North Downs line electrification

[SpacePhoenix]

AC is more dangerous than DC because it can interfere with the signals within the body. Two cyclists fell onto the third rail at St Leonards Warrior Square in seperate incidents over the past 10 years and both survived with burns.

For someone to come into contact with AC they'd have to generally be trespassing or have evacuated/left a train before the power has been switched off.

There's more chance of someone coming into contact with DC as for example a rail employee could trip and fall onto the 3rd rail. DC is also more prone to arcing from external factors eg Gatwick when the drinks can bridged the gap between the running rail and the juice rail

 

[swissrailpassion]

It just suffers from being incredibly dangerous and grossly inefficient.

But not as dangerous as a road. They're incredibly dangerous; people are killed on them daily.

 

[JamesRowden]

For someone to come into contact with AC they'd have to generally be trespassing or have evacuated/left a train before the power has been switched off.

There's more chance of someone coming into contact with DC as for example a rail employee could trip and fall onto the 3rd rail. DC is also more prone to arcing from external factors eg Gatwick when the drinks can bridged the gap between the running rail and the juice rail

I was referring to electricity in general. Imagine an AC third rail. The poster was suggesting having houses connected to the grid with third rail.

 

[najaB]

AC is more dangerous than DC because it can interfere with the signals within the body.

DC causes muscles to contract, making it harder to let go of or move away from the conductor.

Two cyclists fell onto the third rail at St Leonards Warrior Square in seperate incidents over the past 10 years and both survived with burns.

In the same time period zero people fell from the platform onto OHLE. Just saying...
--- old post above --- --- new post below ---

But not as dangerous as a road. They're incredibly dangerous; people are killed on them daily.

True. But the topic being discussed is electrification of the North Downs Line.

 

[JamesRowden]

DC causes muscles to contract, making it harder to let go of or move away from the conductor.
In the same time period zero people fell from the platform onto OHLE. Just saying...

I am not saying that third rail is safer than OHLE. Just that I don't find its level of danger to be 'incredible' like you seem to.

And I think that someone who chooses to cycle down steps onto a platform has to take responsibility for the direct consequences of their actions.

 

[Phil.]

Inefficiency is important - as far as I'm aware we still rely on large amounts of Gas to produce our power, and any losses that you can get rid of should be gotten rid of. Also remember that an inefficient system means less power for the train. On the NDL it may not be massive worry, but as a general argument for OLE v Third Rail, inefficiency is a big concern

It's the North Downs line that is under discussion.
--- old post above --- --- new post below ---

Exposed 750V conductors at ground level able to deliver thousands of Amps into anything that provides a path to earth without detecting a short circuit.

Or do you have bare mains voltage wires lying around your house?

No, but then again I don't have a railway line running through it.
--- old post above --- --- new post below ---

For someone to come into contact with AC they'd have to generally be trespassing or have evacuated/left a train before the power has been switched off.

There's more chance of someone coming into contact with DC as for example a rail employee could trip and fall onto the 3rd rail. DC is also more prone to arcing from external factors eg Gatwick when the drinks can bridged the gap between the running rail and the juice rail

"For someone to come into contact......" Do explain how a person evacuated off a train may come into contact with the overhead contact wire.
Rail employees tend not to trip over the conductor rail as they have been sent on expensive courses before being let near a line equipped thus.

 

[SpacePhoenix]

"For someone to come into contact......" Do explain how a person evacuated off a train may come into contact with the overhead contact wire.

Knitting down, someone pulls the passcomm or egress handle, door opens, they climb down and come into contact with downed wires

Rail employees tend not to trip over the conductor rail as they have been sent on expensive courses before being let near a line equipped thus.

They could have been sent on a course costing £1,000,000 they'd still have just as much chance of tripping over then having been on a course costing £1 or even £0.01 They'd only need to loose their footing on the ballast

 

[FenMan]

Picking up a point in the Council's statement.

More than 5.5 million passengers used the route last year

That's nearly 108,000 passengers a week on average (allowing for Xmas and engineering closures). I'll speculate that breaks down to 18,000 each weekday, 10,000 on Saturdays/BHs and 7,000 on Sundays.

There are 80 services a day on weekdays, so 18000/80 = an average of 225 passengers using each service.

Given that many passengers make intermediate journeys rather than end to end, I'd hazard a guess that the 225 figure would mean an average loading at any one time of c.150 passengers.

As a regular user of NDL services (mainly off peak) I know they are well used, but not this well used!

 

[DerekC]

Knitting down, someone pulls the passcomm or egress handle, door opens, they climb down and come into contact with downed wires

So how many passengers have been killed that way in the past 50 years? I suspect the answer is zero, for a very good reason. The moment the wires touch something they short to earth and the protection trips.


This argument is getting a bit silly. Both 3rd rail and OLE work well. 3rd rail is much cheaper but is electrically much less efficient (losses up to 30% of the energy put in - and electricity isn't cheap) and also more hazardous for railway staff and trespassers (yes, I know they shouldn't be there, but....). No difference in safety for passengers. If want to go at more than 100mph then you need OLE. So in a logical world it's a balance. There doesn't seem much doubt that 3rd rail would be the logical choice for the North Downs Line, unless there is a long term plan to change 3rd rail to OLE, which there was. It remains to be seen whether it will survive the new clearance rules (which are UK self-inflicted, not a product of the EU), OLE cost escalation and latest energy cost predictions. What needs to be done is for RSSB to re-run the study it did about 3-4 years ago to see whether the case for 3rd rail to OLE conversion still stands up. Then some logical decisions can be taken.

 

[Domh245]

Knitting down, someone pulls the passcomm or egress handle, door opens, they climb down and come into contact with downed wires

Fairly sure that wires coming down usually results in them tripping various circuit breakers and thus not being live.

 

[Phil.]

I am not saying that third rail is safer than OHLE. Just that I don't find its level of danger to be 'incredible' like you seem to.

And I think that someone who chooses to cycle down steps onto a platform has to take responsibility for the direct consequences of their actions.

You can do what you like but you can't legislate for idiots. That's what many H&S desk jockeys don't/can't understand.

 

[TheKnightWho]

You can do what you like but you can't legislate for idiots. That's what many H&S desk jockeys don't/can't understand.

So people deserve to die due to ignorance, do they?

 

[Mordac]

So people deserve to die due to ignorance, do they?

Of course they don't deserve to die, but the question is how much cost should we as a society be willing to incur to protect people from the consequences of their own folly.

 

[Phil.]

So people deserve to die due to ignorance, do they?

No and you should know that that's not what I'm alluding to. You can take every safety precaution known to mankind but there's always someone who manages to hurt/injure/kill themselves. I refer you to A.H.B. crossings. Barriers, bells, lights yet still people get killed on them.
Late 1970s Hornsey. A 312 in a siding with a plastic bin-liner thing wrapped around the pantograph. What caused a fully trained passed-out Guard after seeing it there to climb up and try and remove it?
Brian was a lovely chap and the eulogies at his funeral were fulsome and generous but, like I said you can't legislate for idiots.

 

[TheKnightWho]

No and you should know that that's not what I'm alluding to. You can take every safety precaution known to mankind but there's always someone who manages to hurt/injure/kill themselves. I refer you to A.H.B. crossings. Barriers, bells, lights yet still people get killed on them.
Late 1970s Hornsey. A 312 in a siding with a plastic bin-liner thing wrapped around the pantograph. What caused a fully trained passed-out Guard after seeing it there to climb up and try and remove it?
Brian was a lovely chap and the eulogies at his funeral were fulsome and generous but, like I said you can't legislate for idiots.

Well you're literally saying that we shouldn't spend money ensuring that people don't die through ignorance, and are implying it's their own fault if they die, as though that's more important than the fact that they're dead regardless of who's to blame.

 

[JamesRowden]

Well you're literally saying that we shouldn't spend money ensuring that people don't die through ignorance, and are implying it's their own fault if they die, as though that's more important than the fact that they're dead regardless of who's to blame.

`Ignorance' is not always the reason for people putting themselves in such situations since some people choose to take the risk.

 

[Mordac]

Well you're literally saying that we shouldn't spend money ensuring that people don't die through ignorance, and are implying it's their own fault if they die, as though that's more important than the fact that they're dead regardless of who's to blame.

But where do you draw the line? I'm assuming (perhaps cavalierly) that you agree there is some hypothetical level of spending that is too much, given we live in a world of finite resources and there are other things society needs to have money spent on. The question is where do we draw the line, and should costs be incurred to protect people from their own recklessness (which is the issue people are highlighting, not ignorance as you want to make it about).

 

[The Ham]

But where do you draw the line? I'm assuming (perhaps cavalierly) that you agree there is some hypothetical level of spending that is too much, given we live in a world of finite resources and there are other things society needs to have money spent on. The question is where do we draw the line, and should costs be incurred to protect people from their own recklessness (which is the issue people are highlighting, not ignorance as you want to make it about).

There is an argument that there is a level of spending which is such that means that staff only spend time in training and have no time to come in contact with high voltage electrification.

 

[Elecman]

Fairly sure that wires coming down usually results in them tripping various circuit breakers and thus not being live.

Not if they don't touch Earth at a reasonably low impedance as sufficient current has to flow through the protection relays to operate the tripping mechanism. If the wires don't touch anything earthed then they will remain live. ( the weaver area driver incident earlier this year for instance).

 

[HSTEd]

Inefficiency is important - as far as I'm aware we still rely on large amounts of Gas to produce our power, and any losses that you can get rid of should be gotten rid of. Also remember that an inefficient system means less power for the train. On the NDL it may not be massive worry, but as a general argument for OLE v Third Rail, inefficiency is a big concern

The cost of running a train in electricity terms is pence per vehicle-km. (Only about ~2.2kWh/vehicle-km for a Cl357 IIRC). So 30% being lost before it makes the train isn't going to bankrupt the railway given all its other costs. And power can be increased, primitively, by apply more aluminium cable or conductor rail - which aren't that expensive.
30% losses at the current 5-6p/kWh for big electricity users is going to come to about 5p/vehilce-km or something.

And all the high traffic areas in and around third rail land have already been electrified. So it isn't really a concern for new construction.

Exposed 750V conductors at ground level able to deliver thousands of Amps into anything that provides a path to earth without detecting a short circuit.

If it was that dangerous we would have reports of people being cooked left right and centre. We don't.
Are the exposed busbars in an aluminium smelter ludicrously dangerous?

Or do you have bare mains voltage wires lying around your house?

No Comment

 

[Elecman]

The cost of running a train in electricity terms is pence per vehicle-km. (Only about ~2.2kWh/vehicle-km for a Cl357 IIRC). So 30% being lost before it makes the train isn't going to bankrupt the railway given all its other costs. And power can be increased, primitively, by apply more aluminium cable or conductor rail - which aren't that expensive.
30% losses at the current 5-6p/kWh for big electricity users is going to come to about 5p/vehilce-km or something.

And all the high traffic areas in and around third rail land have already been electrified. So it isn't really a concern for new construction.


If it was that dangerous we would have reports of people being cooked left right and centre. We don't.
Are the exposed busbars in an aluminium smelter ludicrously dangerous?


No Comment

Your 5-6p/kWh is way to low

 

[najaB]

If it was that dangerous we would have reports of people being cooked left right and centre. We don't.

Are you saying that third-rail DC electrification doesn't require that there are exposed conductors at ground level capable of delivering thousands of amps to ground without detecting a short?

 

[HSTEd]

Your 5-6p/kWh is way to low

Set this to a one year graph. [£10/MWh is 1p/kWh]
Remember the railway pulls the supply direct from the 132kV or even 400kV network. It basically does not pay any significant grid distribution costs. And even with the railways costs they are far lower than typical because it has no enormously expensive 400/230V network that stretches for huge mileages to maintain.

 

[NSEFAN]

Are you saying that third-rail DC electrification doesn't require that there are exposed conductors at ground level capable of delivering thousands of amps to ground without detecting a short?

I think his point is that we would see a higher death rate if 3rd rail is more dangerous in practice (do we? I honestly don't know). Of course you wouldn't design such a system like that from the outset these days for safety or power delivery efficiency reasons, although the sheer amount of legacy infrastructure using it makes it far more justifiable to use the same system for infill, particularly given that the infrastructure providers have their hands full on the AC electrification front...

 

[dviner]

The cost of running a train in electricity terms is pence per vehicle-km. (Only about ~2.2kWh/vehicle-km for a Cl357 IIRC). So 30% being lost before it makes the train isn't going to bankrupt the railway given all its other costs.

Maybe it won't bankrupt the railway, but a 30% loss is still a lot of loss, and quite wasteful if it can be otherwise prevented.

 

[HSTEd]

Are you saying that third-rail DC electrification doesn't require that there are exposed conductors at ground level capable of delivering thousands of amps to ground without detecting a short?

No - I am saying that it is not ludicrously dangerous.

Maybe it won't bankrupt the railway, but a 30% loss is still a lot of loss, and quite wasteful if it can be otherwise prevented.

But as we have seen from the ever escalating costs of the Great Western programme, its massive descoping and the shelving of other proposed electrification projects [including Hull] - that it is highly unlikely that it can be reasonably prevented. The increase in the clearances required for projects is going to be staggeringly expensive to deal with in future.

It [electricity loss] is a negligible cost and is overwhelmed by the apparent capital and other benefits of simply providing a third rail solution for the route.
30% of 1% of the operating costs sounds like a lot but is only 0.3% of the cost after all.
And remember that those 30% loss figures are typical for the entire system, they can be significantly lower in a lower traffic scenario like the North Downs.

EDIT:

Looking for actual data I have found this report.
Apparently in 2014-15 there were 43 non-suicide fatalities on railways in total, with 39 on the mainline, one on LU and one on another railway operation. 10 of these fatalities were Level Crossing users (mostly pedestrians hit by trains, but two were killed in car(s)).
That leaves a total of 33 fatalities from other causes.

Overall stats by cause of death are not listed, however two staff members were killed by electrocution in 2014-15. Although I have no idea how they came to be electrocuted.
Either way the numbers are so small I am not convinced that even if the data existed it would be possible to show that third rail was significantly more (or less) dangerous than 25kV supplies in practice.

EDIT #2:
This report has the statistics for 2013-14.
It indicates that in that year there were ~3 trespass deaths [estimate from a graph] by electrocution. There were apparently no workforce or passenger electrocutions that year.

In other words we are in low single digit numbers, across all sources of electric shock on the railway network.
Even if all three tresspass deaths were from third rail - that is still an absolutely tiny number for so many vehicle-kilometres run and passenger-km provided.

 

[The Ham]

No - I am saying that it is not ludicrously dangerous.



But as we have seen from the ever escalating costs of the Great Western programme, its massive descoping and the shelving of other proposed electrification projects [including Hull] - that it is highly unlikely that it can be reasonably prevented. The increase in the clearances required for projects is going to be staggeringly expensive to deal with in future.

It [electricity loss] is a negligible cost and is overwhelmed by the apparent capital and other benefits of simply providing a third rail solution for the route.
30% of 1% of the operating costs sounds like a lot but is only 0.3% of the cost after all.
And remember that those 30% loss figures are typical for the entire system, they can be significantly lower in a lower traffic scenario like the North Downs.

EDIT:

Looking for actual data I have found this report.
Apparently in 2014-15 there were 43 non-suicide fatalities on railways in total, with 39 on the mainline, one on LU and one on another railway operation. 10 of these fatalities were Level Crossing users (mostly pedestrians hit by trains, but two were killed in car(s)).
That leaves a total of 33 fatalities from other causes.

Overall stats by cause of death are not listed, however two staff members were killed by electrocution in 2014-15. Although I have no idea how they came to be electrocuted.
Either way the numbers are so small I am not convinced that even if the data existed it would be possible to show that third rail was significantly more (or less) dangerous than 25kV supplies in practice.

EDIT #2:
This report has the statistics for 2013-14.
It indicates that in that year there were ~3 trespass deaths [estimate from a graph] by electrocution. There were apparently no workforce or passenger electrocutions that year.

In other words we are in low single digit numbers, across all sources of electric shock on the railway network.
Even if all three tresspass deaths were from third rail - that is still an absolutely tiny number for so many vehicle-kilometres run and passenger-km provided.

Those sorts of low figures are the reason that it is hard to claim that one thing is safer than another on the railways (be it electrification method, DOO, or whatever else you care to think of)

Take for instance the 3 electrifications above, if the average is that they are split 50:50 but in any one year they could be all from OHLE or 3rd rail then there could be a short term (day over a 3 year period) where 3rd rail could look unsafe as it could have a 75:25 split on the deaths. However, it could well be that another 3 year period a few years later has the split 25:75 in the favour of OHLE deaths. Yet over 10 years it could still be that it is 50:50 (or at least close enough to make no difference).

 

[DerekC]

Well you're literally saying that we shouldn't spend money ensuring that people don't die through ignorance, and are implying it's their own fault if they die, as though that's more important than the fact that they're dead regardless of who's to blame.

The "value of preventing a fatality" according to RSSB is £1.826M in 2016. The work on DC to AC conversion done in 2012 did some digging to find out what the likely difference in fatality rate would be if the DC third rail network was converted to AC OLE. The figures used were roughly 9 fatalities per year for the DC network (this includes trespassers and staff) and 1 for the same network if converted to AC. So the saving per year in economists' terms would be £16M.

The figures on reliability of the infrastructure are interesting too. The DC network is about twice as reliable as the AC network (in terms of Schedule 8 costs) in normal conditions, but when weather is factored in the difference reverses because of the impact of snow and ice on the conductor rail. Overall the AC network came out about 20% more reliable than DC based on historical figures - but of course it depends what weather you assume for the future.

 

[XDM]

Are you saying that third-rail DC electrification doesn't require that there are exposed conductors at ground level capable of delivering thousands of amps to ground without detecting a short?

Facts not fantasy please. The test of the safety,& therefore extension of third rail on the north downs line,is the statistics,the science. There is no evidence that third rail is more of a killer per electrified mile than AC. And since Network Rail cannot deliver new AC work effectively,let the TOC supervise the far simpler third rail extension as per Grayling's new rules.

 

[SpacePhoenix]

They might not even bother with either AC or DC, they might just use bi-modes. Is there any stretches that have a top speed above 60mph?