Re: Enigma, the cipher famously cracked by Tutte's colleague Alan Turing
It was Colossus that emulated the Lorenz machine; the Bombe emulated the Enigma machine. If I have correctly understood the tour guides at Bletchley and TNMOC, the aim of both machines was to find the rotor settings, i.e. the crypto key.
This was done by testing "cribs": guesses at typical message headings, date and time, etc. Colossus/Bombe used two paper tapes, one with the encrypted message and the other with the crib. C/B tested many, many key settings and displacements of the crib from the start of the message.
The original Enigma message was then transcribed on a Typex machine, a British "Enigma" modified to mimic the original Enigma. As pointed out above, there were numerous variations of the Enigma.
Equally, there was a pseudo-Lorenz machhine. The Lorenz machine was a weighty beast, fit only for a headquarters role. The Enigma was portable.