Greetings Gentlemen,

I have to ask this question now that the topic has come up

This business of the open fuel tanks in U-boats has always confused me. It seems to me - specific gravity differences between water and fuel notwithstanding - that there would be a very real possibility of the formation of water/fuel emulsions, particularly if the sub had a rough patrol (depth charging, rough seas, crash dives etc. etc.). These water fuel emulsions would wreck havoc on the diesel engines so my question is, was there some king of water-fuel separater in the U-Boat\'s fuel delievery system and what kept the fuel from leaking out of the bottom of the open tanks during a rough passage where the whole mixture would be severely jostled about?

Yes, theoretically, the fuel should rest on top of the salt water, but when the vessel is bouncing around in a chop, or is being hammered by depth charges, all bets are off.

regards,

Robert Eno