“Execute Unrestricted Air and Submarine warfare against Japan,” declared the United States Naval Department on December 7, 1941, mere hours after the attack on Pearl Harbor. This was the submarine fleet’s opportunity to avenge all of the Americans lost on the day that will go down in infamy. Submersible vehicles were first used in combat for more than a century and a half before World War II. During the American Revolution, colonists used parts of barrels to make a crude submarine which would later become known as the Turtle.
On the night of September 6, 1776, the Turtle first saw action, when it tried to sink a British frigate. The Turtle dawned an age of undersea warfare that would turn the tide of many battles, especially in World War II. Many new types of submarines were developed and became more efficient during the 1940s. Submarines were the most successful new technology used in sea warfare during World War II because they sank enemy ships, remained undetected in hostile waters, and formed blockades around enemy ports.
Just like all other types of technology and machinery, submarines have had major improvements and upgrades. After the first World War, Germany had to pay reparations for the damages they caused. As a payment to the United States, Germany handed over six of their latest submarines. Germany was more advanced than the United States when it came to submarines, so these six submarines became models for the United States to replicate them. Germany’s submarines were class VIIB U-boats which had increased fuel storage and extra weapons.
Most submarines used in World War II had two different engines, one for traveling above water, and one for underwater (Hopkinson 45). The engine used for the surface was a diesel engine that creates 2,310 horsepower. Electric motors that made 750 horsepower, powered by batteries were used underwater. While engines are crucial to a submarine’s mobile capabilities, torpedoes were also an important part of a submarine.
Type VIIB submarines had five torpedo tubes for firing and could carry up to 14 additional torpedos (Adams 25). The main problem with torpedoes is that sometimes they do not explode. In 1943, torpedo experts developed a lightweight firing pin that could overcome friction and explode on impact which solved the problem to dud torpedoes. Other than torpedoes, some submarines had mounted Mark 51 rocket launchers on the front of the deck for attacking targets on the shore. The rocket launcher attached to some submarines could launch a full volley of 12 rockets in 5 seconds (Roblin). In order to find their targets, submarines used sonar and radar equipment. Radar equipment was used to detect aircraft traveling overhead while sonar detected nearby ships. The U.S. Navy did an excellent job of applying all this new technology into combat.
Submarines had many different purposes and played a critical role in taking the fight to Japanese territory. After the attack on Pearl Harbor, most of the U.S. warships were out of action, but the submarine fleet went rather unscathed. They were able to strike back against Japan and defend against further invasions. Due to the fact that a submarine’s presence can be difficult to detect, submarines performed reconnaissance missions and gathered information. The USS Nautilus among other submarines had attachments for its periscope that attached a camera to it for taking pictures of Japanese held islands. According to War under the Pacific, in 1943, a group of U.S. Submarines created Spyron which is short for Spy Squadron(Wheeler 130). Type VIIB U-Boats could stay on patrol for long periods of time which made them perfect for long-distance patrolling. The weather was also studied and reported by submarines to the rest of the fleet.
Besides reconnaissance, submarines also transported supplies and sometimes troops to various islands in the Pacific. Important people such as cryptanalysts that decoded secret messages, and even the Philippine President at the time, Manuel Quezon were evacuated from islands by submarine. Although these tasks were still helpful, a submarine’s primary objective was to destroy enemy ships. Japan had very few natural resources and depended heavily on imports which were often sunk by torpedoes. The USS Barb laid waste to Japanese islands using a deck machine gun. The U.S. submarines mainly targeted Japanese destroyers to leave their fleets defenseless against attack. Blockades were formed around enemy ports to prevent military and non-military ships from entering or exiting. Submarines were also used to defend and escort other ships. The USS Tang helped rescue survivors of airplane crashes that were stranded in rafts.
The U.S. Navy was very successful in sinking enemy ships in large numbers. According to Warships and Submarines of World War II, the USS Tench sank six Japanese ships in hostile waters during May 1945(Darman 175). The USS Cavalla sank the Shokaku which was a Japanese aircraft carrier that was infamous among Americans for taking part in the Pearl Harbor attack. Final Patrol: True Stories of World War II Submarines states that the USS Cobia sank a transport ship with more than 24 tanks on board (Keith 104). Three ships were sunk in 3 days by the USS Batfish which is almost impossible because the Pacific Ocean is so big and submarines seldom encountered each other in such a small period of time. The USS Barb operated a ground assault on the main Japanese Island when the crew used remote explosives to blow up a train. “U.S. Pacific Submarines in World War II” expresses a daring escape by the USS Pollack when it fired two torpedoes head-on at a destroyer then dove at full speed to avoid a collision (Gruner). German submarines also sank a large number of Allied submarines.
U-48 sank around fifty-seven ships in two years. “American submariners wrote an unsurpassed chapter in the annals of the U.S. Navy’s history for their courage, dedication, and loyalty to their country,” wrote Deborah Hopkinson. As submarines sank many ships and defended the United States from Japanese invasion, they proved to be the most successful form of new technology in World War II. Submarines are often overlooked when thinking about the War in the Pacific. The technology and capabilities had greatly advanced from World War I to World War II and made the U.S. Navy a much more formidable aggressor in their attacks. The U.S. Navy and submarines were able to help avenge all the losses at Pearl Harbor and ultimately help the Allies win World War II.