Why no longer Third Rail Electrification?

[Juniper Driver]

I think this thread is getting distracted between DC and AC - whereas the OPs question was why no more 3rd rail.

You can of course have DC on overhead....

The reason why no more on 3rd rail is probably a mixture of factors, for longer stretches of line the infrastructure needed for AC make it more economic to go that route, which conspires against 3rd rail.

There are then the obvious health and safety concerns around having a high voltage, high current power source laying about on the floor with no protection. And whilst I accept members of the public *shouldn't* be on the rails, the fact remains some do end up there being electrocuted. Then again there have been no shortage of cases of rail workers being electrocuted by the 3rd rail and they're safety trained to be aware of it. And as others have pointed out, it does tend to frazzle certain types of wildlife which stray across the tracks - badgers and foxes seem to be the most common.

In terms of reliability, despite the claims of some posters, I don't believe that OHL is inherently less reliable than 3rd rail - 3rd rail is as susceptible to problems such as damage to the rail, yet it probably isn't reported in that way.

This post hits the nail right on the head.

 

[DarloRich]

what about the third rail in the sky installed at St Pancras Thamelsink ( and elsewhere?)

( aka Rigid Overhead Conductor Rail System)

 

[swt_passenger]

Perhaps this statement in the draft Kent Route Study with respect to the cost of electrifying the Marshlink with either OHLE or third-rail will surprise you:

Originally Posted by Kent Route Study - Draft for Consultation, pp 65
The cost of electrification is significant at £250m-£500m for 25kV AC overhead or £100m-£250m for 750V DC third rail.

I suspect (without any figures) that the capital costs of the hardware may be less, but the metered traction charge for the TOC over the lifetime of the equipment will quickly cancel that out.

 

[AM9]

I suspect (without any figures) that the capital costs of the hardware may be less, but the metered traction charge for the TOC over the lifetime of the equipment will quickly cancel that out.

Not to mention the higher maintenance charges and shorter life of the 3rd rail equipment.

 

[AM9]

Can you provide multiple references to prove for your accusation? What happened with the CP4/CP5 estimated electrification costs could be explained as one mistake, underestimating the cost of OHLE. You seem to be coming with a conspiracy theory to `steer the recipients' of your post `towards' your `preferred projects'.

Wilful underestimating costs, just like overestimating them is a well trodden route to drive a particular preferred option. Preparing official documents, (such as an RUS) is part of that practice. It happens everwhere with large projects, particularly infrastructure, (think 2012 Olympics preparation), but also major issues such as government IT, (NHS and other computer systems that have completely gone off the rails that were so carefully described in original proposals). It has been going on for decades.
The current crop of Rail overspends have recently been put down to practices like 'estimates on the back of envelopes' by Mark Carne no less, so it seems to be endemic within some areas of the rail community. The recent overspends on electrification schemes, (OLE of course because 3rd rail is no longer in the frame) have been blamed on poor record keeping (GWML buried signal cables), and bridge clearances (vacillating over TSI derogations). None of that is related to OLE per se as an effective successor to 3rd rail electrification.

 

[AM9]

There are plenty of arched bridges which have been there since the routes opened, so I would expect them to last for as long as they are maintained.

Or as long as maintenance is sustainable. Eventually, patching up victorian engineering becomes an obstacle to a cost-effrective railway, and only if it is pretty enough for somebody to put their hand in their pockets should the railway pay over the odds just to keep it there.

 

[JamesRowden]

If you read the technical appendix and do some maths you will see that the OHLE cost is mostly bridges etc. not the electrification

Rebuilding bridges must therefore be required for OHLE of the Marshlink and so is part of the electrification costs.

 

[JamesRowden]

Wilful underestimating costs, just like overestimating them is a well trodden route to drive a particular preferred option. Preparing official documents, (such as an RUS) is part of that practice. It happens everwhere with large projects, particularly infrastructure, (think 2012 Olympics preparation), but also major issues such as government IT, (NHS and other computer systems that have completely gone off the rails that were so carefully described in original proposals). It has been going on for decades.
The current crop of Rail overspends have recently been put down to practices like 'estimates on the back of envelopes' by Mark Carne no less, so it seems to be endemic within some areas of the rail community. The recent overspends on electrification schemes, (OLE of course because 3rd rail is no longer in the frame) have been blamed on poor record keeping (GWML buried signal cables), and bridge clearances (vacillating over TSI derogations). None of that is related to OLE per se as an effective successor to 3rd rail electrification.

The cost of OHLE projects being underestimated might explain why all of the projects given the go-ahead were OHLE rather than the four short gaps within the third rail network.

 

[yorksrob]

Or as long as maintenance is sustainable. Eventually, patching up victorian engineering becomes an obstacle to a cost-effrective railway, and only if it is pretty enough for somebody to put their hand in their pockets should the railway pay over the odds just to keep it there.

There are a hell of a lot of them around on the electrified and unelectrified network, the majority of which I'm presuming aren't listed, so we're clearly not at that stage yet.

 

[yorksrob]

Wilful underestimating costs, just like overestimating them is a well trodden route to drive a particular preferred option. Preparing official documents, (such as an RUS) is part of that practice.

There must be practical reasons why the RUS considers third rail to be the preferred option. Or is it just they know that this pipe dream of converting the whole Southern Region to OHE is never going to happen, so if we are to electrify the diesel islands at all, it will have to be third rail.

 

[AM9]

There must be practical reasons why the RUS considers third rail to be the preferred option. Or is it just they know that this pipe dream of converting the whole Southern Region to OHE is never going to happen, so if we are to electrify the diesel islands at all, it will have to be third rail.

Pursuing that line of thought even further, maybe Network Rail had to appease the local authorities on the viability of Marshlink electrification so they went for the one that will be challenged by the ORR meaning that they have done their bit and the problem is parked. The local protest groups can then busy themselves arguing the safety case with the ORR.

 

[JamesRowden]

Pursuing that line of thought even further, maybe Network Rail had to appease the local authorities on the viability of Marshlink electrification so they went for the one that will be challenged by the ORR meaning that they have done their bit and the problem is parked. The local protest groups can then busy themselves arguing the safety case with the ORR.

The route study considers third rail, OHLE, class 802s and battery powered class 377s.

 

[yorksrob]

Pursuing that line of thought even further, maybe Network Rail had to appease the local authorities on the viability of Marshlink electrification so they went for the one that will be challenged by the ORR meaning that they have done their bit and the problem is parked. The local protest groups can then busy themselves arguing the safety case with the ORR.

Or it could be just that it doesn't actually cost as much as OLE to install, so they put it in the study !

 

[Elecman]

But what about while you are applying or removing the shorting straps and the shrouding?

You test for dead before applying the shorting straps, and always connect the running rail end first before the 3rd rail. As for shrouds you just lower them onto the live rail using thier handles on the top perfectly safe.

 

[najaB]

For those who say that third-rail electrification doesn't pose a risk of electrification electrocution: Coroner's report into the death of George Dicker.

 

[JamesRowden]

For those who say that third-rail electrification doesn't pose a risk of electrification: Coroner's report into the death of George Dicker.

I can't see anyone who's made that statement (including what you meant to type if you hadn't made a typo).

 

[Elecman]

Assume you mean risk of electrocution there, interesting that no one has seen/ heard the responce to the coroners request for alarms to signallers on access gates.

 

[najaB]

I can't see anyone who's made that statement (including what you meant to type if you hadn't made a typo).

LOL, yes, it was a typo indeed. Will correct it.

There were some (in other threads if not this one) who claimed that they had never seen or heard of a death due to third rail electrification.

 

[edwin_m]

LOL, yes, it was a typo indeed. Will correct it.

There were some (in other threads if not this one) who claimed that they had never seen or heard of a death due to third rail electrification.

There doesn't seem to be any report of the verdict in this case, but the cached link below suggests trespasser rather than rail staff:

http://webcache.googleusercontent.c...16+&cd=1&hl=en&ct=clnk&gl=uk&client=firefox-b

An inquest heard how George was hit by a train following his death and had to be identified from his finger prints. He suffered from schizophrenia and was paranoid about voices coming from the TV and had taken an overdose of anti-psychotic medication the week before his death, although he said afterwards this was an attention-seeking act rather than a suicide attempt.

Despite the inquest finding that the death was “accidental,” his sister-in-law Juliet Holton is raising money for the charity Papyrus, which prevents suicide in young people, when she runs the Brighton Marathon in George’s memory next year.

 

[najaB]

There doesn't seem to be any report of the verdict in this case, but the cached link below suggests trespasser rather than rail staff.

I believe that is correct - that he was a trespasser - but that doesn't change the fact that he appears to have died due to contact with the third rail.

 

[Surreytraveller]

I doubt an alarm on the gate would have prevented him from passing through it or his death. A signaller isn't going to isolate the juice or stop the trains because of an alarm on a gate - the most that would happen is the trains would be cautioned. I woube interested to read LUL's response back to the coroner.

 

[yorksrob]

For those who say that third-rail electrification doesn't pose a risk of electrification electrocution: Coroner's report into the death of George Dicker.

Does anybody actually say that the third rail doesn't pose a risk to people ?

The fact is that it does pose a risk to people if you don't respect it, just like the whole railway. Somebody trespassing on the track could as easily have been mown down by a train, however I would suggest that the risk posed by the third rail to someone using the train day to day is extremely low.