The US 6812 Division Bombe Report Eastcote 1944 Page 61

Tony Sale's Codes and Ciphers

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- 49 - TOP SECRET-T

PROCEDURE WHEN BOMBE STOPS.

Whenever the bombe has found a possible solution it stops. A definite

procedure should be used in obtaining the information from the stop and
restarting the bombe as follows:

1. Bombe slows down and stops automatically.
2. One or more relays fall on indicator on the side of the machine.
3. Check the relay by lifting the bail lever. If the relay does not
fall again call a technician.
4. Note on which chain the relay fell and record mentally.
5. Note the settings of the indicator drums.
6. Write in the appropriate column on the job sheet the readings you
have taken from the drums and correspondingly the relay that has
fallen in the column for this reading.
7. To restart the bombe:

a. Press the Start Key.
b. Then lift the Bail lever.
DO NOT PERFORM THESE TWO OPERATIONS SIMULTANEOUSLY.


MAKING OUT STOP SLIP.

When a stop is reached the operator makes out a stop slip, putting

down the stop number, the name of the bombe, the relative ringstellung and
stecker of the input letter, and the wheel order, as follows:





EXCESSIVE STOPS PER WHEEL ORDER.

Approximately 4 stops per wheel order is the maximum number

that one man can comfortably check. It takes about 15 to 20 minutes to
make a run with 4 stops per wheel order. Should the menu yield more than 4
stops per wheel order a call should be made to the Bletchley Park
Controller (BP &) to obtain additional links (subsidiary).

(AES Note: this paragraph was on a separate slip pinned to the original
page. It obscures the original text. )


Depress the relay letter which is the stecker of the input letter, thereby
lighting the stecker of the letter at the other end of the link. In the
example this is W. Follow round until all links on the menu have been
checked. The checker must go round every closure to ascertain that the
stecker returns to the original letter, in the case of the above stop it
will be seen that this did happen in tile case of the closure I-Q-D and
that this was indicated on the check sheet by the check mark against the
third stecker letter. Check all steckers against the alphabet at the
top of the Check Sheet and mark the confirmations and self steckers. In the
example the only confirmation is in the case of steckers R and L. There are
no self steckers. All entries onto the subsidiary chain must be checked.
When checking


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