Options for 3rd rail conversions to 25KvAC

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Peter Sarf

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Thread prompted by mentions of 25KvAC from Reading to Southampton, mentions of the reliability of the (ancient) 3rd rail technology and hints of future conversion to 25KvAC.

Occurs to me that wireing up for 25KvAC most/all of the Southern half of the Thameslink routes would be a good place to start. Then, at least, the new Thameslink trains would not need to be dual voltage (DC capable). The 3rd rail need not be removed straight away as this is needed for other services (e.g. Victoria to Brighton). However there are plenty of existing dual voltage units that could cope if some of it was removed.

If conversion is on the cards then the above would, in my opinion, be a good place to start. I expect its not on the cards but any views ?.

Any other ideas/priorities ?.
 
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swtandgw

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I'd say that the lines that connect with Ashford International would be an ideal candidate, given that platforms 3-6 are already wired, and that it could make for a fully-AC HS1 service. All it just takes is for the remaining platforms that are 3rd rail-only to be wired up, and then for Margate and Dover lines to go full AC, since it would then give the HS1 services a boost in time savings.
 

tbtc

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the Southern half of the Thameslink routes would be a good place to start. Then, at least, the new Thameslink trains would not need to be dual voltage (DC capable)
I presume that the variety of Thameslink termini on the Southern region would mean no chance of wiring up all the various lines to save the cost of dual voltage Thameslink trains.

The South West Trains area seems a logical place to start, as do the Kentish routes alongside HS1 - presumably the Brighton Main Line will be about the final bit of DC left as the (re)electrification teams move along from Hampshire and Kent towards Brighton.
 

swt_passenger

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Basingstoke to Southampton PORT is the place to start because it allows for freight capacity improvements. AC locos can pull longer faster trains, increasing capacity. There is no existing DC capacity for the use of DC locos such as 92s, in addition to the passenger timetable.

That is the main reason it has been chosen for the pilot, it's primarily a freight scheme.

As said, Thameslink's proposed routes in their entirety, and all the relevant diversionary routes, and also the fact that much of it is a four track line, makes it a massively more complex place to start.
 

Peter Sarf

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Damn. Talking if Kent Coast lines (thanks swtandgw & tbtc) which were electrified more recently than Brighton ?, makes me think. The 3rd rail lines that have had a power supply upgrade would (past tense) perhaps have been the most eligible (yes SWT_passenger) ?.

Another criterior would be routes most susceptable to snow/ice problems. Perhaps outer North Kent as that is the most exposed to NE winds of the North sea.

Perhaps the heaviest used lines which would be London suburban would give the best benefit !. November 2010 reminds me of few roads in South London that would have benefited from being heated like South Norwood hill. Then I would not have had to bus & walk home for eight hours (Elephant & Castle 16:00, South Croydon 01:00 via a pub for food), I still have flashbacks :cry:.
 

yorksrob

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If we're going to do this sort of thing, the South Western Division seems the place to start, since there is more interaction with Inter-City type services as well as freight (as mentioned above). There's also the ability to extend Salisburywards, taking in another long route which is currently diesel. Then move progressively Eastwards finishing with the South Eastern which is probably the most self contained area on the Southern.
 

Peter Sarf

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Prolongs the chance of a preserved EPB ever getting out on the good hold South Eastern again :lol:.

I suppose the South Western does give the most National advantages. Exeter area/junctions will then get two excuses to be wired up. Except that Thameslink probably causes more interactions out of the South east. I can also see crossrail being happy to go beyond Abbeywood.

If we are going to work Eastwards from the West does that mean units will be swapped around. I suppose most of them are dual voltage capable so can be converted or switched from 3rd to AC. But it makes sense to have a pool of dual voltage units for whatever area is being converted and then AC only units on the areas completely converted.

On the other hand these AC only units might be new as by then the existing 375/377/450/444s etc might be getting life expired. Timescale ideas anybody ! ?.
 

hwl

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Thread prompted by mentions of 25KvAC from Reading to Southampton, mentions of the reliability of the (ancient) 3rd rail technology and hints of future conversion to 25KvAC.

Occurs to me that wireing up for 25KvAC most/all of the Southern half of the Thameslink routes would be a good place to start. Then, at least, the new Thameslink trains would not need to be dual voltage (DC capable). The 3rd rail need not be removed straight away as this is needed for other services (e.g. Victoria to Brighton). However there are plenty of existing dual voltage units that could cope if some of it was removed.

If conversion is on the cards then the above would, in my opinion, be a good place to start. I expect its not on the cards but any views ?.

Any other ideas/priorities ?.
The HLOS suggests 10 car platform extensions on the Uckfield (non electrified line) assuming new DMUs are a little unlikely is this a hint to NR and southern develop a proposal to 25kv AC electrify as southern have lots of dual voltage or easily convertible to dual voltage 377s. This would make more effective use of East Croydon paths in to London Bridge in the rush hour as the trains could be longer.

Ditto for electrifying Salisbury etc as you could get more coaches and passengers into out of Waterloo with the same number of paths. (HLOS hint at capacity into Waterloo)???

The key dates could be when the lineside electrics and substations hit 50 years old and need replacing. Addition supply capacity to allow more / longer trains might also provide the push if it occurs about the same time.

Most of SWT and southern fleets are either dual voltage or designed to have the equipment easily fitted. The problem is effectively the 455/456/465/466 fleets not being AC upgradeable so any branches or lines outside the London core routes are more likely for conversion as they could be served exclusively by 377, 444, 450, 458 etc that are dual voltage or easily retrofittable. Lets hope the 458 refits retain the ability to easily convert to AC.
assuming an EMU life of 40 years 455 will need replacing in 2024 making SWT and Southern networks easier to completely swap at that point.
 

jopsuk

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regarding "leaving the third rail in place", do read the discussions on the "Electric Spine" fully to understand why this is not practical.

The problem with doing Thameslink/ the Brighton Mainline is complexity in inner south London
 

JamesRowden

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I wonder if Ashford/Tonbridge/Redhill/Guildford/Reading should be given 25 KV AC with the addition of the proposed viaduct across the Brighton Mainline at Redhill.

There are a lot of reasons at to why I think that this would be a good idea.

Firstly, It would provide a fully AC connection between the Channel Tunnel and the Electric Spine that freight services could use. There are presently only two trains an hour between Ashford and Tonbridge, one train per hour between Tonbridge and Redhill and only two trains per hour between Redhill and Reading. So there is plenty of capacity for freight services along most of the line. At Guildford the train could wait outside the station for a path to become available. The underpass east of Reading station is being reopened meaning that freight trains would not need to cross the paths of the intercity services.

Almost all of the line between Wokingham and Reigate is not presently electrified.

The line between Ashford and Redhill is very straight and so 125 mph running should not be a problem. This would mean that if a Crosscountry service ran down this line from Reading it might make connecting at Ashford for Eurostar services more appealling than using the London Underground/Crossrail whilst carrying heavy bagage. It might also be an appealing option for anyone traveling from the Birmigham/Bristol direction to Kent / Sussex who doesn't want to change at London. Also, it would mean a fast connection between East Kent and Gatwick.

The services that would need to turn bi-mode would be:

Charing Cross - East Kent (2tph)
Tonbirdge - Redhill / London Bridge / Gatwick Airport (1 tph) (Possibly)
Waterloo - Reading (2tph)
 

bangor-toad

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The problem with doing Thameslink/ the Brighton Mainline is complexity in inner south London
Hi there,
Yes, the inner London system is complex. That's why I think that if the 3rd rail to OHLE conversion is done, it will be from the outside in.

By that I mean that the branches and lesser used routes would be done first. These would all have changeovers in stations or just off the main lines, probably in a similar way to the WLL rather than the complexity of City Thameslink.

With these branches done and tested, it could be easier to have a complete conversion over a short time period as resources would have to be focused only on the main lines.
(Amusingly this logical extension of this thought is that Uckfield could see OHLE before Brighton!)

Of course, if some clever electrical engineers figure out a way to permit dual 3rd rail and OHLE operation at low cost or even equipment that could be moved from section to section once a block is converted then it'll be very different.
Jason
 

D6975

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Given the move towards 25kv overhead, why was the ELL reopened with 3rd rail??
It could have been overhead at least as far as New Cross/New Cross Gate surely - or is the tunnel under the Thames too small and would have cost too much to enlarge?
 

hwl

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Hi there,
Yes, the inner London system is complex. That's why I think that if the 3rd rail to OHLE conversion is done, it will be from the outside in.

By that I mean that the branches and lesser used routes would be done first. These would all have changeovers in stations or just off the main lines, probably in a similar way to the WLL rather than the complexity of City Thameslink.

With these branches done and tested, it could be easier to have a complete conversion over a short time period as resources would have to be focused only on the main lines.
(Amusingly this logical extension of this thought is that Uckfield could see OHLE before Brighton!)

Of course, if some clever electrical engineers figure out a way to permit dual 3rd rail and OHLE operation at low cost or even equipment that could be moved from section to section once a block is converted then it'll be very different.
Jason
That was exactly what I was getting at with my previous post far easier to work from the outside in. Electrifying to 25kv AC with a simple change over in a station (preferable the first one after the junction on the branch) to keep things as simple as possible is the easiest solution

Would love to see some detail in due course on what they are thinking up for the Uckfield line. (Tapping into the HLOS innovation fund for a few £m for trialling and developing simple cheap 3rd rail to OH change over where the frequencies train are lower?) Southampton and Basingstoke won't be simple or cheap in a similar manner to City Thameslink.

The nominal 40 year lifespan of the 455s expires around 2024 so doing anything on the inner SWT or southern routes before then is tricky.

By removing branches from the 3rd rail network to 25kV AC it will presumable enable more current to be taken from the 3rd rail elsewhere enabling longer or more frequent trains with out upgrading 3rd rail supplies.
 

jopsuk

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Given the move towards 25kv overhead, why was the ELL reopened with 3rd rail??
It could have been overhead at least as far as New Cross/New Cross Gate surely - or is the tunnel under the Thames too small and would have cost too much to enlarge?
I wondered this as well- could have had changeover at New Cross Gate and where a Surrey Canal Road station could have been (even without the station). Surely space in the tunnel (clearence doesn't look that low?) for a solid-bar solution?
 

swt_passenger

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Given the move towards 25kv overhead, why was the ELL reopened with 3rd rail??
It could have been overhead at least as far as New Cross/New Cross Gate surely - or is the tunnel under the Thames too small and would have cost too much to enlarge?
Could be the tunnel, but it was being designed 7 or 8 years ago - or more. Who would realistically have been thinking at that time about SR OHLE conversion?

Network Rail have only publicly mentioned conversion by using the renewals budget in about the last 18 months.

--- old post above --- --- new post below ---

Ditto for electrifying Salisbury etc as you could get more coaches and passengers into out of Waterloo with the same number of paths. (HLOS hint at capacity into Waterloo)???
Electrification wouldn't automatically allow longer trains, as they can already run 10 x 23m length trains using 158/159s in multiple. 10 x 23m is generally considered equivalent to 12 x 20m, in terms of overall capacity.

That could already be done by returning all of SWT's DMUs that operate elsewhere to the Salsibury line. So all that needs is more EMUs...
 
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yorksrob

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Prolongs the chance of a preserved EPB ever getting out on the good hold South Eastern again :lol:.
Well that would be a bonus :D

I presume everything from the 1988 Thameslink stock onwards has the ability to be dual voltage, so that only leaves the 455's (which are getting on a bit anyway) that you couldn't convert ?
--- old post above --- --- new post below ---
I wonder if Ashford/Tonbridge/Redhill/Guildford/Reading should be given 25 KV AC with the addition of the proposed viaduct across the Brighton Mainline at Redhill.

There are a lot of reasons at to why I think that this would be a good idea.

Firstly, It would provide a fully AC connection between the Channel Tunnel and the Electric Spine that freight services could use. There are presently only two trains an hour between Ashford and Tonbridge, one train per hour between Tonbridge and Redhill and only two trains per hour between Redhill and Reading. So there is plenty of capacity for freight services along most of the line. At Guildford the train could wait outside the station for a path to become available. The underpass east of Reading station is being reopened meaning that freight trains would not need to cross the paths of the intercity services.

Almost all of the line between Wokingham and Reigate is not presently electrified.

The line between Ashford and Redhill is very straight and so 125 mph running should not be a problem. This would mean that if a Crosscountry service ran down this line from Reading it might make connecting at Ashford for Eurostar services more appealling than using the London Underground/Crossrail whilst carrying heavy bagage. It might also be an appealing option for anyone traveling from the Birmigham/Bristol direction to Kent / Sussex who doesn't want to change at London. Also, it would mean a fast connection between East Kent and Gatwick.

The services that would need to turn bi-mode would be:

Charing Cross - East Kent (2tph)
Tonbirdge - Redhill / London Bridge / Gatwick Airport (1 tph) (Possibly)
Waterloo - Reading (2tph)

The many overbridges between Ashford and Tonbridge were rebuilt in about 1992 just before the commencement of Eurostar services, so I don't know whether they would have to be rebuilt again.
 

Peter Sarf

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Thanks yorksrob, I cling on to the hope that anything new built since say the 1970s was built with the thinking it should allow for OHLE (Overhead Line Equipment) regardless of the likelyhood.

I will have to look up the "Electric Spine" stuff. Thanks jopuk - I did not know dual AC & DC lines was a no-no. that ruins the flexibility somewhat. Found the thread http://www.railforums.co.uk/showthread.php?t=68562&highlight=Electric+Spine
How did I miss that !.

I know Eurostars used to switch between overhead AC and 3rd Rail DC on the move albeit not at full speed. 378s cannot do it moving but something else can (350s) ?.
 
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hwl

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Thanks yorksrob, I cling on to the hope that anything new built since say the 1970s was built with the thinking it should allow for OHLE (Overhead Line Equipment) regardless of the likelyhood.

I will have to look up the "Electric Spine" stuff. Thanks jopuk - I did not know dual AC & DC lines was a no-no. that ruins the flexibility somewhat.

I know Eurostars used to switch between overhead AC and 3rd Rail DC on the move albeit not at full speed. 378s cannot do it moving but something else can (350s) ?.
Unfortunately not, 3rd rail stuff build since 2000-ish can easily be retro fitted. Pantograph well and space left for the transformer under the floor etc.
 

LNW-GW Joint

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All this will have an impact on Merseyrail.
At the very least they should acquire dual-voltage kit to replace the 507/8s.
Maybe cascaded 319s/377s will come into play again here.
There might well be some serious engineering issues in the various tunnel sections.

And then there's Euston (LO).
I've never understood why the last DC mile into Euston was not converted to AC before now, allowing AC-only working from Queen's Park, but now there's no excuse.
I assume the DC-only 378s can be readily converted to dual mode?

With wires coming towards Aylesbury from the east (Bletchley-Calvert), and 3rd rail already out to Amersham, there will be some head-scratching by Chiltern/TfL over what to do with that route.
I can't see TfL being much interested in AC.
 

Peter Sarf

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Unfortunately not, 3rd rail stuff build since 2000-ish can easily be retro fitted. Pantograph well and space left for the transformer under the floor etc.
Sorry, I was not clear, I meant lineside stuff like bridges not rolling stock.
 

ushawk

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I wouldnt change from 3rd rail to OHLE until more lines are electrified, money could be better spent electrifying lines which havent yet been done !!

Only then should you start re-electrifying, which would be a long time away from happening. By then RS which cant be fitted with pantographs would be at the end of their lives too (e.g. 455s).
 

Peter Sarf

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Some of the 3rd rail routes need the power supplies (lineside substations etc) replacing as they are life expired OR need upgrading for heavier traffic. The cost is, apparently, similar to do it as OHLE so not really a waste as the money has to be spent anyway. Note also 3rd rail is so unreliable in bad weather (diesel better ?) and these are very busy routes (12 coach trains nose to tail at the London end). So I can see the temptation.
 

D365

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As has been reported several times, running OHLE and 3rd Rail on the same tracks is not a preferred option, especially over long distances. In particular, dual voltage running on the upgraded Thameslink only exists between Farringdon and City Thameslink, along with a crossover in Snow Hill Tunnel which will be used to turn back trains that fail to switch between traction supplies. There's no point in installing OHLE on the Brighton Main Line just yet as the 3rd Rail supply has just been upgraded (Ludgate Cellars substation), and the Class 442s wouldn't be useful if 3rd Rail was removed.

I say get the Kent high-speed and South West/Great Western borderline routes done first, alongside upgrading them to higher linespeed. Complete the other lines progressively as infrastructure reaches the end of its useful life and 3rd Rail only stock is taken out of service (442, 455, 456, 465 and 466). I assume the current Class 458/460 fleets will be merged and rebuilt to an entirely identical, OHLE future-proofed specification; the 460s are not compatible.
 

yorksrob

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Thanks yorksrob, I cling on to the hope that anything new built since say the 1970s was built with the thinking it should allow for OHLE (Overhead Line Equipment) regardless of the likelyhood.
Ah, you see, I'm not entirely sure. The bridges in question went from being traditional brick arches to slightly more angular concrete ones, however, they don't look much higher at the centre (to me anyway).
 

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It must be stressed that on many of the Southern area lines clearances are tight so the main consideration in installing 25kv is the reconstruction work to provide clearances through tunnels and bridges. Many of the tunnels such as Oxted Tunnel, tunnels on the Tonbridge-Hastings line have been modified to just permit 3rd rail stock so the thought of complete reconstruction to provide height clearance for 25kv is enormous.
The two tunnels on the Redhill -Tonbridge line (Bletchingly and Penshurst) had to be closed for 6 weeks in the early 1990s for reconstruction work for tunnel modifications in preparation for 3rd rail electrification. The track through Penshurst Tunnel was relaid on slab concrete base to improve clearances.
 

Peter Sarf

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Ah, you see, I'm not entirely sure. The bridges in question went from being traditional brick arches to slightly more angular concrete ones, however, they don't look much higher at the centre (to me anyway).
It would have been rather sensible !. Should ask what the original reason was for altering the bridges in the first place ?. The way you describe it it sounds like its to fit squarer things through like bigger containers ?. So the question is does W10 (or do I mean W12) make the space big enough for a container AND the wire ?.

Though I seem to recall altered bridges on the WCML have a squarer concrete top to the arch. My memory places that as far back as the 1970s but it could still be nothing to do with electrification but containers. Someone on here will know ?.
 

yorksrob

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Some of the tunnels on the Hastings line were reduced from double track to single, so might possibly accommodate OLE more easily than most with the track down the centre.
--- old post above --- --- new post below ---
It would have been rather sensible !. Should ask what the original reason was for altering the bridges in the first place ?. The way you describe it it sounds like its to fit squarer things through like bigger containers ?. So the question is does W10 (or do I mean W12) make the space big enough for a container AND the wire ?.
.
I'm sure someone more knowledgeable on here than me will know :)
 

Peter Sarf

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Another safe bet is Higham tunnel which finishes just by Strood station. Its enormous. It was built for a waterway to provide a short cut from the river Thames to the river Medway. That was during the napoleonic wars I believe but sailing boats were bigger than the canal boats that came later.
 
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