North Downs line electrification

[ScotGG]

You can only wonder what part of The Planet Zog the NR theoreticians come from. It's like the old definition of An Economist ("one for whom the Real World is a Special Case")

South of London has a huge 3rd rail system which has worked well for 100 years. You are discussing this with one who saw BR put the 3rd rail down on Custom House to North Woolwich in the 1980s in, guess what, one WEEKEND! This by a Chesterton Junction (Cambridge) 08-hauled train and a PW crew who had little experience of 3rd rail, a couple of lads from Hoo Junction (Gravesend) came over to assist and advise if required.

You generally know straw-clutching is in hand when tasks are micro-broken down into tiny bits, each presented as a major issue. Oh dear, all those substations. never mind that on the 25Kv railway each 4-car unit is hauling round its own substation/transformer, under the frames, at all times, each of which has to be bought from Bombardier (££) or Siemens (£££).

How is the GW electrification going, to the original budget and timescales? How is that High Output Plant System coming along then with erecting the overhead? Ought to be finished by now, surely?

http://www.bbc.co.uk/news/uk-33425743

Hey, Patrick McLaughlin, the DfT's budgets are safe in their hands.

The speed third rail is replaced in South London is very impressive. Miles in a weekend. And of course there are other things like power upgrades, but even those have gone very well in South London for various upgrades.

It seems that it can be installed quite cheaply and very quickly. OK, so it's more expensive long term but when looking at the alternatives it seems very tempting.

 

[DerekC]

That's one of the reasons why Basingstoke to Southampton was chosen for the pilot scheme, lots of good quality equipment that can be recovered for re-use elsewhere.

It's also one of the routes with the largest transmission and distribution losses, from memory, only the section out to Weymouth is worse but it really was a budget installation, and I don't believe there's much more strengthening work possible on the network in the area either.

There was also a suggestion from permanent way that they might be able to do something with the linespeed between Southampton and Basingstoke, 110mph might have been achievable if there was more power available and the appropriate modifications were made to the Desiro fleet.

All good stuff and there is no doubt in my mind that replacing third rail with OLE is the right thing to do in the long term. I have two or three (sorry, four) worries:

1) That what is planned in a Control Period isn't final until the last HLOS/ORR review carried out immediately before the start - so there is plenty of room for slippage and changing of minds, which will happen even more now the Treasury controls the purse strings direct.

2) Replacement of third rail by OLE has the best whole life cost and there is no "do nothing" option, but there is a danger of adopting a "make do and mend" strategy if OLE costs escalate too much (I share PP's hope that they will get better rather than worse, but it is only a hope).

3) If the infrastructure dates on SWML move too much to the right, cold feet over modifying the Desiro fleet to AC/DC towards the end of their working lives will emerge (yes, I know they were designed for it, but it still costs money).

4) If "make do and mend" of third rail goes on for too long it will undermine the case for conversion (because a lot of the 750VDC kit will get gradually replaced)

The getting on for 20 years of inability of the industry to create a stable plan for ERTMS rollout is a dreadful lesson ... but I am getting a long way off the point of the thread!

 

[snowball]

Electrification RUS is due later this year, which will lay out the electrification schemes we want to undertake from CP6 through to CP8.

Good to know its publication is still planned relatively soon and has not been pushed well into the future.

 

[Deepgreen]

There was also a suggestion from permanent way that they might be able to do something with the linespeed between Southampton and Basingstoke, 110mph might have been achievable if there was more power available and the appropriate modifications were made to the Desiro fleet.

That's one mph faster than a 442 achieved not far from there (albeit under special conditions)!
--- old post above --- --- new post below ---

The speed third rail is replaced in South London is very impressive. Miles in a weekend. And of course there are other things like power upgrades, but even those have gone very well in South London for various upgrades.

It seems that it can be installed quite cheaply and very quickly. OK, so it's more expensive long term but when looking at the alternatives it seems very tempting.

The juice rail is squeezed out of a tube mounted on a yellow train!

 

[hwl]

That's one of the reasons why Basingstoke to Southampton was chosen for the pilot scheme, lots of good quality equipment that can be recovered for re-use elsewhere.

It's also one of the routes with the largest transmission and distribution losses, from memory, only the section out to Weymouth is worse but it really was a budget installation, and I don't believe there's much more strengthening work possible on the network in the area either.

There was also a suggestion from permanent way that they might be able to do something with the linespeed between Southampton and Basingstoke, 110mph might have been achievable if there was more power available and the appropriate modifications were made to the Desiro fleet.

I have the report on the Bournemouth Electrification '65-'67 somewhere and it states the reason 3rd rail was chosen over national guidance at the time for 25KV OHLE was that only 3rd rail could be delivered in time to eliminate steam before the national deadline, they (Southern Region and BR) knew it was sub-optimal then! Bournemouth was done comparatively cheaply looking at the report and the losses will be relatively high given the way it was engineered also hence the need for massive reinforcement when the Desiros came along (and Weymouth for the "Olympics").

"Sparks effect" was measured at 20% over steam traction.

 

[Philip Phlopp]

Good to know its publication is still planned relatively soon and has not been pushed well into the future.

It will include between 1000 and 1250 single track miles of electrification schemes to go forward to DfT and Treasury for funding between mid CP6 and end of CP8. The precise routes aren't quite finalised as yet.

That takes us to around 60% to 65% of the network being electrified by 2034 (the precise mileage depends on new track and DC->AC conversion).

 

[Deepgreen]

I have the report on the Bournemouth Electrification '65-'67 somewhere and it states the reason 3rd rail was chosen over national guidance at the time for 25KV OHLE was that only 3rd rail could be delivered in time to eliminate steam before the national deadline, they (Southern Region and BR) knew it was sub-optimal then! Bournemouth was done comparatively cheaply looking at the report and the losses will be relatively high given the way it was engineered also hence the need for massive reinforcement when the Desiros came along (and Weymouth for the "Olympics").

"Sparks effect" was measured at 20% over steam traction.

That may be so, but did it also apply to Tonbridge to Bo Peep Junction, Sanderstead to East Grinstead and Tonbridge to Redhill, all of which were long post-steam? They were 'third railed' as infill projects, I assume, but they simply consolidated the network of DC in the south east.

 

[Bald Rick]

Although Thameslink was stuck with two different systems north and south, so there must be a changeover somewhere, Farringdon was a poor location for it. I've seen it suggested that Kentish Town, with a 4-track platform arrangement and the ability to isolate electrically a track with a problem train would have been more resilient for such a high output route.

The GN 313s have a better chance because if there's a problem at Drayton Park some service can be diverted to Kings Cross.

The (unfortunately) less-than-stellar performance and regular suspensions of the London Overground seems to owe something to supply system changeover issues.


Do bear in mind that the calamitous evening breakdown a few years ago in the tunnel at Kentish Town started with a changeover problem. I'm not saying these issues would all happen, but surely it's a risk which the present DC network doesn't have and which should be avoided by keeping clear of changeover points.

I think many of the issues above are from a Network Rail, only, perspective rather than an overall system one. There will still be substations, in fact many more, they are just transferred from NR's lineside to the TOC's train equipment. Regarding 3rd rail equipment being bespoke to the old SR, that's just not correct, there are a substantial number of Metros all round the world which happily use it and buy mainstream kit from manufacturers, and manage to have perfectly reliable signalling.

Track layouts under 25Kv always seem to have to be far more set in stone and unalterable, whether for points, superelevation, or whatever, than in 3rd rail land.

1) What less than stellar performance of LO? There's only 2 places they change over in regular service, and almost all the changeover issues I have ever heard of on LO are drivers forgetting to drop the pantograph. This happens about once a 'regular suspensions' are nothing to do with the changeover, and indeed rarely anything to do with the power system. Except that is south of Gunnersbury, where the signalling is notoriously unreliable, caused in part by the presence of the third rail return currents.

2) the Kentish Town incident was not changeover related. It was debris in the pantograph well.

3) (hopefully to kill this thread). Network Rail has no current plans to electrify the North Downs Line with either system. There's limited money and other lines have priority.

 

[abn444]

That may be so, but did it also apply to Tonbridge to Bo Peep Junction, Sanderstead to East Grinstead and Tonbridge to Redhill, all of which were long post-steam? They were 'third railed' as infill projects, I assume, but they simply consolidated the network of DC in the south east.

That's why it would surely be better to 3rd rail the North Downs Line, for continuity, rather than have a mish mash of 3rd rail and OLE. Surely it would be better to reduce the number of switchover points even if it means not using the best system, rather than slowing trains down with them constantly having to change power supply.

Talking about continuity, how much would it take to extend the OLE from Acton to Richmond on the North London Line? There would be an overlap with the 4th rail system for the Underground but surely the LO trains could still run on overhead even with there being a 3rd/4th rail around.

 

[HSTEd]

There is nowhere near enough 25kV resources to go around.

3rd rail luckily requires different resources.
It is not a case of 25kV or 3rd rail.

It is, in this case, a choice of 3rd rail or nothing.

I, apparently unlike Phillip, would rather have an electric railway than a diesel one, even a suboptimal electric one.
As for AC to DC conversions - the political fallout from the announcement that electrification work in the North has been stopped so the resources could be diverted to marginally improving the performance of Southern Region routes would be enormous.

 

[Deepgreen]

1) What less than stellar performance of LO? There's only 2 places they change over in regular service, and almost all the changeover issues I have ever heard of on LO are drivers forgetting to drop the pantograph. This happens about once a 'regular suspensions' are nothing to do with the changeover, and indeed rarely anything to do with the power system. Except that is south of Gunnersbury, where the signalling is notoriously unreliable, caused in part by the presence of the third rail return currents.

2) the Kentish Town incident was not changeover related. It was debris in the pantograph well.

3) (hopefully to kill this thread). Network Rail has no current plans to electrify the North Downs Line with either system. There's limited money and other lines have priority.

I don't think it's necessary to "kill this thread"; just widen it to the general future of the NDL, as it's an interesting oddity in the south east's network. From a purely selfish view (literally), I hope the OHLE is hugely delayed as I can see the line from my house! Roll on usable fuel cell technology, I say (make sure those 442s are stored in cotton wool until they can be so fitted!).

 

[TheKnightWho]

3) (hopefully to kill this thread). Network Rail has no current plans to electrify the North Downs Line with either system. There's limited money and other lines have priority.

If you'd actually read the thread, you'd have seen that that isn't actually true.

 

[Phil.]

Could I be as bold as to mention that third rails are limited to 100mph running as well as all the other disadvantages so excellently laid out by PP? I'm sure there are stretches on the southern network that could run faster under wires.

We're talking about the North Downs line. You ain't never gonna see 100 mph over there. The silly thing is, is that the third rail infill for the North Downs is so relatively simple. There are no bridges to work on and no track in tunnels to lower. Reigate - Shalford Junction and Ash - Wokingham and Robert's your father's brother.

 

[Domh245]

I, apparently unlike Phillip, would rather have an electric railway than a diesel one, even a suboptimal electric one.

But how much are you willing to pay for it?

As for AC to DC conversions - the political fallout from the announcement that electrification work in the North has been stopped so the resources could be diverted to marginally improving the performance of Southern Region routes would be enormous.

Given the amount of 3rd rail that exists, I almost wonder if it is worth setting up a group of people and resources - specifically for converting third rail to OHLE. Whilst you could get regular OHLE installers in to do it, it does (as you say) divert resources away from non-electrified routes, but it also strikes me that conversion isn't quite as simple as regular installation (especially when it comes to the clean up, removing all the third rails and gubbins)

If you'd actually read the thread, you'd have seen that that isn't actually true.

I read it as more of they have a plan to plan to electrify. It isn't a current plan!

 

[Bald Rick]

If you'd actually read the thread, you'd have seen that that isn't actually true.

If you actually sat at my desk, you'd know what is true!

 

[Deepgreen]

We're talking about the North Downs line. You ain't never gonna see 100 mph over there.

Oh I don't know - there's a nice straight from just east of Betchworth summit to Reigate!!

 

[HSTEd]

But how much are you willing to pay for it?

Well given the costing problems 25kV has been having recently, I am not sure how a minimum spec North Downs 750V solution could come out much worse.

Given the amount of 3rd rail that exists, I almost wonder if it is worth setting up a group of people and resources - specifically for converting third rail to OHLE. Whilst you could get regular OHLE installers in to do it, it does (as you say) divert resources away from non-electrified routes, but it also strikes me that conversion isn't quite as simple as regular installation (especially when it comes to the clean up, removing all the third rails and gubbins)

It would probably be better to set up an extra dedicated 25kV installation team.
As regards clearing up after conversions, is there any pressing need to actually remove all the third rails and the like? Sure you come along and install earthing bonds and the like, and you would probably cut off all the copper section cables, but the aluminium steel rails probably aren't worth removing until the track comes along for relaying.
Ditto the largely aluminium cabling that is being installed these days.
It is probably not worth going digging for stuff that is not exposed on the surface.

 

[Alfie1014]

Although Thameslink was stuck with two different systems north and south, so there must be a changeover somewhere, Farringdon was a poor location for it. I've seen it suggested that Kentish Town, with a 4-track platform arrangement and the ability to isolate electrically a track with a problem train would have been more resilient for such a high output route

Remember that when it started Thameslink connected two very different BR regions (SR and LMR), it was difficult enough persuading them to crew throughout with many changes at Farringdon at the start which hardly helped robust operation. The AC/DC changeover gear was originally limited to small number of trains, significantly exceeding this would bring the end of the world as we knew it according to the M&EE, (slight exageration there!) But over time the equipment was enhanced an more and more trains were able to operate.

 

[GRALISTAIR]

Given the amount of 3rd rail that exists, I almost wonder if it is worth setting up a group of people and resources - specifically for converting third rail to OHLE.

This would be my preferred approach too. A nice steady rolling program and good long term thinking.

https://en.wikipedia.org/wiki/North_Downs_Line
I added the wiki link as a way of bookmarking and keeping info together

 

[Philip Phlopp]

Well given the costing problems 25kV has been having recently, I am not sure how a minimum spec North Downs 750V solution could come out much worse.

25kV catenary is actually getting cheaper, it's the additional payments for all the engineers standing around trackside looking sheepish after they've hit yet another signal cable that shouldn't have been where it was, the additional payments for more equipment hire, and the compensation payments to TOCs that have blown the budget to bits on the GWML.

Signalling cable runs on third rail routes have traditionally been much more disciplined, they've had to be, and we're no longer dealing exclusively with the Western region, which did have certain unusual habits, and which told its engineers for 20+ years that electrification was never going to happen, so don't worry about it.

Southern was always prepared for further electrification - that's how Weymouth went relatively smoothly at the time, though BR not having to hand over a sack of gold coins in compensation for a train being cancelled that the TOC and ROSCO would rather didn't run anyway certainly helped.

It would probably be better to set up an extra dedicated 25kV installation team.
As regards clearing up after conversions, is there any pressing need to actually remove all the third rails and the like? Sure you come along and install earthing bonds and the like, and you would probably cut off all the copper section cables, but the aluminium steel rails probably aren't worth removing until the track comes along for relaying.
Ditto the largely aluminium cabling that is being installed these days.
It is probably not worth going digging for stuff that is not exposed on the surface.

I'd definitely want a dedicated team, not pulling manpower, plant and experience off other projects. I would want a team becoming experienced in third rail conversion work, and I'd have them pull the third rail and cabling as they go, it would generally need to be considered live until removed for safety purposes until removed, and that's just a PITA.

You'll have every Tom, Dick and Harry trying to help themselves to third rail the minute it's switched off, the trouble that would cause in terms of delays and probably fatalities in the fullness of time, would easily justify cleaning and tidying as they go. The reusable stuff in particular (switchgear etc) needs recovered before it falls prey to metal thieves.

Pulling the third rail as you go also leaves the route open to regular OTP.
--- old post above --- --- new post below ---

If you'd actually read the thread, you'd have seen that that isn't actually true.

It's in the RUS to be planned for CP7, but it almost certainly won't happen in CP7. I'd guess CP8 at the earliest. That's just the process to get approval to electrify the route, once that happens, it's the full GRIP process to go through first.

The Electrification RUS refresh that's coming is the same - it's going to suggest further electrification, but until it's authorised, the most that will happen is that the design teams will make things at the end of each current electrification scheme neat and tidy, ready and waiting.

 

[Domh245]

I'd have them pull the third rail and cabling as they go, it would generally need to be considered live until removed for safety purposes until removed, and that's just a PITA.

You'll have every Tom, Dick and Harry trying to help themselves to third rail the minute it's switched off, the trouble that would cause in terms of delays and probably fatalities in the fullness of time, would easily justify cleaning and tidying as they go.

And perhaps most importantly of all, we don't want another debate about trackside scrap!

 

[Philip Phlopp]

And perhaps most importantly of all, we don't want another debate about trackside scrap!

Please no.

 

[hulabaloo]

We're talking about the North Downs line. You ain't never gonna see 100 mph over there. The silly thing is, is that the third rail infill for the North Downs is so relatively simple. There are no bridges to work on and no track in tunnels to lower. Reigate - Shalford Junction and Ash - Wokingham and Robert's your father's brother.

Apologies, I was thinking more broadly across the whole of the DC network down south, London to Brighton etc.

 

[Class 170101]

There was also a suggestion from permanent way that they might be able to do something with the linespeed between Southampton and Basingstoke, 110mph might have been achievable if there was more power available and the appropriate modifications were made to the Desiro fleet.

Why must 110mph wait for the Desiro fleet? Voyagers are already cleared to operate at that speed and don't require 3rd Rail or OLE.

There is nowhere near enough 25kV resources to go around.

3rd rail luckily requires different resources.
It is not a case of 25kV or 3rd rail.

It is, in this case, a choice of 3rd rail or nothing.

I, apparently unlike Phillip, would rather have an electric railway than a diesel one, even a suboptimal electric one.
As for AC to DC conversions - the political fallout from the announcement that electrification work in the North has been stopped so the resources could be diverted to marginally improving the performance of Southern Region routes would be enormous.

How long does the 3rd Rail last in terms of life cycle? Control Period 8 is around 15 years away. If there are no OLE teams available but 3rd Rail teams are available and the life cycle is only 15 years is it not better to electrify with 3rd Rail now?

In any event I thought NR had gone somewhat cold on wiring Basingstoke to Southampton?

 

[Philip Phlopp]

Why must 110mph wait for the Desiro fleet? Voyagers are already cleared to operate at that speed and don't require 3rd Rail or OLE.

Basingstoke to Southampton is mainly 90mph except for Classes 442, 444, 450 and HST which are permitted to travel at 100mph.

How long does the 3rd Rail last in terms of life cycle? Control Period 8 is around 15 years away. If there are no OLE teams available but 3rd Rail teams are available and the life cycle is only 15 years is it not better to electrify with 3rd Rail now?

In any event I thought NR had gone somewhat cold on wiring Basingstoke to Southampton?

40 years typical life expectancy for most third rail equipment, maybe longer with the newer generation of equipment.

Reading to Basingstoke electrification (at 25kV) straddles CP5 and CP6, with completion expected in CP6. The rest of the Electric Spine has been bundled into CP6, there's nothing happening at the moment, though there should be a couple of people double checking nothing is done to make it any more complicated.

 

[HSTEd]

Its not as if there is any shortage of third rail to convert - so there is little chance that new third rail equipment will have to be ripped out before it is life expired.

And 25kV resources will always have more lines to do if there is no life expired third rail to replace.

 

[Philip Phlopp]

Its not as if there is any shortage of third rail to convert - so there is little chance that new third rail equipment will have to be ripped out before it is life expired.

And 25kV resources will always have more lines to do if there is no life expired third rail to replace.

You know how it's likely to 'go down'. New switchgear goes in and suddenly conversion becomes a top priority, keep the old gear running way beyond its service life and the nod will never come.

 

[abn444]

40 years typical life expectancy for most third rail equipment, maybe longer with the newer generation of equipment.

Isn't that not much less than how long OLE equipment can last then?

Anyway, if they really do go for OLE for the North Downs line electrification, wouldn't the best thing to do to be to have a new OLE system all the way from Reading or Wokingham on the line but keep the existing 3rd rail in place? That way the NDL trains would either not have to switchover or only switchover once but the existing trains that also use the sections with existing 3rd rail at various places along the route wouldn't have to switch either.

 

[Philip Phlopp]

Isn't that not much less than how long OLE equipment can last then?

Anyway, if they really do go for OLE for the North Downs line electrification, wouldn't the best thing to do to be to have a new OLE system all the way from Reading or Wokingham on the line but keep the existing 3rd rail in place? That way the NDL trains would either not have to switchover or only switchover once but the existing trains that also use the sections with existing 3rd rail at various places along the route wouldn't have to switch either.

Yes, very little difference between 750V DC and 25kV in terms of life expectancy.

Too much dual voltage electrification isn't good for signalling and is to be avoided. If there is to be a widespread conversion, changeovers will need to be used more frequently. They're not something you want to have everywhere, but they'll need to be more frequent than at present.

 

[greaterwest]

NDL trains having to switch over anywhere except for Reading is a very silly idea indeed (it's a commuter line, after all; Farringdon is a very special case), and as I have said before, the line would come under a third rail infill scheme. It's just not practical to have OLE and thid rail there.

Then there's the issues I pointed out earlier regarding low bridges, etc.