> Of course, there is a reason for the separation of the closing and locking functions, but not the opening and unlocking functions: it avoids a Denial of Service attack where someone can just press “close” and then jump out before the door closes. If the interior “close” button automatically locked the door, this would result in the toilet becoming permanently inaccessible.
This was done in my elementary school (~7-15yo) "back in my times", with analog doors with hand-turned locks. Those door locks usually had a 'screw-like' interface on the outside (similar to this: https://m.media-amazon.com/images/I/51KhCg9ZDFL.jpg ), so one of the kids would "have to pee" 5 minutes before the end of the lesson, go to the toilets and lock all the doors from outside with a screwdriver/swiss army knife so all of the toilet stalls would seem occupied.
Here in the UK the pendolino class trains, at least while operated by Virgin, were notorious for entering into an oscillating open/close loop. So much so that several times the staff would announce which cars had working toilets after each pickup station. Often times, apologising for the smell in the other cars.
We had these payphones years ago, some of them still exist but time is running out.
Probably the first attempt at a digital payphone in Australia.
What we found is that if you held down the language button (IIRC a flag with an L on it), before and as you are lifting the handset, the payphone will display "Out of Order" and you could replace the handset and the message would persist until the handset is lifted again.
Of course this was high school, and so we took a purely scientific approach to ruining a lot of peoples lives.
If you had a bank of 3 payphones, and you took 2 out of commission in this manner, no one would investigate the out of order handsets long enough to reverse the condition. So you would get a very long line behind the working handset.
However if you took all 3 offline, angry telephony consumers would test the handsets and restore them to working order.
It was a repeatable study on almost every bank of payphones in our town.
> Of course, there is a reason for the separation of the closing and locking functions, but not the opening and unlocking functions: it avoids a Denial of Service attack where someone can just press “close” and then jump out before the door closes. If the interior “close” button automatically locked the door, this would result in the toilet becoming permanently inaccessible.
There was a class of rolling stock used on UK lines (I encountered them over near Bradford IIRC) that had precisely that misdesign for the inside close button.
I had to be really careful using those because my natural reflex is to hit 'close' on my way out for tidiness' sake, and I think I actually -did- the first time I used one of those and only realised what I'd done to my fellow commuters immediately after I heard the click.
Think I was on them in '03 when they were shiny and new and I was commuting from Morecambe to Bradford due to getting unceremoniously redeployed from Salford to Bradford after an acquisition.
I do not recommend this as a life choice, though other than the toilet door problem they -were- rather pretty rolling stock.
People definitely got confused by the old design, but I don't understand why they didn't go with the obvious fix: just add an unlock button.
Or use a mechanical lock that people can obviously trust.
The worst designed toilet lock I ever saw was some kind of weird button you push to lock it. It was so untrustworthy (in the sense that you couldn't tell if it had really locked) that the owners had put up a sign explaining exactly what to do to lock the door and that yes it really was locked.
Was there anything wrong, with the good old mechanical locks in train toilets?
I have seen so many (elderly) people struggle to properly use the fancy electric ones (and lots of embarrassment, with doors that were indeed not locked) and apparently some people have fun, intentionally disabling them.
You know, some people sometimes just have a urgent buisness and are in need of a working toilet on a train.
I'm not elderly yet, but I have struggled with a similar train toilet door. _Why_ does this stupid thing need a lock button? In what scenario do I want to go into a toilet, hit the "close door" button, and _not_ want the door to be locked? It didn't help that the design of the buttons wasn't particularly clear, either.
I can see the benefit of the electric opening/closing mechanism, because sliding doors are heavy, but the lock should've been a physical mechanism, or at least acted like one.
Without the lock button you could hit the "close door" button and leave the toilet while it is closing, and then no-one would be able to enter to unlock it. But I agree something familiarly mechanical with the mechanism clearly visible would be better than any fancy solution.
Your question is answered at the start of the article, which also shows a photograph of your suggested solution on the newest trains in use in Britain.
They mention it in the article but it is to keep people from pressing 'close' and then jumping out while it closes and becomes unable to be opened from the outside.
A physical lock can get stuck. Especially on a moving trains with vibrations that could tense up the door.
Weakened people, anxious people and other people with disabilities need to be able to lock and unlock the doors without getting stuck.
My guess is that the metaphor used for this train is too allow people full control over door lock.
I don't think many people realise what it takes to build toilet in trains in a place like the UK where the disabled associations and protections are really strong.
My guess is that this type of round sliding door takes up much less space compared to solutions where you manually close the door. Unfortunately, manually round sliding doors can be very heavy to close. Especially for wheel chair users.
My guess is that this is probably the only way, if you also want to support disabled users while ensuring them most agency in the intimate process of using a toilet.
(Author here.) I have seen videos (not on trains) of one hybrid - a power-operated round sliding door, but with a physical lock on it, that hooks onto the door frame. So that would be one option.
I think the current iteration is fine though - the replacement of the confusing "lock button" with the physical handle, even if emulated, is comprehensible to most, I would think. The "the door is now locked" voiceover also helps reassure people. (Most people are just trying to lock the door and not "fuzz test" the lock handle...)
This makes some sense, but I think you still could have used an actual mechanical lock on the door. So open and close still be buttons, but once the electric door closed, you engaged the lock (some electronics required there obviously, to tell the state to the system, so it does not try to open with the lock engaged).
The context here is toilets specifically designed for disabled people. Some disabilities make it very hard to operate latches or levers, and in that context pushing a button is considered the more accessible control option.
- mechanical cannot be easily unlocked by conductors in case of emergency
- mechanical would break more often because people don’t care and would push on door even if it is occupied.
- in a hurry might be more convenient to simply push button assuming one is already familiar with the system.
- having only buttons it is easier to keep it clean and having people less contact with door handles/latches.
- can be automatically locked on stations so people use them between stations so you don’t get foul smells while boarding and waiting
Was there anything wrong, with the good old mechanical locks in train toilets?
The only thing wrong was the fact that they weren't "modern" enough, i.e. too simple and predictable.
That said, you can easily "DoS" a mechanical lock too, if it doesn't have any form of interlock. Everyone who has locked themselves out of cars and buildings (e.g. leaving the key inside) will clearly remember this.
These mechanical hacks are always fun to discover. Although, that poor soul waiting for the toilet, just to find that it was locked with nobody inside - that could be you.
These things are harder to test. It’s not just software and state machines.
And then there are the truly dangerous mechanical “hacks”. Eg the radiology machine that incorrectly dosed radiation. Therac-25.
> require McDonnell Douglas to redesign the door locking system so that it would be "physically impossible to position the external locking handle and vent door to their normal locking positions unless the locking pins are fully engaged."
Readit News
This was done in my elementary school (~7-15yo) "back in my times", with analog doors with hand-turned locks. Those door locks usually had a 'screw-like' interface on the outside (similar to this: https://m.media-amazon.com/images/I/51KhCg9ZDFL.jpg ), so one of the kids would "have to pee" 5 minutes before the end of the lesson, go to the toilets and lock all the doors from outside with a screwdriver/swiss army knife so all of the toilet stalls would seem occupied.
I had the handle in reach so I tried to push it back, but eventually I had to prioritize getting my trousers on.
Also in this kind of car the toilet is wider than a usual double seat so there were actually seats outside facing the toilet.
Rather embarrasing situation but we are all born naked so it was mostly a fun story.
I have no idea what happened, i was not curious enough to go back and investigate, I just got back into my seat and tried to look invisible.
Probably the first attempt at a digital payphone in Australia.
What we found is that if you held down the language button (IIRC a flag with an L on it), before and as you are lifting the handset, the payphone will display "Out of Order" and you could replace the handset and the message would persist until the handset is lifted again.
Of course this was high school, and so we took a purely scientific approach to ruining a lot of peoples lives.
If you had a bank of 3 payphones, and you took 2 out of commission in this manner, no one would investigate the out of order handsets long enough to reverse the condition. So you would get a very long line behind the working handset.
However if you took all 3 offline, angry telephony consumers would test the handsets and restore them to working order.
It was a repeatable study on almost every bank of payphones in our town.
Dead Comment
There was a class of rolling stock used on UK lines (I encountered them over near Bradford IIRC) that had precisely that misdesign for the inside close button.
I had to be really careful using those because my natural reflex is to hit 'close' on my way out for tidiness' sake, and I think I actually -did- the first time I used one of those and only realised what I'd done to my fellow commuters immediately after I heard the click.
Think I was on them in '03 when they were shiny and new and I was commuting from Morecambe to Bradford due to getting unceremoniously redeployed from Salford to Bradford after an acquisition.
I do not recommend this as a life choice, though other than the toilet door problem they -were- rather pretty rolling stock.
Deleted Comment
There’s also a psychological aspect to performing the separate action of locking.
There are trains in Denmark that only have the ’close’ button. Quite jarring the first time.
Or use a mechanical lock that people can obviously trust.
The worst designed toilet lock I ever saw was some kind of weird button you push to lock it. It was so untrustworthy (in the sense that you couldn't tell if it had really locked) that the owners had put up a sign explaining exactly what to do to lock the door and that yes it really was locked.
I have seen so many (elderly) people struggle to properly use the fancy electric ones (and lots of embarrassment, with doors that were indeed not locked) and apparently some people have fun, intentionally disabling them. You know, some people sometimes just have a urgent buisness and are in need of a working toilet on a train.
I can see the benefit of the electric opening/closing mechanism, because sliding doors are heavy, but the lock should've been a physical mechanism, or at least acted like one.
Weakened people, anxious people and other people with disabilities need to be able to lock and unlock the doors without getting stuck.
My guess is that the metaphor used for this train is too allow people full control over door lock.
I don't think many people realise what it takes to build toilet in trains in a place like the UK where the disabled associations and protections are really strong.
My guess is that this is probably the only way, if you also want to support disabled users while ensuring them most agency in the intimate process of using a toilet.
I think the current iteration is fine though - the replacement of the confusing "lock button" with the physical handle, even if emulated, is comprehensible to most, I would think. The "the door is now locked" voiceover also helps reassure people. (Most people are just trying to lock the door and not "fuzz test" the lock handle...)
- mechanical cannot be easily unlocked by conductors in case of emergency - mechanical would break more often because people don’t care and would push on door even if it is occupied. - in a hurry might be more convenient to simply push button assuming one is already familiar with the system. - having only buttons it is easier to keep it clean and having people less contact with door handles/latches. - can be automatically locked on stations so people use them between stations so you don’t get foul smells while boarding and waiting
The only thing wrong was the fact that they weren't "modern" enough, i.e. too simple and predictable.
That said, you can easily "DoS" a mechanical lock too, if it doesn't have any form of interlock. Everyone who has locked themselves out of cars and buildings (e.g. leaving the key inside) will clearly remember this.
These things are harder to test. It’s not just software and state machines.
And then there are the truly dangerous mechanical “hacks”. Eg the radiology machine that incorrectly dosed radiation. Therac-25.
https://admiralcloudberg.medium.com/a-legal-and-moral-questi...
> require McDonnell Douglas to redesign the door locking system so that it would be "physically impossible to position the external locking handle and vent door to their normal locking positions unless the locking pins are fully engaged."
The glue comparison would be more akin to him breaking out logic probes.