What causes overhead line problems?

[danielcanning]

Everyday there are disruptions to services due to ‘overhead line problems’ why is this? Is our infrastructure so poor that a slight gust of wind can blow down miles of wiring? What is going on here?

 

[thedbdiboy]

It's not the same on every route. The ECML (East Coast Main Line) has the highest number of problems presumably due to some factor of design and/or location of its overhead wires; if you discounted the ECML the number of incidents would be considerably lower.

 

[skyhigh]

Everyday there are disruptions to services due to ‘overhead line problems’

Every day?

 

[bramling]

It's not the same on every route. The ECML (East Coast Main Line) has the highest number of problems presumably due to some factor of design and/or location of its overhead wires; if you discounted the ECML the number of incidents would be considerably lower.

As it happens, the London end of the ECML seems to have gone down just now.

 

[Brooke]

As it happens, the London end of the ECML seems to have gone down just now.

And the WCML today, my wife’s train was a mere 101 minutes late arriving in Manchester today for her meeting, which her clients were obviously delighted about!

 

[LNW-GW Joint]

While there are weather-related issues (mainly high winds and associated flying debris), most of the problems seem to be wear and tear related.
Neutral sections seem particularly prone to dewirements.
Dewirements may be also due to faulty rolling stock rather than faulty OHLE - it's not always the infrastructure at fault.
Increased high-speed traffic also plays a part, some lines are carrying up to double the number of electric trains that BR operated, and at higher speeds.
The WCML is also a much faster railway than it was under BR (125mph v 110mph).
The GWML supposedly has more resilient OHLE - this week's major dewirement was in the older 1990s wiring.
The MML will be another line with a mix of older BR wiring south of Bedford, and new designs north of there.

 

[BrianW]

While there are weather-related issues (mainly high winds and associated flying debris), most of the problems seem to be wear and tear related.
Neutral sections seem particularly prone to dewirements.
Dewirements may be also due to faulty rolling stock rather than faulty OHLE - it's not always the infrastructure at fault.
Increased high-speed traffic also plays a part, some lines are carrying up to double the number of electric trains that BR operated, and at higher speeds.
The WCML is also a much faster railway than it was under BR (125mph v 110mph).
The GWML supposedly has more resilient OHLE - this week's major dewirement was in the older 1990s wiring.
The MML will be another line with a mix of older BR wiring south of Bedford, and new designs north of there.

Surely (!) there must be failure analysis done that feeds into programmes of maintenance/renewal and improved design for the future.
Delays and disruption are a pain of course, but not totally avoidable, esp at reasonable cost.

I recall the days of early diesel 'failures' and recovery by steam locos. Lovely to see but not to endure!
I imagine overhead electrification is still 'worth it'- if not then what?

 

[800001]

As it happens, the London end of the ECML seems to have gone down just now.

Which is believed to be caused by an object from an over bridge coming in to contact with the OHL and parting the catenary wires on the Down Slow.
Lines reopening again in 10 min.

 

[zwk500]

Surely (!) there must be failure analysis done that feeds into programmes of maintenance/renewal and improved design for the future.
Delays and disruption are a pain of course, but not totally avoidable, esp at reasonable cost.

There is, hence new designs being more robust (compare GWML East/West of Airport Junction) and programmes like the Headspan-to-Boom replacement on the ECML.

 

[GRALISTAIR]

Everyday there are disruptions to services due to ‘overhead line problems’ why is this? Is our infrastructure so poor that a slight gust of wind can blow down miles of wiring? What is going on here?

Every day?

Hyperbole much?

 

[zwk500]

Hyperbole much?

Anybody have the stats to settle the point? @Bald Rick?

 

[Bald Rick]

Anybody have the stats to settle the point? @Bald Rick?

This week is not a good one to try and win that argument, even if the facts support it.

however todays fun and games at Stevenage are, at least, not caused by an OLE fault (nor a train fault).

 

[zwk500]

This week is not a good one to try and win that argument, even if the facts support it.

however todays fun and games at Stevenage are, at least, not caused by an OLE fault (nor a train fault).

How very diplomatic of you!

 

[Bald Rick]

How very diplomatic of you!

Well yesterday was not a good one for the Western; it took the shine off an otherwise great few days for the railway and some exceptionally hard work by many, many people behind the scenes.

 

[Western Sunset]

Is there any research being undertaken to find more resilient ways to power 25kV ac electric trains, rather than picking up the electricity via a bit of metalwork attached to the vehicle's roof, which physically rubs against a piece of wire strung over the track?

 

[Nicholas Lewis]

Well yesterday was not a good one for the Western; it took the shine off an otherwise great few days for the railway and some exceptionally hard work by many, many people behind the scenes.

Indeed and despite the current poor industrial relations it does show that deep down the railway family DNA is alive and fully functioning which makes it such a shame that management and DfT don't realise how much goodwill is worth keeping cultivated to deliver for passengers when the chips are down and ultimately ensuring the revenue continues to flow.

Back on topic well sought of you rarely here about displaced conductor rails causing delays!!

 

[Bald Rick]

which makes it such a shame that management and DfT don't realise how much goodwill is worth

they do, very well

Back on topic well sought of you rarely here about displaced conductor rails causing delays!!

it is an oddity that all the problems with the DC rarely get reported, even the very disruptive incidents like we had the a week or so ago.

 

[stuu]

it is an oddity that all the problems with the DC rarely get reported, even the very disruptive incidents like we had the a week or so ago.

What do they get reported as?

"Overhead line problems" is clearly not unusual, been caught out by that before (including at Exeter St Davids)... but even when I lived in South London, I don't remember a specific delay reason relating to the third rail

 

[Nicholas Lewis]

What do they get reported as?

"Overhead line problems" is clearly not unusual, been caught out by that before (including at Exeter St Davids)... but even when I lived in South London, I don't remember a specific delay reason relating to the third rail

Conductor Rail is pretty robust and the shoegear is designed to part company with the shoebeam if too much force is imposed on it but that can you leave you with a stranded train if you wipe off all the shoegear down the side of the train that con rail is predominantly located over a section of route. The other beauty of con rail is if it is displaced its generally a matter of replacing damaged pots and getting plenty of muscle out there with bars and just dropping it back into the pots so doesn't have all the challenges of registration that OLE does so rectification much quicker. Of course that counts for nothing in todays elf & safety world.

 

[dosxuk]

Back on topic well sought of you rarely here about displaced conductor rails causing delays!!

But you do get demands for replacement with OLE after a couple of days of heavy rain or snow disrupting services.

 

[Bald Rick]

I don't remember a specific delay reason relating to the third rail

Normally it is reported as ‘a problem with the power supply’ (where the con rail or distribution is directly at fault), or a signal failure (where the bonding has blown a track circuit).

 

[pdeaves]

But you do get demands for replacement with OLE after a couple of days of heavy rain or snow disrupting services.

Yes. Both systems have advantages and disadvantages; neither is more perfect than the other, overall.

 

[scotraildriver]

I remember when a brand new Waitrose supermarket opened at Cardross near Helensburgh all of a sudden there were daily OHL issues due to disposable carrier bags being blown into the lines. It was a huge issue and caused alot of damage and delays that never occurred before.

 

[Horizon22]

One issue has been outside interference - whether that’s people deliberately damaging OLE with objects on the line or issues with the weather blowing objects onto the line that ought to be tethered down.

Also the changing climate of the UK will have an impact; the weather is expected to get warmer but storms stronger when they do happen. This is more likely to lead to weather conditions that will damage the OLE, either through wind and debris, or sagging.

Another reason also appears to be newer units having pantograph issues and damaging the OLE, but I’m not an expert on why or how that’s happening (or indeed if any figures show that it is).

And finally much of the OLE is probably not to the same spec as it would be built now - that’s not to say it’s unsafe or not fit for purpose but may be slightly more prone to failing.

There’s also an issue with the premise of the question that it happens “every day”.

== Doublepost prevention - post automatically merged: 20 Sep 2022 ==

What do they get reported as?

"Overhead line problems" is clearly not unusual, been caught out by that before (including at Exeter St Davids)... but even when I lived in South London, I don't remember a specific delay reason relating to the third rail

They are enabled in the CIS but normally get rolled into other reasons. For instance ice & snow is a major problem for the third rail, something that isn’t such a big risk for OLE.

 

[Nicholas Lewis]

But you do get demands for replacement with OLE after a couple of days of heavy rain or snow disrupting services.

Fortunately thats all it is a couple of days every few years if that but it is its weakest point

 

[Horizon22]

Fortunately thats all it is a couple of days every few years if that but it is its weakest point

There are also non-disruption related reasons why OLE trumps 3rd rail. Power distribution and safety for track workers being some.

 

[TheEdge]

Is there any research being undertaken to find more resilient ways to power 25kV ac electric trains, rather than picking up the electricity via a bit of metalwork attached to the vehicle's roof, which physically rubs against a piece of wire strung over the track?

I'm intrigued to know how you expect Network Rail to bend the basic properties of electromagnetic energy to somehow to get away from conductor to conductor contact in an electrical circuit. Short of plasma based OHL and pantographs I think its a pretty insurmountable issue.

 

[GRALISTAIR]

Is there any research being undertaken to find more resilient ways to power 25kV ac electric trains, rather than picking up the electricity via a bit of metalwork attached to the vehicle's roof, which physically rubs against a piece of wire strung over the track?

GWML west of airport junction is extremely robust. Problem is people then say it is ugly and functional rather than aesthetic.

 

[Gloster]

I understood that BR could only get the East Coast electrifaction project past the DoT/Treasury bean-counters by specifying the lightest and least robust OHL equipment. This probably applied to other projects of the same era.

 

[JamesT]

I'm intrigued to know how you expect Network Rail to bend the basic properties of electromagnetic energy to somehow to get away from conductor to conductor contact in an electrical circuit. Short of plasma based OHL and pantographs I think its a pretty insurmountable issue.

Inductive charging exists, you may even be using a device capable of it at this moment.
Whether it can be scaled up to the power levels required by a train, especially in a dynamic (non-static) environment may well be another matter.