Should third rail be considered again for future electrification projects?

[contrex]

With advances in power electronics and SCADA systems we have options that were not available historically. For example we could have intrusion alarms that rapidly isolate the rail when tresspassers cross the fence.

Won't all the local scrotes cross the fence, or interfere with it, just to stop the job for a laugh? Rush hour for maximum lolz.

== Doublepost prevention - post automatically merged: 7 Dec 2021 ==

As for safety, studies reaching conclusion that says its dangerous, despite being surrounded by thousands of miles of track safely operating for nearly 100 years, and likely to continue so for another hundred sounds more academic than substance.

After the SR third rail spread in the 1920s and 1930s questions were being asked in Parliament about electrocuted children incidents that had started occurring.

Brigadier-General Clifton Brown: (must have held the rank before 1921) Conservative MP for Newbury:

I do not want to quarrel with my hon. Friend, who is a much greater agriculturist than I am, and who is a director of the Southern Railway Company, and I do not in the least want to exaggerate the danger, but my hon. Friend the Member for Aylesbury (Mr. M. Beaumont) the other day asked a question and was informed that in 1934 five children were killed by live rails, in 1935, six, and last year 11 were killed and there were two other casualties. That shows a progressive rate of accidents and, as you electrify the live rail more and more over England, you will have that rate doubled, and so on, as you get on. The Electric Lighting Act, 1888, provides that, where an electric line is laid down, even on private land, in such a manner as not to be entirely enclosed, the Board of Trade may require that it shall be used only in accordance with such conditions and subject to such regulations for the protection of public safety as the board may require. We ask that some notice may be taken of that in the case of railway companies.

Hansard, 1937 https://hansard.parliament.uk/Commo...7-ebba-4ee5-89c0-d9806253e7d8/PrivateBusiness

I think the Brigadier-General was on shaky ground logically when he predicted an annual doubling of the child deaths. There wouldn't have been anybody left, child or adult, by 1958, when, as Excel tells me, the deaths would have reached 50 million. I think in 2019-2020 17 trespassers died from all causes.

 

[HSTEd]

Won't all the local scrotes cross the fence, or interfere with it, just to stop the job for a laugh? Rush hour for maximum lolz.

Willfully obstructing the safe operation of a railway is a very serious crime.

Given that tresspassers on the line results in a total stoppage anyway (at least that's my understanding), turning the power off in the area around the tresspass doesn't seem too unreasonable.

 

[contrex]

Willfully obstructing the safe operation of a railway is a very serious crime.

Given that tresspassers on the line results in a total stoppage anyway (at least that's my understanding), turning the power off in the area around the tresspass doesn't seem too unreasonable.

OK foxes then.

== Doublepost prevention - post automatically merged: 8 Dec 2021 ==

Willfully obstructing the safe operation of a railway is a very serious crime.

Given that tresspassers on the line results in a total stoppage anyway (at least that's my understanding), turning the power off in the area around the tresspass doesn't seem too unreasonable.

If trespassers are seen and reported, then a stoppage might take place, certainly, but automatic fence sensors would set the trigger point much lower and result possibly in false and/or mischievous settings-off from naughty kids, wildlife, etc.

 

[Meerkat]

Absolutely no doubt that automatic sensors would become a game for kids. They wouldn't even need to be particularly scrote types, as it would be just the sort of challenge bored kids would love.

 

[WAO]

I am pleased to see that the ORR thinks that 750V inside 2m fences is unsafe and c800V (I am told) in a private battery driven car, perhaps kept in a garage with DIY maintenance is safe and good for the environment (population control?).

I would be more sympathetic to the ORR's case on 750V dc electrification extensions if it insisted on a sensible reduction in dc mileage such as by wiring 25kV OLE from Pirbright Jn to Weymouth instead of dc upgrades (which logically should also be banned). If that's not cost effective then dc is clearly safe.

WAO

 

[MarkyT]

If all trains using one of these notional 3rd rail traction extensions were fitted with a moderate capacity traction battery, then long conductor gaps (a few hundred metres) might be possible either side of each potential access point to the railway, at a level crossing for example, so trespassers entering at that location would not be in any immediate greater danger than if electrification was not present. Thus sensors provided for detecting incursions needn't automatically isolate the power supply, rather they would provide an advance warning to signalling or electrical control room staff to allow a swift review of the incursion via local video monitoring/recording and a decision on isolation. Even where isolation was settled on as the correct response to the particular event, trains could still continue to move under caution via battery power.

 

[Bald Rick]

I am pleased to see that the ORR thinks that 750V inside 2m fences is unsafe and c800V (I am told) in a private battery driven car, perhaps kept in a garage with DIY maintenance is safe and good for the environment (population control?).

how many bare conductors are there in a battery driven car?

 

[WAO]

It will be far easier to access your car battery HT than to climb over a tall spiked fence.

As a child, I had a classmate impaled on one, so that's a risk also.

Safety can only be relative, not absolute.

WAO

 

[AM9]

It will be far easier to access your car battery HT than to climb over a tall spiked fence.

WAO

Accidentally? Do you invite children into your home to take the covers off your consumer unit to accidentally touch the busbars there?

 

[zwk500]

It will be far easier to access your car battery HT than to climb over a tall spiked fence.

A car is usually more closely supervised than the fence

As a child, I had a classmate impaled on one, so that's a risk also.

This phrasing suggests you ordered it to happen!

Safety can only be relative, not absolute.

Agree in the sense that something cannot be 100% safe. But disagree if you meant safety can only be considered in comparison to other things.
The comparison between 3rd rail and a car battery isn't really valid. A comparison between 3rd rail and other forms of live conductor transmission (tram wires, 25kv OLE) is valid, but safety is most usefully considered in the context of the theoretical and likely risks of the item itself, without need for comparison

 

[Bald Rick]

It will be far easier to access your car battery HT than to climb over a tall spiked fence.

As a child, I had a classmate impaled on one, so that's a risk also.

Safety can only be relative, not absolute.

WAO

last time I looked, there weren’t tall spiked fences along platform faces, or at their ends.

 

[WAO]

There aren't any fences along most platforms, with a 3' drop in the way of several hundred tons moving at high speed. Kinetic energy probably kills more than electrical energy.

At least the live rails are in the 6', although on LUL you'll fall onto a -110V 4th rail quite easily.

I don't like third rail either but I see no attempt to reduce it where it isn't necessary like the SWML.

WAO

 

[Bletchleyite]

At least the live rails are in the 6', although on LUL you'll fall onto a -110V 4th rail quite easily.

That split on LU is partly to make it less dangerous (though it wouldn't be sensible to test it with your tongue). It does fit with the way 110V stepdown transformers are used on building sites to reduce risk.

 

[AM9]

There aren't any fences along most platforms, with a 3' drop in the way of several hundred tons moving at high speed. Kinetic energy probably kills more than electrical energy.

At least the live rails are in the 6', although on LUL you'll fall onto a -110V 4th rail quite easily.

I don't like third rail either but I see no attempt to reduce it where it isn't necessary like the SWML.

WAO

Actually the centre rail is 210 volts negative WRT ground (250 volts on upgraded parts of the Met). Not a high voltage but falling onto it could easily be fatal as DC might lock muscles to prevent self-removal.

 

[O L Leigh]

If that's not cost effective then dc is clearly safe.

Was safe. Or rather, was permitted at the time of construction.

That something was permitted in the past does not mean that it is permitted today. Just look at the changes to the building regulations down the years. That a house builder must now apply the latest regulations for electrical wiring, for example, does not mean that the owners of much older properties immediately have to upgrade their wiring in order to comply.

 

[Bletchleyite]

Was safe. Or rather, was permitted at the time of construction.

That something was permitted in the past does not mean that it is permitted today. Just look at the changes to the building regulations down the years. That a house builder must now apply the latest regulations for electrical wiring, for example, does not mean that the owners of much older properties immediately have to upgrade their wiring in order to comply.

Though continuing that analogy, there are only a very small proportion of the newer electrical regulations that an electrician must upgrade if extending an installation, e.g. with a new spur to an existing circuit. A lack of earth bonding is one, there are probably a couple more but there are not many.

 

[WAO]

Actually the centre rail is 210 volts negative WRT ground (250 volts on upgraded parts of the Met). Not a high voltage but falling onto it could easily be fatal as DC might lock muscles to prevent self-removal.

My slip. Thanks for the correction.

WAO

== Doublepost prevention - post automatically merged: 9 Dec 2021 ==

https://twitter.com/NoelDolphin

The perfect ORR solution to the pedestrian road/rail interface.

WAO

 

[HSTEd]

Given that many unelectrified railways where third rail is being talked about would have relatively simple stopping patterns involving only one type of stock.

What would it cost to install platform edge doors at those stations?
I know that a disproportionate number of the passenger fatality-weighted-injuries from third rail incidents occur at stations.

 

[Bletchleyite]

Given that many unelectrified railways where third rail is being talked about would have relatively simple stopping patterns involving only one type of stock.

What would it cost to install platform edge doors at those stations?
I know that a disproportionate number of the passenger fatality-weighted-injuries from third rail incidents occur at stations.

I would reckon on quite a bit more than switching the electrification to bottom-contact third rail.

I'd be unsurprised to see PEDs at Liverpool Central fairly soon. But the idea of fitting them at Capenhurst or Aughton Park seems borderline comedic.

 

[Bald Rick]

There aren't any fences along most platforms, with a 3' drop in the way of several hundred tons moving at high speed. Kinetic energy probably kills more than electrical energy.

For new electrification proposals, the platforms are already there. There third rail isn’t. That’s the difference.

 

[WAO]

For new electrification proposals, the platforms are already there. There third rail isn’t. That’s the difference.

I appreciate your point. I would argue that the minor infills should enjoy grandfather rights, albeit with reasonable mitigations such as fencing and contact rail side insulation etc. They should not be treated as "green field" schemes.

At the same time I would argue that overall safety (if it really is accepted by Govt as an issue) would improve if the overall mileage of third rail were progressively reduced, such as the SWML I've mentioned and the 75 route miles of Merseyrail above ground, avoiding more upgrades of undesirable systems.

But then, I'm an engineer not a bureaucrat.

WAO

 

[AM9]

I appreciate your point. I would argue that the minor infills should enjoy grandfather rights, albeit with reasonable mitigations such as fencing and contact rail side insulation etc. They should not be treated as "green field" schemes.

At the same time I would argue that overall safety (if it really is accepted by Govt as an issue) would improve if the overall mileage of third rail were progressively reduced, such as the SWML I've mentioned and the 75 route miles of Merseyrail above ground, avoiding more upgrades of undesirable systems.

But then, I'm an engineer not a bureaucrat.

WAO

It reads more like the words of s politician, trading new risks in an area not used to the risks of bare 750VDC conductors at ankle level against removal of another to balance the statistics of ksi cases. Sounds like an excuse to perpetuate the risk.

 

[Wolfie]

Given that many unelectrified railways where third rail is being talked about would have relatively simple stopping patterns involving only one type of stock.

What would it cost to install platform edge doors at those stations?
I know that a disproportionate number of the passenger fatality-weighted-injuries from third rail incidents occur at stations.

Platform edge doors are far from perfect. If TfL wish to replace the Jubilee line stock they'll have either to buy new stock with doors on exactly the same place or replace all of the platform edge equipment.

 

[AM9]

Platform edge doors are far from perfect. If TfL wish to replace the Jubilee line stock they'll have either to buy new stock with doors on exactly the same place or replace all of the platform edge equipment.

But the life of a ped installation is probably similar to that of a fleet of trains.

 

[zwk500]

I appreciate your point. I would argue that the minor infills should enjoy grandfather rights, albeit with reasonable mitigations such as fencing and contact rail side insulation etc. They should not be treated as "green field" schemes.

What would the tickover point be? 10 route miles, 20 track KM?

At the same time I would argue that overall safety (if it really is accepted by Govt as an issue) would improve if the overall mileage of third rail were progressively reduced, such as the SWML I've mentioned and the 75 route miles of Merseyrail above ground, avoiding more upgrades of undesirable systems.

It's the ORR not the government that rule on the safety elements. However, the government do accept that safety is an issue, but the primary concern is the cost of replacing third rail. It's very expensive, not to mention disruptive.

 

[AM9]

What would the tickover point be? 10 route miles, 20 track KM?

It's the ORR not the government that rule on the safety elements. However, the government do accept that safety is an issue, but the primary concern is the cost of replacing third rail. It's very expensive, not to mention disruptive.

Any new route miles of 3rd rail only increases the total that must eventually be removed, disruptive or not.
If the motive is to save money, it's just mortgaging the future safety of some who will live near the lines.

 

[zwk500]

Any new route miles of 3rd rail only increases the total that must eventually be removed, disruptive or not.
If the motive is to save money, it's just mortgaging the future safety of some who will live near the lines.

I will be astonished if we see wholesale conversion of the 3rd rail network to an alternative system (be that OLE, Batteries or something else) in my lifetime. I think we're more likely to see disruptive technologies that make trains unnecessary than conversion.
I agree with you that we should, but I just don't see that level of money or strategic direction forthcoming from the industry or from Government.

 

[yorksrob]

Any new route miles of 3rd rail only increases the total that must eventually be removed, disruptive or not.
If the motive is to save money, it's just mortgaging the future safety of some who will live near the lines.

We're talking about electrifying the Marshlink, not sending future generations to the trenches.

 

[AM9]

We're talking about electrifying the Marshlink, not sending future generations to the trenches.

We are taliking about whether to increase the mileage of railway electrified with an antiquated system that has a higher ksi rate than the dominant standard formally adopted in 1955.

 

[mr_jrt]

I would imagine that within the timescales of any new (i.e. non-commited at this moment in time) electrification coming online that the last DC-only stock is life-expired, so it makes sense that if you are going to spend money doing design work, you do so for a new AC installation, so Ashford to Ore would be fine with the dual-voltage stock that will be available. Converting beyond there, well. However you want to cut it, really. The equipment will become life-expired at some point, and before that, equipment in less-operationally-practical locations elsewhere will likely need replacing sooner so recovery from the extremities might be an option there.