Feynman's Safes/Locks

Cepasaccus

Hi, after seeing something about Feynman, I wondered what safes did they use at Los Alamos and with which locks did Feynman work? I searched online and really found nothing really, only that it was normally a Mosler filing cabinet. Any idea? Maybe one with a B-101?

Doug MacQueen

When I just happened to be reading a Feynman book years ago, I was surprised that I had never heard about his technique in the safe trade. And from what I remember, the technique was to back dial from the stop (open) position and carefully paying attention to wheel pickup. It wouldn’t have mattered which brand but Moslers are certainly possible. This was pre GSA manipulation resistant lock era.

Cepasaccus

From what I have read he did not feel for pick up, but tested how long the lock still opens. Let’s say lock stopped at 0 when doing the final right turn. One can than turn left to 20, right to 0, left to 25, right to 0, left to 30, right to 0, … When the lock won’t unlock the number before was the last code number (more or less). The brand of lock would not have been relevant that for this although it seems he had problems with a vault door (high end friction fence lock?) and would have had problems with a lock, that did not cleanly lock. And the brand would not be relevant at all for his psychological “tricks”. Nonetheless it would really be interesting to know which lock model it was.

Doug MacQueen

Doing what you are describing would get you in the ballpark of only one number, the last number. It has been at least 30 years ago when I read his book and what you are describing does not sound familiar. And I remember thinking that he had come up with a possible quick method of determining combinations when the door is already open. Potentially much faster than tearing the lock down. I also tried it a few times myself and did have some success. Does not work well when the wheel pickup is very faint. If I am not mistaken it was in his Surely Your Joking Dr. Feynman book.

wylk

IIRC he would determine the last two numbers by fiddling with the dial “absentmindedly” while talking to the office occupant, then add them to a list he built up. If he needed access (usually he was asked by somebody while the cabinet’s owner was out of town) he would find the first number simply by trial and error. Sometimes he would go into an office, close the door, read a magazine for a while, open it, read some more, then walk out; this gave the impression to others that it was a difficult task.

At the end of the war the project leader (General Grove) left and his safe was locked. Feynman could not open it so they called a locksmith who opened it almost immediately, revealing that it was still set to the factory default combination.

It’s an interesting read in general, and his locksmith tales in particular.

Doug MacQueen

And to think that all this time I thought it was Feynman that had arrived at something apparently unknown to the safe trade, when in fact it was really me. Huh.

wylk

I think the issue with Feynman’s technique is that it’s useless to a safe tech. He was only successful if the lock was unlocked; to a safe tech, one question would be “if it’s open why would you call a technician at all?” If a tech did show up, simply removing the back of the lock would yield the combination much more easily. It’s an interesting attack (especially since he could concentrate enough to carry on a conversation at the same time) but it’s more of a bad-guy surreptitious technique that has little application elsewhere. At the very least it’s entertaining!

I believe he kept his secret list inside the case of his own cabinet’s lock.

Tom Gordon

Cepasaccus wrote
Hi, after seeing something about Feynman, I wondered what safes did they use at Los Alamos and with which locks did Feynman work? I searched online and really found nothing really, only that it was normally a Mosler filing cabinet. Any idea? Maybe one with a B-101?

He found and noted the last number from safes while they were dialled open, which is a simple technique but unavailable where the safe is locked. He then took account of manufacturing tolerances to find 20 combinations which would include the working one on safes that had been set to a favourite date and on which he had fiddled with the lock while it was open.
safe techs have always used the manufacturing tolerances to make it quicker while decoding locks, but His was more a triumph of drama dependent on lax security, rather than skill or invention.

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