In 1939, when a British submarine was diving, the lid of the torpedo tube was suddenly washed away by the sea. More than 100 tons of seawater were instantly poured into the boat, taking 99 lives. After the investigation, the culprit who caused the lid to burst open was a drop of paint!
The submarine, named HMS Sitis, was Britain's most advanced submarine of the time and probably Britain's most unlucky submarine.
Construction began in 1936, and during the first sea trial in 1938, the cabin in front of the ship failed and was sent to the shipyard for repair before it set sail. After a full year of repairs, the Sitis finally had its second sea trial.
On the morning of 1 June 1939, accompanied by a tugboat, the Sitis left the docks and headed for Liverpool Bay. At the time, the 53-man submarine had a crew of 103. Among those additional personnel were naval officers who watched the new submarine, as well as technicians who escorted the sea trial.
At 14:00 p.m., the Sitis successfully arrived at the test area and began to dive. However, before the submarine was fully immersed in the water, Captain Frederick noticed that something was wrong - the instruments showed that the hull was not maintained level, and the bow was too heavy and slightly downward. The sailors on the tugboat saw that a lot of bubbles were bubbling up from the bow!
The captain suspected that the front cover of the 10 torpedo tubes located in the bow was not closed, and that seawater was pouring into the pipes, which were several meters long. This judgment was entirely correct, and the front cover of the No. 5 torpedo tube was indeed open. Curiously, however, when the crew inspected it later, they found no problem.
At that time, the captain suspected that the torpedo tube was entering the water and immediately ordered an investigation. The crew inspected the test plugs mounted on the back cover of the torpedo tubes, and if the torpedo tubes had water, the plugs would have water dripping out, but after checking the test plugs of all the torpedo tubes, none of them dripped out. Inspectors then determined that all the torpedo tubes were in normal condition and were not submerged.
This result turned the captain to suspect that the problem might be that the submarine was carrying too many people. So he did not investigate deeply, so he ordered the submarine to continue diving. This wrong decision will soon kill everyone!
As the depth of sitis's diving gradually increased, the pressure on the outside sea water on the rear cover of the Torpedo Tube 5 increased. Finally, the back cover could not withstand it, the locking mechanism broke free under the pressure, and more than a hundred tons of seawater instantly poured into the first and second compartments of the submarine. The 84-meter-long submarine exploded in weight, and then plunged head down and tail into the seabed at a depth of tens of meters at a 45° angle.
In the face of the sudden change, the crew reacted quite well. They first closed the watertight doors of the compartments and then moved toward the command module urgently. Immediately afterward, the captain ordered the sea water of the ballast water tank to be removed, forcing the submarine to float. However, due to the fact that the bow is too much water, the submarine eventually only has a few meters long tail out of the water, and most of the hull is still obliquely inserted in the water. As for the crew, they are still trapped and unable to escape.
The biggest danger we faced at that time was the lack of oxygen. The number of people on board the boat doubled the normal number of nuclear carriers, which undoubtedly increased this risk.
In order to minimize oxygen consumption, the captain ordered everyone not to move, to stay asleep, and to wait for rescue. However, the time when the rescuers arrived greatly exceeded the captain's expectations.
In fact, at the first time of distress, the Sitis released an indicator buoy. Unfortunately, the tugboat on the surface of the sea, which was more than 6 kilometers away from the submarine at that time, did not see anything on board. It was not until more than 3 hours later, when the Hitis did not float as scheduled, that the people on board felt that something was wrong and quickly sent a distress telegram to the submarine command.
After receiving the telegram, a huge search operation was quickly launched. Two submarines, a rescue ship, eight destroyers, and two reconnaissance planes participated in the operation. Incredibly, though, by misplacing the submarine's dive, the huge rescue team spent the night in vain. It was not until after dawn the next day that a reconnaissance plane inadvertently spotted the Sitis, with only the tail protruding from the sea.
Unfortunately, nearly 18 hours had passed since the submarine was in distress. Ninety-nine people on board had died of suffocation from carbon dioxide poisoning, and only four were rescued.
The consequences of this incident were extremely tragic and shocked the whole of Britain. People are very curious to know, obviously the front cover of the No. 5 torpedo tube is not closed, it is full of seawater, why did the crew check and did not find it? After careful investigation, the culprit turned out to be a drop of paint!
It turned out that a few weeks ago, a painter at the shipyard was so careless as to paint the torpedo tube that he accidentally dropped a drop of paint on the test plug installed on the back cover of the torpedo tube. The test plug was stuck in the paint, causing the torpedo tube to be filled with seawater, but it could not flow out, so the crew made a wrong judgment.
The salvage process of the Sitis was also unusually bumpy. At that time, the rescue team planned to tow the submarine back to the dock with a steel cable. Unexpectedly, the hull filled with seawater was too heavy, and during the towing, the steel cable was overwhelmed and broken. The Hitis then lost control and sank completely to the bottom of the sea. It was not until more than three months later that the submarine was salvaged out of the water again.
The British Navy had planned to completely dismantle this unfortunate submarine, but with the British declaring war on Germany on September 3, they changed their minds and finally repaired the "Sitis" and renamed it "Thunderbolt"!
Reborn from the ashes, the Thunderbolt successfully sank several ships in World War II. However, in an attack on an Italian fleet on 12 March 1943, Raiden was sunk by a depth charge dropped by an Italian cruiser, and none of the more than 60 sailors on board survived. The Sitis submarine thus became a rare submarine in the history of the world's navies that has been sunk twice...
It is worth mentioning that the first sinking of the Sitis submarine prompted the invention of a safety device. This device is a screw bolt mounted on the back cover of a torpedo tube. The effect is that if the torpedo tube locking device breaks free, the back cover will not suddenly burst open. In order to commemorate that tragic accident, people named this spiral bolt "Sitis Bolt"!
