North Downs line electrification

[Domh245]

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.

Also worth noting that in an ideal world, you would have the changeovers at strategic points where there are facilities to accommodate a train that doesn't want to behave itself, or at the least, a way of reversing trains, and preferably at places where the timetable has a longer than normal layover (which on the NDL would be Redhill). It doesn't always work out that way though.

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

Because NR have never had to raise a bridge or lower track before? It feels like half of the NW electrification albums maintained by LDECRexile consist of photos of bridge works!

 

[Philip Phlopp]

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.

If third rail infill is such a good idea, why is it completely absent from the Wessex RUS, and why is 25kV AC there instead ?
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Also worth noting that in an ideal world, you would have the changeovers at strategic points where there are facilities to accommodate a train that doesn't want to behave itself, or at the least, a way of reversing trains, and preferably at places where the timetable has a longer than normal layover (which on the NDL would be Redhill). It doesn't always work out that way though.

I'll do a Golden Pantograph award for TOCs and ROSCOs who manage to have zero changeover failures in the year.

 

[greaterwest]

Because NR have never had to raise a bridge or lower track before? It feels like half of the NW electrification albums maintained by LDECRexile consist of photos of bridge works!

Of course they have, but that just means even more work for them (and if they lower track at Crowthorne, they have to lower the platforms because the bridge is literally at the platforms, and is already a very steep bridge)
--- old post above --- --- new post below ---

If third rail infill is such a good idea, why is it completely absent from the Wessex RUS, and why is 25kV AC there instead ?

I don't know, because I haven't seen the Wessex Electrification RUS. Do you have a link to it?

 

[Philip Phlopp]

I don't know, because I haven't seen the Wessex Electrification RUS. Do you have a link to it?

http://www.networkrail.co.uk/Public...ssex-route-study/Wessex-Route-Study-Final.pdf

 

[greaterwest]

http://www.networkrail.co.uk/Public...ssex-route-study/Wessex-Route-Study-Final.pdf

Indeed? Could you point me to the page, as I was referring to this document earlier (as I said, I hadn't read the whole thing, but pages 109 and 110 contained my points)

 

[Philip Phlopp]

Indeed? Could you point me to the page, as I was referring to this document earlier (as I said, I hadn't read the whole thing, but pages 109 and 110 contained my points)

Table 6.1 Page 123.

Potential CP7 and beyond schemes ('beyond' being the operative word here)
'AC electrification (North Downs Line)'. I'd move everything in the RUS relating to electrification back by at least one control period, as I've said previously.

 

[greaterwest]

Table 6.1 Page 123.

Potential CP7 and beyond schemes ('beyond' being the operative word here)
'AC electrification (North Downs Line)'. I'd move everything in the RUS relating to electrification back by at least one control period, as I've said previously.

Thanks for that.

I do have to say though, it does only say "Potential" (it could change) and I still stand by my point that it would be very illogical to electrify it at 25kV AC at this point in time.

 

[Philip Phlopp]

Thanks for that.

I do have to say though, it does only say "Potential" (it could change) and I still stand by my point that it would be very illogical to electrify it at 25kV AC at this point in time.

You're totally correct when you say it's illogical to electrify the route at 25kV AC at this point in time. It should be totally logical to use 25kV at the time it's electrified though, and if it doesn't, then it wouldn't be electrified.

 

[greaterwest]

You're totally correct when you say it's illogical to electrify the route at 25kV AC at this point in time. It should be totally logical to use 25kV at the time it's electrified though, and if it doesn't, then it wouldn't be electrified.

Even in CP6-7 third rail would make sense, that would take far less effort.

 

[Mikey C]

As an aside it's notable that on the Overground the ELL extensions up to Highbury and Islington were done with 3rd rail, despite this being a "new" line presumably to avoid trains having to change systems after emerging from Whitechapel

 

[TheKnightWho]

Even in CP6-7 third rail would make sense, that would take far less effort.

Effort is not relevant; cost is. The long-term costs of AC electrification are lower.

 

[HSTEd]

Table 6.1 Page 123.

Potential CP7 and beyond schemes ('beyond' being the operative word here)
'AC electrification (North Downs Line)'. I'd move everything in the RUS relating to electrification back by at least one control period, as I've said previously.

Problem is whenever I see potential electrification system dates I start thinking about a certain 50s document I have a copy of that has Newcastle-London under development with work expected to progress within the next decade.

It looks likely that North Downs AC would be at least 30 years out, even if it retains its existing placement in the priority schedule.
A DC scheme in the short term doesn't look rather bad, and after all the third rail extension restriction is not a hard ORR/HMRI requirement - it is a presumption that third rail will not be used.

You could probably make a strong case that a third rail railway is better than a diesel one in terms of passenger capacity, environmental aspects and such.

Effort is not relevant; cost is. The long-term costs of AC electrification are lower.

Perhaps they are (although I am not sure how we can be sure considering no third rail project has progressed since... 88? A lot has changed since then).
But cost is largely irrelevant. The options are not between 25kV and third rail tommorrow.
No 25kV resources will be available for decades, you can either have a third rail railway for 30 years or you can have a diesel railway for 30 years.

Most likely the third rail project with proper scoping will come out cheaper on that horizon, which is the one that really matters, as the project is the very definition of infill.
The thing that British Rail largely understood, and Network Rail sometimes forgets, is that the long term cheapest solution sometimes isn't available because in the real world we do not have unlimited capital resources to actually spend in any given year.
Sure if you had unlimited money 25kV would be better in almost every situation, but we don't. You effectively let the good become the enemy of perfect.

EDIT:

A cursory examination of the timetable indicates that it would (probably) be rare for more than 4 trains to be in the Wokingham-Aldershot South section and no more than 6 in the Shalford-Reigate section.
Trains would likely be 3 car EMUs with roughly 800 traction kilowatts each.
3200kW and 4800kW peak sounds a little small for a GSP. And I doubt conversion of Reading to Waterloo to 25kV is imminent so feeding is going to become a little problematic.
In fact a pair of tram type substations in each section could probably handle it if you gave it a supercap reinforcement once diversity is taken into account.
Think tram infrastructure, just it plugs into the juice rail instead of an overhead line.

 

[greaterwest]

Effort is not relevant; cost is. The long-term costs of AC electrification are lower.

Remember that the North Downs Line comes under infill, which could be cheaper than thorough AC electrification.

 

[AM9]

Would the environment that the line passes through be a consideration?
I imagine that much of the route passing south of the Downs would be subject to severe frosts. 3rd rail doesn't exactly star in the winter on the Portsmouth Direct, but at least it has a frequent enough service to warrant the expense of regular treatment. The North Downs Line isn't in the same league though so there might be several days of iced conductor rail that decimate services every winter.

 

[Taunton]

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.

Not so at all.

When Bakerloo Underground trains stopped running on from Harrow & Wealdstone on to Watford Junction over the DC Line in the 1980s, the former 4th rail in the centre was no longer in use. It just lay there for years afterwards, without being any problem, in some cases having the insulator pots removed for reuse (possibly by Messrs. Tom, Dick or Harry) elsewhere, and the rail being dropped onto the sleepers. It was eventually removed when convenient.

So the situation described is really a fiction, which does of course make us wonder about the rest of the NR justification for conversion, with AC installation issues trivialised and DC issues overblown out of proportion.

 

[Domh245]

As an aside it's notable that on the Overground the ELL extensions up to Highbury and Islington were done with 3rd rail, despite this being a "new" line presumably to avoid trains having to change systems after emerging from Whitechapel

That would have been more to do with the fact that it was running along the old ELL core, where the clearance is rather tight in some places

 

[Philip Phlopp]

Problem is whenever I see potential electrification system dates I start thinking about a certain 50s document I have a copy of that has Newcastle-London under development with work expected to progress within the next decade.

It looks likely that North Downs AC would be at least 30 years out, even if it retains its existing placement in the priority schedule.
A DC scheme in the short term doesn't look rather bad, and after all the third rail extension restriction is not a hard ORR/HMRI requirement - it is a presumption that third rail will not be used.

You could probably make a strong case that a third rail railway is better than a diesel one in terms of passenger capacity, environmental aspects and such.

Perhaps they are (although I am not sure how we can be sure considering no third rail project has progressed since... 88? A lot has changed since then).
But cost is largely irrelevant. The options are not between 25kV and third rail tommorrow.
No 25kV resources will be available for decades, you can either have a third rail railway for 30 years or you can have a diesel railway for 30 years.

There was a very good reason why third rail wasn't considered as an option when the Wessex RUS was finalised, despite the number crunching for performance considering third rail.

It's not specifically to do with third rail itself, yes it would be more expensive and less efficient than 25kV AC, that's not the main reason. Synergies is probably the official buzzword to use but you'll (quite rightly) point and laugh.

The main reason is planning for the eventual replacement of the Class 158 and Class 159 fleets, which is long enough in the future for a realistic electrification program to be developed to allow for their eventual replacement with EMU stock.

That requires electrification from Basingstoke to Exeter, the feeding arrangements for that allow conversion from Basingstoke east towards Farnborough for little more than the OLE and conversion to Woking becomes quite considerably cheaper than like for like DC replacement as a feeder in the Farnborough area powers a section halfway between Basingstoke and Farnborough through to Woking and what would be the south-eastern section of the North Downs Line, with the north-western section fed from Reading.

I understand the feeding arrangements for DC to Exeter were looked at by British Rail and losses reach something like 50% because of the distances involved, even today, things wouldn't be much better because there's limited regenerative braking capability (few or no other trains within each electrical section to use the regenerated electric).

The staff who did the Wessex RUS were still, at the time, briefed that 25kV AC would be reaching Basingstoke from Reading during CP5, and that electrification resources would be available from the GWML project during CP6, as a result, they were rather hoping to electrify Basingstoke to Salisbury during CP6, at 25kV AC, and continue west to Exeter during CP7/CP8 (it sounds a big job but Salisbury to Exeter is only 110 single track miles).

That's all still perfectly achievable even with things slipping one control period to the right, the Class 158/159 fleet still has 20-25 years of life left, so there's a big window available unless there's a further prioritisation of removing diesel stock from London termini under the auspices of air quality.

 

[The Ham]

It's not petty name calling, at least not directly, and he's perfectly right. Why replace perfectly capable & functioning 750vDC with 25kV AC? An infill would certainly be cheaper!

It is functioning now, but when does it need replacing/significant work to maintain it (IIRC the justification for the conversion between Basingstoke and Southampton).

If the third rail it needs a lot of money spent to keep it going and OHLE replacement is of a similar value but with lower ongoing costs, which is the better to do?

As an example, if you have a non electrified line and the DMU's are up for replacement and the cost difference to replace with EMU's is enough that electrification starts being sensible why should we keep using DMU's just because they currently work well?

 

[greaterwest]

As an example, if you have a non electrified line and the DMU's are up for replacement and the cost difference to replace with EMU's is enough that electrification starts being sensible why should we keep using DMU's just because they currently work well?

There are other problems with using DMUs though, e.g. the environment, lack of maintenance facilities, age of the stock. The price of re-electrifying the current 3rd rail infrastructure would probably cost as much as the long term maintenance of said third rail.

Also remember Network Rail's appalling estimates for both time and money (look at the GWML) and that's a relatively short and straight route!

 

[Mikey C]

That would have been more to do with the fact that it was running along the old ELL core, where the clearance is rather tight in some places

I wasn't referring to the tunnel section, but rather what happens when the line gets past Whitechapel, the new section along the Broad Street viaduct. It clearly was easier operationally to lay new third rail up to Dalston Junction and Highbury & Islington rather than changeover to OHLE.

 

[Philip Phlopp]

Also remember Network Rail's appalling estimates for both time and money (look at the GWML) and that's a relatively short and straight route!

Short and straight ? Please don't talk nonsense.

We're electrifying just over 650 single track miles, of which the majority is 125mph and good proportion is four track railway, there's active provision for 140mph running with the OLE, 170 bridges needed adjustments of some sort, there's the Severn Tunnel and the World Heritage Site at Bath to consider.

And the route mileage hasn't remained static, Government added to it during the CP5 settlement, Network Rail has taken some of that in total silence, as late as February 2015 HM Treasury were still intending to proceed with Bristol to Derby via Birmingham in CP6, which needed the electrification work around Bristol to be double checked. We've got Goring residents with pitchforks. The Welsh Government don't appear to have a clue what they're doing with the Valley Lines, and Swansea has been in and out and back in the electrification plan.

The good news - piling rates are often approach twice the rate used in the GWep business case (33/34 v 18) and the steelwork erection and wiring itself is, where it can be measured, faster than previously planned.

The real geniuses are the Scottish team though, doing EGIP and the rolling program, they're doing everything on time and on budget, and making a really good job of everything.

 

[FenMan]

Assuming no change in rolling stock on the NDL, the Class 166s, which are well suited to the line, will be 35 years old in 2027-28 ...

CP8 is 2029-34, so it's already looking as though the wiggle room for scheduling the NDL electrification has been used up. Are NR praying for significant advances in battery technology in the meantime?

 

[Philip Phlopp]

Assuming no change in rolling stock on the NDL, the Class 166s, which are well suited to the line, will be 35 years old in 2027-28 ...

CP8 is 2029-34, so it's already looking as though the wiggle room for scheduling the NDL electrification has been used up. Are NR praying for significant advances in battery technology in the meantime?

The Class 165/166 fleet will see 40 years, and probably 50 years before they're replaced, likewise with the Class 158/159 fleet. The oldest Class 150 units are 32 years and they've got at least a decade before anything will happen with them, the Class 156 fleet is almost 30 years and they're being prepared for another 15 to 20 years in service.

Pacers aside, I'll be shocked and amazed if any diesel stock is withdrawn at less than 40 years old.

 

[greaterwest]

Short and straight ? Please don't talk nonsense.

We're electrifying just over 650 single track miles, of which the majority is 125mph and good proportion is four track railway, there's active provision for 140mph running with the OLE, 170 bridges needed adjustments of some sort, there's the Severn Tunnel and the World Heritage Site at Bath to consider.

That's great but what about the unforseen signalling cables NR "found" which complicated matters? Looks like poor planning from my point of view. I was also on about the relatively short stretch they are working on between Paddington and Didcot, not all the way to Bath, Bristol, the Severn Tunnel and Wales, rather than the whole stretch, so I should have probably pointed that out.

What's to say NR won't poorly plan the NDL AC electrification (if indeed 25kV AC DOES go ahead there).

They don't seem to learn from their mistakes. But that is not what this thread is about.

 

[hwl]

That's great but what about the unforseen signalling cables NR "found" which complicated matters? Looks like poor planning from my point of view. I was also on about the relatively short stretch they are working on between Paddington and Didcot, not all the way to Bath, Bristol, the Severn Tunnel and Wales, rather than the whole stretch, so I should have probably pointed that out.

What's to say NR won't poorly plan the NDL AC electrification (if indeed 25kV AC DOES go ahead there).

They don't seem to learn from their mistakes. But that is not what this thread is about.

By the time many future electrification or conversion schemes come up the signalling cable is likely to have been replaced with resignalling already. On many routes it wasn't buried and it location is well known and it readily accessible.
And if it has been buried there is plenty of time to plan what to do about it.

 

[Domh245]

That's great but what about the unforseen signalling cables NR "found" which complicated matters? Looks like poor planning from my point of view. I was also on about the relatively short stretch they are working on between Paddington and Didcot, not all the way to Bath, Bristol, the Severn Tunnel and Wales, rather than the whole stretch, so I should have probably pointed that out.

You mean those that were hidden by the former western region because they thought that electrification wasn't going to happen, and what few plans existed were lost by railtrack? Those ones that have been well document, including by PP earlier in the thread?

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.

Not to mention of course the fact that as the first use of Series 1 OHLE, the HOPS train, and the first major electrification since the ECML, it was never going to be an easy turn up and go job. As I said earlier, if MML electrification follows a similarly calamitous route, then maybe there should be cause for concern, but until then, it's a bit like criticising a 3 year old for not being able to ride a bike

What's to say NR won't poorly plan the NDL AC electrification (if indeed 25kV AC DOES go ahead there).

They don't seem to learn from their mistakes. But that is not what this thread is about.

For all everyone goes around saying that NR couldn't organise a **** up in a brewery, if they were really as incompetent as everyone said, we'd be in a somewhat Railtrack-esque era of mismangement. Not to mention that with practice comes experience. If you hadn't done something on as complicated a scale as this for several decades, you'd quite rightfully be quite rusty at it!

 

[AM9]

Not so at all.

When Bakerloo Underground trains stopped running on from Harrow & Wealdstone on to Watford Junction over the DC Line in the 1980s, the former 4th rail in the centre was no longer in use. It just lay there for years afterwards, without being any problem, in some cases having the insulator pots removed for reuse (possibly by Messrs. Tom, Dick or Harry) elsewhere, and the rail being dropped onto the sleepers. It was eventually removed when convenient.

So the situation described is really a fiction, which does of course make us wonder about the rest of the NR justification for conversion, with AC installation issues trivialised and DC issues overblown out of proportion.

Slight difference there. Just because the redundant centre rail was disconnected and even lifted from the pots and laid in the 4-foot, there is still the rather nagging problem of the 3rd rail with +630VDC waiting to bite just a few inches outside one or other of the running rails. It would need either a very well equipped (or incredibly stupid) Tom, Dick or Harry to try and lift 150lb/yard conductor rail under those conditions. And that's not to mention the need for quite a long period between trains and maybe the need to use cutters to break it up where welded.

 

[GRALISTAIR]

They don't seem to learn from their mistakes. But that is not what this thread is about.

I would love you to give an example of a lesson not learned from a mistake.

You mean those that were hidden by the former western region because they thought that electrification wasn't going to happen, and what few plans existed were lost by railtrack? Those ones that have been well document, including by PP earlier in the thread?

Not to mention of course the fact that as the first use of Series 1 OHLE, the HOPS train, and the first major electrification since the ECML, it was never going to be an easy turn up and go job. As I said earlier, if MML electrification follows a similarly calamitous route, then maybe there should be cause for concern, but until then, it's a bit like criticising a 3 year old for not being able to ride a bike.

Exactly. I confess I am a "glass is half-full" person, but with the timetable of electrification post-Hendy now more realistic, plus all the teams getting up to speed (and lessons learned!!!) I am sure we should see North Downs electrified in my lifetime at 25kV AC OHLE.

I just need to learn patience - as I am looking forward to the electrification RUS being published later this year. I will kill some trees and print off the entire document and have a wonderful read with my Gin and Tonic.

 

[Mikey C]

The Class 165/166 fleet will see 40 years, and probably 50 years before they're replaced, likewise with the Class 158/159 fleet. The oldest Class 150 units are 32 years and they've got at least a decade before anything will happen with them, the Class 156 fleet is almost 30 years and they're being prepared for another 15 to 20 years in service.

Pacers aside, I'll be shocked and amazed if any diesel stock is withdrawn at less than 40 years old.

I suspect that emissions concerns will reduce the life span of DMUs, unless they can be re-engined/re-engineered.

 

[Deepgreen]

Slight difference there. Just because the redundant centre rail was disconnected and even lifted from the pots and laid in the 4-foot, there is still the rather nagging problem of the 3rd rail with +630VDC waiting to bite just a few inches outside one or other of the running rails. It would need either a very well equipped (or incredibly stupid) Tom, Dick or Harry to try and lift 150lb/yard conductor rail under those conditions. And that's not to mention the need for quite a long period between trains and maybe the need to use cutters to break it up where welded.

I think the point was that the fourth (redundant) rail could simply be left in place seemingly without being an issue, notwithstanding the third rail still being in use. Whether the fourth rail staying in situ is ideal, given the H&S link to clutter removal is another issue, but it seems not to have caused a problem so far, perhaps because it was continuous rather than intermittent and therefore more 'expected' by workers on the track.