THE NAZIS AT WAR WITH AYRSHIRE (1): THE CASE OF U-33

Very few British counties contributed as much to defeating the evils of Naziism as Ayrshire. Despite its remote location, far from London, it was a strategically vital part of the United Kingdom, situated next to Britain's Atlantic backdoor -- the Clyde estuary. 

Hitler himself recognized this strategic value when he personally ordered one of his dreaded U-boats, U-33, to the Clyde to lay mines in order to sink ships bringing vital supplies and reinforcements to Britain from her colonies. 

Uboat.net takes up the story with the tale of the submarine's ill-fated chief, Kapitänleutnant Hans-Wilhelm von Dresky:

Hans-Wilhelm von Dresky joined the Kriegsmarine in 1929. He served as a Watch Officer (WO) on U-20 Feb 1936 - Sept 1937, when he took command of the small type IIA U-boat U-4 on 30 Sept 1937.

Von Dresky left U-4 on 28 Oct 1938, and the following day took command of the larger type VIIA U-boat U-33. On his first two patrols he sank ten small ships (19,261 tons) and destroyed another of 3,670 tons.

For his third patrol he was sent to the Firth of Clyde lay eight TMC mines close to the British naval base there - a highly dangerous task. When he nosed his boat into the Firth she was detected by the British minesweeper HMS Gleaner, but von Dresky mistook her for a cruiser and thought she would pass him and head for open waters. He thus dived, and after Gleaner dropped six depth charges on the boat, surprising the Germans, and causing severe damage and several leaks, the boat bottomed at only 36m (119 ft). Over the next hour, two more batches of depth charges followed, which caused further damage. Von Dresky ordered the boat to surface and then scuttle, distributing the Enigma cipher machine wheels to three of his men to throw into the sea away from the boat.

The freezing cold water temperatures meant only 17 men survived the sinking, and 25 died from the shock of immersion and hypothermia, including Kapitänleutnant von Dresky (Blair, 1996, Sebag-Montefiore, 2001). One of the survivors had failed to dispose of his cipher wheels, and they were discovered by the British. They played a crucial part in the British breaking of the German navy Enigma codes (Sebag-Montefiore, 2001).

The entry for HMS Gleaner provides additional details, including detailed times of events:

On 12 February 1940 HMS Gleaner was on patrol off the Firth of Clyde. At 0250 hours a hydrophone contact was picked up and traced until at about 0316 hours a U-boat, U-33, was seen on the surface. U-33 dived and lay on the bottom. Gleaner carried out a depth charge attack at 0353 hours but little damage was done. A second attack was carried out at 0412 hours which caused more serious damage to gauge glasses, lights etc. and caused several leaks. The German Commanding officer, Kptlt. Hans-Wilhelm von Dresky, decided to bring U-33 to the surface which she broke at 0522 hours. HMS Gleaner opened fire on the U-boat and turned to ram her, firing as she approached, but before she could do so the crew started to abandon ship. U-33 finally sank taking 25 of her crew with her, leaving 17 survivors.

The U-boat sank about 6 miles south of Pladda, the small island at the tip of Arran.

Victim of the Clyde, Von Dresky

As the attack happened on a cold February night, Captain von Dreseky froze to death in the icy waters of the Clyde. He was just 32 years old.

I assume that the freezing cold water played a part in the German sailor forgetting to dispose of the Enigma machine rotors, as he would have been numbed to the bone.

The capture of these vital components greatly harmed the German war effort by giving vital clues to British code breakers and are part of the reason why we are not all speaking German today.