“The only thing that ever really frightened me during the war was the U-boat peril,” British Prime Minister Winston Churchill reportedly said reflecting on the Second World War.
By the end of the war, Hitler’s Kriegsmarine, the navy of Nazi Germany, built 334 U-boats, which is short for the German word “Unterseeboot,” or undersea boat.
In the fall 2015 issue of Weapons of World War II magazine, Marc DeSantis explains how the U-boats terrorised the seas during World War II.
At the beginning of the war, the commander of the German U-boat fleet, Karl Dönitz, said that if he had 300 U-boats, 'he could strangle Britain and win the war.'
The U-boat was not a true submarine in today's sense of the word, more of a submersible craft. The diesel engines required air, so while underwater, the craft was powered by 100 tons of lead-acid batteries, meaning it had to surface every few hours when air and battery power were exhausted.
The battery power made the U-boats exceptionally slow underwater, clocking in at 8 knots (9.2 mph), compared to 17.2 knots (19.8 mph) above water on the VII-B models.
The U-boat featured a fearsome 88 millimetre cannon on the deck, as well as a 20 millimetre anti-aircraft gun. Here's the cannon in action:
However many early torpedoes fired by U-boats did not function properly, either exploding prematurely or not at all.
By 1943, Allied forces began fiercely hunting U-boats at sea. Here's an Allied pilot bombing a U-boat.
Towards the end of the war, the U-boats were death traps. Of 40,900 men who manned U-boats, some 28,000, or 70% were killed. Here's a photo of US troops boarding a captured German U-boat.
Source: Weapons of WWII magazine
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