Which lines do you think would benefit from 3rd rail electrification?

[StewLane]

Moderator note: Split from https://www.railforums.co.uk/thread...extension-of-3rd-rail-electrification.205175/

Hurst Green to Uckfield is a diesel island and should be 3rd rail or battery if that is suitable. Ashford to Hastings could be either 3rd rail or overhead whichever is easiest/cheapest
Basingstoke to Salisbury is outside the existing 3rd rail area and should be OHLE as that is the future with Basingstoke to Reading done at the same time

 

[RichT54]

Though most of the extensions we're talking about (the likes of Skem/Wigan, Burscough Bridge, Uckfield etc) would be very simple trackwork as they're just branch lines or very minor junctions.

I don't think there's a case anywhere where it would make sense to add it to a major terminus that doesn't already have it.

Indeed, what are the cases? I can only think of Skem/Wigan, Burscough Bridge (at a push Southport that way but not really necessary), Ellesmere Port-Helsby (which needn't even have a connection to the mainline at all), Oxted-Uckfield, Ashford-Hastings and maybe Hunts X-Warrington C at a push. Are there actually any other viable cases than those ones? There are maybe more odd bits of Merseyrail which could be reinstated e.g. Aintree-Bootle via Ford or Gateacre, but those are maybe a little far-fetched as reopening them isn't even on the agenda yet.

Fill in the non-electric parts of the North Downs Line?

 

[Bletchleyite]

Fill in the non-electric parts of the North Downs Line?

Would be as easy to extend the 25kV down from Reading. It's going to be operated using 769s anyway.

Similarly if you did Preston-Ormskirk in its entirety (or Preston-Burscough Bridge or even Southport) you'd just run the 25kV down from Preston to Ormskirk, like Windermere it could I suspect be done without any substations.

 

[Elecman]

Would be as easy to extend the 25kV down from Reading. It's going to be operated using 769s anyway.

Similarly if you did Preston-Ormskirk in its entirety (or Preston-Burscough Bridge or even Southport) you'd just run the 25kV down from Preston to Ormskirk, like Windermere it could I suspect be done without any substations.

Preston-Ormskirk may well overstretch the available power from Catterall feeder. Blackpool is pushing it as the voltage can drop to very close to the acceptable Lower limit. But a modern 11/33Kv feeder located On both branches somewhere could solve the problem.

 

[fgwrich]

Hurst Green to Uckfield is a diesel island and should be 3rd rail or battery if that is suitable. Ashford to Hastings could be either 3rd rail or overhead whichever is easiest/cheapest
Basingstoke to Salisbury is outside the existing 3rd rail area and should be OHLE as that is the future with Basingstoke to Reading done at the same time

Basingstoke to Reading will be tacked on to the GW project, which makes sense as the local services are operated by Great Western (and can be operated by both 387 & 769).

It does make sense to consider expanding the third rail across some areas of the South though with as you say Hurst Green to Ucklfied and Hastings to Ashford. I wonder if the Salisbury 6 rounder would be another ideal candidate - allowing the 158s to be cascaded by 450s.

 

[JonathanH]

I wonder if the Salisbury 6 rounder would be another ideal candidate - allowing the 158s to be cascaded by 450s.

Not in the grand scheme of things - you could equally justify OHLE on the basis of the full route from Cardiff to Southampton for a traction change there.

 

[swt_passenger]

Not in the grand scheme of things - you could equally justify OHLE on the basis of the full route from Cardiff to Southampton for a traction change there.

A lot depends on how complex you want to make your changeover area(s). One changeover area at (say) Romsey would be a lot less complex than having two at Eastleigh and Southampton.

 

[Ashley Hill]

Surely Basing-Salisbury would allow all Waterloo-Salisbury services to be 3rd rail. Leaving only the West of England services to be DMU.

Hurst Green to Uckfield is a diesel island and should be 3rd rail or battery if that is suitable. Ashford to Hastings could be either 3rd rail or overhead whichever is easiest/cheapest
Basingstoke to Salisbury is outside the existing 3rd rail area and should be OHLE as that is the future with Basingstoke to Reading done at the same time

would it be really cost effective to install OHLE Basing-Sarum as even when Reading-Basing is installed there will be no through traffic to Salisbury to warrant it!

 

[Bletchleyite]

There's no point transitioning Merseyrail to 25kV, nor in any long extensions - all that's needed is minor infill to basically complete the 1970s plan, and that's much simpler done as third rail.

 

[Class 170101]

Fill in the non-electric parts of the North Downs Line?

Would be as easy to extend the 25kV down from Reading. It's going to be operated using 769s anyway.

I would say 3rd Rail from Wokingham to Reigate as the bit from Wokingham to Reading is already 3rd Rail and putting overhead on top causes issues keeping the supplies from interfering with each other.

 

[geoffk]

There's no point transitioning Merseyrail to 25kV, nor in any long extensions - all that's needed is minor infill to basically complete the 1970s plan, and that's much simpler done as third rail.

Bidston - Wrexham not yet mentioned.

 

[philthetube]

Though most of the extensions we're talking about (the likes of Skem/Wigan, Burscough Bridge, Uckfield etc) would be very simple trackwork as they're just branch lines or very minor junctions.

I don't think there's a case anywhere where it would make sense to add it to a major terminus that doesn't already have it.

Indeed, what are the cases? I can only think of Skem/Wigan, Burscough Bridge (at a push Southport that way but not really necessary), Ellesmere Port-Helsby (which needn't even have a connection to the mainline at all), Oxted-Uckfield, Ashford-Hastings and maybe Hunts X-Warrington C at a push. Are there actually any other viable cases than those ones? There are maybe more odd bits of Merseyrail which could be reinstated e.g. Aintree-Bootle via Ford or Gateacre, but those are maybe a little far-fetched as reopening them isn't even on the agenda yet.

Possibly Marylebone, if you consider that major, also with the other end of the line from Amersham to Aylesbury done.

 

[Bletchleyite]

Bidston - Wrexham not yet mentioned.

Not sure what makes sense there. It's a weird line - as far as Neston or Shotton it is similar in character to the rest of Merseyrail, but beyond that it's a rural branch line which would be a bit like taking the third rail to Preston from Ormskirk, which wouldn't to me make any sense. But having a separate Liverpool-Shotton and Shotton-Wrexham service probably wouldn't be sensible either.

Having said that, it is a natural connection point a bit like Burscough.

 

[4-SUB 4732]

Obvious true candidates...
- Ellesmere Port to Helsby.
- Wokingham to Ash
- Guildford to Reigate
- Hurst Green to Uckfield
- Ore to Ashford
- Basingstoke to Salisbury
- Redbridge to Salisbury
- Eastleigh to Romsey
- the Totton ‘Riverside Line’

 

[GRALISTAIR]

Possibly Marylebone, if you consider that major, also with the other end of the line from Amersham to Aylesbury done.

No no and no. Marylebone and all Chilterns should be from the outset 25kV AC OHLE

 

[philthetube]

Possibly Marylebone, if you consider that major, also with the other end of the line from Amersham to Aylesbury done.

No no and no. Markle one and all Chilterns should be from the outset 25kV AC OHLE

otherwise would need a fleet of dual voltage trains unless the tracks from Harrow to Amersham were dual voltage, and that will not happen.

 

[alangla]

Where to transition to 25kV would be a key part of any strategy. I agree it makes little sense to consider 25kV islands in the likes of Uckfield which would be worked as part of the general Southern fleet so a microfleet of 25kV-fitted units would be difficult to manage. Also a 25kV feeder is a major item, normally feeding several tens of kilometres and needing a high voltage Grid supply. This might be a bit easier with the solid-state inverter feeder stations now being pioneered.

Southern already have a set of DV 377s for their WCML services. Surely if Uckfield was to go to OHLE it would just be managed as part of that service? For the avoidance of doubt, I think 3rd rail should be the first choice for that particular route, but OHLE seems perfectly workable.

 

[DelW]

I would say 3rd Rail from Wokingham to Reigate as the bit from Wokingham to Reading is already 3rd Rail and putting overhead on top causes issues keeping the supplies from interfering with each other.

Ash (near Aldershot) to Shalford Jn (south of Guildford) already has third rail, so it would only need to be added over Wokingham to Ash and Shalford Jn to Reigate. Putting OHLE over those sections would mean four pan up / pan down transitions per journey, and mean the route would need dual voltage stock in perpetuity.

 

[Bletchleyite]

otherwise would need a fleet of dual voltage trains unless the tracks from Harrow to Amersham were dual voltage, and that will not happen.

Why wouldn't it happen? Plenty of dual voltage trains have been built over the years, including recently (Class 350/1s are, for example, as are many Electrostars), no reason more couldn't be.

 

[S&CLER]

Ash (near Aldershot) to Shalford Jn (south of Guildford) already has third rail, so it would only need to be added over Wokingham to Ash and Shalford Jn to Reigate. Putting OHLE over those sections would mean four pan up / pan down transitions per journey, and mean the route would need dual voltage stock in perpetuity.

I seem to recall reading in Modern Railways a few years ago (in an article about Gordon Pettitt, the SR General Manager), that detailed design work for the North Downs line third rail electrification had been done before privatisation.

 

[HamworthyGoods]

Surely Basing-Salisbury would allow all Waterloo-Salisbury services to be 3rd rail. Leaving only the West of England services to be DMU.

The vast majority of Waterloo to Salisbury services continue beyond Salisbury anyway to Yeovil or beyond.

 

[edwin_m]

Southern already have a set of DV 377s for their WCML services. Surely if Uckfield was to go to OHLE it would just be managed as part of that service? For the avoidance of doubt, I think 3rd rail should be the first choice for that particular route, but OHLE seems perfectly workable.

I do largely agree with that - it could be managed but having one uniform system across the Southern network (other than the MK service) is sensible.

For other extensions of electrification, dual voltage capability comes almost free on new stock. Something like Salisbury electrification would need a new fleet anyway so dual voltage could be specified. For me the potential for electric freight operation to Southampton (removing diesels all the way to the Midlands and beyond) makes 25kV a must for that route.

 

[hwl]

No no and no. Marylebone and all Chilterns should be from the outset 25kV AC OHLE

Most Chiltern could be 25kV but some running would have to be on 4th rail hence dual voltage units.
Chiltern also run along side 4 tracks of LU 4th rail south of Harrow/ Neasden complicating installing OHLE.
A good chunk of the inner Chiltern route is LU owned track...

 

[Bletchleyite]

I do largely agree with that - it could be managed but having one uniform system across the Southern network (other than the MK service) is sensible.

For other extensions of electrification, dual voltage capability comes almost free on new stock. Something like Salisbury electrification would need a new fleet anyway so dual voltage could be specified. For me the potential for electric freight operation to Southampton (removing diesels all the way to the Midlands and beyond) makes 25kV a must for that route.

I suppose before deciding this a decision needs to be made if third rail is staying long-term or if any conversion project is likely to be started in the coming 20 years or so as installations become life-expired. There will be lines where it never makes sense to convert - there would be little point converting Merseyrail, as it's a low speed system which isn't anywhere near life-expired - if the safety issue became unacceptable it'd be easier to convert it to DLR or Hamburg-style (same system) bottom-contact third rail instead, with which it is basically impossible to come into accidental contact even if you step over it. But there might be benefits of converting the much faster, much longer-distance Southern and SWR networks to OHLE - perhaps that could even include speeding up of mainline services to 110 or even 125mph - and if that is a long-term aspiration any infill might as well be 25kV using dual voltage EMUs from the get-go. While not all Electrostars have pantographs and transformers, all of them have passive provision for installation.

 

[edwin_m]

I suppose before deciding this a decision needs to be made if third rail is staying long-term or if any conversion project is likely to be started in the coming 20 years or so as installations become life-expired. There will be lines where it never makes sense to convert - there would be little point converting Merseyrail, as it's a low speed system which isn't anywhere near life-expired - if the safety issue became unacceptable it'd be easier to convert it to DLR or Hamburg-style (same system) bottom-contact third rail instead, with which it is basically impossible to come into accidental contact even if you step over it. But there might be benefits of converting the much faster, much longer-distance Southern and SWR networks to OHLE - perhaps that could even include speeding up of mainline services to 110 or even 125mph - and if that is a long-term aspiration any infill might as well be 25kV using dual voltage EMUs from the get-go. While not all Electrostars have pantographs and transformers, all of them have passive provision for installation.

That was the proposal in a RSSB report a few years ago - start with conversion of the outer parts of the SWML where speeds are higher, density of trains lower, most of the signaling is modern and therefore easier to immunise, and most of the trains have provision for dual voltage. The idea was picked up by government as part of the "Electric Spine" proposal but was lost in the general cull of schemes a few years later.

The numbers in that report are largely fictitious now general electrification costs have risen and the DC supply equipment that needed replacing and helped the economics of conversion has probably now been replaced anyway. But the general logic still holds that this is a sensible place to start if conversion is wanted - and 25kV on the Salisbury line would help to kickstart it.

 

[stuu]

otherwise would need a fleet of dual voltage trains unless the tracks from Harrow to Amersham were dual voltage, and that will not happen.

Why not? From my (limited) understanding it would be easier to install 25kv over LU 4 rail DC as the return currents are kept separate.

 

[MidlandMainlie]

Obvious true candidates...
- Ellesmere Port to Helsby.
- Wokingham to Ash
- Guildford to Reigate
- Hurst Green to Uckfield
- Ore to Ashford
- Basingstoke to Salisbury
- Redbridge to Salisbury
- Eastleigh to Romsey
- the Totton ‘Riverside Line’

Wokingham to Ash, Guildford to Reigate and Hust Green to Uckfield all make sense to me as third rail infill schemes because any OHLE electrification would be isolated pockets in a wider sea of third rail.

Wasn't there a plan to upgrade the Ore to Ashford line a few years ago to double track and electrify to allow through running onto HS1 and improved journey times for Hastings to London (although that woud have some work to connect the line to HS1 at Ashford). I understand that third rail needs feeder stations more frequently than OHLE so could the line be fed from Ashford as looking on Google maps the are no over bridges or obstacles beyond Ore tunnel that could cause clearance probe for OHLE. If clearance on zone tunnel is a problem then that could be dealt with through a short extension of third rail through the tunnel.

Any electrification to Salisbury needs to be considered as part of a wider electric fright network so should be electrified as OHLE.

 

[4-SUB 4732]

The vast majority of Waterloo to Salisbury services continue beyond Salisbury anyway to Yeovil or beyond.

In theory that’s only hourly. Based on the fact that I believe we should be ‘aiming for’ half hourly to Yeovil Junction, in theory third rail to there for diesel forward could work. Dual voltage 750v DC / Diesel units. Beast.

 

[NotATrainspott]

I suppose before deciding this a decision needs to be made if third rail is staying long-term or if any conversion project is likely to be started in the coming 20 years or so as installations become life-expired. There will be lines where it never makes sense to convert - there would be little point converting Merseyrail, as it's a low speed system which isn't anywhere near life-expired - if the safety issue became unacceptable it'd be easier to convert it to DLR or Hamburg-style (same system) bottom-contact third rail instead, with which it is basically impossible to come into accidental contact even if you step over it. But there might be benefits of converting the much faster, much longer-distance Southern and SWR networks to OHLE - perhaps that could even include speeding up of mainline services to 110 or even 125mph - and if that is a long-term aspiration any infill might as well be 25kV using dual voltage EMUs from the get-go. While not all Electrostars have pantographs and transformers, all of them have passive provision for installation.

As I understand it the problem is that the loading gauge makes side- and bottom-contact third rail difficult to install without losing interoperability with the rest of the network. Sure, you might not have many arbitrary trains run on Merseyrail tracks but not being able to send a 66 down on an engineering train will make everyone's lives quite a bit more miserable. Widespread swapping of top- to side- or bottom-contact is also going to be a large expense for relatively little gain, other than safety. 750V DC third rail to 25kV AC OHLE conversion means changes to power supply and network capabilities (more, faster trains) as well as the safety impact.

If you're going to spend a lot of money just for the sake of safety alone there's probably a better way to spend that cash. For instance, you could blanket the entire Merseyrail track network with CCTV to detect trespassers or line obstructions. Add in some batteries to the 777s and your safety case could be that the third rail gets turned off in a section whenever there's a human (authorised or unauthorised) on the track.

 

[MarkyT]

Why not? From my (limited) understanding it would be easier to install 25kv over LU 4 rail DC as the return currents are kept separate.

4 rail DC with OHLE AC is definitely preferable to 3 rail with OHLE from a stray current perspective, but still needs dual immune equipment for induced effects and much thought given to fault currents if the DC return rail was unexpectedly shorted to the running rails. Dual AC/DC electrification of any kind really needs to be minimised as much as possible, even teh two systems running closely alongside. Having dual equipped rolling stock is a much better option for any significant distance. On the unelectrified Chilterns sections where they closely parallel the already 4 rail Metropolitan/Jubilee corridor, the use of this system seems to be a 'no brainer' as then new trains thus equipped could also use the existing electrification on the shared parts of the route north of Harrow as well. How these trains run into Marylebone or get to Aylesbury is another matter. I suggest battery storage could be realistic, possibly with some discontinuous 4 rail in open rural sections north of Amersham away from any trespass risk. Short switched charging sections could also be provided at Aylesbury in the platforms and depot, only energised when a train is parked directly above them, and at the Marylebone terminus, which could coexist happily with 25kV if necessary for the High Wycombe route trains, although trains for that route could also employ batteries for the terminal approach if wires were difficult in the tunnels.