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

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

Stephanie Schoppert - May 20, 2017

From the Depths: 8 of the Most Daring Submarine Missions of the 20th Century
The USS Falcon with the rescue chamber on board.

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.

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

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.