BID 590 (Noreen)

Her Name Was Noreen But She Was No Queen
By David Smith

Communicators in Foreign Affairs Canada (and elsewhere) knew this crypto device as Noreen but her official title was BID590.   If you treated her gently, charged her batteries and had a good sense of rhythm, you just might get to like her. Then again, probably not!!!

The Noreen crypto unit came into being in the early 1960's and saw service with Canada’s Foreign Affairs (External Affairs at the time) until the early 1980’s.  Her passing was probably not mourned by many, but those who used her agreed she was a quantum leap forward from the days of book cyphers.

The BID 590 was a British designed crypto machine and was used by Canada's Foreign Service Communicators at various diplomatic missions to communicate with various government departments. BID591 was the designator for the Instruction Manual. (Photo courtesy COMWEB Museum)

Basic operations were fairly straight forward and routine but one’s environment could add to the fun when it came to using the gummed (sticky) tape that Noreen was famous for (reminders of TYPEX).  For those communicators who lived and worked in the tropics, the gummed tape could get stuck on the work surface and just about anything else other than what one really wanted it stuck to. Things got even messier as the end of the roll of gummed tape was reached. The “gummer” tool for sticking the tape to blank paper pages was always a challenge as well.  Tongues were not unknown as a substitute – and the result was a “bad taste” to go along with the “bad water” some had to endure.

Encryption procedures could be challenging:   Message preparations were a team effort and the communicator relied on the secretaries to adhere to certain parameters, specifically, 69 characters per line, 25 lines to a page and so on.  The Communicator would place the appropriate key tape (in this case YELLOW) on the reel, place the key tape under the gate on the first indicator block, move a switch to EN (encode)  and begin typing the plain language text.

If it was a long message, one ended up with an impressive pile of gummed tape where, in especially humid conditions, the result could be a backlash that any novice fisherman would be proud of.  Noreen has been described as an “intransigent beast” which, while actually doing a fairly decent job, could be most irritating with the hesitations one had to endure after hitting a key and experiencing the resulting action by the machine – something around a half-second but, coupled with its pauses for the indicator blocks, and the non-printing characters such as a line feed or letter shift would result in a rhythm that did not match the normal typing patter that most Communicators were accustomed to.

There was one little process that was the bane of any communicators that actually followed these procedures, and that involved verifying the message using something called “Check Decrypt”.  Operators were expected to start a decrypt at the beginning of the message for approximately 25 groups, then another 25 groups in the middle of the message and then the final 25 groups. The decrypted groups were to be pasted on the back of the outgoing message form as proof the operator actually used the check decrypt process.  Because a red decrypt reel differed from a yellow encrypt reel, a supplied washer was used to hold the sensor up while the red key tape reel was in the reel holder – it served to “fool” Noreen into thinking a yellow reel was being used.  The operator could not do a “check decrypt” if the yellow reel was in the machine.

Once the encryption process was complete, the real fun began with the communicator now having to stick down the gummed tape (consisting of 5 letter groups) on plain paper sheets with the rule of 10 groups to a line and 5 lines to a block.  Once that messy task was complete (and please don’t mix the pages up), it was over to a teleprinter to type up a tape consisting of all these 5 letter groups (and woe to those who were less than stellar typists).  Following this task, the teletype tape was then transmitted. Message done!

Click to enlarge images

keytape_indicator_in_card_s.jpg Keytape Indicator - In Card. Actual Colour. Used during message deciphering.
keytape_indicator_out_card_s.jpg Keytape Indicator - Out Card. Actual Colour. Used during message enciphering.
A communicator was well advised to keep careful track of the indicators since the worst sin they could probably commit would be to use the same indicator block (about a yard of tape) more than once.  It could be done, it was done and they were suitably chagrined during those rare times. (Images courtesy David Smith)

Decryption was basically a reverse process of the above. The operator would insert a RED crypto tape (decrypt =RED) on the reel, place the crypto tape on the first indicator block, move a switch to DE (decode) and begin typing the 5 letter groups.  Any line hits or typos by the originating communicator would result in some garbled text but this would be corrected on the fly when typing the final copy.  Again, the gummed tape of plain language text would be posted on blank paper sheets and this would be typed on a teleprinter to produce a final copy for the recipient.

Lots of typing? – You bet!  Sticky tape problems – often!

The Noreen had a mind of its own.  A couple of former communicators described things this way. “In all fairness to the “little Bitch”, she wasn’t so bad once you got the knack of typing on her. You pushed hard, and felt resistance and kept pushing until the key finally depressed and then on to the next one. I was satisfied with my ability to type on the Noreen but I can assure you we had some Communicators that could really make her sing”

“Noreen was the particular expertise of one of our technicians. He could tune them so we could get much more from them that the manufacturers claimed. I believe the posted speed was around 10-12 words per minute (WPM), but this tech could coax them up to around 15. Aside from the usual idiosyncrasies that Noreen presented, our machines worked quite well.”

For those with sharp eyes, a lock button can be seen on the front panel of the Noreen. This little button would put the printing mechanism back into letters if the operator made a type that resulted in figures vice letters. Those same sharp eyes might have noted that the keytape reels were identical to those used in Rockex machines.

And to answer the obvious question, yes, one could use a Noreen to encode and a Rockex to decode the same message and more than one sharp individual took advantage of that fact. A testimonial from a retired Foreign Affairs technician reads thusly:

“I remember when I was asked to go into Vietnam to close the embassy in l975; I took a Noreen with as the communicator was severely overloaded with traffic in the falling days of Saigon. Upon arriving and seeing the backlog, I shared the fact that when posted in Saigon in 1970 I maintained the Rockex at the Australian Embassy. A little P.R. visit to the Aussies who had no technician at the time and some of my natural charm resulted in an offer to use their Rockex and their comcentre from 18:00 until the next morning.  As a result, the communicator and I would spend 5 or 6 solid hours decyphering all the Noreen messages that otherwise would have been impossible to do in the same timeframe with our 12 wpm Noreen.

Yup, she was cranky and at times recalcitrant, but she was a quantum leap ahead of Book Cypher.  We used her and abused her and when Rockex and BID610’s were introduced to our workplaces, no one was sad to say goodbye to the old girl. RIP old Lady.


Canadian Noreen security requirements mandated they be powered using lead-acid  battery power exclusively although it was understood that some countries ran them from the mains. A Noreen battery produced 12 volts and was encased in a wooden box, complete with lid. Within the wooden box was a wire “cage” which contributed to the integrity of the secure aspects of this power source and provided shielding. The batteries were permanently installed in their boxes and connected to the Noreen by means of cable with an 8 pin plug protruding from the end of the case.  When it was necessary to recharge, one simply disconnected the plug, and reconnected to the same type of plug attached to a charger.

One has to question how healthy it was to be charging the batteries in the comcentre while working in such an enclosed area especially as the filler caps had to be removed during charging . Poor ventilation in the crypto centres did not help.   Batteries could be tested using a bulb and glass tube hydrometer. Over time the batteries could leak and give off noxious vapours. The wet appearance on the battery tops was either spillage when topping up the battery or the battery bubbling while on charge which was why it was best to place a paper towel or rag over the open filler caps to contain any splashes caused by bubbling. The tops could get pretty cruddy after awhile. The battery case came with strapping, the purpose being to provide shielding for the case. Strapping was a rectangular copper braid approximately ½ - ¾  inches wide which was to ensure that there was no TEMPEST once the top of the case was secured. The strapping for the batteries was classified.

Most communicators admit they didn't always secure the top while operating Noreen given the plethora of hold-down screws and the requirement for frequent charging. Operators would be lucky to get 5 or 6 hours per charge; 3 or 4 was the norm. Each Noreen came with two battery boxes.  Batteries were shipped from Canada in a dry state and this left the communicator having to source and obtain a supply of acid which could prompt questions by mission administration and locally engaged drivers as to why they would need a supply of acid. One former communicator shares this story. “ The original battery maintenance kit came with gigantic, above the elbow, very heavy rubber gloves, rubber apron, eye protection goggles, etc.  Luckily I had a full bathroom adjacent to the line room, where I performed this dreadful operation. One day one of the secretaries appeared just as I was about to perform the deed. She almost passed out when she saw me”.

A UK Foreign Office site was still producing Noreen units in 1971. Also known as the Mk 854M, at that time they were classified SECRET (marked on the rear label) as were the battery boxes and their wiring harnesses and diagrams. The Mk 854M number was the unit type number allocated by the manufacturing facility where they were assembled and tested. Every production job had either an Mk type number (for complete units) or an SK type number for complete "kits" or modification kits for existing equipment.
The battery boxes for the Noreen were interesting for another reason too. When new, the foam rubber padding used between the batteries and the enclosure gave off a very pungent odour sometimes described as rotting fish. 
This Noreen photo set courtesy David Smith. 
bid590g_s.jpg A bottom view of Noreen which illustrates the electronics. Click to enlarge. (Photo via Raymond Fortin) 

Contributors and Credits:

1) David Smith  <drdee(at)>
2) Raymond Fortin <raymondfortin(at)>


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May 3/12