> 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.
> We just smoked outside the back of the building.
I don't care if someone smokes, as long as I don't have to inhale the smoke. A lot of campaigns against smoking in public places, from school until today, made life unpleasant and dangerous for people like me: smoke filled the few remaining non-enforced places, from bathrooms to elevators to airport exits. Turns out there's correlation between "smoking ban not enforced" and "I can't avoid going there". Whenever they instead end up with smokers gathering in the corner of the street I can just go around: that's great, hope that no one disturbs smoking in that corner as long as possible!
Actually, the modern thinking is that "anybody smoking is bad for all of us because it puts unnecessary pressure on the healthcare system". Same thing with drinking and other harmful things. Well that is for countries that have public healthcare that is.
> Same thing with drinking and other harmful things.
I'm not sure where you're from, but other burdensome things aren't looked at that way in Australia, nor in other public healthcare countries I've been to.
Drinking, low quality/high calorie food, Netflix, food delivery, extreme sports - all things that place pressure on healthcare - yet I've never seen someone approach somebody eating McDonalds and asking then to not do that for the good of society, as I have with smokers.
We had full on stalls with brick/cement walls up to the ceiling (stall sized still, but private), so even the farts were muffled. Communist construction was no joke. Later in college, with some "modernized", capitalist toilets, we got an "open room", thin wooden "walls" that left the botton 20 centimeters open and left a gap on top.
In the old part of the buildings, we still had proper stalls, some even with a small sink inside the stall.
I kid you not I went to a bar once, and the toilet was just directly across from the door in plain view of most of the bar when someone opened the door, and it also had urinals. It was not a door that locked.
No toilet paper or soap either. You only used those bathrooms if the alternative was shitting your pants, and even then it was a good idea to do it during class to minimize the likelihood of someone walking in on you.
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.
> 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.
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.”
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.
Weakened people, anxious people and other people with disabilities need to be able to lock and unlock the doors without getting stuck.
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.
"Weakened people, anxious people and other people with disabilities need to be able to lock and unlock the doors without getting stuck."
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."
I never said it was a bad thing. I merely point out that is is ignorant to straight up believe that a "simple lock" is the solution without properly understanding the issue - just like you do.
Ah, I did not try to imply that you did. I was actually unsure how you meant it, but just wanted to emphasize anyway, that those regulations are very useful for disabled people. Because in most places, you would just get stuck using a wheelchair on your own. (German trains for example, in most trains you would just not get into - and if you managed to arrive at your destination, you might find out, that there are only stairs and no elevator, despite there should be one. But on this day they maybe changed the lane or whatever, they don't care. I noticed while travelling with a 2 person stroller)
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?
Because in the past people did not care about people with disabilities. It's like saying why we need wheel chair ramps when we didn't in the past.
Don't get me wrong, I'm not defending the current implementation, but it makes sense to me to try and improve the world to make it more disability friendly.
Do you mean the exterior door beeping (officially known as a "hustle alarm" in the rail industry - now you know)? There has been a wave of adapting or replacing train door controllers to comply with the latest disability regulations recently. But all motorised train doors that I know of in the UK have had a hustle alarm.
I don't much care for the new "compliant" controllers though, not least because the sounds they emanate are quite unpleasant and often much less nice than the ones emitted by the door systems they replaced. Older hustle alarms, etc. sounded like they were produced by something at least slightly polyphonic, whereas all of these new systems seem to produce all of their sounds via an ear-piercing piezo buzzer only.
Besides the hustle alarm there's the sound to notify you the doors can now be opened (often not present on older, non-compliant systems, but now seemingly deemed required). I was always fond of the sound the Class 365/465 Networker used for this - an actual mechanical bell, which produced a pleasant sound. Of course it's now been torn out and retrofitted with an awful piezoelectric tone of the most ear-violating variety. It feels like nobody even tried to make these sounds pleasant, and probably went with a piezo buzzer rather than a mechanical bell because it costs less, and what hardware designer even knows how to integrate a mechanical bell these days?
The closest to not having a hustle alarm I'm aware of in the UK is for London Underground and DLR stock, which basically starts to play the hustle alarm at the same time as the doors close, making it a bit of a token affair.
Those interested in this sort of thing might be interested in this TfL report which actually studied in minute detail whether they should change the delay on the doors closing after the warning sounds. I encountered this once and was fascinated by the details. https://assets.publishing.service.gov.uk/government/uploads/...
BTW, the applicable safety requirements standard for power-operated passenger train doors is GM/RT2473 (or its predecessor on older rolling stock, GO/OTS300). Don't ask me how I know this...
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...)
Ah, you were the author as well. Have you noticed anyone from the train company about this flaw? (not saying that much would come out of it, but I think one should try)
I've just way too often seen these fake-physical locks be broken, or working in an unexpected way (with a fucking explanatory sticker with three lines of text explaining it). Who signs off on such crap?
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.
They are rare, but if you build a specific toilet targeted for people with disabilities (next to ordinary, simpler, smaller toilets) then you generally try to make it as accessible as you reasonably can and target a wide variety of different disabilities. Such toilets tend to have many adaptations e.g. different controls for faucets on the sink, different handling of toilet paper, different dimensions and spacing, etc.; and yes, for some people a button instead of a knob that needs to be turned is all the difference in the world, as they simply can't turn a knob. For a trivial (but not nearly the only) scenario imagine a person with prosthetic hands, or extremely limited grip strength caused by e.g. some cases of cerebral palsy.
> Is turning the lock really that different to pushing a button?
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??
There are other benefits to this too. With an electronic lock you can display the state of the toilet to other passengers on digital signage screens onboard the train. You could do this with physical locks but it would likely be more costly.
Putting a simple contact sensor on the deep end of a mechanical lock (costs about as much as a button since it can be the same hardware, except it needs to neither be big nor have controllable lights around it) is more expensive than designing a whole bunch of electronic circuitry and state machines and figuring out the best text you can write to make (young and old) people understand the state machine?!
The doors are also slow as heck, both because they slide a large distance at the speed of a snail in a hairpin turn and because half the people don't get the system. I'd be surprised if these electronic systems merely halve a toilet's hourly capacity compared to it being fully mechanical besides that 10-pence "occupied" sensor in the frame/wall side of the lock
- 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."
I don’t understand why we have to put microcontrollers in everything. I think a toilet on a train is basically the same use case as a toilet on a plane and all the planes I’ve been on, all had an old fashioned sliding lock mechanism that works totally ok. I wonder if the train bathroom the poster describes has a timer to avoid people from occupying the bathroom for the complete duration of the journey, and that’s why a mechanical lock won’t work?
The microcontroller obsession is real. As is the desire to do everything via software and not mechanically - see touchscreens in cars. I'm pretty sure it's because as developers, we're addicted to the notion of making everything software-defined so you can change everything later if needed. As a developer it's a thought process I understand well, but seems to increasingly lead to detrimental outcomes, like the extreme touchscreenisation of cars - awful from a safety perspective.
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.
> which involved the entire chamber being filled with liquid
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:
oh gawd, is this the trend of videos now? i knew we had gotten bad, but this is just wow. is this one of those situations where if you give speed to an adhd person, things become calmer for them? so if you have adhd, this seems normal?
It’s not because developers want to work with toilets or other mundane things. Is because the system we all live in has become obsessed with taking everything we do.
You're saying the entire indoor volume of the "superloo" gets flooded with water, like a sinking submarine? Don't be absurd. That'd be a monumental waste of water and it wouldn't even clean that well.
It sounds odd to me. I'm merely recollecting a news report from probably about 20 years ago, which is probably going to be hard to dig up. If it's another case of the press getting something totally wrong, that wouldn't be surprising.
I would imagine getting suddenly sprayed with cleaning solution from multiple directions is probably sufficiently unpleasant that it will get exaggerated as it's re-told.
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.
These train door locks also report to a light at the front of the train that the toilet is occupied. That way you know where on the train the nearest unoccupied toilet is, and can decide to stay in your seat a bit longer or venture to a further away part of the train if your need is desperate.
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.
While that certainly explains why they might use a microcontroller, it's certainly not necessary. The lock can be connected to a simple switch used for signalling occupancy, same as any security or commercial fire protection system. Auto-closing and auto-opening are akin to an automatic door, which operates just fine as a regular door, but has a fairly dumb motor attached for accessibility. Perhaps the microcontroller solution ended up being cheaper - but based on this (particularly going to out of order after such a trivial "hack"), the mechanical solution is far more robust, because at worst you can still operate the door manually.
A lot of it is reduced BOM. You can get a more robust solenoid lock and control it with a microprocessor for less than the cost of a robust, fully mechanical system, which is a system that needs mechanical maintenance and is subject to all sorts of false inputs like people putting all their weight on a lever.
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.
Won't a solenoid lock with microcontroller circuitry have a higher risk of failure due to water damage, power surges, and other factors(software bugs, hackers, cosmic rays!), in addition to wear and tear of a mechanical lock?
Well, it’s not such a big problem as it is in, say, health care.
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.
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.)
This doesn't pass the smell test at all. There are multiple redundant CDUs and I'm not aware of any reliability issues with their keyboards in the countless other aircraft models which use them. And I second everything @etskinner just said above.
It's 100% about programmers wanting to make everything software defined.
And it makes no sense from a usability/safety perspective.
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?
The flight deck of the Airbus A380 widebody airliner must be the most comfortable and ergonomic in existence, with a full laptop-style QWERTY keyboard for each pilot and two additional mini QWERTY keyboards on the center pedestal. There have also been no fatal accidents on the type; maybe the well-designed cockpit has something to do with that.
Also the fact that with a set of switches, if one doesn't work, it doesn't affect the others. Touchscreens seem to fail all-or-nothing, or at least have large areas suddenly become unusable.
Not really. It's a cost-cutting measure. Keeping the old UI lets them pretend it's the same plane as the original model from the 60s and pilots don't need training.
I had a similar thought untill I read that actually for or people with motor/muscle issues issues, a push button or something like the lever in the above which doesnt require physical strength is much easier.
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.
I suspect it just boils down to minimising the number tasks staff are responsible for, so you can reduce the number of staff needed. Aircraft need to have attendants for safety reasons, and the minimum number of attendants is dictated by the number of passengers. Most of the time airplanes aren’t in emergency situations, so you’re got lots of spare staff aboard, and you can use them to look after toilets and feed passengers.
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.
An old fashioned handle and lock is about as low maintenance as you can get - far less than a complex locking mechanism requiring a computer reboot from the cab to handle when a passenger gets stuck in because they can’t figure out the “open” butto
Train toilets have become complex systems since the days of there just being basically a hole the floor. This is due to many factors such as not having to prevent people from using them when at a station or people getting hit by sewage in the country side when a train passes. Additionally the toilets need to be accessible and environmental friendly nowadays.
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.
There’s no reason you can’t flush in a station - modern trains don’t just drop onto the track (and people have to work on the track, so the station is just a PR thing to avoid offending passengers)
In the U.K. any train from the last 30 years fills a tank, like an RV, including ones with physical locks.
Yes, but nothing in your answer actually justifies why the locking mechanism needs to be so complicated. As the previous poster rightly pointed out, airplanes are also not slinging shit overboard at Mach 0.8, and they manage with a perfectly simple sliding mechanism. Or, staying with modern trains, the French TGVs also don't have such an over-engineered solution.. Although, agreed, they don't have on board nuclear reactors to prenuke their toilet waste.. That might warrant a 3 button system with voice control..
It's a treasure trove of data to know the bathroom utilization rate normalized for passenger volume and time spent per session. Maybe train bathrooms are highly unoptimized. Do trains which frequent downtown areas with bars and sports stadiums need more bathrooms? Maybe there is some kind of flex use option for low passenger count trains to make use of that space but also provide a buffer for commute hours? Does the speed/acceleration/jerk of the train impact bathroom habits? Could this be used as an early warning system for possible food poisoning outbreaks? How can all of this be factored into ads we can serve the bathroom user?
Seems a bit overengineered. Especially when you are in a rush, the last thing you want is fiddling with locking mechanisms. You want to control the door yourself. Swing it open, then slam it, and shut it asap.
UK train toilets are a classic in the bad design book. You have people who haven't locked the door being exposed to the carriage, you have people unable to close the door and people unable to open the door. And that's if you manage to get to the toilet and it hasn't been ruined by a previous occupant.
Older toilets were far smaller with a normal kayak handle which opened and closed quickly and had a big simple lock.
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.
That's a nice excuse at first sight, but there is no reason not to just use a normal, physical lock, instead of making the lock worse for absolutely everyone and excusing it with "but accessibility!", all because a few people with lots of good intentions but absolutely no clue at all want to pat each other's backs for being oh so considerate.
The increased size is indeed very nice from an accessibility perspective, but it seems to me that practically everyone capable of going to the lavatory on their own is also capable of operating a (well-designed) mechanical lock on their own. And for everyone who needs help to do this it's a non-issue because the person helping them can close and lock the door.
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.
You’re right that a normal toilet can have an appropiate physical handle. Howver normal toilets are easy to push open as they aren’t moving. Opening a large (and thus heavy) swing door, wide enough to allow a chair to get in, manoeuvre, and close, without it smashing back when the train lurches, doesn’t work, meaning a sliding doors which isn’t appropriate.
As such the solution is an electronic sliding door (as many couldn’t provide enough strength over distance to open a sliding door manually), meaning an open/close button
Once you have that feature adding an electric lock makes sense. A physical lock would be trickier to incorporate.
> As a society we choose what level to have it at.
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.
> Modern trains in the UK have disabled toilets with power-operated doors.
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.
A traditional sliding deadbolt[1], which cannot be locked while the door is open since the tongue will prevent the door from closing completely, takes very little force to operate (for those arguing that this overly complex design is "because accessibility"), and can be combined with a switch to prevent the power operated mechanism from attempting to move the door if the lock isn't all the way open (i.e. the switch actuates before the tongue protrudes.)
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.
And how do you deal when someone felt sick inside a toilet? Or when a little child locked himself and can't unlock? Or when someone without a ticket went in?
Always lovely to see a reminder that electromechanical (non-software) systems can also be hacked. This is the sort of stuff "place hackers" use to get into buildings.
Most systems can be hacked with force. You can also "hack" you way into a bank vault if you have 15 million tons of dynamite and an atomic bomb (not sure if there would be anything to come for in the vault at this point, though)
This is a fixable bug though. And no force of any kind was used here. As mentioned other trains use the same lever design, but with the lever being spring-returned, which doesn't exhibit this 'vulnerability'. It could also just be fixed in software by making the lock lever input to the microcontroller edge-triggered instead of level-triggered, so that if someone does actually do this it won't lead to a DoS.
>The problem with this design is that most people don't understand state machines, and this design confused a lot of people who were unable to lock the door correctly, or believed they'd locked the door when they hadn't.
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
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.
My train once stopped in Bremen because only one toilet was working and soccer fans were aboard the train. In Bremen we could all leave the train, go to the toilet there and resume our trip some 20 minutes later.
That was a bizarre experience.
I've ridden almost all of the long-distance Amtrak lines and not seen what you describe. There are "long stops" where there are crew changes and refill and restock, but they are not primarily for passengers to visit the train station (and through-passengers that wish to get some fresh air are explicitly warned not to leave the platform, though this is not generally enforced if someone wants to take their chances).
Oh it's still absolutely a clever hack. It's social engineering rather than a software hack, and it's also fraud, but the official sticker is definitely an example of playing within a system and testing its limits.
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.
What's the Polish train hacking debacle? The thing where the company added software so the train disabled itself if repaired anywhere other than company headquarters? Who are the saboteurs in that case? The manufacturing company itself?
There were actually two Polish train hacking debacles, and I'm not 100% sure which one the GP means.
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]
"Saboteurs" suggests it's the third-party-repair-prevention case. Stopping trains by playing the right tones on analog unencrypted radio (with the tones and frequencies being public knowledge) is hardly hacking anyway.
If playing with a bunch of buttons to see what happens is frowned upon, we have the worst possible denial of service attack on entire humanity by dumbing everyone down. It was not a given that toilet would get disabled and now the problem can be reported to manufacturer and fixed. If someone made it a habit to keep disabling toilets in every train deliberately, different story. Although fixing the flaw is still the most practical solution.
Maybe some even more sinister monster could think of also poisoning the passengers with a laxative while locking the toilet doors. This sounds like a good script for a comic. ;)
I would probably not use the word hacked here, more ruined – Yes, if we use things out of their intended use, block doors, forces switches even though locked, hold switches in intermediate states, it will ruin things.
Maybe this is why toilets never work on trains when I need them. What a shame...
If this were a system controlling a complicated device, perhaps.
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.
I mechanical system probably would not satisfy the requirements of a train toilet in a public train - in particular that it needs to be used by disabled people.
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.
what i intended to say was that the current design of the door probably has its reason in order to support disabled people.
people who remove things from supermarkets without paying are thiefs regardless of they knew they did something illegal. In law it is never an argument that you didn't know the law this is principally your own responsibility.
> This is the second time I've successfully tested this on a Class 800. For some reason this time I seem to have actually confused the toilet door controller enough that it decided "screw this" and went into out of order mode, which didn't happen the previous time.
So, yes, the author _did_, in fact, disable the door.
They didn't intend to, though, and I can see why they wouldn't expect it to actually break. I mean: why should it?
Actually doing the jumping out and leaving the cubicle locked and empty thing would be unethical. Seeing if it would be possible is less of an issue. Accidentally breaking something in the process is a hint not to try it a third time.
He is intentionally putting the toilet door controller into a state where a vacant toilet can no longer be accessed. That toilet is of no use to people needing the toilet ... he broke the toilet.
It reads as if the first time (of two) it was stuck this way. So, for some reason you tried playing around again with the lock?! Come on.
In any case, on behalf of British train users, please stop occupying the toilet needlessly and playing with the door locks. What happens if you or the next person gets locked in there? What happens if someone thinks you're being suspicious and calls the transport police? The services are delayed enough as it is.
Somehow the "Wow, that's amazing, now shut up nerd!" vibes of the bully in me
got raised reading his write-up. In the video he even managed to fail showing how he could DoS the toilet by stepping out after "locking" the toilet from the inside, because he was pushing open the closing door in order to be able to get out, and that disabled the whole system.
At the bottom of the article there's a link to a talk he did if you want to see what kind of a person was doing these "hacks"...
Or maybe he just wanted to show how it worked, but actually not disable the toilet for others.....?
Holy crap, you and the person you're replying to sounds much worse and annoying than what this person did on the train. Get down from your high horses.
Please don't cross into personal attack in HN comments, regardless of how foolish others are or you feel they are. It's not what this site is for, and destroys what it is for.
ha! this reminded me of 1969 when i rode from my english boarding school to my parent's flat in paris, france. my dad was working from the UK embassy, helping to organise the RAF stuff at the paris airshow. i was about 15.
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.
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.