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.
And "the entire chamber being -sprayed- with liquid" plus "I felt like I was drowning" could easily get misquoted as well (or misremembered, 20 years ago is certainly more than long enough for me to screw up details).
So my guess is that what actually happened is something of that ilk.
Man, hammer, nail, etc
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:
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.
It’s in the train co’s interest to have working toilets (not too many, because they displace seats but some) and have them reliable and easy to maintain (else costs go up, maybe even they need more per train). This is why they care about a denial of service attack (btw an electronic one can tell the conductor when the toilet is locked for a grossly atypical duration).
So to that degree the interest of the carrier and the passenger are aligned. This applies to most of the carriage decisions (robust seating, working doors and brakes, and so on).
But the if the trains pass first inspection, then it no longer is a development issue but a maintenance issue. [1]
It's not as if train companies can afford to run a statistically significant number of carriages from different suppliers to see which one gives them the actual best bang for buck 5 years down the road.
[1] Rule-proving exception: the Fyra trains. https://en.m.wikipedia.org/wiki/Fyra
The short version: high speed trains failed and were eventually returned (2014) to the manufacturer for ~2/3rds of new price. (That's the exception part.) There have not been high speed trains on this traject since. (That's the rule-conforming part.)
https://www.gableseng.com/wp-content/uploads/2020/05/G7330-....
I am lost for words...
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?
https://upload.wikimedia.org/wikipedia/commons/a/a4/Airbus_A...
It's 100% about programmers wanting to make everything software defined.
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.