Hi Jonny,

I have no idea why the U-boats that ran aground did so, but mechanical trouble (steering problems, rudder problems, loss of power, etc.) could cause this. The mechanical problems could also have been the result
of sabotage while in port which was not uncommon. Depth charges and bombs took their toll on U-boats and left many of them unable function correctly. The engineers aboard U-boats had to be extremely good at their job just to keep them from sinking. Additionally a crew that was unable to function due to food poisoning, or leaking chlorine gas (seawater & battery acid) could do it. I read of a case where something happened to the air inside a U-boat that caused most of the crew to pass out once but I can’t remember where I read it. Instrument failure could probably do it too. I am sure there are a number of other ways for a boat to ground itself by accident as well.

My dad was a merchant seaman (an engineer not a navigator) and one of his letters home was about being on a ship that ran aground twice in the same area in the 50’s. The second time it took tugs to get them off.

There was a case during WWII of a U.S. sub that was damaged in an attack and lost power that drifted into shallow water. They were seriously grounded when the tide went out. They used the time waiting for the tide to come back in to repair the damage. They were lucky and weren’t spotted and when they had enough water under them they managed to get the engines started again and they got off. This story was on the History Channel a while back and was told by an officer (the commander I think) of the sub.

Sometimes the maps available to U-boat men weren’t very good. I also read an account of a U-boat leaving port only to discover they hadn’t drawn the correct maps for their patrol. If I remember correctly, they went back and got the correct maps. It also may not be too far fetched to imagine a U-boat scheduled to operate in one area being diverted at sea to an area they didn’t have the best maps of.

I believe there is an account (I could be wrong as I don’t have the book with me) in Showell, Jak P. Mallmann. U-boats at War Landings on Hostile Shores. Shepperton: Ian Allan Publishing Ltd., 2000. ISBN: 1-55750-864-X. that describes a crewman on deck with a knotted rope measuring the depth as they were trying to get close enough to shore to drop off some special ops guys at night. At that point they could have run aground pretty easily. Of course they were going very slow just in case that happened but they could have ended up on a reef or other submerged obstacle anyway. This would only happen this way to a boat that was trying to get very close to shore at night though and a U-boat on a normal mission wouldn’t try to get that close to land.

Regards,

Ken Dunn