submarine's navigation rate.

At that time, submarines of the same class built by different German shipyards were required to have common parts. When designing submarines of different classes, they also tried to make parts as common as possible with submarines already in service.

However, due to the low degree of standardization of Italian submarine technology, it is difficult for submarines of the same class but produced by different shipyards to have common parts, and the number of submarines at each class is not large. Therefore, the maintenance difficulty and cost of the Italian submarine force have always been high. No less.

As an advocate and leader of submarine special operations, Valerio Borghese, then commander of the Italian Navy's Special Submarine Forces, proposed many bold plans for submarine attacks.

One of them is to use pocket submarines and frogmen to attack New York Harbor, and then the pocket submarines go straight up the Hudson River to attack as many ships as possible along the way.

"The Leonardo da Vinci submarine was selected as the carrier for this mission. It was modified at the Italian Navy submarine base in Bordeaux, where the guns on the deck were removed and a clamp was installed on the foredeck to attach the CA-2 The mini-sub was secured to the front deck and carried across the Atlantic.

The pocket submarine was shipped by rail from Italy and testing began in late 1942.

Borghese believes that this kind of attack will have a great psychological shock on the Ugly people. In essence, it is closer to a kind of psychological warfare.

However, the performance of the CA-2 pocket submarine could not achieve the expected results and required design modifications, so the "Leonardo da Vinci" gave up this mission.

While the New York attack plan was being revised, the Leonardo da Vinci continued its combat cruise.

It conducted 11 combat cruises in the vast Atlantic waters from Africa to America, and once entered the Indian Ocean.

Different from the "lone wolf" operations used by the Italian Navy in the past, these operations were not completed by the "Leonardo da Vinci" alone. During the cruise, it and the Italian submarines "Tazzoli" and "Vinci" ” cooperated and sank a number of Allied ships.

The Leonardo da Vinci reinstalled its dismantled deck guns before entering the Atlantic cruise. On November 1942, 11, it attacked a Dutch merchant ship (1 tons) with its artillery. The merchant ship burst into flames. sink.

On March 1943, 3, the "Leonardo da Vinci" sank the Canadian cruise ship "Queen of Canada" (14 tons) off the coast of West Africa, which had been drafted for military transportation.

But the Italian commander on the submarine did not know that the ship was carrying refugees and Italian prisoners of war.

There were more than 1800 people on board, and 392 died in the attack, half of them Italians.

Then the "Leonardo Da Vinci" sailed around the Cape of Good Hope and entered the Indian Ocean, where it sank three more ships on the east coast of South Africa.

On May 5, the submarine sent a telegram to the base indicating that it was returning to the base. This message was intercepted by the British who had been conducting radio monitoring and the precise location of the submarine was determined.

The British immediately dispatched two warships, the destroyer "Active" and the frigate "Nice" from the nearby escort formation, specifically to round up the Italian submarine on its way back.

On May 5, two British warships discovered the Leonardo da Vinci.

The Italians did not know that the two British warships came specifically for it, thinking that they could get away by hiding under the water. As a result, the British launched an intensive depth charge attack on the submarine.

The Leonardo da Vinci was sunk with no survivors on board.

Lieutenant Commander Gianfranco Gasana Priya Loggia, the captain of the Leonardo da Vinci, had a total of 90601 tons in the Second World War, more than any submarine commander except Germany. record.

In the Italian Navy, the bizarre pocket submarine force is definitely the dazzling star.

1941年12月18日第10快艇支队的6名突击队员驾驶3条“猪”式袖珍潜艇潜入戒备森严的亚历山大港，一举炸沉英国战列舰伊丽莎白女王号和刚勇号，其勇气和技术无可挑剔。

But as far as the Italian Navy itself is concerned, it is actually not very satisfied with pigs.

Because the original design of the pig comes from the One Station period, it is better to be called a human-operated torpedo rather than a pocket submarine.

Because it is too crude, its ability to perform tasks autonomously is poor.

And the crew basically cannot return after completing the mission. Although it is not a suicide attack, it is not much different from a suicide attack (there are still commandos who swim ashore after completing the attack and then return home).

Therefore, the Italian Navy believes that they need a more complete pocket submarine.

In 1938, the Italian Caproni Company built two pocket submarines for the Navy under strict confidentiality. This submarine was called the CA class.

This class of submarine has a crew of 2, a total length of 10 meters, a displacement of about 13.5 tons, and is equipped with a 60-horsepower diesel engine and a 25-horsepower electric motor. The speed is 6.5 knots on the surface and 5 knots underwater.

The submarine has a submersible depth of 55 meters and can travel 3 kilometers underwater at a speed of 105 knots. The submarine's weapons are two 450mm torpedoes mounted on outboard launchers.

Although the CA-class submarine is about the same size and weight as a bus, after all, it has all the internal organs and looks like a submarine, which is much more perfect than a pig.

The Italian Navy has high hopes for it. In addition to the traditional penetrating raids of pocket submarines, it also hopes to use it to undertake offshore patrols and port anti-submarine tasks.

However, after being towed to sea trials, the Italian Navy was greatly disappointed. Experiments proved that CA1 and CA2 basically had no possibility of independent cruising.

First of all, this kind of submarine is too light. At periscope depth, even small sea conditions will cause the ship to sway; secondly, the water in the Mediterranean is too transparent, and small submarines crawling on the seabed offshore are seen from the air and the surface. Everything is clear.

After the war began, the Italian Navy still did not find a suitable use for CA1 and CA2. These two boats were used most of the time for anti-submarine warfare in the harbor.

In 1941, due to pressure from the German Navy, the Italian Navy decided to make use of the two CA-class ships. It planned to use a mother boat to bring the CA-class to an important enemy port, and then use the darkness to sneak into the port to place explosives to launch an attack.

Prince Valerio Borghese, commander of the 10th Speedboat Detachment, set two possible attack targets for the CA class. One is the British fleet base in Freetown, Sierra Leone, and the other is a port on the east coast of the United States.

However, it was later discovered that the defense system of the British base had no possibility of penetration, so the CA1 attack plan was abandoned.

On the other hand, plans for attacks on the east coast of the United States were progressing steadily. The physical damage caused by a small boat was minimal, but the psychological damage was considerable, so the Italians decided to play the big game and set their target in New York.

In 1942, CA2 was transported by rail to Bordeaux for modification testing, and the Marconi-class submarine Leonardo da Vinci was selected as the mothership of the pocket submarine.

The Leonardo da Vinci removed the deck gun and installed a protective seat ring and clamp in its original position to fix the CA2 in it.

Sea trials have shown that the Leonardo da Vinci can release CA2 from underwater, and can also recover CA2 after surfacing and reload it into the seat ring.

This was done to avoid being seen as a purely suicide mission, which would have negative political consequences.

This protective seat and the shape of the CA2 surrounded by it soon earned the Leonardo da Vinci the nickname Kangaroo, and CA2 was also called the Kangaroo Cub.

In order to complete the destruction mission, CA2 also needs to undergo a large number of modifications.

The boat's conning tower, periscope, outboard torpedoes, and diesel engine were all removed, and built-in ammunition racks were added to the superstructure. A diving conversion cabin and a bottom hatch were added to the hull, through which the crew could exit from the mother boat. Gun access hatch into CA2.

改装后的CA2排水量减少到12吨，水下航速提高到6节，以2节速度航行时航程为129公里，乘员增加到3人。

Later, CA3 and CA4 were built according to this standard. These two ships were called the second batch of CA-class ships.

(End of this chapter)