TrainGeekUK
Member
- Joined
- 15 Jun 2019
- Messages
- 109
How much in revenue would this cost roughly to fix this if they had to physically pull it apart to free the pantograph?
-
Our booking engine at tickets.railforums.co.uk (powered by TrainSplit) helps support the running of the forum with every ticket purchase! Find out more and ask any questions/give us feedback in this thread!
Thameslink Core pantograph strike
- Thread starter londonmidland
- Start date
- Status
Sponsor Post - registered members do not see these adverts; click here to register, or click here to log in
R
RailUK Forums
It will carry on as far as the last shoe off the juice. Then can still coast up. It's steep but with a 700 it's pretty manageable, especially if the Driver had a run up.
If so this could be enforced via signals then - the railway equivalent of a stop sign
Not really, because unnecessary reds build in other risks, degrade performance etc. plus, how would the signalling system know whether the pan was in the correct position? Drivers just need to remember to do it, at the end of the day.
A low tech solution the 319s used was a buzzer sounding in the cab when pulling into Farringdon southbound, which then had to be actively silenced by the driver (I’m not sure how it was triggered - presumably some sort of primitive trackside balise - perhaps @Bald Rick could confirm). Perhaps something like that could be considered for the 700s, albeit not exactly “progress”
.
Last edited:
Definitely more risk in an ECS - even if they're meant to stop, there's always more of a risk of a driving being in "automatic" mode as there's not the usual stop - dispatch - start - stop - dispatch - start process to go through.
Purple Train
Established Member
What about a similar system to the "SPAD trap" flashing signals fitted at some junctions where two tracks converge into a single line?
SPAD indicator, I think you mean.
A warning of some kind in the cab is likely to be cheaper than anything external, and potentially more effective - it’s telling that this was the solution arrived at before.
It’s surprising the 700’s own systems aren’t smart enough to warn of the pan being in the wrong position based on location, irrespective of stopping pattern, whether the train is ECS etc.
How does the equivalent scenario on London Overground work? (@baz962 might be able to shed some light)
I'd assume a similar laser system to what is used on train doors to detect objects could work for detecting if a pantograph is still up and then if it is, either the signal stays red(imo this makes more sense because either way if the pantograph gets past the pan down area and gets ripped off the delays will upset any reduced performance either way) or some sort of warning triggered by a track side magnet or balise connected to the laser system will trip off a clearly audible and discernable alarm with some indication warning about the breached pan.Not really, because unnecessary reds build in other risks, degrade performance etc. plus, how would the signalling system know whether the pan was in the correct position? Drivers just need to remember to do it, at the end of the day.
A low tech solution the 319s used was a buzzer sounding in the cab when pulling into Farringdon southbound, which then had to be actively silenced by the driver (I’m not sure how it was triggered - presumably some sort of primitive trackside balise - perhaps @Bald Rick could confirm). Perhaps something like that could be considered for the 700s, albeit not exactly “progress”
That way imo if its actual a mechanical fault where the train seems to have dropped the pans like the 319 incident at Blackfriars in 2014 or a driver has simply forgotten then at least the train is inhibited from moving till its solved.
Last edited:
Purple Train
Established Member
Sorry, I'm the dual horror of a guessing laymanSPAD indicator, I think you mean.
Sorry, I'm the dual horror of a guessing layman
No need to apologise for what, terminology aside, was a thoughtful and relevant suggestion.
For reference SPAD traps mean scenarios likely to lead to SPADs, eg departing a platform on a single yellow.
I'd assume a similar laser system to what is used on train doors to detect objects could work for detecting if a pantograph is still up and then if it is, either the signal stays red(imo this makes more sense because either way if the pantograph gets past the pan down area and gets ripped off the delays will upset any reduced performance either way) or some sort of warning triggered by a track side magnet or balise connected to the laser system will trip off a clearly audible and discernable alarm with some indication warning about the breached pan.
That way imo if its actual a mechanical fault where the train seems to have dropped the pans like the 319 incident at Blackfriars in 2014 or a driver has simply forgotten then at least the train is inhibited from moving till its solved.
Yes, I’d imagine the 319 buzzer involved a magnet of some sort. I know the tube used to have a system of mercury filled tubes that would be broken if trains of sub surface gauge were sent the wrong way.
I suppose what surprises me is that the 700 balises are able to know when the pan needs to be dropped in normal operation, so why wasn’t one provided at the south end of the northbound city Thameslink platform to catch ex Smithfield sidings workings, where this issue has occurred several times), and also that the pans can’t be dropped on the move (which AIUI London overground can do).
And yet, the pantograph smashing into the tunnel at Farringdon was still a regular occurrence.
The dual voltage alarm got cancelled and ignored. Having the same alarm trip, at the same point, on every trip quickly becomes something you cancel and forget.
No magnet, it was just the traction system detecting both voltages - it only buzzed when the pan was up.
IIRC it couldnt be cancelled.
Yes was an 8 car
There was a 'buzzer cancel' button on the desk which could be pressed to silence the buzzer for 30 seconds.
Ah thanks. Odd that I rarely heard that used!
313s down the Northern city line had the best setup to stop units leaving Drayton Park to Moorgate with a pan up. Buzzer in cab would go off as you hit the 3rd rail but would only stop once the pan had lowered. Heading back the otherway you had a button in the cab to silence the buzzer once you put the pan up to head to Finsbury Park. The silence button was only in the north end cab.
Purple Train
Established Member
Thanks
greatkingrat
Established Member
- Joined
- 20 Jan 2011
- Messages
- 2,770
There is no warning system of any sort at North Pole Jn (between Willesden and Shepherds Bush), and pans hitting the A40 bridge is a fairly regular occurence! At Acton Central there is an APC magnet as you enter the station, so you can't take power unless you have switched over.SPAD indicator, I think you mean.
A warning of some kind in the cab is likely to be cheaper than anything external, and potentially more effective - it’s telling that this was the solution arrived at before.
It’s surprising the 700’s own systems aren’t smart enough to warn of the pan being in the wrong position based on location, irrespective of stopping pattern, whether the train is ECS etc.
How does the equivalent scenario on London Overground work? (@baz962 might be able to shed some light)
The Class 710s have an auto-changeover feature, but it is not currently in use.
It's a mix of personal experience, policy, and those pesky non technical skills.
You would hold off for a few seconds then hit the button. Come to a stand and the alarm then sounds just after you arrive. This prevents distraction from the annoying buzzer as you approach your stop.
Or some Drivers would let it sound all the way and then drop the pan to turn the alarm off.
It did get modded a few times and there were even units that wouldn't sound anything. I think there was also a visual representation in the cab too.
Again, it wasn't very effective. Plenty of Drivers would stop suddenly after dispatch and drop the pan.
Going Northbound, we had a policy that you had to check the pan was up before departing. All you would do in reality was watch the wire bounce and that 'confirmed' it was up.
Any system, automated or otherwise, will have it's limitation.
It depends how cheap of a 'solution' you want. In the grand scheme of things. I doubt it meets any cost/benefit for any real technical solution to be implemented.
It didn't even look like a lot of damage so repair costs might not justify any change either.
I know a Driver who's done it and he's still here so it's not career ending. Just very embarrassing.
norbitonflyer
Established Member
As has been said elsewhere, a pantograph going overheight should drop automatically. Why did this not happebn here? Is the distance between the end of the wires and the next overheight structure (the office building) too short for that process to operate?
The auto system may have failed or mechanical failure may have led to it staying up.
Gaelan
Member
Wow - surprised they were that consistent about never reversing trains.
whoosh
Established Member
- Joined
- 3 Sep 2008
- Messages
- 1,377
Not really, because unnecessary reds build in other risks, degrade performance etc. plus, how would the signalling system know whether the pan was in the correct position? Drivers just need to remember to do it, at the end of the day.
A low tech solution the 319s used was a buzzer sounding in the cab when pulling into Farringdon southbound, which then had to be actively silenced by the driver (I’m not sure how it was triggered - presumably some sort of primitive trackside balise - perhaps @Bald Rick could confirm). Perhaps something like that could be considered for the 700s, albeit not exactly “progress”
It was detection of 3rd rail and overheads that would activate the buzzer. However the third rail section is now extended between Farringdon and City Thameslink in both directions. There would be a lot of buzzing happening which would be annoying and be part of normal routine - it would be crying wolf a lot.
SPAD indicator, I think you mean.
A warning of some kind in the cab is likely to be cheaper than anything external, and potentially more effective - it’s telling that this was the solution arrived at before.
It’s surprising the 700’s own systems aren’t smart enough to warn of the pan being in the wrong position based on location, irrespective of stopping pattern, whether the train is ECS etc.
How does the equivalent scenario on London Overground work? (@baz962 might be able to shed some light)
On a normal service, when the train stops southbound at Farringdon within the Stopping window (where there is a balise which gives a green icon on the cab display), the pan will lower automatically. This happens in ATO, manually driven ETCS, and manually driven on conventional lineside signals.
If the Stopping window is overshot, or the ballise not detected (an orange icon on the cab display), the doors cannot be opened normally and have to be overridden to be released. This is called 'FASDO (Fully Automatic Selective Door Opening) override'.
When the doors are released in this manner, the unit will think, "Oh I know where I am now, I must be at Farringdon, because the last stop was St Pancras, I've travelled this much distance and now FASDO override has been operated by the driver. I shall drop the pans then." And then the pans lower automatically.
If the stopping window is missed by stopping outside of it (orange icon), and the doors not opened (like on an ECS train), or if the train doesn't stop at all(!!) the automatic voltage changeover will not happen.
If the train doesn't stop at Farringdon but does stop at City Thameslink (within the stopping window [green icon], or outside the stopping window [orange icon] and FASDO carried out), then the train will do the voltage changeover there. So there's a "second chance" if you like.
That all applies northbound as well, although there aren't the same repercussions of getting it wrong in that direction.
Trains on the GN never got turned anywhere. Thameslink though, with the Sutton loop....
Peter Mugridge
Veteran Member
I think we can all agree on two things in this thread:
1) It is unacceptable that this is still happening.
2) Something must be done to prevent it from happening again.
2a) That "something" has to remove any human input and must also be failsafe.
1) It is unacceptable that this is still happening.
2) Something must be done to prevent it from happening again.
2a) That "something" has to remove any human input and must also be failsafe.
Deepgreen
Established Member
How many extra reds would be involved (and surely they would only show in the event of a trangression) - one or two, and could they be, say, white like a SPAD signal? I think human error has proved itself enough times here to be excluded as a fail safe element. Earlier I suggested an alarm in the train cab when, say, a movement sensor is triggered. Even if it was a pigeon it would just take a moment for the driver to check the panto was in the correct position, so the odd false alarm wouldn't be an issue. BTW, does the reverse apply - if leaving the third rail, are the shoes retracted at all or has the northern end been cleared for lowered shoes?Not really, because unnecessary reds build in other risks, degrade performance etc. plus, how would the signalling system know whether the pan was in the correct position? Drivers just need to remember to do it, at the end of the day.
A low tech solution the 319s used was a buzzer sounding in the cab when pulling into Farringdon southbound, which then had to be actively silenced by the driver (I’m not sure how it was triggered - presumably some sort of primitive trackside balise - perhaps @Bald Rick could confirm). Perhaps something like that could be considered for the 700s, albeit not exactly “progress”
700s don't have the ability to retract the shoes. Only 717s can do this.
It's already acceptable. The risk is minimal and incidents are rare.
ALARP has been applied and the risk accepted. How much should be spent to either reduce the risk further or eliminate altogether ?
Are you talking about a fully automated train with no Driver input ?
As already stated. The 'automatic process'. Still needs to be triggered by stopping in the correct place and having the unit setup correctly.
Is there any system that will automatically force a pan down purely by the passing of the train ? Is there any onboard system that can do the same ?
bahnause
Member
ETCS could. It could do a system change as well. Obviously only if the train is driven with ETCS. Might need Baseline 3 however.
GWR 80x uses zero balises to trigger the pan to lower in the event the driver forgets to do so (and the balise actually triggers the change to diesel, even though the driver's supposed to do it manually). The balises are Eurobalises and it's the onboard ETCS system doing the work, even though the trains technically aren't running in ETCS, they're running in BR-ATP or TPWS (actual TPWS, not Level NTC).
That sounds as unnecessarily complex as the APCo on 80x: if the changeover location is at a station, it's triggered by the driver releasing the doors. But if the train gets a not-to-call order, it doesn't do the changeover. It's that complexity that meant GWR have stuck with manual changeover, with zero balise protection to mitigate the effects of driver error.
- Status