 Once Tutte had made this breakthrough, the rest of the Research Section joined in to study the other impulses, and it was established that the five "chi" wheels all advanced with each new character and that the five "psi" wheels all moved together under the control of two "mu" or "motor" wheels.Over the following two months, Tutte and other members of the Research Section worked out the complete logical structure of the machine, with its set of wheels bearing cams that could either be in a position (raised) that added x to the stream of key characters, or in the alternative position that added in •.Diagnosing the functioning of the Tunny machine in this way was a truly remarkable cryptanalytical achievement which, in the citation for Tutte's induction as an Officer of the Order of Canada, was described as "one of the greatest intellectual feats of World War II".