- The sinking of U-33 gave the Allies access to vital components of the Enigma machine
- U-33 was a German submarine that the Royal Navy sank off the Clyde in 1940.
- The Enigma cogs decoded all German naval communications at Bletchley park.
- These secrets helped Britain win the war.
- U-33 was a VIIA U-boat that Germaniawerft built for laying mines.
The British Army recounted the story of a World War Two German submarine wrecked just eight miles off the Ayrshire coast on its 83rd anniversary. The impact was pivotal in Britain’s victory.
In February 1940, the Royal Navy minesweeper HMS Gleaner (J83) detected the submarine while attempting to lay mines in the Firth of Clyde. Following the discovery, HMS Gleaner attacked the U-33 with depth charges and scuttled it eight miles west of Maidens harbor.
However, before sinking, U-33 revealed some of Germany’s closely guarded secrets – secrets that helped Britain win the war.
The Tragic Final Voyage of U-33
On 5th February, 1940, U-33 set out on its final voyage. The submarine departed from Wilhelmshaven, Germany, under Kapitanleutnant Hans Von Dresky. The crew of 42 onboard, unaware of their fate, set out to lay mines in the Clyde under the direct order of Hitler.
Meanwhile the Allied assigned codebreakers at Bletchley Park were to intercept and decode German communications. The German system was robust, and thus, their communications were unbreakable. Hence, they were known as “Enigma” messages.
These messages were a significant challenge for the codebreakers. But they cracked the code in the end and provided valuable intelligence to the Allies.
The Attack on U-33
On the night of 12th February, U-33 was cruising slowly on the water’s surface in the Firth of Clyde.
Meanwhile, HMS Gleaner, captained by Lieutenant Commander Hugh Price, was patrolling the area when it made its first hydrophone contact with U-33 at 2:50 am. As soon as Von Dresky received the alert, he ordered his crew to their battle stations. But now the roles were reversed, for the submarine was now the target.
HMS Gleaner sprung into action by firing its guns and dropping depth charges. As a result, the German captain had to submerge U-33 rapidly. However, despite his efforts, the damaged vessel was forced to resurface, with the crew abandoning it eventually.
Still trying to prevent more loss, Von Dresky ordered three of his men to retrieve and scatter the cipher cogs from the Enigma machine. The men followed his orders. They recovered the cogs and stuffed them into their pockets until it was time to drop them in the water.
In an unexpected turn of events however, one sailor failed to scatter the cipher cogs because of his numb, frozen hands. After successfully capturing that crew member, the sailors aboard HMS Gleaner found the cogs in his possession. They sent him and the cogs to Bletchley Park for further investigation.
At Bletchley Park, the German naval messages were finally decoded.
Only 17 Crew Survived
That led to the revelation of some of Germany’s most incredible secrets and is said to have shortened World War Two by years in an incident that proved devastating for the Germans. Out of U-33’s 42 crew members, only 17 survived.
Cold-water shock and hypothermia claimed the lives of the others, including Von Dresky.
The Career of U-33
The Ship building company Germaniawerft based at Keil built the German submarine U-33 in 1935. It was a type VIIA U-boat that served in the Kriegsmarine during World War Two. It entered service on July 25 1936.
The submarine contained five tubes for firing torpedoes and laying mines. The four main tubes were present in the bow with one in the stern. It also had a single-deck gun mounted in the front of the conning tower and an AA gun. The submarine had dimensions of 211.7′ x 19.1′ x 14.2′ and a displacement of 745t.
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The U-33 had a short but fairly successful career, sinking three British steamships during its first voyage in the Western Approaches. In addition, the U-33 earned ten iron crosses for its crew members.
On its second voyage, in the Bristol Channel, the German submarine’s mission was to lay mines. However, it also managed to sink five trawlers. After completing this journey, the U-33 returned to Wilhelmshaven for a major refit.
As evident, its departure from Wilhelmshaven for its final voyage proved fatal. Today, the remains of U-33 are present in 58 meters of water, about 5 miles south of Pladda, at coordinates 55° 21.483’N, 005° 01.683’W. The wreckage protrudes 3-4 meters above the seabed with the bows (front) pointing east toward the Ayrshire coast (100°/180°).