This country is at war with Germany.

We shall go on to the end.

I remember the sheets of flame which came up and almost blinded us from our guns. Just two days before D-Day,

Captain Galleries' anti-submarine task group

managed to force the German U-boat U-5 to the surface. In a bull move, a boarding party secured the submarine before it could be scuttled,

capturing an enigma machine and the current Craig's Marine code books.

This remarkable operation earned Lieutenant Albert David the Medal of Honor for his leadership.

However, it could have had catastrophic consequences.

If the Germans suspected that their ciphers were compromised, it might have jeopardised the Allied Operation Ultra,

which was already decrypting German signals. The chief of US naval operations

Ernest King was so incensed about the capture of U-505

that he threatened to fire Admiral Gallery.

I'm Angus Wallace and joining me today to discuss this incredible operation is Charles Lachman, author of Code Name Nemo, the hunt for a Nazi

U-boat and the elusive Enigma machine.

Welcome Charles.

So let's start by looking at U5, which is now on display at the Science and Industry Museum in Chicago

and who features in that wartime newsreel now it can be told. I think U505 was

launched in 1941 and we're discussing 1944 when it had had 11 patrols. So what kind of service had it seen?

Well, it didn't have a spectacular record. Thank goodness for that.

After all, they were fighting for the Nazis.

It had a what I would consider to be a respectable service record.

It knocked down I believe eight merchant, marine ships British some American one Dutch but when it came

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