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Post by Deleted on Oct 15, 2010 13:00:40 GMT
I've yet to see an 09 have any door issues myself, and I've been on quite a few now. It's the sort of thing that platform staff are unlikely to see and could most certainly not be seen on the OPO monitors in-cab that caused that fatality. I stand behind my reasoning and am in full support for the sensitive edges on 09s. You aren't supposed to lean on the doors or wedge 'em open. The sensitive edges are supposed to negate the need for staff to see if anyone's clamped in the doors, no?
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Post by Deleted on Oct 15, 2010 13:23:28 GMT
I seem to remember someone getting some clothing caught in the doors on the and unfortunately getting dragged under. It was some to ago though so I may not have all the details correct.
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Post by Deleted on Oct 15, 2010 14:11:52 GMT
I still stand by my opinion that sensitive edges are an unnecessary device that is creating complications simply because not enough care is being used by both the system and its users.
In any case, sensitive edges can fail, and when they do, where is the backup? On the platform, if/when it is crowded enough for someone to get something caught in the doors, there should be platform staff to watch out; also, due to the crowds, someone should be able to alert staff by activating the emergency alarms.
Unfortunately, nobody cares, so the sensitive edges have to be installed.
My tuppence.
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Post by Deleted on Oct 15, 2010 15:27:31 GMT
The sensitive edges are only causing delays because of the way they have to be handled. All it should do is not give a visual, and therefore not allow the train to move.
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Post by Deleted on Oct 15, 2010 15:37:02 GMT
The sensitive edges are only causing delays because of the way they have to be handled. All it should do is not give a visual, and therefore not allow the train to move. I suppose that could be done... No trip, so no reset? Thus once the doors clear all goes? Right, sounds good.
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Post by Deleted on Oct 17, 2010 20:59:47 GMT
The sensitive edges are only causing delays because of the way they have to be handled. All it should do is not give a visual, and therefore not allow the train to move. To give full benefit from a safety perspective, it has to apply the emergency brake. Think of an edge activating leaving the platform (there have been many of these, but the item triggering the edge has been within the car, not outside it), stopping the train ASAP is the best measure.
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Post by Deleted on Oct 19, 2010 13:45:47 GMT
The sensitive edges are only causing delays because of the way they have to be handled. All it should do is not give a visual, and therefore not allow the train to move. To give full benefit from a safety perspective, it has to apply the emergency brake. Think of an edge activating leaving the platform (there have been many of these, but the item triggering the edge has been within the car, not outside it), stopping the train ASAP is the best measure. I'm a little puzzled; could you please explain why the emergency brake is needed when the train is not allowed to move at all in the first place? I think what Charlie means is that if the doors are blocked, the train cannot move in the first place. Unless you mean something getting caught after the doors close and the train moves?
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Post by Deleted on Oct 19, 2010 15:46:08 GMT
Racka, if you lose visual, the train will do exactly that in the first place. It does seem that they require resetting however, but... on any stock that will cause major delays as you can hardly open doors in a tube tunnel safely! But with the sensitive edges the train should not move, somewhat negating this. The only difference is, the edges are sensitive to objects, rather checking if the doors are closed or not.
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Post by Colin on Oct 19, 2010 22:33:31 GMT
I think somewhere along the way the concept of sensitive edges has been misunderstood....
The incident Zoe refers to was a child wearing parker coat whose toggle got trapped between two door leafs. The pilot light lit because the bit of string that was trapped did not prevent the doors closing.
I don't think we need to describe the incident itself any further, but the idea of sensitive edges is to prevent something similar.
The sensitive edge system kicks in after the doors have closed and a pilot is obtained, thus movement is possible. Now should anything be trapped and the train moves, the sensitive edge will pick up on the resistance and apply the emergency brake.
As prjb (who pushed for it's introduction) once said, if it saves one life in the 40 years the stock is planned to operate, it will be worth it. In the mean time this is a new technology to LU so there's bound to be teething issues whilst the best tolerances are found.
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Post by Deleted on Oct 22, 2010 23:43:18 GMT
Racka, if you lose visual, the train will do exactly that in the first place. It does seem that they require resetting however, but... on any stock that will cause major delays as you can hardly open doors in a tube tunnel safely! But with the sensitive edges the train should not move, somewhat negating this. The only difference is, the edges are sensitive to objects, rather checking if the doors are closed or not. Losing visual only stops the train taking traction, it does not stop the train from moving. The reason the brakes need to be applied is that the edges do not detect small stationary objects, such as a bag strap at 1-2mm thick (to be this sensitive would cause spurious trips in a railway environment). It is when a force is applied to the strap that the edge will activate. Think of a person having an item trapped in the door. They may try to free the item as soon as they realise it is stuck, which would put the EB on while train is stationary. The other scenario is that the person runs alongside the train as it departs (item of expensive clothing stuck and don't want to damage it). The train can be moving at a fair speed before the person stumbles or gives up running and applies some force to the item of clothing. In this instance, the train needs to be stopped ASAP, to minimise the chance of dragging the person to their death. And regarding only giving a visual, how many operators would honestly say they had never tried to take traction without having obtained a door close visual?!
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Post by singaporesam on Oct 23, 2010 0:37:46 GMT
I think somewhere along the way the concept of sensitive edges has been misunderstood.... The incident Zoe refers to was a child wearing parker coat whose toggle got trapped between two door leafs. The pilot light lit because the bit of string that was trapped did not prevent the doors closing. I don't think we need to describe the incident itself any further, but the idea of sensitive edges is to prevent something similar. The sensitive edge system kicks in after the doors have closed and a pilot is obtained, thus movement is possible. Now should anything be trapped and the train moves, the sensitive edge will pick up on the resistance and apply the emergency brake. As prjb (who pushed for it's introduction) once said, if it saves one life in the 40 years the stock is planned to operate, it will be worth it. In the mean time this is a new technology to LU so there's bound to be teething issues whilst the best tolerances are found. The 1 in 40 years argument is something that been used since the poison dwarf advocated installation of intercar barriers in response to the Ealing Common incident. How much longer are LUL going to keep using this argument to continue to waste Taxpayers money making the system more expensive and less reliable ? ALARP has its place but is this sensitive edge it ? Whats not being appreciated here is that the functionality that LUL have for this edge is unlike any other sensitive edge in operation on any transit system in the world. In most of these the sensitive edge is cut out just as locking is achieved . CX 100s work like that so do a number of American LRVs, what LUL is doing here by activating only after locking is extremely unproven and has enormous consequences on reliability. The 1 life in 40 years vs the reliable service for millions each day is a perrenial debate where LUL continually insist on the former rather than the latter, if they keep going like this the trains they will eventually get to the point where the trains never run.
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Post by Colin on Oct 23, 2010 3:28:48 GMT
To put it bluntly, seeing as you obviously haven't read my reply #8 above, the child referred to in the incident described died as a result of meeting the platform headwall. If that can be prevented in the future, then it's damm right LU should make use of the technology to do so
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Post by Chris M on Oct 23, 2010 7:14:08 GMT
I agree with Colin's various posts here.
Just because this is new technology doesn't mean it's bad. Every single new technology has to be trialled somewhere, and for a change LU is becoming a leader in a new standard of safety rather than being a follower. Because this technology hasn't been applied in a live environment before it will take some time (and trial and error) to determine what is the correct tolerance to use. When that figure is arrived at on the Victoria Line and the technology understood by the travelling public, it will result in minimal extra delay to the service and will save lives (possibly including yours) and prevent injuries.
The tolerance will then be used as a starting point when the technology is applied to other lines and other systems around the world where only minimal adjustment (if any) will be required.
Each safety system must be assessed on its own merits. Whether the inter-car barriers are value for money and a net positive benefit, etc has no bearing on whether the sensitive edges on the doors are.
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Post by singaporesam on Oct 23, 2010 10:39:37 GMT
To put it bluntly, seeing as you obviously haven't read my reply #8 above, the child referred to in the incident described died as a result of meeting the platform headwall. If that can be prevented in the future, then it's damm right LU should make use of the technology to do so You're missing the point,allegedly these events have an occurance rate of 1x 10 -8 however there have been a number, all of which have caused various piecemeal low cost actions in response by LUL when nearly all could now be prevented by EVF or other newer intrusion detection systems. My point here is if you're going to deal with the PTI issue you should do it properly not persistently keep on using half baked potentially unreliable solutions to each specific type of PTI incident. The intentions of LUL are good, its the execution of those intentions that is wrong.
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Post by Colin on Oct 23, 2010 11:59:30 GMT
EVF? Sorry singaporesam but on this occasion you are talking a load of rubbish. Low cost solutions? Well LU is a publicly owned company spending public money - as you say, these type of incidents are thankfully very rare - of course the solutions ought to be cheap!! Inter-car barriers do a completely different job to sensitive edges on doors. Maybe once you've revealed what EVF stands for we'll all go "aghh" and nod in agreement, but somehow I cannot see the one solution stopping both dragging incidents and people falling in between cars. By your logic LU shouldn't have bothered introducing extra train stops in terminal platforms after Moorgate or slow speed circuits for 3 minutes following tripping after Leytonstone. They may have been one off incidents but it's through those incidents that we learn how to make things safer. To say the risk is worth not bothering with is something I cannot agree with.
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Post by londonstuff on Oct 23, 2010 12:52:22 GMT
By your logic LU shouldn't have bothered introducing extra train stops in terminal platforms after Moorgate or slow speed circuits for 3 minutes following tripping after Leytonstone. They may have been one off incidents but it's through those incidents that we learn how to make things safer. To say the risk is worth not bothering with is something I cannot agree with. What happened at Leytonstone and when? Can't find anything on the internets about it.
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Post by Tom on Oct 23, 2010 13:51:22 GMT
I think Colin means Leyton. Four collisions since 1948, all on curves after passing Signals at Danger under rule.
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Post by Colin on Oct 23, 2010 14:20:14 GMT
Yes, I did Tom!!
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Post by singaporesam on Oct 23, 2010 15:23:08 GMT
Lets be quite frank here. There have been a lot of deaths on LUL at the PTI, but only certain types of death / victims seem to merit a technological solution to prevent further occurrences, Why I do not know. But I do know that LUL have passed up a big opportunity with the Victoria Line upgrade in terms of implementing either PEDs / low barriers or an electronic virtual fence / intrusion detection system along the platform in order to protect against all sorts of incidents. Claiming that lives are saved by half baked incomplete solutions to the issue is a fallacy. Saving 1 in every 40 years and hyping the merits of that solution that while conveniently ignoring the others that would have been saved by a more complete solution is not good Engineering or good management, its scandalous.
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Post by mrfs42 on Oct 23, 2010 15:37:58 GMT
I'm guessing that you mean the rather nebulous concept of 'Platform - Train Interface' rather than Positive Train Identification, here? Please be careful with abbreviations - probably better to quote in full in the first instance and then abbreviate.
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Post by Tom on Oct 23, 2010 16:08:35 GMT
Saving 1 in every 40 years and hyping the merits of that solution that while conveniently ignoring the others that would have been saved by a more complete solution is not good Engineering or good management, its scandalous. Maybe so, but if the risk is already mitigated to ALARP with an incomplete solution where is the justification for spending more money?
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Post by Deleted on Oct 23, 2010 17:16:19 GMT
If it makes the Underground safer I'll happily take a hike in my taxes.
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Post by Tom on Oct 23, 2010 23:33:45 GMT
If it makes the Underground safer I'll happily take a hike in my taxes. You clearly can't be paying taxes then! Applying your logic, you would spend money on all safety improvement works, regardless of priority or actual need. Unfortunately LU doesn't have an unlimited pot of money and priorities have to be made somewhere. There are probably many examples where things could be done to make things safer, however the ALARP principle then applies. The principle is that a risk must be mitigated unless the cost of mitigation is grossly disproportionate to the benefit provided. In the case mentioned, there risk is mitigated to an acceptable level, but not to a situation where there is no risk. To go to an ideal situation where no risk occurs would mean spending considerable sums for limited benefit. In an environment where LU has got to justify every pound they spend (to the extent that basic items of stationery aren't available as a cost-cutting measure), is spending hundreds of thousands of pounds on a project which gives a limited return on the investment really a sensible use of public money?
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Post by singaporesam on Oct 24, 2010 3:54:14 GMT
The question is has the risk really been mitigated to ALARP ? The basis for this argument is that by skimming a little bit off of a remote risk by using an unproven technology that doesn't cost to much, everything that reasonably can be done to reduce the risk has been done and its as low as it reasonably can be. In this case is this really true ? Would the technology have prevented all of the cases of trapped clothing causing deaths? I'm sure the analysis is interesting , but inevitably it will be flawed because the outcome has been prejudged and the numbers made to fit. (this is what everyone does)
ALARP is at the heart of all evils in the UK rail industry
Whereas if GAMAB (globalement au moins aussi bon) is applied then a lot of the spurious experimental no value modifications to ALARP something don't have to be done, but the big issues like pursuing a proper Platform train interface safety measures through proven technologies would probably need to. I hate to say it but the French principle seems better.
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Post by Colin on Oct 24, 2010 4:56:40 GMT
I'm not going to argue the point any further as it'd just end up with us all going round and round in circles failing to agree.
And just cos something works in France, there's no guarantee it would also work in exactly the same way in London. Much like what works in London probably wouldn't work elsewhere.
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Post by Tom on Oct 24, 2010 12:13:00 GMT
The question is has the risk really been mitigated to ALARP ? The basis for this argument is that by skimming a little bit off of a remote risk by using an unproven technology that doesn't cost to much, everything that reasonably can be done to reduce the risk has been done and its as low as it reasonably can be. In this case is this really true ? The cost of inter-car barriers for the existing fleet and including sensitive edges on new trains would in my mind be considerably less expenditure than the provision of Platform Edge Doors across the network, which you seem to be advocating. In my mind, without consulting the figures, I'd say that's ALARP. So says someone who isn't in the UK rail industry any more. It's very easy to criticise from the outside. As Colin says, just because something works in France doesn't mean it will work everywhere. We're working to the UK legal setup, so regardless of what the French principle is, we can't use it.
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Post by Deleted on Oct 24, 2010 22:11:47 GMT
Wondering aside - why Singaporeans like abbreviations so much?
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Post by singaporesam on Oct 24, 2010 23:53:44 GMT
A couple of points 1) I'm not Singaporean.
2) I'm definitely not advocating a systems across the whole of the network. The key point here is that this is the Victoria Line , the only line built entirely post war that benefits from straight platforms with no curves or gaps . It is also one with some of the most dangerous overcrowding on the system that can easilly lead to people being pushed off platforms. It is therefore the easiest one to do a number of improvements on and that is why the unambitious upgrade has in my view been a flop
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Post by Deleted on Oct 25, 2010 0:32:37 GMT
A couple of points I'm not Singaporean. What about your location? Then again, I've been in Singapore and know that expats are not immune to excessive use of abbreviations either
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Post by Ben on Oct 25, 2010 2:23:00 GMT
Just a quick aside on the PEDs, I was under the impression that the added maintence costs, installation costs, and reliability issues/costs/implications made something of a case for them not to be installed to start with?
Perhaps it would have been prudent to fit a couple of 67ts a few years back with the sensitive edge function to test its practicality?
The UK rail industry (and engineering as a whole) suffers from having too many people trying to sap what little money it has out of it; too many chiefs, not enough indians and such. And the legal set up in this country certainly does not help things, nor does the British mentality. However, if a solution can be found thats not quite as well rounded, yet dirt cheap in comparison to a full blown solution, surely its a more practical proposition for a company like TfL.
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