Some U boat successes in the South Western Approaches due to SI.
Glorious sunk as a result of the use of SI.
Rawalpindi sunk as a result of the use of SI.
AMC Andania sunk as a result of the use of SI.
On 20/1/41, the British tightened up their encyphering procedures, this resulted in a dramatic lowering of reading the British codes.
Germans turned to the greater use of air reconnaissance to fill the gap.
MANY U boat interceptions of RN units in the Norway campaign, but no hits due to faulty torpedoes.
There are volumes on this stuff.
: Do your sources relate what specific
: successes the Germans had as a result of
: reading the fleet codes?
: --Previous Message--
: The Germans read extensively the British
: codes for the first year of the war. This
: was the Germans most successful period for
: reading British codes. A time lag of only
: twenty four hours was normal.
: The RN changed all the Fleet codes
: simultaneously in August 1940, after
: becoming aware of German successes in
: reading the codes..
: Germans then had trouble reading the Fleet
: codes, but could still read about 50% of
: traffic but with a greater time lag than
: The Germans never read the RNs high level
: book codes.
: In September 1941, the indicators in British
: naval codes ceased to be encyphed.*
: This improvement on its face, as far as the
: Germans were concerned, did NOT translate
: into better operational results at sea.
: British SI now held the upper hand.
: * NB This allowed false data/disinformation
: to be fed to the Germans , sustaining what
: they believed and what the British wanted
: them to believe. Sneaky Brits.