I am told that "superloos" (those automated self-cleaning toilets installed on the pavement) do have some kind of time limit and will play some kind of audial warning a few minutes before opening.
More concerning about those toilets are stories where people somehow managed to be inside the toilet when the self-cleaning process started (which involved the entire chamber being filled with liquid). Supposedly this would happen when someone used the toilet, but held the door open as they left so someone else could use it without paying. The toilet, then thinking it was empty, proceeds to unwittingly try and drown the "undeclared" occupant.
It doesn’t. That would use way too much water and not even be a good way to clean surfaces.
There’s jets of pressurized water spraying and sometimes (I believe) air to dry everything afterwards, so the worst that would happen is that the person inside would get an unexpected shower:
Man, hammer, nail, etc
They also auto-close the toilet door when not in use to keep smells away.
And the main reason: Doors aren't really wheelchair friendly - many wheelchair users aren't strong or agile enough to move a door.
With those 3 things to deal with, it's pretty hard to design a mechanical door system that can meet everyone's requirements.
Having said that, the UI could certainly be better. I would personally have had the 'close' button require to be held down the whole time the door is closing. If you release the button early, the door opens again. Only when it is fully closed will it then stay closed and 'locked'. No need for an actual mechanical lock, but there should be a big red padlock light that comes on.
Buttons flush with the surface or low profile levers such as the ones shown in the picture can be more robust against certain mechanical attacks simply by having lower weight, lower travel, and being smaller (don’t need to exhibit mechanical advantage).
I’m a fan of simple mechanisms with no software in them whenever possible, but I don’t have to deal with the cost and reliability problems.
Nobody (neither mfr nor customer) takes this path for the sex appeal. This is a B2B product (train car) so BOM and TCO drive everything.
https://www.gableseng.com/wp-content/uploads/2020/05/G7330-....
I am lost for words...
It's 100% about programmers wanting to make everything software defined.
Touchscreens are harder to hit buttons right when you're being jostled about by turbulence. Not to mention how easy it is to hit the wrong button even when there's no turbulence. Have you noticed how liberal all smartphones are with autocorrect lately?
I think the original introduction of the button was due to accessiblity. my understanding is that on newer planes they are trying to move towards a similar system for the same reasons.
Trains on the other don’t have such minimum staffing requirements and usually operate with only one or two staff total (driver plus maybe a ticket inspector). Train operators want to keep staff on train to an absolute minimum (people cost money after all), but those staff still have some safety responsibilities which can’t be removed. Instead you try to remove every other responsibility they might have, such as dealing with toilets.
Automated toilets means the toilets themselves can be responsible for the vast majority of their operations, and can be trusted to fail safe if something unexpected happens. Meaning there’s no need for staff to perform regular inspections while the train is in service, and no need to worry about something going silently wrong and hurting someone. Instead the toilets can ensure that unsafe situations don’t happen, and proactively alert staff if something unsafe does happen.
Sadly all of this adds complexity and more possibilities for failure.
In Switzerland we have bioreactors [1] in newer trains which are like a mini sewage treatment plants. These are still very new and still have bugs that are being worked out such as how much oxygen needs to be provided etc. Until recently it caused a bad smell at the main station which is ironic since that is what we used to have in the 80s with the old dumb toilets.
[1] https://news.sbb.ch/artikel/114447/unangenehmer-geruch-aus-b... (German)
In the U.K. any train from the last 30 years fills a tank, like an RV, including ones with physical locks.
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.
According to the article, you can do that anyway.
“you can close the door, then hold the lever just beyond the point at which the locking pin could engage with it, but not to the point where it reads as “locked”. Then you can open the door, but the locking pin projects into thin air; thus the lever is free and can be moved to the locked position. The door close button remains active and you can then close the door. I confirmed that the door will then immediately lock as soon as the door is closed. Since I could do this and then jump out before the door closes, this is effectively a toilet DoS vulnerability on a train.”
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.
Simple levers don't need much force to operate.
The idea of a motorised door and the rest of that automated mechanism just scares me. There's so much more complexity and points of failure that I could imagine someone getting crushed if other interlocks fail, or otherwise having the door open / close unexpectedly.
I have never experienced a simple lock to get stuck, but there are panic buttons inside the toilets as well.
"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."
And I don't think this is a bad thing.
Seriously, why it was not a problem for two centuries yet nowadays it's suddenly a new problem which requires a complex, electromechanical computer operated solution?
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...)
I don't know what type of hypothetical disability the person above means, but I know the problem of round doorknobs and gloves so I suppose something like that?
But a horizontal sliding lock as seen on many types of bathroom stalls already should be similar enough that anyone who can push a button in the right direction can also push these in the right direction
However, does a mechanical lock glow and look fancy when you can sell your electronic high-tech locking system to the train manufacturer??
- 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.
For real though, this is a cool idea and hack, but only a real bastard would put the toilet out of action deliberately. Of course that sort of person does happen to frequent British trains and this is hence valuable research.During the Polish train hacking debacle it was suggested that saboteurs be charged with harming vital national infrastructure, I hope that toiletblockers would be similarly indicted.
Here in Germany, the railway itself is the worst culprit - in December, when DB took over the notorious Hof-Munich line, I travelled on a 6-car double decker train that had 5 broken toilets, all of them because either the water was out or the sewage tank full. Not fun.
The second worst culprits are idiots throwing trash into the toilet. Diapers, tampons and wet wipes don't belong into regular toilets - but especially not into vacuum toilets like on trains or planes.
It's not a free ride, your nephew is just dishonest.
It's not particularly admirable behavior, but it's not all that different in kind from using a whistle from a cereal box to make free phone calls.
The one you describe is the more famous one, but there was another one a few months earlier, where a group of actually malicious hackers used simple radio signals to trigger emergency stops on dozens of trains over the course of a few days.[1]
[1] https://www.wired.com/story/poland-train-radio-stop-attack/
Maybe this is why toilets never work on trains when I need them. What a shame...
In this case, we're talking about a door and a sliding lock. A mechanical design would not have had any of these failure states. All the system needed, was to connect the locking switch to the physical door lock, and none of this would've caused a problem.
If you're automating something as simple as a door lock, you need to be able to deal with this stuff. If you can't, stick to what works instead.
Unless you have been a part of the design process of train toilets (and please enlighten me if you are) then your beliefs really does not justify vandalism of public amenities.
If someone says "huh, I can just take this gum and walk out of the supermarket with it", calling them a thief is unwarranted.
Of course you can damage or break any physical system if you apply too much force or use it the wrong way intentionally.
However those don’t work with some passengers - wheelchair users for example, people with difficultiy holding handles etc.
Making toilets more accessible for some groups makes them less accessible for others (. As a society we choose what level to have it at.
Some trains in the U.K. have a good balance - a large wheelchair accessible toilet, and a small traditional one, although they sometimes struggle with communicating it.
The caveat here is that I'm not an expert on this, and that I'm possibly argueing from a position of ignorance. But none of the people claiming accessibility benefits (there are several) have made a very convincing case, beyond a mere assertion that it's more accessible. The door design as such is more accessible, but I don't think it actually matters in this context.
It's kind of off-topic but please correct me if I'm wrong.
Local government chooses the train service operator. The operator chooses the providers of machines (trains and carriages). Engineers design those machines according to some more or less specific guidelines from product designers. Their managers and peers provide the missing details.
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.
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.
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.
But in this case they clearly attempted to complicate things as much as possible, so no surprise that additional edge-case bugs and points of failure were also introduced.
You add a mechanical override cylinder. Conversely, I could ask "how do you deal with electronic failures that leave the door locked?"
Or when someone without a ticket went in?
If you got on the train, you already have a ticket. Or do you need a separate ticket just to enter the toilet(!?)
i got down to dover and across the channel ok, but at calais the trains were all screwed up. i had a seat reserved but it was filled with an elderly frenchwoman in full black regalia who womanfully resisted all efforts of me and the train conductor to pry her out of it.
i retreated to the loo (train was packed) and spent the next hour or so pretending dire gastric problems.
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.
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.
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.
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.
Don't say more.
Did anyone else find this sentence hard to grok? I was trying to work out why the UK had stopped modern train power-operated door based toilets from working for a moment.
no, the problem was that it's a stupid state machine that even conducting experiments with you can't be sure how it works unless you're Shrodinger's cat and and you have Shrodinger outside the door and you can communicate
