Reading a KTB
 

Hi all,
while i was reading a german KTB i noticed that when the captqain express the depth of the boat he uses a notation like this "A+20", "A-40".
What s this mean?

tnx

I've seen this in a KTBs and U-boat diaries and assumed it meant the submerged depth of the sub in metres, with the 'A' being short for 'aufgetaucht' - surfaced. i.e. A-50 = 50m.

If you've seen A+20 in a KTB, then I may be wrong, unless the rumours were true about the secret flying U-boat, which could have won the war for the Germans. :)

:rotfl: btw 160 posts! :rock:

looking here

http://www.uboatarchive.net/U-516logGerman.htm

in the last image on the top there is an A + 20 the sign "+" seems a correction.

I have found a translated extract from a KTB -

http://www.uboatarchive.net/U-220U256log.htm

It clearly states A+10 and A+20, so my assumption about 'A' meaning surfaced is clearly wrong. :oops:

I am curious now,also, as to what the references mean.

I believe A=80m (at least from one book I've read, "Grey Wolf, Grey Sea", where it was clearly defined as that) - which I think is the crash dive depth. :hmm:

u-boat skippers used "A" as a shorthand for their max diving depth to keep it a secret from the allies. mentioned in das boot (novel).


or not.

Letter A like deep 80 m

A-10 = 70 m

A+ 20 = 100 m

Exactly, several letters were used during the war meaning different depths, to keep the capabilities of the U-boat a secret. As it was changed a few times, it's a bit hard to guess the right depth.

In the das boot novel (which I've read like 20 times so far) the crush depth of the type 7 was described as "3 times 'r' plus 60". Could it be possible that the allies did not know what 'r' was?

http://www.uboatarchive.net/KTB/KTBNotesVocabulary.htm

see the second line