The US 6812 Division Bombe Report Eastcote 1944 Page 85

Tony Sale's Codes and Ciphers

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- 70 - TOP SECRET-T

actuated by a long armature mounted in a fashion similar to a telegraph
sounder bar. The armature lies in a plane parallel to the base and is
attracted by the spool magnets. It is fixed at the end nearest the spools
and attached at the other end to the moving springs of the pile-up. The so-
called Siemens relay is used for the sensing relay. This relay is somewhat
similar to the HS-10 and HS-11 relays but much smaller. It consists of two
independent armatures each actuated by a spool magnet. The magnet spool
windings are connected in series. The spools are mounted vertically with
respect to the base. The springs are mounted in cantilever arrangement with
the free end extending over and slightly beyond the spool magnet. The relay
is of relatively light construction and is designed to operate in a minimum
of .002 seconds. The two clutch magnets are connected in series and attract
or release a clutch arm. This clutch arm when attracted permits a dog to
engage a ratchet transmitting power from the motor to the driven mechanism.
When released the clutch arm seizes the spider carrying the dog and stops
the driven mechanism at the proper point. There are two sets of Carry
magnets per bank of enigmas or a total of 12 magnets. One set engages the
mechanism which advances the "intermediate" drums, while the other controls
the advance of the "slow" drums. Each set consists of a pair of magnets
connected in series and all the magnets controlling the same type of
magnets for all banks are connected in series. Thus each time the C-3



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