Why do we use overhead lines in this country, given we experience windy weather conditions? Would third rail be better?

[southernyoshi]

Moderator note: Split from

https://www.railforums.co.uk/threads/ecml-south-disruption-ole-down-09-12.259086

Been a lot of these, especially on the ECML, it's got me wondering - now please remember I am just a layman passenger, so this is almost certainly a deeply stupid question, please don't jump on me... but as the windy, wet, drastically variable weather island that we are, why do we even use overhead lines?

There must be a strong technical reason, because I'd have thought third rail would be hugely more reliable for us, to the point where installing it everywhere (except HS1) would be desirable.

There must be a good reason why we don't, why it never escaped the south & Merseyside, I'd be interested to know why overhead is better.

Thank you

 

[JonathanH]

Third rail can suffer worse from ice than overhead lines suffer from wind. Moreover, it isn't very efficient, and doesn't allow trains to run as fast.

Overhead power provides electricity at a higher voltage, but is generally safer as it is 'out of reach'.

Overhead line issues in wind tend to result from 'cheaper' installations based on suspending wires from wires, rather than more substantial steel 'arms'.

 

[Samzino]

Third rail is not more reliable. It costs technically more to run when you consider it isn't efficient in distributing energy well. I think its almost a substation every 3.5 Miles to maintain usable current.

The higher voltage of the OHLE means energy distribution is much better for the same amount of current. Extreme enough wind to cause trees to fall on OHLE or to cause sway are quite rare compared to as the poster above mentioned the effect of snow/ice and light flooding/ bogging that caused 3rd rail to suffer.

 

[southernyoshi]

Ok, thank you - I thought there had to be good reasons . Maybe there's a case for using some of the saved HS2 money for a complete replacement of the ECML electrification system then with better wires etc, especially through the Midlands, that seems to be the worst place. Unless it's maintenance that's the problem.

 

[Nym]

The money “saved” from HS2 is gone and won’t come back.

 

[dangerousdids2]

Cant recall my local service ever being disrupted by ice on the third rail.

It's not cost effective though and the trains are limited to 100mph.

 

[CarrotPie]

Cant recall my local service ever being disrupted by ice on the third rail.

Lewisham?

 

[dangerousdids2]

Lewisham?

Well I say disrupted but really mean cancelled. That was snow if I remember right, and that was due to points failure I think.

The problem with ole is if a bit of wire comes down the track is blocked and the power has to be turned off, meaning all the trains in the area come to a grinding halt.
Whereas on the odd occasion I've heard of damaged third rail the trains continue to run, over the section at restricted speed or just divert along a adjacent line.

 

[CarrotPie]

Well I say disrupted but really mean cancelled. That was snow if I remember right, and that was due to points failure I think.

It was heavy icing on the third rail that hadn't been de-iced as it should have been. All points were working fine.

 

[dangerousdids2]

Anyway the ole isn't the problem. I think the problem is mainly cost cutting and poor maintenance.

It's been used in this country for more than half a century and only until recently have I heard of problems with downed lines etc.

 

[CarrotPie]

Anyway the ole isn't the problem. I think the problem is mainly cost cutting and poor maintenance.

It's been used in this country for more than half a century and only until recently have I heard of problems with downed lines etc.

British knitting is fine, except in: extreme heat, extreme cold, snow, ice, wind, or when trains use it.

 

[dangerousdids2]

It was heavy icing on the third rail that hadn't been de-iced as it should have been. All points were working fine.

That's one incident in decades. I've seen ice cause overhead lines to come down plenty of times over the years. Also cause damage to the panto and the the equipment on top of the train. Even seem to recall emr trains being damaged by ice recently and I don't even think they were in service.

 

[stuu]

If the Norwegians can keep it working over the Hardangervidda through the winter, we should be able to cope with the wilds of Lincolnshire. It's an engineering problem, the GWML hasn't had any problems, that I can remember, west of Stockley Jct

 

[dosxuk]

Ah, the good old RailUK Forums "let's use the other type of electrification" thread, that appears after every spate of incidents with an electrification type.

Both OLE and 3rd-rail have their benefits and drawbacks. The fact that basically the entire rest of the world has gone with (and stuck with) OLE for all electrification (outside of low-speed metro systems) should give a good indication as to which is overall seen as the better option.

 

[dangerousdids2]

Obviously ole is the better option. Just not in the UK it appears.

 

[bib]

I wonder if there are any stats on how much less reliable an OLE electrified railway is due to things getting stuck in the wires, wires coming down etc. In the last week there's been the GWML, ECML and Castlefield corridors all gone down due to OLE issues, and I wouldn't say it was particularly windy.

Obviously you can still get trees down, snow, floods, landslides etc on un-electrified track, and EMU reliability is generally better which might balance things out overall, although a DMU that's given up is less likely to close a route for multiple hours I'd have thought.

 

[dangerousdids2]

Something definitely ain't right for this to happen so often recently.

With a broken down dmu it can easily be moved, either by a locomotive or by another dmu. There's no power shortages stopping it, unless the signalling goes down.

But these days it's not easy with all the red tape!
Years ago I was on a train that broke down and within half an hour another train stopped along side it and the passengers where transferred across.
Nowadays health and safety and lawsuits says it's not possible to do that kind of thing.

I would have thought that the other night, engineers could have cut off the section of damaged cable and switched the power back on so the stranded trains could move to the nearest stations at least but I guess health and safety prohibits that also.

 

[dosxuk]

Years ago I was on a train that broke down and within half an hour another train stopped along side it and the passengers where transferred across.
Nowadays health and safety and lawsuits says it's not possible to do that kind of thing.

Cross transfers still happen - seen only this weekend during the Castlefield incident.

 

[dangerousdids2]

Cross transfers still happen - seen only this weekend during the Castlefield incident.

That's good to know. Common sense is still a thing. I did wonder how passengers can be trusted to cross the gap between the platform and the train but not the gap between 2 trains.

 

[AM9]

That's good to know. Common sense is still a thing. I did wonder how passengers can be trusted to cross the gap between the platform and the train but not the gap between 2 trains.

"Common Sense" is a myth, it only exists in the minds of people who don't agree with the way some things are done. Often used with expressions like "be reasonable/sensible, - do it my way".

 

[JohnElliott]

I've certainly seen the suggestion made that side-contact third rail would cope better in icy conditions than the top-contact we have now. Even suggestions that it would be worthwhile switching the entire third rail area over to use it.

 

[Trainguy34]

After the incident currently unfolding (OHLE damage between KGX and Peterborough meaning no leccy only trains), I think many people would rather 3rd rail at least for suburban.

 

[Samzino]

After the incident currently unfolding (OHLE damage between KGX and Peterborough meaning no leccy only trains), I think many people would rather 3rd rail at least for suburban.

Not when it will be less reliable to the weather elements.

 

[AM9]

After the incident currently unfolding (OHLE damage between KGX and Peterborough meaning no leccy only trains), I think many people would rather 3rd rail at least for suburban.

So you would need every stretch of line out of each city to be dual electrified to the limit of the commute area. Hmm, that's going to be expensive just to mitigate the occasional OLE issue, (or conversely every time there is ice on the conductor rail).

 

[Trainguy34]

So you would need every stretch of line out of each city to be dual electrified to the limit of the commute area. Hmm, that's going to be expensive just to mitigate the occasional OLE issue, (or conversely every time there is ice on the conductor rail).

Not very occasional - GWML a couple of days ago, ECML on Saturday and ECML today. I think it's more likely to be windy enough for OHL problems then ice on the 3rd Rail

 

[AM9]

Not very occasional - GWML a couple of days ago, ECML on Saturday and ECML today. I think it's more likely to be windy enough for OHL problems then ice on the 3rd Rail

So just for a few days disruption, you would force dual electrification on the two busiest inter-city routes in the country. Dual electrification is very expensive, and by its complexity may introduce higher failure rates on signalling as well as higher energy costs, lower performance and a need for all IC rolling stock to be dual voltage. Hardly worth the occasional disruption which it is of you don't just cherry pick a recent bad weekend and look across a sensible representative period, e.g. several years, (which is probably less than how long it would take to dual electrify all the services that "people would rather 3rd rail").

 

[Samzino]

Not very occasional - GWML a couple of days ago, ECML on Saturday and ECML today. I think it's more likely to be windy enough for OHL problems then ice on the 3rd Rail

Still not worth the extra costs DC will amount to. The ECML catenary is also sub-standard and was done quite cheaply its not a proper use case here.
The amount of substations required to accommodate a 3rd rail DC electrification between Kings Cross and Peterborough would amount to 72miles / 3.5miles(Average distance required per substation on a dc route) which equals about 21 Substations. I'd not want to find out how much that would cost let alone the rest of changes required just to mitigate wind disruption and gain much more drawbacks.

 

[dangerousdids2]

Well the way things went with the last 2 big rail projects id estimate 3rd rail electrification somewhere around 1bn cough cough 15bn

 

[SECR263]

Third rail might be old tech but ole does have a problem especially when recovering pass which seems to be way down the priorities in these events. Tell RAIB the concerns re 3rd rail are noted but pass come 1st. The trains might not go as fast but 3rd rail gets you there. HS2 going at speed will bring down 2 miles of string, 3 days u/s.

 

[Elecman]

Third rail might be old tech but ole does have a problem especially when recovering pass which seems to be way down the priorities in these events. Tell RAIB the concerns re 3rd rail are noted but pass come 1st. The trains might not go as fast but 3rd rail gets you there. HS2 going at speed will bring down 2 miles of string, 3 days u/s.

3rd rail doesn’t when it’s ices up in Winter