From August 1941, as a result of the fact that some of its signals were re-encyphered in the Enigma and re-transmitted, and of GC and CS's ability to isolate these signals, the 'Werft' decrypts made, in return, an invaluable contribution to the daily cryptanalytical assault on the naval Enigma settings.
And besides this Rosetta stone, the 'naval meteorological cypher' also 'turned out to be of especial importance'.
It was first broken in February 1941 and in May of that year the Meteorological Section at GC and CS discovered that it carried weather reports from U-boats in the Atlantic which had originally been transmitted in the naval Enigma.
Thereafter its decrypts were no less useful than those of the dockyard cypher in helping to break the Enigma keys.
These developments, while a triumph for Bletchley, were something of a personal blow for Alan.
He had worked out subtle mathematical methods for the cryptanalytic attack earlier in the year, only to have an almost insultingly direct method thrust upon him by the dockyard and weather 'cribs'.
But he had to give way to the events which his own pioneering work had made possible.
The key to the development of GC and CS now lay in the integration of its work, rather than in individual brilliance.
These new discoveries were the final vindication for all that the new men had been fighting for.
The dockyard messages held nothing of operational value, and according to Room 40 standards, would never have been touched.
But at GC and CS they had established a principle of attacking everything, however apparently insignificant, and thinking big had now paid off.
It was also crucial that a single organisation handled all the decrypts, and was allowed to use them as it saw fit.
Had the Admiralty been allowed to recapture naval cryptanalysis, this might never have been possible.
But these were considerations of a kind which did not call for Alan Turing's expertise as much as for administrative and political skill.
He could well appreciate what was being done, but his own strength lay in the more self-contained problems.