Which is better and why - over head or third rail electrification?

[Harbornite]

Should the judgement be based only on technical factors?

OLE looks a mess. All those support girders, support wires, conductor wires, insulators, hangers, all the bits and bobs that spoil the look of the railway and its surroundings. With third rail, well, there's just an inconspicuous third rail.

Yes, of course it should. Who cares if the 'look' is somehow spoiled when OHLE is both safer and more effective.

 

[whhistle]

It should be judged on suitability for purpose, i.e. providing a transport service, that is safe for both users and non-users, at an acceptable through-life cost, meeting environmental legislation (which doesn't just mean not spoiling the view for a few people).

Ah ha, but this is where the OP hasn't been specific enough.

What if the title was expanded to "which is better (for asthetically pleasing views) and why..."
I appreciate they didn't but this shows how this forum instantly jumps to technical aspects than encompassing all points of view. But then again, as you say it's the main function of the power supply.

What I'm trying to say is that the guy has a valid point, and "it" shouldn't just be judged on suitability for purpose. A screwdriver is excellent for it's purpose. But if it's the wrong one, totally not suitable.
The way you worded it makes it sound like you have an axe to grind against people who think OHLE looks ugly.

 

[Lucan]

The latest recommendations are for live parts to be at lest 3.75M from a public access area presumably cope with a tall person holding an umbrella.

I thought that the biggest issue was anglers waving carbon fibre fishing rods, possibly carrying them over level crossings if not on a platform.

OHLE isn't ugly or unsightly, it's just there. From a distance it's barely noticeable.

To me it is ugly. I think you are merely demonstrating that different people see things in very different ways. That is why different people prefer very different types of art (in the broadest sense) or do not see the point of it at all. You cannot say that I (or any other particular person) do not find OHL ugly because you cannot see into my mind; what is undisputable however is that there are some people who find OHL ugly and some people who do not - you and I alone prove that.

Having said all that, I am nevertheless pleased to see electrification, OHL or not.

 

[Busaholic]

I thought that the biggest issue was anglers waving carbon fibre fishing rods, possibly carrying them over level crossings if not on a platform.

To me it is ugly. I think you are merely demonstrating that different people see things in very different ways. That is why different people prefer very different types of art (in the broadest sense) or do not see the point of it at all. You cannot say that I (or any other particular person) do not find OHL ugly because you cannot see into my mind; what is undisputable however is that there are some people who find OHL ugly and some people who do not - you and I alone prove that.

Having said all that, I am nevertheless pleased to see electrification, OHL or not.

I absolutely agree with you on the ugliness of overhead lines. Although I'd like to see electrification of the line down to Cornwall, given that it would require OHL perhaps it's as well it's not going to happen in my lifetime. I grew up in Southern Electric land so, for me, electrification doesn't have to mean unsightly infrastructure.

 

[2HAP]

Trains running on 3rd rail electrification are capable of operating in floodwater. Modern Nanny State rules prevent it now.

https://upload.wikimedia.org/wikipe...n_Railway_(CJ_Allen,_Steel_Highway,_1928).jpg

 

[NSEFAN]

Trains running on 3rd rail electrification are capable of operating in floodwater. Modern Nanny State rules prevent it now.

https://upload.wikimedia.org/wikipedia/commons/a/ac/Flooding_on_the_Southern_Railway_(CJ_Allen,_Steel_Highway,_1928).jpg

Nanny state? Or train operators being unwilling to trash thousands of pounds of traction equipment?

 

[PaxVobiscum]

OHLE isn't ugly or unsightly, it's just there. From a distance it's barely noticeable. It's certainly less unsightly than the black sooty residue left behind from diesel exhaust, not to mention the noise.

It depends on your point of view (in more senses than one)
Before and after.

I am not suggesting that the aesthetic appeal is the prime consideration. Anyway, side on to the railway line, often (but not always) one hardly notices the OHLE.

 

[jadmor]

I recall a writer called Michael Bonavia making a case for high speed 3rd rail in Modern Railwys some years ago. Sorry! I don’t have any specifics about these articles.

 

[Bromley boy]

Yes, of course it should. Who cares if the 'look' is somehow spoiled when OHLE is both safer and more effective.

As someone who works with it every day (including walking about in third-railed yards and depots) I don’t consider it dangerous, so long as care is used. I believe figures were posted previously that showed it’s no more dangerous than OHLE to staff or passengers.

Of course it’s much less efficient than OHLE, and shouldn’t be expanded on a large scale, but it’s ridiculous that areas where expansion is a no brainier (uckfield line, Marsh link) are denied it simply because NR is against ANY expansion.

 

[Sapphire]

It’s interesting, as I say I live in third rail territory which contributes to this, but I find overhead feels much more dangerous as an average passenger than third rail.

 

[Elecman]

It’s more the ORR are against any expansion of 3rd Rail

 

[PudseyBearHST]

It’s interesting, as I say I live in third rail territory which contributes to this, but I find overhead feels much more dangerous as an average passenger than third rail.

Do you think the respective voltage values contribute to this- 25000V OHLE and 750V third rail- or is it because of where they are physically located?

 

[2HAP]

Nanny state? Or train operators being unwilling to trash thousands of pounds of traction equipment?

Presmably back in the 1920s, the cost of an EMU was proportionally similar to what it is today? As has been shown, it is perfectly feasible to run 3rd rail EMUs in floodwater. Why is it that the Southern Railway was willing to run the risk, yet todays TOCs aren't?

 

[edwin_m]

It’s interesting, as I say I live in third rail territory which contributes to this, but I find overhead feels much more dangerous as an average passenger than third rail.

ORR claims third rail is more dangerous when "normalised" to take account of the different amounts of the two types of electrification, but when we last discussed this a few months ago nobody could point to any actual statistics to justify this. However the overhead line is probably less dangerous than it looks - although "safe distance" for working near live line is several metres, the actual distance the voltage will jump is much less - as shown by how close the wires can be underneath a bridge. Again there are no statistics but I believe nobody has ever been electrocuted by overhead line by using a platform in the normal way - it is usually kids who climb up on a train.

 

[mmh]

With a third rail 100 miles/160 kilometers is still posible. However with a third rail there might be more suicide if the railway is not more isolated from the surroundings.

I doubt that, there are countless places on the third rail networks where live rails are easily accessible - every station and every level crossing. I don't think electrocution is a common suicide method, the danger is more accidental or misadventure than deliberate.

 

[Bromley boy]

as shown by how close the wires can be underneath a bridge.

Always amazes me how low it is in the TL core!

 

[mmh]

Presmably back in the 1920s, the cost of an EMU was proportionally similar to what it is today? As has been shown, it is perfectly feasible to run 3rd rail EMUs in floodwater. Why is it that the Southern Railway was willing to run the risk, yet todays TOCs aren't?

I wouldn't want any train to go over track where the driver would expect to see, umm, the rails, no matter how it's powered.

Nothing to do with caring whether the train could or couldn't do it, or elfin safety gone mad.

I can't find it, but I'm sure I read something about this a few years ago which claimed going through water above a certain level (the under of the railhead, maybe?) was a no-no. Sounds sensible to me.

 

[randyrippley]

Trains running on 3rd rail electrification are capable of operating in floodwater. Modern Nanny State rules prevent it now.

https://upload.wikimedia.org/wikipedia/commons/a/ac/Flooding_on_the_Southern_Railway_(CJ_Allen,_Steel_Highway,_1928).jpg

thats a wooden bodied vehicle so much safer for the occupants in a flood than a conductive metal body would be

 

[mmh]

What about umbrellas held high? Numerous umbrellas in a rush hour platform?

You'd have to be remarkably tall, be using an umbrella so high it wouldn't be keeping the rain off you, and have an overhead line above the platform.

That combination of things doesn't happen!

 

[urbophile]

Last week I was in Italy and took a trip on this: https://www.ferroviagenovacasella.it/geca/

It's what probably would be a 'heritage' railway in this country, but is run by the local public transport authority. It runs through beautiful scenery and the overhead lines are barely noticeable. But they are effective.

 

[mmh]

Of course it’s much less efficient than OHLE, and shouldn’t be expanded on a large scale, but it’s ridiculous that areas where expansion is a no brainier (uckfield line, Marsh link) are denied it simply because NR is against ANY expansion.

Exactly. It's insane they weren't electrified and mean there's a bizarre need for an ever increasing number of DMUs in a region with no other use for them. I'm sure Northern passengers would be delighted to know Southern run 10 coach 170s (is that the longest DMU in the country?) for the sake of 30 unelectrified miles.

If new third rail isn't possible, how did Surrey Quays to Peckham happen, or Whitechapel to Highbury & Islington? Or more recently, the Three Bridges Thameslink depot.

 

[brad465]

While snow/ice is an issue for 3rd rail more than OHLE, if the "Beast from the East" taught me something its that it doesn't matter what the resilience of OHLE is to those conditions, the actual railway can get covered in it enough to be disrupted as a result. (I already believed snow/ice can do this to the physical rail network, not just the power supply, but earlier this year I remember pictures of actual snow drifts on high traffic mainlines, not just low use branch lines).

 

[Merthyr Imp]

It’s interesting, as I say I live in third rail territory which contributes to this, but I find overhead feels much more dangerous as an average passenger than third rail.

I find that being on a station platform where there is overhead electrification feels much less dangerous than walking alongside the road into town with tons of metal hurtling past at 30mph.

 

[brad465]

I find that being on a station platform where there is overhead electrification feels much less dangerous than walking alongside the road into town with tons of metal hurtling past at 30mph.

As I cyclist I completely concur, but that's another matter

 

[Sapphire]

Do you think the respective voltage values contribute to this- 25000V OHLE and 750V third rail- or is it because of where they are physically located?

Both but predominantly the physical presence. Knowing electricity can jump from the wires, knowing the wires can come down, then knowing the voltage if these things happen. I’m well aware that my interpretation of the danger is completely disproportionate to reality doesn’t change how those gantries and cables make me feel

 

[Bromley boy]

how did Surrey Quays to Peckham happen, or Whitechapel to Highbury & Islington?

Or more recently, the Three Bridges Thameslink depot.

Apparently going from 4th to 3rd rail doesn’t count. Neither does depots.

It’s completely and utterly bonkers. The Marshlink 171s are run ECS from selhurst, I believe (how inefficient is that!?), in passenger service they run over the rail, as opposed to under the wires, for much of the journey. An entire sub fleet that could have been avoided if the relevant areas had been given 3rd rail.

SE 395s (which are dual voltage) could also run along an (electrified) Marshlink to Ore, Hastings, and beyond. Had a few more units been ordered, high speed trains to/from the Sussex coast via HS1 and the Marshlink could already be a reality!

Meanwhile in other parts of the country they’re sticking to diesel as OHLE proves too expensive.

 

[Bromley boy]

Both but predominantly the physical presence. Knowing electricity can jump from the wires, knowing the wires can come down, then knowing the voltage if these things happen. I’m well aware that my interpretation of the danger is completely disproportionate to reality doesn’t change how those gantries and cables make me feel

As a staff member, I’d also much rather third rail.

Reports like the below explain why: when 25kV OHLE comes down (and it does) it’s far more dangerous than the third rail you already know is there, and can switch off yourself with a short circuit bar, if necessary.

(“Serious injuries” presumably means wheelchair/vegetable status for the rest of his life. I’m not aware of any such incidents from
Third rail equipment other than for trespassers or people “falling out” of trains in depots (people who shouldn’t have been there in the first place)).

https://www.gov.uk/government/news/report-072015-accident-involving-a-train-driver-at-sutton-weaver

Following a call to the signaller, he left his train and came close to, or made contact with, an electrically live wire which had broken and was low hanging. The train driver suffered serious injuries.

...

The driver had left the train to obtain information as to his location to assist in restoring train services as he was trained to do, but did not see the broken wire.

 

[ert47]

I can't find it, but I'm sure I read something about this a few years ago which claimed going through water above a certain level (the under of the railhead, maybe?) was a no-no. Sounds sensible to me.

Not 100% relevant, but there was the flooding in the Clerkenwell Tunnels in 2015 caused by a burst water main that damaged several ThamesLink trains after several went through it (OHL section)

Farringdon flooding damaged 25 Thameslink trains

The flooding caused by a burst water main between Farringdon and St Pancras has damaged at least 25 trains in the Thameslink fleet.

As of Friday, 6 February, the operator was still seven trains short of the number needed to operate regular services because of water damage, with a further two out of action because of a person being hit by a train earlier in the day, at Hackbridge. This meant that on Friday, many services ran with fewer carriages than normal, causing overcrowding, especially at peak times.

Water from the burst main penetrated gear boxes, axle ends, wheel bearings and in some cases electrical components; one of the trains most seriously affected is one of the new Class 387s.

SOURCE

But I guess that sort of damage could happen to any train regardless of traction (isnt a ScotRail 156 out long term after going cab deep in water?)

 

[edwin_m]

thats a wooden bodied vehicle so much safer for the occupants in a flood than a conductive metal body would be

The metal body is electrically connected through the wheels to the rails so there is no risk of electocution to those inside it.

In a flood I imagine the current from the third rail will travel through the water to the adjacent running rail. This would probably not be detectable as a short circuit so would continue until somebody reported it and got the power shut off. In the meantime it would be electrolysing the water, generating an explosive mixture of hydrogen and oxygen. This is only my guess though - anyone know what actually happens?

 

[NSEFAN]

Presmably back in the 1920s, the cost of an EMU was proportionally similar to what it is today? As has been shown, it is perfectly feasible to run 3rd rail EMUs in floodwater. Why is it that the Southern Railway was willing to run the risk, yet todays TOCs aren't?

Perhaps it was a similar cost, but then trains were much simpler electrically in those days and so "easier" to fix in the event of a flashover, given enough man power at the depot. Rescue of failed trains was also probably easier, using a steam locomotive which would make light work of that much flooding.

thats a wooden bodied vehicle so much safer for the occupants in a flood than a conductive metal body would be

On the other hand, an electrical fire caused by a short circuit then poses the risk of the carriage bodies igniting.