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Gloria funicular derailment initial findings report (EN) [pdf]

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Re: Gloria funicular derailment initial findings report (EN) [pdf]

#11

Post by rcruzeiro »

weinzierl wrote: post #8
ljlolel wrote: post #7

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 backgroun…

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.

Re: Gloria funicular derailment initial findings report (EN) [pdf]

#12

Post by phire »

DetroitThrow wrote: post #6
robocat wrote: post #4

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.

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.

Re: Gloria funicular derailment initial findings report (EN) [pdf]

#13

Post by mastazi »

DetroitThrow wrote: post #6
robocat wrote: post #4

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

Re: Gloria funicular derailment initial findings report (EN) [pdf]

#14

Post by mastazi »

vlfig wrote: post #10
DetroitThrow wrote: post #6

Earlier quoted context omitted.

So, the brakes would have never worked if connecting cables broke? And this specific failure has just never happened before? Jesus.

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"

Re: Gloria funicular derailment initial findings report (EN) [pdf]

#15

Post by mixdup »

vascocosta wrote: post #2

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

Re: Gloria funicular derailment initial findings report (EN) [pdf]

#16

Post by davelondon »

mixdup wrote: post #15
vascocosta wrote: post #2

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...

Re: Gloria funicular derailment initial findings report (EN) [pdf]

#17

Post by sho »

mastazi wrote: post #14
vlfig wrote: post #10

Earlier quoted context omitted.

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 th…

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.

Re: Gloria funicular derailment initial findings report (EN) [pdf]

#18

Post by DetroitThrow »

mastazi wrote: post #13
DetroitThrow wrote: post #6

Earlier quoted context omitted.

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

>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.

Re: Gloria funicular derailment initial findings report (EN) [pdf]

#19

Post by Animats »

mastazi wrote: post #14
vlfig wrote: post #10

Earlier quoted context omitted.

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 th…

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...

Re: Gloria funicular derailment initial findings report (EN) [pdf]

#20

Post by qingcharles »

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.
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