The US 6812 Division Bombe Report Eastcote 1944 Page 54

Tony Sale's Codes and Ciphers

| previous page | next page | index page |

- 44 - TOP SECRET-T

The menu is made in duplicate. The operator's copy is numbered in color for
plugging and the settings of the enigmas are listed in groups of four on
the right hand side of the menu. The IC OPS signs his initials and places
the time in the lower left hand corner of the operator's copy. The IC OPS
checks the menu against the T.P. slip. T.P. slips marked DDD are urgent and
are to be given necessary priority.

REARRANGEMENT OF MENU.

A new procedure has been adopted for transmitting menus. Previously

the Controller at B.P. indicated what links if any should be run as
phantoms. Due to the Controller B.P.'s increased work load and also a
desire to leave more flexibility for the Outstation, it has been decided to
send through the menus without indicating what links shall be run as
phantoms. The Outstation may then adjust the number of phantoms in
accordance with the letter-closure chart. It is desirable to obtain at
least one stop per wheel order. Suppose the menu as received has 14 letters
with no closures on the main chain and 6 letters with no closures on the
subsidiary chain. This will give 0 stops per wheel order. The chart shows
that removing 2 links from the subsidiary results in 1/2 stop per wheel
order, and removing 3 links results in 1 1/2 stops per wheel order. Since
the possibility is good of getting at least one machine stop per wheel
order by removing 2 links ,it would be decided to make that arrangement.

(AES note: the above paragraph is on a separate slip pinned to the original
page and obscures some of the original text from "priority" to "The
operator")


The operator is required to post his last wheel order when finishing a job
on the blackboard in the IC OPS room. It is desirable to have all the
bombes running a job finish at about the same time. The total number of
wheel orders is therefore roughly divided among the bombes with the
exception that one of the three is given a slightly lager amount to cause
it to finish last. This machine is not stripped immediately in case there
need to be re-runs of any of the wheel orders. Having selected the
initial wheel orders the Wheel Order Man then enters them on the Wheel
Order Sheet, the Job Sheet and on the back of the operator's copy of the
menu. If the wheel order is changed from that previously on the machine, it
will be short tested.
Sample Wheel Order and Job Sheets are shown on succeeding pages.

Wheel Order Sheet Explanation. (See Fig. 40)
Job 381 M 60 w/os are to be run and all w/os have already been given

to the operators. A few w/os have yet to be checked against the
operators job sheets. No w/os are crossed off the w/o sheet
unless checked on operators job sheet.

Jot 150 C Only run Nig. X on the L H S of the w/o sheet. All w/os not

to be run are immediately crossed out. In this illustration
some of the w/os have been given to the operator while the
remainder are yet to be assigned.

Job 262 C Only run Nig. Y Pref. n/c 524. First cross out all w/os not

to be run; then place a small x for the n/os to be run as
preference. Pref. w/os are completed before the remainder of
the Nig. Y are to be run.

Job 251 C All w/os are to be run except Nig. Z, therefore all Nig.

Z's are crossed out. In this case the job has been completed,
Hut 6 has been notified, and we have been told to strip.

Job 233 C N/c 513 is being run. Whenever a not crashing job is run,

there are always 32 w/os left to be run after the n/c w/os have
been crossed off. In this case some of the w/os have been
completed, a stop has brought the job up, and as a result the
operator automatically strips the machine. JOB UP is written on
the W/O sheet.



---




| previous page | next page | index page |