At the beginning of July a new policy was adopted for Dolphin. The weekly Report states; "After consultation with Naval Section we have decided to run all wheel order cribs on Dolphin when good ones are available and not to wait for the Banburismus to come up. We are doing this (a) because there is less pressure on 3 wheel bombes now that we have eased up on Short Signal cribs (b) Dolphin is now more important intrinsically (c) we depend on reencodements from Dolphin to get into Shark."
The cribs in question did in fact normally come out and 3 weeks later the Weekly Report gloomily records:
"Dolphin is coming out with what some of us feel is lamentable regularity and we have had no Banburismus to do lately".
Cribbing and the increased number of bombes had in fact killed Banburismus and it was finally abandoned in the middle of September and with it disappeared the art of depth cribbing; at one blow our two most pleasurable pastimes had been removed. The raison d'etre of Banburismus had been the saving of bombe time, and bombe time was now no longer valuable enough to justify the expenditure of human effort which Banburismus involved or the delays in breaking. Occasionally, of course, if 2 or 3 cribs failed, we might break later than the Banburismus would have done, but normally a much earlier time of breaking was attained. There always remained the comforting possibility of restarting Banburismus if the cribs began to fail, but this never proved necessary in fact, although the crib which had really finished Banburismus, the Bereich 7 reencodement, did not live for very much longer.
From now on the history of Hut 8 is an account of the ups and down of the crib situation and of keys dividing and going onto 4 wheels. The problems which arose between September 1943 and the end of the war were, with the exception of the final Grundstellung and bigram table problems, essentially of the type which could be tackled with known methods. The work of Hut 8 was a matter of applying these methods successfully to an ever increasing number of keys in a world upset by allied advances. The cryptographer thrives on stagnation and the activity of the last 18 months of the war made our lives much more difficult.
Little else happened in 1943 except the breaking away of Black Sea Porpoise on October 1st. This key was christened Grampus and resembled its parent in all respects. Both keys could be and were broken with very little difficulty. Delays in breaking Grampus were fairly considerable as there was rarely sufficient traffic until the day was nearly complete.