Dolphin if it should spread to that key but it would have been foolhardy to rely on this and Squadron Leader Jones and ourselves set to work to improve the Fillibuster technique and the fairly complex organisational problem it involved. At the same time arrangements were made to borrow senior staff from other sections if May should produce further complications as the small staff of Hut 8, very much though it had enjoyed itself, had clearly been working at too great a pressure and could not really cope efficiently with a large scale Grundstellung problem as well as its normal cribbing commitments.
The position at the beginning of May proved to be worse than we had hoped and 6 members of other Sections were called in to assist. Plaice went onto a new Grund table and Dolphin started the new system with a table of its own. On May 5th it was intended to introduce new bigram tables.
The bigram table change presented a problem much more interesting than the Grund problem in April. The normal method of building up bigram tables was to find the set-up of an individual message and to transpose that set-up at the Grund so as to obtain the tetragram and thus the values of the 4 bigrams in the indicator groups.