From the Depths: 8 of the Most Daring Submarine Missions of the 20th Century

Project Azorian

Project Azorian was also called “Jennifer” by the CIA due to the top-secret nature of the project. In 1974 the CIA wanted to recover the Soviet submarine K-129 from the floor of the Pacific Ocean. K-129 was sunk in 1968 and fell to the ocean floor 1,560 nautical miles northwest of Hawaii. It was a project that was not only very secretive but also one of the most expensive covert operations ever attempted by the CIA.

After the K-129 sank the Soviets spent weeks trying to find the sub but never succeeded. The gave up and in July 1968, the United States Navy began Operation Sand Dollar which was their own mission to find the sunken sub and photograph it. The USS Halibut was able to locate the K-129 in three weeks using robotic remote cameras. They spent several weeks taking more than 20,000 photos of the top secret Soviet submarine. It was based on these photographs that in 1970, that Defense Secretary Melvin Laird and National Security Advisor Henry Kissinger decided to attempt to recover the sub.

The cost of the project was $800 million in 1974 or $3.9 billion in 2016 dollars. Part of the reason why the mission was so expensive was due to the fact that a ship had to be built for the specific purpose of bringing the large submarine up from the depths. The Hughes Glomar Explorer was built with the cover story of the ship being built to mine manganese nodules from the bottom of the ocean. The K-129 rested at a depth of 16,000 feet and would therefore be the deepest salvage operation ever attempted.

The Hughes Glomar Explorer was built with a large mechanical claw known as “Clementine” which was meant to grab the targeted nuclear portion of the submarine and bring it to the surface. However, during the mission the “Clementine” suffered catastrophic failure an only part of the submarine was recovered. The recovered portion had two nuclear torpedoes and there were rumors of code books and other relevant materials being recovered that kept the mission from being a complete failure. The bodies of crew members were also found and given military burials at sea in metal caskets (due to radioactivity concerns).

The HMS Venturer and the U-864

The HMS Venturer sinking the U-864 on February 9, 1945 remains to this day the only intentional sinking of a submarine by another submarine when both were at periscope depth. The U-864 was a U-boat designed by the Germans for ocean-going voyages that were long a long way from home ports. In February of 1945 the submarine was a on a mission code-named Operation Caesar to give high sensitive technology to the Empire of Japan. The technology included jet engines, missile guidance systems and 65 tons of mercury.

The British had learned about Operation Caesar due to their ability to crack the Enigma code. The British wanted to stop the Germans from giving the Japanese anything that might prolong the war and therefore wanted to stop the U-864. The Royal Navy submarine command dispatched the HMS Venturer to destroy the U-864 before it was able to deliver its cargo to Japan. At the time, Lieutenant Jimmy Landers was in control of the Venturer and was given little more than the estimated whereabouts of the U-864 and the orders to bring down the sub.

Landers decided to turn off the sub’s ASDIC in order to prevent the ping from being overheard by the U-864. The submarine relied on its hydrophone to pinpoint where the U-864 was. The plan was successful as the Venturer’s hydrophone operator was able to hear the diesel engines of the U-boat as it passed the Venturer’s location. The Germans did not have sonar at the time and their hydrophone was unable to hear the electric motors of the Venturer over the sound of its own diesel engines.

The crew of the Venturer knew that their target was close but after tracking the U-boat for several hours it became clear that it was not going to surface. Never before had a firing solution been computed in four dimensions – time, distance, bearing and target depth, despite it being possible. The crew of the HMS Venturer was running out of battery life and knew they had to make an attempt. The made the calculations and made assumptions about the defensive maneuvers of the U-boat and fired all torpedoes out of four bow tubes. The fourth torpedo struck the target, puncturing the pressure hull and instantly imploding the U-boat.

The NR-1

The NR-1 was a submarine that was never officially named or commissioned but was rather known as “Nerwin.” It was the smallest nuclear submarine ever put into the operation. The submarine was built by the Electric Boat Division of General Dynamics and was launched on January 25, 1969. The missions of this submarine remain as mysterious as its lack of name and official commission.

The NR-1 was built as an engineering and research submarine with missions that generally included search, oceanographic research, object recovery, geological survey and the installation and maintenance of underwater equipment. The NR-1 has the unprecedented ability to remain in one spot and completely map an area with an unmatched degree of accuracy. This made it an invaluable asset on a number of secret missions.

The NR-1 was equipped with a claw that was able to rake the sea bed and pull up objects. When the Challenger space shuttle exploded in 1986, the NR-1 was called to search for fragments that fell into the water. To this day that is one of the few missions that is known about the submarine. The 10-man crew that was on board the NR-1 during the Cold War remains sworn to absolute secrecy to this day. They were told that they could not even tell their wives where they were or what they were doing.

The submarine had no weapons but it could dive deeper than any other vessels. It was dismantled after it exited service but some parts of the submarine were reassembled to put on display. Toby Warson commanded the small sub from 1970 to 1973 and earned a service medal for “hazardous military operation” for an operation in the Mediterranean code-named Racoon Hook. He remains unable to tell what he earned the medal for and has since stopped wearing it to avoid questions he is forbidden to answer.

Australian Cold War Submarine Missions

During the Cold War, it was not only the United States and the Soviet Union that was competing to get ahead in the intelligence game. Other countries saw it as a way of increasing their own prestige in the international community and strengthen their ties with either of the two major powers. The Australians were no different, during the Cold War they used their Oberon class submarines to collect crystal clear video of Soviet nuclear submarines which strengthened their ties with the United States.

The missions undertaken by the Australian submarines were so secret that they were kept under wraps even from the highest levels of government. When the Australian Navy wanted to get the authorization from the Prime Minister Bob Hawke to build six Collins-class submarines they did so by showing video of what the Australian O-boats had been able to accomplish in Asia during the Cold War.

Commander Kim Pitt showed the Prime Minister a video of the one of the surveillance missions that the O-boats had undertaken in Vietnam. They had been able to their submarine escaping any notice from the Charlie-class Soviet nuclear submarine by traveling underneath and behind the sub as it moved toward the Soviet naval base in Vietnam. The camera that was attacked to the periscope of the Australian sub clearly showed the movements of the enemy sub and then the Australian sub dived to get a clear picture of the underside of the secret Soviet sub.

The missions were risky, if the Australians were caught it would have caused an international incident. It nearly did when the subs tried to get close to a Chinese naval base but instead found the area around the base filled with fishing boats. The sub got caught in a fishing net and reportedly even sunk a fishing boat before fleeing in order to escape detection and the mission was a massive failure. This mission was not revealed to the Prime Minister however, and the Australian Navy proved the benefit to their surveillance missions and the need for the Collins-class submarines.

A Nuclear Submarine in the Vietnam War

During the Vietnam War the attack submarine Sculpin was sent on a daring mission by President Nixon. It was believed that supply trawlers in the South China Sea were supplying the Viet Cong. When U.S forces found ground troops unloading one of the trawlers on a South Vietnamese beach a massive firefight broke out. The brutal fight caused many soldiers to believe that the trawler crews were elite forces that were willing to fight to the death.

After the firefight, the U.S. forces wanted to stop the trawlers. It was estimated that each trawler could deliver 100 tons of munitions after the ships were photographed in international waters. Since the trawlers could not be attacked in international waters and there were concerned about accidentally attacking a legitimate trawler in the region. A plan was created to use a submarine to follow one of the trawlers all the way from Hainan to South Vietnam in order to mark it for destruction by U.S. forces.

On April 12, 1972, the Sculpin was patrolling off Hainan and found a trawler that matched the description of the trawlers sending supplies to the Viet Cong. When the trawler made a turn toward the Philippines, the men of the Sculpin realized that they were following a supply ship and not a fisherman and kept close watch. They turned off active sonar and used only passive sonar, using the distinctive shaft rub and propeller sound to keep tabs on the trawler’s position. As they followed the trawler from China to Vietnam, with covert air support above them, the Sculpin operated in water that was perfectly calm and as shallow as six fathoms.

When the trawler was followed all the way to the Vietnamese coast, the crew of the Sculpin requested permission to shoot but Admiral John McCain believed that it would not work. Instead the South Vietnamese naval forces were called in on April 24. As the Vietnamese destroyer closed in the trawler raised a Chinese flag and indicated they were fishing. This caused the Vietnamese to hesitate but the men aboard the Sculpin insisted it was a trawler filled with weapons that they had followed for 2,400 miles.

On this identification, the South Vietnamese hit the trawler and it and its cargo exploded. A few men survived and were rescued. They spoke Vietnamese, not Chinese, and provided valuable intelligence about their operations, making the mission a complete success.

Squalus Rescue

The Squalus was diesel-electric submarine that was commission on March 1, 1939. It was a 310 feet and displaced 2,350 tons when submerged. Just a few weeks after it was commissioned the Squalus would capture the attention of nearly every American, causing newspapers to run extra editions to provide updates. On March 23, 1939, the Squalus sank off the coast of New Hampshire. It was the Sculpin who saw the marker buoy and was able to make contact in order to confirm there were survivors on board, however they were already suffering from the chlorine gas that was leaking from the battery compartment.

The Squalus had 56 sailors and three civilians on board when it dived on March 23. The air induction valve failed and water poured into the aft engine room. The submarine sank down 240 feet to the bottom. The aft section flooded and killed 24 sailors and 2 civilians. In the forward compartment 32 crew members and one civilian sent up the marker buoy and red smoke bombs to alert those on the surface of their plight.

The communication did not last long as the cable parted. The Sculpin stayed by its sister sub and the following morning the USS Falcon arrived. The rescue ship lowered the Momsen-McCann rescue chamber immediately. The chamber was little more than a modified diving bell manned by deep-sea divers but it managed to reach the Squalus and the crew. In three agonizingly slow trips 26 men were brought to the surface.

With seven men still trapped the cables of the rescue chamber became tangled and delayed dive. But in the pitch-black hours just before midnight a fourth trip rescued the final seven men after 39 hours of being trapped. In one more desperate dive the aft compartment was searched to verify that there were no survivors. Several weeks later a massive effort brought the Squalus to the surface and then it was towed to Portsmouth. There an investigation was conducted on the engine room compartments and the submarine was decommissioned on November 15, 1939.

The Olterra and Midget Submarines

The Olterra was a 5,000-ton Italian tanker that happened to be in the Bay of Gibraltar on June 10, 1940, the day Italy entered into World War II. That day the Italian ship was sabotaged and partially sunk by British commandos. The Olterra remained where it was in the Bay and became an observation post for the Italians as they carried out human torpedo missions from Villa Carmela. From July to September 1942 combat swimmers from Villa Carmela were able to take out five merchant ships.

It was about this time that Lieutenant Licio Vistintini had the idea of turning the Olterra into a secret mother ship for the maiali. Maiale (“pig” in Italian) was the nickname for the manned torpedoes used by the Italians. A team of Decima who designed themselves as civilian Italian workers took control of the tanker. They towed the ship to the nearby Spanish city of Algeciras in order to perform “repairs” so that the ship could be sold to a Spanish owner.

Once the ship was at the docks, the cargo holds and boiler room was modified to support the building and maintenance of human torpedoes. There was also an observation station built into forecastle to watch the Bay and keep tabs of the Allied ships there. There was also a scene of civilian workers in place outside the ship in order to convince both the Spanish and the British that there was nothing suspicious going on. A sliding hatch was built six feet before the water line that allowed the miniature submarines to exit the ship.

The first mission took place in December 1942. Three subs were launched with two men in each. Three of the men died and two were taken captive. They told the British they had come from a submarine and therefore kept the Olterra from being exposed. Another mission in 1943 was successful in sinking three cargo ships. Another mission that same year sunk another three ships. The British never realized where the mini submarines were coming from until the Italians surrendered and told them.