The submarine is known as an important invention that proved successful in the World War Two era. Eighty-five of Mussolini’s and a breath-taking seven hundred eighty-two of Hitler’s submarines were sunk during the war, in addition to an unknown amount of Japanese submarines (Rush 35). A 1943 German prototype of this submerged killing machine was capable of carrying fourteen torpedoes or up to sixty mines, showing how submarines were superior to their time period. For example, the USS Perch is renowned for her famous journey in the Arctic Circle, withstanding ice floes and below-freezing temperatures (Rush 69). However, certain drawbacks were also in place in different areas around the world. The Dutch and British attempted to send U-Boats to the Far East in aid of the U.S., but their European-crafted boats were too unstable for the waters of the Pacific (Morison 481). The submarine was also used in reconnaissance and transportation missions. Japanese admirals found the strategy of transporting supplies using submarines quite useful in the Pacific War, and Imperial Navy Admirals set up a major supply transportation system in 1943.
The revolutionary technological development of the submarine in World War II impacted the way of war for many countries by creating an efficient weapon that could complete many objectives such as transportation, combat, and reconnaissance.The strategic development of the submarine is the most important aspect of the weapon itself. The world’s major navies relied on its strength, speed, and stealth to attack and defend other military units. Germany had over 1600 submarines constructed at one point in the war, making an all-time record. Hitler’s Kreigsmarine forces overdid all other European forces just by sheer numbers. For example, France had only 77 subs to begin with, which included “38 large (1300 to 1500 ton) ocean boats, 32 medium (600 ton) boats; six minelayers (750 ton), and the monstrous (3000 ton) white elephant Surcouf” (Blair 74). While this sounds impressive to a lowly navy like Denmark’s, Hitler’s numbers outranked France by far.Mine laying was a popular strategy that both the Allies and their enemies used by specializing squadrons of submarines in laying mines (Feifer 268). While the Pacific War raged, the Japanese carefully placed mines in the straits of Tsugaru, Soya, and Tsushima in hope of destroying U.S. submarines and surface boats (Feifer 354).
Special U-Boat freighters of the Kreigsmarine called ‘Milch Cows’ were used to refuel minelayers on long journeys (Hutchinson 109). To put mine laying into place, special medium-weight submarines were modified so that mines were stored and laid instead of the original use as a torpedo shooting ship. Most navies did not possess many minelayers because they were less likely to be lost in combat than any other ship. They were not used in direct ship-to-ship battles, so If an ambush or raid was predicted, minelayers would prepare mine fields, or areas covered in mines in hope of destroying enemies, before the assault was launched. The Japanese tactic helped destroy the 38 US submarines that were sunk in the Second World War (Rush 95). The United States Navy had many advantages in World War II against the Germans, Italians, and Japanese. Among these was the aircraft lifeguard program. Originally formed in 1943, this strategic system was used in the Gilbert Islands and other nearby American-occupied territories (Morison 510). The purpose of the lifeguard program was to rescue pilots that were shot down. It was a successful use of US submarines that were not suited for combat. By the end of the Pacific War in 1945, the lifeguard program had rescued over 350 aviators that had been shot down by Japanese B-29s (Morison 511).
When programs like these were put into place, organization was key. So, the most common method of travel was to travel in wolf packs. Wolf packs were units of submarines, usually consisting of eight to 12 submarines and as units were very effective. For instance, it allowed submarines to travel in numbers that could easily assist other ships or attack with strength, unlike a single submarine, which could helplessly sink in the middle of the Pacific with no support at all. The use of wolf packs allowed submarines to be evacuated or repaired by larger surface craft. Also, wolf packs allowed for easy navigation because submarines would simply follow each other instead of using a direction-finding system or navigational system. A solitary submarine very easily became lost if navigation or radio equipment broke. Submarines now travelled in distinct units, aided other ships in need, had strength in numbers, and helped each other navigate to certain destinations (Morison 510).With the idea of wolf packs spreading into Europe, the U.S. Navy developed the tactic of hunter-killer groups to keep their enemies at bay. These typically consisted of a small aircraft carrier with destroyers.
The destroyers were heavily equipped with antisubmarine weapons such as flak guns or machine guns mounted upon the deck. Hunter-killer units were created to search for and attack enemy submarines that happened to be surfaced, or just in plain sight through the use of surface craft. This was effective for one reason only: the speed of submarines. All submarines were slow in this era, so therefore, even when submerged, surface craft could easily pick them off with antisubmarine weapons (Rush 35). Attacking enemy merchant shipping was another popular strategy among high-ranking Admirals. Almost all of the countries involved in naval warfare during World War II used a form of this system, so therefore the element of surprise quickly wore off as the enemies anticipated the usage of these submarines. Britain found this useful against Germany and even elaborated by creating a convoy system. British convoys disguised themselves as innocent merchant ships (Rush 34). Then, when a Kreigsmarine attack was in place, the soldiers on the convoys opened fire and used explosives in a daring attempt to single-handedly take down a squadron of subs.
This crafty trick was effective for a few months at most, but it certainly made a dent in Hitler’s navy (Rush 108). Japan’s Vice Admiral Inoue Shigeyoshi used this tactic against United States submarines as well (Spector 48). Also, Shigeyoshi deployed submarines in the Pearl Harbor attack after a massive air strike (Feifer 117). The U.S. was also successful while using a variation of this against Japan. By the end of 1944, American submarines had sunk 2,387,780 tons of merchant shipping, delivering Japan its worst industrial blow throughout World War II (King 200). The once powerful Japanese Imperial Navy was depleted, as were the resources to develop new technology or to construct new ships (Sears 426). In addition, U.S. submarines sunk 201 out of the total 686 sunk Japanese warships (Morison 511). U.S. submarines had a major role to play counter attacking the Japanese Imperial Navy.However, the ‘hit-and-run’ concept that many weaker nations used was sometimes inefficient. Bold forces and tactical the U.S. Navy is the most known for famous victories and strategic battles in naval battles throughout World War II. According to Ernest J. King, “The United States Navy’s final successful action against German submarines occurred on 6 May, only two days before V-E Day, when a U-Boat was sunk off Block Island by the destroyer Atherton with the frigate Moberly assisting” (King 204).
One of surprisingly few counter submarine attacks U.S. made on Germany, ambushing the Germans proved successful. For example, the U.S. submarine Tirante blew up a 10,000-ton tanker and two 1,500-ton escort ships in 1944. Tirante sunk all three ships singlehandedly and without air or sea support (King 201). Another example is a German submarine being destroyed at close range with “Molotov cocktails,” or small, breakable bottles filled with gasoline and an alcohol soaked wick thrown to explode on contact an erupt into a series of flames and explosions (Rush 36). Finally, there is the incident on Okinawa, where U.S. submarines “deliberately” killed civilians to clear the island of soldiers. The civilians did not retaliate (Sears 69). These famous and infamous encounters proved the strength of U.S. submarines and their counter-submarine supporting weapons.Another peculiar and unique use of the submarine is that of the miniature or midget submarine. The British developed this idea in 1943, and named their version ‘X-Craft.’ These secret submarines and their operators were built and trained in a base near Loch Erisort, Scotland to attack shipping routes as far as the Middle East and the Mediterranean Sea.
X-Craft were small and sleek, being only 52 feet long in size. Capable of reaching distances up to 1,200 miles, travelling at 6 underwater knots, and diving 300 feet deep, the tiny 4-man submarine became an ideal weapon against the colossal and seemingly undefeatable German U-Boats (Rush 121). The Japanese also used these smaller designs to create a different invention called suicide submarines. These were small submarines, similar to X-Craft, which were cheaper to build and required less of a crew, were used by deploying them in the midst of naval battle as a counterattacking weapon. Military leaders simply assumed they would succeed because their famous Kamikazes were both powerful and essentially for the same purpose, which was to complete suicide missions. However, this was a mistake of the Japanese Imperial Navy. Suicide submarines were too risky and too valuable to lose in the later stages of the war (Sears 151).The submarine also advanced technologically throughout the 6-year conflict.
The German submarines improved capacity and pioneered the snorkel system, which allowed the crew to breathe more easily than before through special filters in the ceiling of the ship (Wheeler 48). The U.S. developed better torpedoes as the war progressed, and also created the first nuclear powered submarine, the Nautilus, in 1954, a decade too late for combat (Rush 9). The British invented Asdic or what Americans call Sonar. The Japanese made combat more efficient through the use of stronger materials like steel and iron. These major developments helped shape the submarine into an advanced killing machine, and also helped improve what navies think of as a submarine today in the modern world.The external structure of the submarine was crucial in order for it to sustain damage gained during combat. For example, early designs of the ship used wooden hulls, because wood was cheap and easy to shape. It was also considered to be durable at this period in time. However, the wooden hull had many disadvantages. For instance, the hull was a potential fire hazard if the ship was struck by a torpedo or mine. Even if shots were not fatal, the fire might burn the crew alive, or consume their oxygen.
The surrounding water that the submarine was in may not prove sufficient to put the fire out. For these reasons the hull of military submarines were built using iron or occasionally steel (Rush 54).The ballast tanks, which are large metal tanks that are placed on the outside of the submarine, were the most vital external parts of the World War II era submarine. Charles W. Rush says the safety tank “contains provides sufficient ballast to offset the effect of accidental flooding of the conning tower” (60). What this means is that the safety ballast tank holds water in case the submarine needs to gradually sink or float. The water round torpedo tanks fire the torpedoes and are also referred to as ‘torpedo tubes.’ The trim tanks control if the submarine is riding bow-up or bow-down, and therefore act somewhat like a balance. Finally, the auxiliary tanks control listing from both sides of the ship.
These are tanks that balance from side to side, just like the trim tanks which balance the ship front to back. The ballast tanks hold air, torpedoes, and water, and are the most essential part of keeping the submarine in proper working condition (Rush 60). In addition to ballast tanks, most war-capable submarines were heavily equipped with various weapons. These included anti-aircraft or AA guns, flak guns, which destroy missiles and missile launchers, and deck guns, which proved useful in coastal combat with other ships. The first ever German submarine to be armed with four mounted 20-mm antiaircraft deck guns was the Bogue. From this point on, the quantity of antiaircraft guns mounted on the deck was increased from one to two to four. German structure influenced many countries because it not only occurred in Germany, but also on U.S., Dutch, British, Japanese, and French submarines (Morison 367).
The internal structure is just as important as the external. For instance, the Germans pioneered the snorkel system, which allowed air to travel down into the submarine and for the crew to breathe. For this to be possible, the submarine had to surface its ballast tanks and filter the air through a special system so water would not get in the way. Also, large batteries were stored inside the engines to help build up energy. A World War II submarine had to come up every 24 to 36 hours to recharge its battery. The more time a submarine was underwater, the less efficient it would be (LeMaistre 1).Secondly, there was the development of torpedoes. Special torpedo tubes held these massive missiles. For the French, there were two standard torpedo sizes. These were 15 inches and 21 inches in diameter. German submarines could blow holes into ships as large as 20 to 40 feet in diameter (LeMaistre 2). However, the U.S. “had the best submarines in the world, but the worst torpedoes” as a major drawback for submarine combat (Spector 20). These show that even though the Allies had high-quality submarines, their weaponry was unorganized and inefficient.
Also, nine U.S. submarines were lost in World War II because of operational failure, some even due to lack of accurate aim and a few friendly fatalities during drills or combat using wolf-packs. Five others went missing for unknown reasons such as possible Japanese capture (Rush 95). Unfortunately for German and Italian submarines, a relatively new antisubmarine missile was produced by the British. The missile, commonly nicknamed because of the way it was shaped, had up to 20 cylindrical bombs attached together at the bottom, with the narrow ends at the top. Thus, it was named the Hedgehog. Hedgehog was extremely successful, and not a single known submarine survived its hit. The Hedgehog was only used in ship to sub combat, and was capable of being fired up to 250 yards underwater, making one of the most efficient torpedoes of all time. Also, it was easily recognizable by the thundering sound it made. By doing this, it served a double purpose: to put Sonar machines completely off track and inaccurate, and to distract the enemy submarines from making a snappy counter attack.
The Hedgehog missile was also feared by surface ships, although it was only known in uses against submarines. This was because the sight of an exploding Hedgehog missile was awe inspiring; water would go in a perfect hedgehog shape, just like the missile. Overall, the Hedgehog missile was exceptionally successful and helped Britain defeat German forces (Rush 95).Therefore, the technological revolution was just as valuable as the strategic one. Submarines developed ballast tanks to control balance, weight, and buoyancy. To counteract the superiority of German submarines, the British used their advanced bomb technology to create the antisubmarine weapon that was known as the Hedgehog. By doing this, the submarine was proven to be one of the most technologically advanced naval weapons of its time.Lastly, the submarine was greatly affected by the invention of Sonar. Originally, this technology was based off of British ‘direction finding’ or DF systems that were used in World War I. The British did not very successfully develop this system any further during the Great War due to primitive resources and hasty construction. Nevertheless, it certainly advanced in the early 1940s.
According to U-Boat scholar Clay Blair, the system functioned as follows, “Called the ‘grid system’: north-to-south latitudes and west-to-east longitudes were defined alphabetically, A to Z. The systems’ operators could therefore locate the exact global positioning of German submarines” (75). The genius invention of the system Americans refer to as Sonar and the British Asdic reformed the power of searching for, finding, and counter attacking submarines. The Germans adopted their own submarine radar system. The German version was named Enigma, and was a near success, just below Sonar and Asdic of the US and British navies. However, an obvious disadvantage was soon found with German submarine commanders was that it was less accurate. Enigma made torpedoes miss targets in plain sight (Blair 75). A similar version of the commonly known Sonar is Radar. Radar was used in aircraft particularly in the US and Britain. This was helpful because at times Sonar was difficult to use, it broke down because of a water spill, or another disadvantage that was commonly found in submarines.
The fact that aircraft was much faster than all submarines made it easy to report back to naval bases in a hurry if a wolf-pack of submarines was unexpectedly coming that way. This way, antisubmarine units like other planes and surface ships could counter attack without being unprepared. In addition to aircraft, Radar was introduced to surface craft in mid-1942. This allowed hunter-killer groups to be prepared for a submarine ambush coming their way. Plus, Charles w. Rush says, “The development of aircraft radar was undoubtedly a major factor in the defeat of the German U-Boat campaign,” proving that Radar systems were both necessary and efficient in finding submarines, whether it was used in the air on planes or on the water with surface craft (. In conclusion, the submarine was a total success, and at times a total failure. Firstly, the submarine went through numerous strategic phases of revolution. This included tactics like mine laying and attacking enemy merchant shipping. “By October 1940, the U-Boats had notched up average sinkings of 60,000 tons of shipping per month, per submarine” proves the strength of German U-Boats (Hutchinson 108).
Secondly, this naval machine withstood many technological changes like torpedoes and Hedgehog missiles. Finally, there is the creation of Radar and Sonar. These two inventions proved to the world that submarines did indeed have a weak spot, and that certain special machines were able to identify their location, even underwater when vision was poor and lighting was even more primitive. Throughout the Second World War, the submarine went through many changes technologically and with radar. The submarine also was used in a very militaristic and strategic manner. Through Sonar, strategy, and systematic technology the submarine is truly famed as the worlds’ most superior naval weapon of its time.