> the air brake and the manual brake were quickly applied by the brakeman of cab #1, but that in the current configuration, the brakes do not have sufficient capacity to stop the cabins in motion without their empty masses being mutually balanced by the connecting cable. Therefore, the existing brakes does not constitute a redundant system in case of a failure in the connecting cable.
No that's not what it's saying. I've read the whole report. The hydraulic brakes are designed to be applied automatically and stop the car in case of cable failure. By mentioning "current configuration" the report is implying that the brakes were not applied fully, and the reason for this is still being investigated
> The evidence confirms that the
emergency system installed in the
flywheel located at the top of Calçada da
Glória, tripping the power switch to the cabins in the event of a loss of cable tension, worked as intended,
which would result in the immediate and automatic application of the pneumatic brake in each cabin.
> At this time, it has not yet been possible to conduct verification checks to confirm whether the system for automatically applying the pneumatic brake to the cabins
following a loss of cable tension in the trambolho
worked.
The cable breaking (or in this case, going loose at its attachment point) should be the detected at the flywheel area at the top, and result in power being cut to both cabins — this happened. This should result in pneumatic brakes being applied at the maximum force — it's unknown whether this worked.
> However, regardless of this, the evidence indicates that the air brake and the manual brake were quickly applied
by the brakeman of cab #1, but that in the current configuration, the brakes do not have sufficient capacity to
stop the cabins in motion without their empty masses being mutually balanced by the connecting cable. Therefore, the existing brakes does not constitute a redundant system in case of a failure in the connecting cable.
Irrespective of the automatic system, the brakeman immediately applied the air brake and manual brake. Then: in this configuration the brakes are not sufficient and are not a redundant system.
One possible interpretation is that the brakes when manually applied are insufficient to stop the vehicle when the counterweight provided by the cable is absent.
Another is that the manual brake is insufficient, but the pneumatic/air (assuming those are the same) brake should be at maximum force, but for some reason, it wasn't applied at maximum force by either the brakeman or the automatic system.
> One possible interpretation is that the brakes when manually applied are insufficient to stop the vehicle when the counterweight provided by the cable is absent.
> Another is that the manual brake is insufficient, but the pneumatic/air (assuming those are the same) brake should be at maximum force, but for some reason, it wasn't applied at maximum force by either the brakeman or the automatic system.
Agree and I would add a third possibility:
The delay between detection and automatic full brake application, or by the cabin driver was long enough to allow enough speed/inertia to build, beyond the threshold until which the brakes would actually make it stop.
>By mentioning "current configuration" the report is implying that the brakes were not applied fully, and the reason for this is still being investigated
Thank you for clarifying since the brakes never being able to stop a high up car is an alarming design. It does make me imagine the reason for this failure will be some horrificly implemented operational process.
The report only states the conclusion that the breaks did not work for the current configuration.
Which is a slightly awkwardly worded way of saying, “well obviously they didn’t work because we know they were applied and look at the result“
This is only an initial report. They still have no idea why the breaks didn’t work, and for how long they haven’t been working. Could have been a recent malfunction, something that happened during redesign, or a an inherent flaw going back to the original design.
Although it isn't yet clear how much the brakes did actually brake, it is known they would never be enough.
So the cable was a critical component and initial findings suggest it wasn't being verified as rigourously, thoroughly and often as it perhaps should have.
No that's not what it says. Brakes were not enough "in the current configuration" in other words they were not applied fully. The investigation will focus on why brakes were not applying full breaking force.
In railway jargon "brake configuration" refers to "how much are you braking" but you seem to have interpreted "braking configuration" as "the number and type of brakes that are currently installed in the vehicle"
The evidence indicates that the air brake and the manual brake were quickly applied
by the brakeman of cab #1, but that in the current configuration, the brakes do not have sufficient capacity to stop the cabins in motion without their empty masses being mutually balanced by the connecting cable. There-
fore, the existing brakes does not constitute a redundant system in case of a failure in the connecting cable.
So the braking system is insufficient to stop after a broken cable.
There's more than a wheel brake system. There's a mechanism to clamp against the track slot from both top and bottom. See Fig. 2, right. Apparently it wasn't enough.
Funiculars are a problem because they're too steep for railroad wheel brakes, too heavy for elevator braking systems, and rare enough that there are not good standards for them. Angels Flight in LA has had two major accidents, one in 2001 and one in 2013.[1][2] Different causes. The 2001 accident was due to bad design - only one cable, no track brakes, and a system where each car had its own winding drum. The spline connecting the drums failed. The 2013 accident, after a total redesign and replacement of the hauling system, was due to bad maintenance.
So bad that it involved a stick being used to hold down an override switch.
Elevator rail brakes are often jam brakes - once they're triggered, a wedge is jammed between brake and rail such that motion forces it into tighter contact. Stops with jam brakes are rather drastic. San Francisco cable cars have a jam brake for emergencies. That's the red lever, which drives a wedge into the slot. When used, there are usually passenger injuries and the wedge will be welded to the track by frictional heating.[3] So that's for serious emergencies only.
It's my understanding that this particular funicular system uses eight shoe brakes, where rubber pads basically clamp a metal track (from above and below) causing friction.
Hearing some local experts, they often mention that this is physically not enough to stop a 14 ton vehicle (plus passengers) going downhill when the slope is as high as 18%. So basically even if in perfectly working condition, the bake pads or wheels would just slide down the tracks as there's not enough friction for the resulting force.
Maybe something like a rack and pinion railway or some other kind of drastic metal locking mechanism are the only realistic way to prevent catastrophic events when the cable breaks/detaches, considering the masses and slopes involved here?
While I personally lean towards your interpretation, the language is ambiguous - perhaps intentionally so - and it is premature to read too much into it in either direction. We’ll just have to wait.
> In railway jargon "brake configuration" refers to "how much are you braking"
I've never heard that terminology in a European rail context, you'll need to provide a citation.
In EU regs, "braking configuration" literally means the mechanical configuration of braking; how much braking force the inertial, hydraulic or pneumatic braking circuits can apply in total.
> In railway jargon "brake configuration" refers to "how much are you braking"
I presume the quote in English is translated from the original Portuguese. I would hope it was carefully translated but I wouldn't personally bet on that.
No entanto, e independentemente disso, as evidências indicam que o freio pneumático e também o freio manual foram rapidamente aplicados pelo guarda-freio da cabina n.® 1, mas que na configuração existente os freios não têm a capacidade suficiente para imobilizar as cabinas em movimento sem estas terem as suas massas em vazio mutuamente equilibradas através do cabo de ligação. Desta forma, não constitui um sistema redundante à falha dessa ligação.
A very unfortunate fatal accident for those involved. It is a sad outcome caused in part by the failsafe mechanisms not being designed situations where the cable broke the way it did. I hope these can be re-engineered to overcome such failures.
I only recently learned what a funicular was thanks to the diagnonal elevators in video games series of YouTube videos by sync-on-luna:
This is not a preliminary report yet, but presents interesting technical data, including a description of how the system works and a detailed timeline of what happened pointing towards the detachment of the balancing cable at the anchoring socket of the cabin that crashed.
Yes, as a Portuguese with some patriotic feelings (but also self critical when needed), I was impressed myself with the quality of this report given the time frame.
Totally unrelated but there’s a Portuguese language Cold War miniseries on Netflix called Gloria that is excellent (set in Gloria city). I just happened to start to watch that this week
Watched it front to back in Portuguese a while ago. It is one of the few series available in European Portuguese, most are Brazilian.
I'd say it was time well spent, it is an entertaining and capturing thriller and you learn a bit about a certain era of Portuguese history.
What annoyed me a bit was that it had many small period inconsistencies. Little things like modern buildings, modern cars visible in the background, the Yamaha grand that did not yet exist in 60s and so on. Where it shines are the landscape shots.
RTP (public TV network, which also produced Gloria and Turn of the Tide, the two Portuguese Netflix shows) is unfortunately the only network investing in this type of fiction television. The other two big networks unfortunately only seem to invest in soap operas, which run for 600+ episodes and are very formulaic. It’s sad because RTP has definitely made some very good stuff (and they’ve been collaborating with Spanish networks on some cross-border shows, there’s a few they’re pretty good), but you can tell that these things suffer from relatively low budgets.
That’s why turn of the tide came as quite a shock in quality compared to the rest of the shows - Netflix actually put a relatively high budget into the show, which just allows them to dedicate so much more time to these little things.
When watching it, the thing that would consistently real the period piece illusion for me were the modern cranes that you could often see in the Lisbon scenes.
Tough to avoid for a budget limited run tv series. Fixing that would be expensive detail special fx for no value (maybe easy to clean up now with ai for a few hundred dollars)
Summary: the wrecked cabin had started its descent from the top station, only got a few seconds down before the steel cable pulled out of its socket; the cabin went into freefall down the tracks; the staff activated all the brakes available, but they were clearly not designed for this situation and could not provide enough stopping force before it derailed and hit a wall and a lamp-post at approx 60km/h.
If it was a modern bus hitting a building at that speed, most occupants would be able to walk out. Really puts into perspective how much safety improved in the past 100 years.
One of the issues is that the body consists of a wooden frame, surrounded by a thin sheet of steel to avoid extra weight. So it's not very strong, plus the bulk of the 14 ton mass lies on the bottom where the bogies are. When it derailed and tipped over, the strong structure underneath the cabin sort of crushed the lightweight structure where the passengers were.
Have to read it with time, however as Portuguese I imagine the service done during the same day of the tragedy was as always in our culture, "good enough" and to move on.
Likewise having all offers turned down for service, in some other cultures, they would rather shut down the funicular than keep it running without such contracts in place.
> Have to read it with time, however as Portuguese I imagine the service done during the same day of the tragedy was as always in our culture, "good enough" and to move on.
Coming from the same country as you, I totally understand. However, in this particular case the maintenance seems to have been done as it was supposed to be.
The problem seems to be that the cable broke at the anchoring point underneath the cabin, already underground. This is hidden from view during a normal daily inspection, where someone goes underground and checks the whole cable during a round trip of the cabin. They check the free cable going through pulleys and a flywheel, but they can't see inside the attachment point where the cable meets the cabin. This is only done in more thorough inspections, which do not happen daily.
Now, why it broke exactly at that point is probably related to how it was installed and not so much poor quality of the cable itself. Although some manufacturing issue could also be related.
We will have to wait and see, but like you said, several innocent people are dead. Hopefully in this case it wasn't down to our culture of "it's good enough, let's move on", which indeed, unfortunately, is part of our history. The least we can do now is find the real causes and make it safer in the future.
Most people here have exactly the same view you expressed. My initial reaction was the same as well. Then, on top of it all there's the political noise where each party is now trying to take some advantage out of the situation, which isn't pretty. Besides, we both know well how things usually happen here, so it's only human to think there was some kind of gross mistake. I want to believe it wasn't the case this time, but who knows... We will have to wait and see.
Key lines:
> the air brake and the manual brake were quickly applied by the brakeman of cab #1, but that in the current configuration, the brakes do not have sufficient capacity to stop the cabins in motion without their empty masses being mutually balanced by the connecting cable. Therefore, the existing brakes does not constitute a redundant system in case of a failure in the connecting cable.
So, the brakes would have never worked if connecting cables broke? And this specific failure has just never happened before? Jesus.
No that's not what it's saying. I've read the whole report. The hydraulic brakes are designed to be applied automatically and stop the car in case of cable failure. By mentioning "current configuration" the report is implying that the brakes were not applied fully, and the reason for this is still being investigated
> The evidence confirms that the emergency system installed in the flywheel located at the top of Calçada da Glória, tripping the power switch to the cabins in the event of a loss of cable tension, worked as intended, which would result in the immediate and automatic application of the pneumatic brake in each cabin.
> At this time, it has not yet been possible to conduct verification checks to confirm whether the system for automatically applying the pneumatic brake to the cabins following a loss of cable tension in the trambolho worked.
The cable breaking (or in this case, going loose at its attachment point) should be the detected at the flywheel area at the top, and result in power being cut to both cabins — this happened. This should result in pneumatic brakes being applied at the maximum force — it's unknown whether this worked.
> However, regardless of this, the evidence indicates that the air brake and the manual brake were quickly applied by the brakeman of cab #1, but that in the current configuration, the brakes do not have sufficient capacity to stop the cabins in motion without their empty masses being mutually balanced by the connecting cable. Therefore, the existing brakes does not constitute a redundant system in case of a failure in the connecting cable.
Irrespective of the automatic system, the brakeman immediately applied the air brake and manual brake. Then: in this configuration the brakes are not sufficient and are not a redundant system.
One possible interpretation is that the brakes when manually applied are insufficient to stop the vehicle when the counterweight provided by the cable is absent.
Another is that the manual brake is insufficient, but the pneumatic/air (assuming those are the same) brake should be at maximum force, but for some reason, it wasn't applied at maximum force by either the brakeman or the automatic system.
> One possible interpretation is that the brakes when manually applied are insufficient to stop the vehicle when the counterweight provided by the cable is absent.
> Another is that the manual brake is insufficient, but the pneumatic/air (assuming those are the same) brake should be at maximum force, but for some reason, it wasn't applied at maximum force by either the brakeman or the automatic system.
Agree and I would add a third possibility:
The delay between detection and automatic full brake application, or by the cabin driver was long enough to allow enough speed/inertia to build, beyond the threshold until which the brakes would actually make it stop.
I disagree. The last sentence kinda strongly implies that there was no redundancy:
"the existing brakes does not constitute a redundant system"
Or from the Portuguese report:
Google translate: Of course it could just be saying that the brakes were critical (not redundant?). Summary reports often have spin rather than facts.It turns out that the brakes were critical and they didn't work for whatever reason (design or maintenance or operation or unforseen failure)
>By mentioning "current configuration" the report is implying that the brakes were not applied fully, and the reason for this is still being investigated
Thank you for clarifying since the brakes never being able to stop a high up car is an alarming design. It does make me imagine the reason for this failure will be some horrificly implemented operational process.
The report only states the conclusion that the breaks did not work for the current configuration.
Which is a slightly awkwardly worded way of saying, “well obviously they didn’t work because we know they were applied and look at the result“
This is only an initial report. They still have no idea why the breaks didn’t work, and for how long they haven’t been working. Could have been a recent malfunction, something that happened during redesign, or a an inherent flaw going back to the original design.
Although it isn't yet clear how much the brakes did actually brake, it is known they would never be enough.
So the cable was a critical component and initial findings suggest it wasn't being verified as rigourously, thoroughly and often as it perhaps should have.
> it is known they would never be enough.
No that's not what it says. Brakes were not enough "in the current configuration" in other words they were not applied fully. The investigation will focus on why brakes were not applying full breaking force.
In railway jargon "brake configuration" refers to "how much are you braking" but you seem to have interpreted "braking configuration" as "the number and type of brakes that are currently installed in the vehicle"
The evidence indicates that the air brake and the manual brake were quickly applied by the brakeman of cab #1, but that in the current configuration, the brakes do not have sufficient capacity to stop the cabins in motion without their empty masses being mutually balanced by the connecting cable. There- fore, the existing brakes does not constitute a redundant system in case of a failure in the connecting cable.
So the braking system is insufficient to stop after a broken cable.
There's more than a wheel brake system. There's a mechanism to clamp against the track slot from both top and bottom. See Fig. 2, right. Apparently it wasn't enough.
Funiculars are a problem because they're too steep for railroad wheel brakes, too heavy for elevator braking systems, and rare enough that there are not good standards for them. Angels Flight in LA has had two major accidents, one in 2001 and one in 2013.[1][2] Different causes. The 2001 accident was due to bad design - only one cable, no track brakes, and a system where each car had its own winding drum. The spline connecting the drums failed. The 2013 accident, after a total redesign and replacement of the hauling system, was due to bad maintenance. So bad that it involved a stick being used to hold down an override switch.
Elevator rail brakes are often jam brakes - once they're triggered, a wedge is jammed between brake and rail such that motion forces it into tighter contact. Stops with jam brakes are rather drastic. San Francisco cable cars have a jam brake for emergencies. That's the red lever, which drives a wedge into the slot. When used, there are usually passenger injuries and the wedge will be welded to the track by frictional heating.[3] So that's for serious emergencies only.
[1] https://www.ntsb.gov/investigations/AccidentReports/Reports/...
[2] https://www.ntsb.gov/investigations/AccidentReports/Reports/...
[3] https://www.cbsnews.com/sanfrancisco/news/cable-car-6-riders...
It's my understanding that this particular funicular system uses eight shoe brakes, where rubber pads basically clamp a metal track (from above and below) causing friction.
Hearing some local experts, they often mention that this is physically not enough to stop a 14 ton vehicle (plus passengers) going downhill when the slope is as high as 18%. So basically even if in perfectly working condition, the bake pads or wheels would just slide down the tracks as there's not enough friction for the resulting force.
Maybe something like a rack and pinion railway or some other kind of drastic metal locking mechanism are the only realistic way to prevent catastrophic events when the cable breaks/detaches, considering the masses and slopes involved here?
rack and pinion will just strip the teeth and/or disengage.
one needs just more pad area and more clamp force
While I personally lean towards your interpretation, the language is ambiguous - perhaps intentionally so - and it is premature to read too much into it in either direction. We’ll just have to wait.
> In railway jargon "brake configuration" refers to "how much are you braking"
I've never heard that terminology in a European rail context, you'll need to provide a citation.
In EU regs, "braking configuration" literally means the mechanical configuration of braking; how much braking force the inertial, hydraulic or pneumatic braking circuits can apply in total.
> In railway jargon "brake configuration" refers to "how much are you braking"
I presume the quote in English is translated from the original Portuguese. I would hope it was carefully translated but I wouldn't personally bet on that.
A Portuguese source document might be clearer.
[edit]
Document in Portuguese: https://www.gpiaaf.gov.pt/upload/processos/d054238.pdf
A very unfortunate fatal accident for those involved. It is a sad outcome caused in part by the failsafe mechanisms not being designed situations where the cable broke the way it did. I hope these can be re-engineered to overcome such failures.
I only recently learned what a funicular was thanks to the diagnonal elevators in video games series of YouTube videos by sync-on-luna:
https://www.youtube.com/watch?v=M2oELc61XHE
https://www.youtube.com/watch?v=Y5EHBoU6Ps4
Hopefully that's what this investigation will lead to. Nice videos.
This is not a preliminary report yet, but presents interesting technical data, including a description of how the system works and a detailed timeline of what happened pointing towards the detachment of the balancing cable at the anchoring socket of the cabin that crashed.
It's also incredibly detailed for a report on an event that happened 3 days ago
Just what I was thinking! Normally these things take months...
Yes, as a Portuguese with some patriotic feelings (but also self critical when needed), I was impressed myself with the quality of this report given the time frame.
Totally unrelated but there’s a Portuguese language Cold War miniseries on Netflix called Gloria that is excellent (set in Gloria city). I just happened to start to watch that this week
Watched it front to back in Portuguese a while ago. It is one of the few series available in European Portuguese, most are Brazilian.
I'd say it was time well spent, it is an entertaining and capturing thriller and you learn a bit about a certain era of Portuguese history.
What annoyed me a bit was that it had many small period inconsistencies. Little things like modern buildings, modern cars visible in the background, the Yamaha grand that did not yet exist in 60s and so on. Where it shines are the landscape shots.
RTP (public TV network, which also produced Gloria and Turn of the Tide, the two Portuguese Netflix shows) is unfortunately the only network investing in this type of fiction television. The other two big networks unfortunately only seem to invest in soap operas, which run for 600+ episodes and are very formulaic. It’s sad because RTP has definitely made some very good stuff (and they’ve been collaborating with Spanish networks on some cross-border shows, there’s a few they’re pretty good), but you can tell that these things suffer from relatively low budgets.
That’s why turn of the tide came as quite a shock in quality compared to the rest of the shows - Netflix actually put a relatively high budget into the show, which just allows them to dedicate so much more time to these little things.
When watching it, the thing that would consistently real the period piece illusion for me were the modern cranes that you could often see in the Lisbon scenes.
Tough to avoid for a budget limited run tv series. Fixing that would be expensive detail special fx for no value (maybe easy to clean up now with ai for a few hundred dollars)
Another great one, based on the same direction approach as Casa de Papel, is Rabo de Peixe.
If you prefer to read it in Portuguese, the link seems to be https://www.gpiaaf.gov.pt/upload/processos/d054238.pdf (source: https://www.gpiaaf.gov.pt/detalhe-noticias?uri=1665 which has both links)
Summary: the wrecked cabin had started its descent from the top station, only got a few seconds down before the steel cable pulled out of its socket; the cabin went into freefall down the tracks; the staff activated all the brakes available, but they were clearly not designed for this situation and could not provide enough stopping force before it derailed and hit a wall and a lamp-post at approx 60km/h.
Wow, only 60km/h.
If it was a modern bus hitting a building at that speed, most occupants would be able to walk out. Really puts into perspective how much safety improved in the past 100 years.
One of the issues is that the body consists of a wooden frame, surrounded by a thin sheet of steel to avoid extra weight. So it's not very strong, plus the bulk of the 14 ton mass lies on the bottom where the bogies are. When it derailed and tipped over, the strong structure underneath the cabin sort of crushed the lightweight structure where the passengers were.
Passenger cars from 40 years ago would struggle to protect you at those speeds.
I find it suprising that the designed life length of the cable is less than 2 years. Is that common also for more modern cable transports?
Have to read it with time, however as Portuguese I imagine the service done during the same day of the tragedy was as always in our culture, "good enough" and to move on.
Likewise having all offers turned down for service, in some other cultures, they would rather shut down the funicular than keep it running without such contracts in place.
Now several people are dead.
As usual, "casa roubada, trancas às portas"
> Have to read it with time, however as Portuguese I imagine the service done during the same day of the tragedy was as always in our culture, "good enough" and to move on.
Coming from the same country as you, I totally understand. However, in this particular case the maintenance seems to have been done as it was supposed to be.
The problem seems to be that the cable broke at the anchoring point underneath the cabin, already underground. This is hidden from view during a normal daily inspection, where someone goes underground and checks the whole cable during a round trip of the cabin. They check the free cable going through pulleys and a flywheel, but they can't see inside the attachment point where the cable meets the cabin. This is only done in more thorough inspections, which do not happen daily.
Now, why it broke exactly at that point is probably related to how it was installed and not so much poor quality of the cable itself. Although some manufacturing issue could also be related.
We will have to wait and see, but like you said, several innocent people are dead. Hopefully in this case it wasn't down to our culture of "it's good enough, let's move on", which indeed, unfortunately, is part of our history. The least we can do now is find the real causes and make it safer in the future.
Thanks for the overview, living abroad I don't follow all details, as close as I would being there.
You're welcome. :)
Most people here have exactly the same view you expressed. My initial reaction was the same as well. Then, on top of it all there's the political noise where each party is now trying to take some advantage out of the situation, which isn't pretty. Besides, we both know well how things usually happen here, so it's only human to think there was some kind of gross mistake. I want to believe it wasn't the case this time, but who knows... We will have to wait and see.