I just watched the movie, The Town, where the bad guy (well, actually, Ben Affleck, the hero) robs a bank because he knows when the time lock will allow the vault to be open. But it got me to thinking …
There isn’t a clock in the world that hasn’t failed at some point. Do these vaults have a back-up plan in case the clocks simply stop working?
IIRC, the vaults have multiple clocks. Only one has to work.
In most such designs, the clock stops the vault from opening except for certain set times. So if the clock fails (stops), the vault can be opened at any time (providing you know the combination).
I suppose the clock might fail in some other odd way – it continues running but resets itself every hour so it never reaches the allowable ‘open’ times – I’ve never heard of that, and I don’t know what they would do. Possibly the headquarters bank or the vault company has a special way of overriding the time clock? But that would seem to defeat the purpose. Maybe they just have tocall in experts to drill out the lock.
A quick googling confirms this. There are two time locks. They are both set to allow the safe to unlock at a set time, but only one of them has to work. I have to assume that with modern day electronics, if one fails it doesn’t just sit there quietly, but has some sort of alarm to alert maintenance personnel. If they both break, I’d think that you’d have to have the lock drilled out. Probably very expensive. In fact, I have to wonder if it would be cheaper to crack open and repair one of the walls or the ceiling instead of the lock or door itself.
I was a bank teller 25 years ago. I worked in a branch with a big walk-in vault. Each night before we shut the vault the manager or the head teller would set the time clocks.
There’s a mechanism set on the inside of the door that holds the time clocks. They are mechanical countdown timers that you wind using a key. There are three timers and you set the number of hours before the vault can open.
I don’t remember for sure but I think just one timer had to run out to allow the vault to open.
Just to add a pointer to one of my favourite O. Henry stories about a time-locked safe (which may or may not have been accurate in it’s description of time-locking but is a cracking good yarn).
Si
[moderating]
bizerta, the beginning of the first post in a thread is readable upon mouseover when looking at the list of threads in a forum. We ask that movie spoilers be hidden in [noparse][spoiler][/noparse] tags, so that people don’t accidentally learn a plot point they didn’t want to know. I’ve edited your post accordingly.
[/moderating]
ETA: Son of a gun. That didn’t work. It looks like you need to have enough text before the spoiler to push it below what shows on mouseover. Oh, well. Between the thread title and the name of the movie in the beginning, it looks like this is going to be a tough plot point to hide. I’m going to add “[open movie spoilers]” to the thread title and take the [noparse][spoiler][/noparse] tags back out of the OP.
nm
Thanks, I enjoyed the story.
A lot of time locks are BS, the place Iworked with a safe had a time lock but it was just for show I suppose we could open the safe whenever
I was the actual safe and vault consultant on the movie the Town. Vault doors and safes that house the money in banks have time locks so that even if you know the combination you can not get in until a set time and even then most Banks split the combo so no one person has the whole thing. On a Vault door there are three time clocks so if you over wind two the third will open it. Or if one or two are broken one still works. In other words they very rarely break all three unless someone does something stupid (which happens) Most of the safes have a dual movement Clock. Anyway they should be cleaned once a year and tested. Ben really wanted to get things right and as close to real as possible and he did a great job doing so! Great flick.
Scott Thistle
It’s also worth remembering that no safe or vault is completely impregnable. The point is to make it take special equipment, a long time, and be noticeable (loud or visible or remote alarm) if someone tries.
So if a bank vault lock fails in the closed position, it may cost the bank some money and take some time to get the vault open, and worst case be embarrassing as passers-by hear the bank jackhammering it open, but they will be able to open it; it’s not like everything inside is lost forever if a timelock fails. So there’s a cost-benefit to redundancy on locks-- how much more redundancy costs against how often they’ll fail and the cost to the bank of breaking into the vault.