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

[Sir Felix Pole]

Hopefully common sense is breaking out and the remaining diesel islands on the SR can be eliminated. The North Downs line has had all the 'difficult' bits electrified for at least 80 years, so it seems an obvious first contender. One of the problems with this line I seem to remember, however, is the high incidence of foot-crossings - hopefully these can be eliminated or bridged. I agree that Worting Jcn to Salisbury and beyond should be at 25kV AC OHLE - although it would be amusing to see third-rail arrive at Exeter before the GW got its act together with 25kV!

 

[JohnElliott]

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.

If I recall the diagrams correctly, stock with side- or bottom-contact shoegear would be out of gauge by current standards, so clearances would need to be increased as part of conversion, with consequent work required to bridge parapets, platforms and so on. But that shouldn't stop trains from elsewhere running on converted areas.

 

[A0wen]

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.

Surely the decision should be based on factors such as cost, what power supplies are needed? If current substations can't support this and to electrify this would need fewer substations to provide a 25kv supply than a 750v one then surely it would be better to go with the former.

The signalling problems of having both schemes in the same place are known and can be mitigated.

 

[HamworthyGoods]

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.

looking at the current timetable its only the 08.50, 10.50, 14.50 daytime from Waterloo that don’t run beyond Salisbury. After 20.00 there’s more but that’s the service shutdown more than anything.

 

[mr_jrt]

Only way infilling the diesel islands makes sense to me is if you did so using the existing equipment from Weymouth-Basingstoke, with that line upgraded to OHLE.

 

[Ashley Hill]

Why is so much effort needed to mitigate risks with 3rd rail,it's not like it's been around for 5 mins. It's benefits and risks are well known . As I asked earlier,would a new installation need to be installed to new or existing standards?
What benefits would putting OHLE between Basing and Salisbury bring,surely that would create an isolated pocket in an otherwise 3rd rail area. Shoes and Pans up at Basingstoke?

 

[edwin_m]

Why is so much effort needed to mitigate risks with 3rd rail,it's not like it's been around for 5 mins. It's benefits and risks are well known . As I asked earlier,would a new installation need to be installed to new or existing standards?
What benefits would putting OHLE between Basing and Salisbury bring,surely that would create an isolated pocket in an otherwise 3rd rail area. Shoes and Pans up at Basingstoke?

The ORR document claimed the risk level was significantly higher but there seems to be no evidence in the public domain to substantiate this. Something the RSSB report ought to try to get to the bottom of.

Several people including me have suggested reasons why 25kV would be the best option to get to Salisbury, whereas third rail extensions would be better for smaller infill schemes.

 

[Snow1964]

The North Downs line crosses an electrified line at Dorking, not sure if you could use existing substation. Historically the Southern Railway often sited substations where they could feed more than one Line. (similarly could probably use some existing supply in Frimley- Farnborough area)

The net substation cost might not be that high, there are a few locations (generally on busy suburban lines) where new high power substations have been installed. There are a few more locations that ideally need to be done. It is not that hard to do these and recover the existing transformers and switch gear.

Most of the infills could easily use these secondhand equipment as they don’t see 10 or 12car trains every few minutes in peak so can use the lower rated stuff.

Adding Ashford-Ore, Wokingham-Ash, Shalford-Reigate, Uckfield Line and few tiny bits like Brentford-Acton. All this only adds 1-2% to third rail line mileage. under 1% to track mileage. Hardly a significant increase over existing electrocution risk.

Regarding Salisbury, I would electrify Reading West-Basingstoke-Salisbury on 25kv system (with Basingstoke-Worting dual system). I would stick to third rail extension for Totton-Hythe and also Redbridge/Eastleigh - Romsey. Probably just need one substation in the junction fork at Romsey as both Eastleigh and Redbridge already have substations.

I would make Romsey a system changeover point if it was decided to continue towards Salisbury (and onto Bath - Bristol - Cardiff). If Bi-modes can put pantographs up/down at (high) speed, then should be able to switch systems at speed on dual system overlap, so don’t even need to stop at stations to change system.

 

[JonathanH]

The North Downs line crosses an electrified line at Dorking, not sure if you could use existing substation. Historically the Southern Railway often sited substations where they could feed more than one Line. (similarly could probably use some existing supply in Frimley- Farnborough area)

The net substation cost might not be that high, there are a few locations (generally on busy suburban lines) where new high power substations have been installed. There are a few more locations that ideally need to be done. It is not that hard to do these and recover the existing transformers and switch gear.

The possible work to fit a third platform at Reigate requires a power supply upgrade - potentially this may be able to supply 750v dc further along the line towards Guildford but I guess there is a danger of scope creep if that is included.

 

[pompeyfan]

Would GTR have enough rolling stock if all their suggested routes went over to 3rd rail?

it’s a shame that many 387s at GWR are going over to Hex operation. A 3rd rail sub fleet 387 with ASDO would be ideal for the NDL, and a step change in passenger quality over a turbo. Revenue patrols by traincrew would likely be easier too as they wouldn’t need to return to the back cab at every station and could dispatch from wherever they wanted.

 

[JonathanH]

it’s a shame that many 387s at GWR are going over to Hex operation. A 3rd rail sub fleet 387 with ASDO would be ideal for the NDL, and a step change in passenger quality over a turbo.

No doubt, under normal circumstances, they would bring in better return on investment working between Paddington and Heathrow than between Reading and Gatwick.

Would GTR have enough rolling stock if all their suggested routes went over to 3rd rail?

I doubt it. Clearly the rolling stock for 'infill' electrification in the 1980s/1990s was found by tightening up diagrams but some of the extensions (eg Uckfield) look like they might need a bit more rolling stock.

 

[yorksrob]

I doubt it. Clearly the rolling stock for 'infill' electrification in the 1980s/1990s was found by tightening up diagrams but some of the extensions (eg Uckfield) look like they might need a bit more rolling stock.

In the 80's and 90's, there was a lot of electric stock displaced by the snazzy new Thameslink units. You could say the same thing now really !

 

[JonathanH]

In the 80's and 90's, there was a lot of electric stock displaced by the snazzy new Thameslink units. You could say the same thing now really !

Yes, except the point is that that stock isn't currently with GTR. The 377s displaced by the introduction of 700s appear to be fully occupied.

 

[alangla]

In the 80's and 90's, there was a lot of electric stock displaced by the snazzy new Thameslink units. You could say the same thing now really !

Would there be an option to make Uckfield a part of Thameslink? 2 TPH in the peak and 1 TPH during the day doesn’t seem overly taxing, maybe divert the Bedford to Three Bridges/Gatwick services?

 

[hwl]

Would there be an option to make Uckfield a part of Thameslink? 2 TPH in the peak and 1 TPH during the day doesn’t seem overly taxing, maybe divert the Bedford to Three Bridges/Gatwick services?

Not easily. The line is also long a twisty and single track with loops makes the timing very relaxed which would need a lot of 700s and there are already too few and Siemens can't get the required number in service.

 

[hwl]

Would GTR have enough rolling stock if all their suggested routes went over to 3rd rail?

it’s a shame that many 387s at GWR are going over to Hex operation. A 3rd rail sub fleet 387 with ASDO would be ideal for the NDL, and a step change in passenger quality over a turbo. Revenue patrols by traincrew would likely be easier too as they wouldn’t need to return to the back cab at every station and could dispatch from wherever they wanted.

No but the 313s on coastway and metro 455/8 will need replacing soon hence given time scales easy to increase the order size there.
Also plenty of 377s sub leased to SE.

 

[yorksrob]

Yes, except the point is that that stock isn't currently with GTR. The 377s displaced by the introduction of 700s appear to be fully occupied.

I was thinking of some of the old Thameslink units which haven't been re-deployed up North yet.

 

[yorksrob]

Would there be an option to make Uckfield a part of Thameslink? 2 TPH in the peak and 1 TPH during the day doesn’t seem overly taxing, maybe divert the Bedford to Three Bridges/Gatwick services?

Theoretically yes. However I'm not sure they'd want to try and fit anything more through the tunnel - and the length of the Thameslink trains might be overkill for Uckfield at the moment ! (Although if they extended it through to Brighton ....)

 

[Bald Rick]

Although if they extended it through to Brighton ....)

They’d be even emptier!

 

[Mikey C]

No but the 313s on coastway and metro 455/8 will need replacing soon hence given time scales easy to increase the order size there.
Also plenty of 377s sub leased to SE.

And there's stock elsewhere which will soon be displaced (e.g. 350/2s, 379s, C2C 387s) and indeed the better Networkers, 376s if they get replaced (and the 707s if they get moved on again)

 

[alangla]

Not easily. The line is also long a twisty and single track with loops makes the timing very relaxed which would need a lot of 700s and there are already too few and Siemens can't get the required number in service.

I guess. Back of an envelope calculation using a random day in August is that East Croydon - Gatwick - East Croydon takes 86 minutes, EC - Uckfield and back is 2 hrs 15, so probably an extra hour onto a round trip assuming the same timings north of EC. Bedford and back including layover is about 3 hrs give or take so might only be one extra unit for 1 TPH. Either way this is heading into the realms of one of the fantasy timetable threads, so I’ll stop now!

 

[daodao]

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

No to both. Amersham to Aylesbury should be 4th rail and transferred to LU operation, with trains running to Baker Street, as was the case when it was part of the Metropolitan Railway. Chiltern could continue to run the service from London to Aylesbury Vale Parkway via High Wycombe, which should be extended to Milton Keynes once the Bicester-Bletchley line has re-opened.

 

[si404]

Amersham to Aylesbury should be 4th rail and transferred to LU operation, with trains running to Baker Street, as was the case when it was part of the Metropolitan Railway.

Where's the room through Finchley Road for those extra trains? Bare in mind that the trains from those destinations are one of the biggest capacity gaps on the last public-facing TfL future crowding map and so you can't just ditch the Chilterns and extend Amershams to Aylesbury.

 

[MarkyT]

No to both. Amersham to Aylesbury should be 4th rail and transferred to LU operation, with trains running to Baker Street, as was the case when it was part of the Metropolitan Railway. Chiltern could continue to run the service from London to Aylesbury Vale Parkway via High Wycombe, which should be extended to Milton Keynes once the Bicester-Bletchley line has re-opened.

Where's the room through Finchley Road for those extra trains? Bare in mind that the trains from those destinations are one of the biggest capacity gaps on the last public-facing TfL future crowding map and so you can't just ditch the Chilterns and extend Amershams to Aylesbury.

A new fleet for this route could have 4-rail capability with battery energy storage. I'd add 4 rail contact rails where the dedicated Chiltern pair closely parallels the Metropolitan, then use batteries to reach the terminus where short switched sections of 4 rail could be provided just in the platforms for layover charging (only energised when a train is present). Beyond Amersham, batteries could be used again but possibly with some segments of 4th rail added in open areas between stations, well away from any level crossings and (most) platforms. New contact rail sections could be remotely switchable from the signalling control centre for swift emergency isolation, and to allow safe maintenance work to take place. Even during such isolations, battery power could allow train movements to continue, albeit at a reduced speed under caution (clearly reducing battery charge which would need a plan to replenish, maybe by swapping sets in a diagram). At Aylesbury (Town and Vale Parkway) short sections of 4-rail could be provided for layover charging in platforms and depot sidings, with switching as at Marylebone.

 

[A0wen]

A new fleet for this route could have 4-rail capability with battery energy storage. I'd add 4 rail contact rails where the dedicated Chiltern pair closely parallels the Metropolitan, then use batteries to reach the terminus where short switched sections of 4 rail could be provided just in the platforms for layover charging (only energised when a train is present). Beyond Amersham, batteries could be used again but possibly with some segments of 4th rail added in open areas between stations, well away from any level crossings and (most) platforms. New contact rail sections could be remotely switchable from the signalling control centre for swift emergency isolation, and to allow safe maintenance work to take place. Even during such isolations, battery power could allow train movements to continue, albeit at a reduced speed under caution (clearly reducing battery charge which would need a plan to replenish, maybe by swapping sets in a diagram). At Aylesbury (Town and Vale Parkway) short sections of 4-rail could be provided for layover charging in platforms and depot sidings, with switching as at Marylebone.

Wandering OT - but dare I say it, it would be easier to revisit the original plans for the northern end of the Met and curtail the Met at Rickmansworth.

There's probably space to run a 3rd line north of the junction with the Watford branch into Rickmansworth station. Ricky station could do with re-development because the platforms are short in any case and focus the Met services on Watford and Rickmansworth - leaving points north to be served by Chiltern.

And in doing so you'd hand the 'fast' lines from Moor Park to Harrow on the Hill to NR.

 

[corfield]

That usually gets shot down as insufficient capacity at Marylebone for the extra services to replace the Mets.

It does seem the most practical. With a bit of demolition of the flats, 2 more MYB platforms could be fitted in, but the capacity may be the shared twin track with the Chiltern Main Line and tunnels that are the issue.

 

[si404]

Wandering OT - but dare I say it, it would be easier to revisit the original plans for the northern end of the Met and curtail the Met at Rickmansworth.

That usually gets shot down as insufficient capacity at Marylebone for the extra services to replace the Mets.

Here you go.

Where's the space at Marylebone for enough service to supply those places? It's a tighter fit than the Met as you'll be trying to squeeze 6tph into a small pot (Marylebone) rather than trying to sneak in an extra 2tph through Finchley Road.

The 2018 Mayoral Transport Strategy has both Met and Chiltern (the latter of which arrive at Amersham with 4-5 standees/m^2) leaving Amersham in the 2041 am peak with over 5 standees/m^2 (which is 'maximum observed standing capacity' that is typically what's given as official capacity of LU trains). Chesham trains give Chalfont and Chorleywood some breathing space, but it quickly reaches an average of 5+/m^2 again. (source: this map). Reduction of frequency isn't an option, even if this is over-optimistic.

Sure you can demolish flats or something, but it's an awful lot of money, just to stand still. Dual-electrification of Chiltern trains, or even of Harrow-Amersham tracks, and just keeping the status quo of two different services on the route is a far cheaper solution!

 

[alangla]

Romford to Upminster is another isn't it?

What about Grove park to Bromley North?

All of which are already electrified, two of which are even inside the London Travelcard zones and one of which is of course third rail and hence on topic.

Balloch, North Berwick, Kirkby, Ormskirk (ok, the Merseyrail ones are kind of short) plenty of electrified OTW sections, some of which feed in to busy areas.

 

[Bletchleyite]

Watford Junction to St. Albans Abbey springs to mind.

Ormskirk-Rufford (though it's axle counter signalled now) and the single line to Kirkby are two more.

 

[Bletchleyite]

Wandering OT - but dare I say it, it would be easier to revisit the original plans for the northern end of the Met and curtail the Met at Rickmansworth.

Or extend it to Aylesbury and run Chiltern only via Wycombe.