Could third rail electrification avoid the requirement for GWR 769s?

[Bald Rick]

Good luck working out the delay codes to include in that search! Mind you, Capacity Planning have just created a new (sort of) Performance and Simulation team, the head of which has been very helpful to me in my former life.

yes that has been testing my brain cells for a little while.

and yes, is he is a good guy.

 

[Bikeman78]

Trying to put GWR drivers in the cab of a 455 isn't going to be any easier that getting them to drive a 769.

I would expect the route to transfer to Southern or SWR if it went third rail. Do Redhill drivers still go to Reading?

 

[Peregrine 4903]

It has in the past been assumed that ORR would not allow such a lengthy extension of third rail electrification on safety grounds. However more recently there have been suggestions that they might be considering allowing some stretches of new third-rail where this connects existing installations (as on the North Downs). Those who really know the situation are probably not revealing it publicly though, so as usual we're left speculating.

This is a myth that new Third Rail electrifications schemes are banned.

 

[AM9]

This is a myth that new Third Rail electrifications schemes are banned.

So how many 3rd rail electrification schemes have been executed in the last 20 years?

 

[Bald Rick]

So how many 3rd rail electrification schemes have been executed in the last 20 years?

To be fair there are a few, but almost all on the approach to new depots (although it was a close run thing for Three Bridges). The other notable third rail project was the East London Line extensions.

 

[A0]

So how many 3rd rail electrification schemes have been executed in the last 20 years?

A slightly misleading way of putting it.

The reality is outside of the old 'Southern Region', Merseyrail and some parts of London, 3rd rail wouldn't even have been considered as the standard for electrification and the major schemes will be 25kv OHLE now.

Of those areas - in the old 'Southern' are the only bits which would be considered are Ashford - Ore, Uckfield - Hurst Green, maybe something around Romsey - that's about it and those haven't reached the top of the "must do" list yet. The West of England mainline between Basingstoke and Exeter would need to be assessed as to which would be the most appropriate system.

Merseyrail would only be a few minor extensions and the London area one which was done as Bald Rick pointed out was the East London Line part of Overground.

3rd rail wouldn't have been considered for the Midland Mainline electrification, nor the Great West Mainline, nor HS1 or HS2, nor the routes around Manchester.

 

[AM9]

To be fair there are a few, but almost all on the approach to new depots (although it was a close run thing for Three Bridges). The other notable third rail project was the East London Line extensions.

Which entirely fall within the ORR's definition of 'minor extensions', including the ELL scheme, - I believe for the reasons given in my post #35 above.

 

[zwk500]

Which entirely fall within the ORR's definition of 'minor extensions', including the ELL scheme, - I believe for the reasons given in my post #35 above.

The ELL scheme is not a minor extension, but satisfied the ORR and RSSB of it's safety case, the line being almost entirely in a tunnel, cutting or on a viaduct. This serves to demonstrate 3rd rail isn't outright banned, but has a very high safety threshold.

The ELL involved the new links at NXG, the conversion of the New Cross-Shoreditch section from 4- to 3-rail, and the total reconstruction of Highbury & Islington to Shoreditch (with a new linking section at Shoreditch High St) to 3rd rail. It was nearly 12km of railway rebuilt to such a standard that all the latest engineering and technical standards/regulations applied. If 3rd rail was banned, it'd have been OLE equipped with Dual-voltage 378s used, not 3rd Rail only.

 

[SouthEastBuses]

it was the leasing companies, to boost residual values.

== Doublepost prevention - post automatically merged: 16 Aug 2022 ==



You might wire into the bay, but you would do everything possible to avoid wiring up all of Basingstoke Unless you were to remove all the DC kit. The bonding for the Dc return would be a nightmare, not to mention all the OLE required.

City Thameslink and Farringdon show that a platform electrified both with DC and AC is no problem at all

 

[JonathanH]

City Thameslink and Farringdon show that a platform electrified both with DC and AC is no problem at all

As if by magic? Do these stations not actually show that a platform electrified both with DC and AC can be done but needs a lot of specific attention by talented engineers to get it working well, which they succeeded with at these locations?

https://www.railforums.co.uk/thread...-to-overhead-lines.210166/page-5#post-5114490

 

[AM9]

City Thameslink and Farringdon show that a platform electrified both with DC and AC is no problem at all

As has been mentioned here before, there is a mountain of complex switchgear controlling the traction current and more importantly the grounding arrangements every time a train enters the section. It is only the critical impact that the Thameslink core has on both north and south of London manlines that such a system was even attempted. There isn't a more practical changeover location that wouldn't affect more than just TL services.

 

[zwk500]

City Thameslink and Farringdon show that a platform electrified both with DC and AC is no problem at all

No, they show quite the opposite! It's a monumental problem and the cost of solving is only justified by how busy and critical said line is.

 

[SouthEastBuses]

Well, how are you going to change potential intercity EMUs (XC from Bournemouth to Manchester, which could well happen one day as I predict Oxford to Coventry will also be electrified) from third rail to overhead then?

What about dual voltage electric freight locomotives like the class 92?

 

[AM9]

The ELL scheme is not a minor extension, but satisfied the ORR and RSSB of it's safety case, the line being almost entirely in a tunnel, cutting or on a viaduct. This serves to demonstrate 3rd rail isn't outright banned, but has a very high safety threshold.

The ELL involved the new links at NXG, the conversion of the New Cross-Shoreditch section from 4- to 3-rail, and the total reconstruction of Highbury & Islington to Shoreditch (with a new linking section at Shoreditch High St) to 3rd rail. It was nearly 12km of railway rebuilt to such a standard that all the latest engineering and technical standards/regulations applied. If 3rd rail was banned, it'd have been OLE equipped with Dual-voltage 378s used, not 3rd Rail only.

In truth, from a health and safety angle, apart from the ramp, only the section on the elevated ex-Broad Street approaches were really new, (and arguably they were 3rd/4th rail until 1986 on the NLL branch). Apart from sume tidying up of the 'railway land stretch south of Surrey Quays, making room for some LO stabling, the rest of the ELL to both New Cross and New Cross Gates was 3rd/4th rail as part of the LU Metropolitan East London branch.
So it was two minor extensions added to an existing 4th rail DC railway and converting it to 3rd rail to make a just over 12km DC line from Highbury and Islington to the two New Cross stations.

The South London loop to Clapham Junction was similarly enabled as a LO. line by another minor extension from Queens Road Peckham to the

 

[A0]

The ELL scheme is not a minor extension, but satisfied the ORR and RSSB of it's safety case, the line being almost entirely in a tunnel, cutting or on a viaduct. This serves to demonstrate 3rd rail isn't outright banned, but has a very high safety threshold.

The ELL involved the new links at NXG, the conversion of the New Cross-Shoreditch section from 4- to 3-rail, and the total reconstruction of Highbury & Islington to Shoreditch (with a new linking section at Shoreditch High St) to 3rd rail. It was nearly 12km of railway rebuilt to such a standard that all the latest engineering and technical standards/regulations applied. If 3rd rail was banned, it'd have been OLE equipped with Dual-voltage 378s used, not 3rd Rail only.

A couple of points about the ELL scheme though - one of which you've touched on which is Shoreditch - New Cross / Gate was already electrified using con-rail, albeit London Underground 4 rail, the other is from Dalston - Canonbury - Highbury and Islington was already 3rd rail equipped for the North London Line. As I understand it the ELL took over the 3rd rail lines and the North London Line was migrated to the new lines which were electrified using OHLE and reduced the 3rd rail stretch of the North London Line to the bit between Acton and Richmond - the other bit that was 3rd rail from Stratford - Woolwich closed in 2006.

So the only "new" bit of DC electrification was actually Dalston Junction - Shoreditch which is actually about 1.5 miles (1 mile 51 chains according to Railmiles) which is less than 3km of genuinely new conductor rail line, so most definitely a 'small' extension.

 

[cle]

So if the North Downs is not minor in entirety (even though it is stretches, given the existing third rail - which in isolation could be deemed minor infill) - Uckfield is long but simple - Ashford-Ore same (in terms of junctions, lines etc) - but there is definite mileage there. So would none of these pass the safety review?

And which would enable the most change/benefit?

NDL in full would be 2-3tph each way, and potential for others possibly (Reading-Portsmouth? who knows)
Uckfield is a winner on a solid London service, but it's hourly and already fairly long. Paths for 2tph don't exist, nor does the capacity on the branch.
Marshlink would be handy, but isn't that useful with all the cutbacks from Brighton, and without the famed HS1 service.

 

[A0]

So if the North Downs is not minor in entirety (even though it is stretches, given the existing third rail - which in isolation could be deemed minor infill) - Uckfield is long but simple - Ashford-Ore same (in terms of junctions, lines etc) - but there is definite mileage there. So would none of these pass the safety review?

And which would enable the most change/benefit?

NDL in full would be 2-3tph each way, and potential for others possibly (Reading-Portsmouth? who knows)
Uckfield is a winner on a solid London service, but it's hourly and already fairly long. Paths for 2tph don't exist, nor does the capacity on the branch.
Marshlink would be handy, but isn't that useful with all the cutbacks from Brighton, and without the famed HS1 service.

I must be missing something, but why would electrifying the North Downs Line enable Reading - Portsmouth ? Surely that would be better done going via Basingstoke, Winchester, Eastleigh and Fareham (albeit there are electrified gaps on that). But Basingstoke, Winchester and Eastleigh would all offer more passengers than Guildford and then Portsmouth 'direct' line.

 

[AM9]

So if the North Downs is not minor in entirety (even though it is stretches, given the existing third rail - which in isolation could be deemed minor infill) - Uckfield is long but simple - Ashford-Ore same (in terms of junctions, lines etc) - but there is definite mileage there. So would none of these pass the safety review?

And which would enable the most change/benefit?

NDL in full would be 2-3tph each way, and potential for others possibly (Reading-Portsmouth? who knows)
Uckfield is a winner on a solid London service, but it's hourly and already fairly long. Paths for 2tph don't exist, nor does the capacity on the branch.
Marshlink would be handy, but isn't that useful with all the cutbacks from Brighton, and without the famed HS1 service.

I would imigine that 'zwk500's suggestion made in post #63 might get approval provided that the short stretch from the junction for the Ash chord to North Camp had suitably high quality tresspass protection, as would the short stretch from Shalford station to Shalford junction. They would fall into the category of 'minor extensions' with enhanced H & S measures, being just 1km and 1.3km long respectively, which with modern BEMUs would release the whole 75km route for carbon-free traction.

 

[Bikeman78]

The ELL scheme is not a minor extension, but satisfied the ORR and RSSB of it's safety case, the line being almost entirely in a tunnel, cutting or on a viaduct. This serves to demonstrate 3rd rail isn't outright banned, but has a very high safety threshold

Does being on a viaduct make any difference? As I look out of the train window near New Cross Gate, there is graffiti everywhere. The spray can artists must have gained access to the track and in some places stood within inches of the live rail. I suspect that's less of a problem between Reigate and Shalford, or Hurst Green and Uckfield.

 

[Bald Rick]

City Thameslink and Farringdon show that a platform electrified both with DC and AC is no problem at all

It is very much a problem.

Well, how are you going to change potential intercity EMUs (XC from Bournemouth to Manchester, which could well happen one day as I predict Oxford to Coventry will also be electrified) from third rail to overhead then?

What about dual voltage electric freight locomotives like the class 92?

you’d have the changeover about a mile north of Basingstoke, where it could be more easily accommodated.

 

[SouthEastBuses]

It is very much a problem.




you’d have the changeover about a mile north of Basingstoke, where it could be more easily accommodated.

I suppose it could work better, one problem about changing over at Basingstoke station would be that the trains would have to spend 2-3 mins longer at a station than they normally would (causing SWR services to become unreliable as a result of this), so changing over north of Basingstoke could definitely be the better option indeed

 

[zwk500]

I suppose it could work better, one problem about changing over at Basingstoke station would be that the trains would have to spend 2-3 mins longer at a station than they normally would, so changing over north of Basingstoke could definitely be the better option indeed

Why would changing at Basingstoke required more than the current 2.5 minutes dwell? Every other traction change on the network is allowed 1 minute.

 

[SouthEastBuses]

Why would changing at Basingstoke required more than the current 2.5 minutes dwell? Every other traction change on the network is allowed 1 minute.

I suppose you are right, on Thameslink the 700s only take a minute or so to change from DC to AC and viceversa, but the 319s and 377s took forever

 

[zwk500]

I suppose you are right, on Thameslink the 700s only take a minute or so to change from DC to AC and viceversa, but the 319s and 377s took forever

They might have seemed it, but I'm fairly sure 319s and 377s were timed for 1 minute as well. The Overground 378s are certainly only given 1 minute at Acton Central.

 

[A0]

I suppose you are right, on Thameslink the 700s only take a minute or so to change from DC to AC and viceversa, but the 319s and 377s took forever

I think the Electrostars were slower probably because all the systems seemed to reboot. I always thought the 319s were pretty quick on changeover at Farringdon.

 

[AM9]

I suppose you are right, on Thameslink the 700s only take a minute or so to change from DC to AC and viceversa, but the 319s and 377s took forever

No, the 319s dropped their pantograph as soon as the doors opened. By the time the doors were closing form a normal passenger change, power had been changed. The Electrostars had to shut the trains system down, the PIS went off and all the onboard fans etc were silenced, for about 5-10 seconds. Once again, a changeover woulld normally be completed within a typical dwell period.
The 700s are very quick in changing, the auxiliary systems (displays, a/c, lights) don't get interrupted.

 

[Bald Rick]

I suppose you are right, on Thameslink the 700s only take a minute or so to change from DC to AC and viceversa, but the 319s and 377s took forever

They might have seemed it, but I'm fairly sure 319s and 377s were timed for 1 minute as well. The Overground 378s are certainly only given 1 minute at Acton Central.

The 700s and 319s change over in a matter of seconds.

The 377s etc took over a minute, typically 75seconds.

 

[73128]

A couple of points about the ELL scheme though - one of which you've touched on which is Shoreditch - New Cross / Gate was already electrified using con-rail, albeit London Underground 4 rail, the other is from Dalston - Canonbury - Highbury and Islington was already 3rd rail equipped for the North London Line. As I understand it the ELL took over the 3rd rail lines and the North London Line was migrated to the new lines which were electrified using OHLE and reduced the 3rd rail stretch of the North London Line to the bit between Acton and Richmond - the other bit that was 3rd rail from Stratford - Woolwich closed in 2006.

So the only "new" bit of DC electrification was actually Dalston Junction - Shoreditch which is actually about 1.5 miles (1 mile 51 chains according to Railmiles) which is less than 3km of genuinely new conductor rail line, so most definitely a 'small' extension.

and the new link from ELL to Queens Road Peckham on SLL

== Doublepost prevention - post automatically merged: 24 Aug 2022 ==

Why would changing at Basingstoke required more than the current 2.5 minutes dwell? Every other traction change on the network is allowed 1 minute.

not everything stops there at all, particularly freight.

 

[zwk500]

not everything stops there at all, particularly freight.

Services not stopping would presumably change on the move on the approach to the station, as freight does on the West London Line and the 80Xs do all over the place.

 

[AzureOtsu]

I would expect the route to transfer to Southern or SWR if it went third rail. Do Redhill drivers still go to Reading?

Adding to this, In the event the route is actually electrified, would it be worthwhile to split the service at Guilford, passing the western section to South Western railway for a Guilford to Reading service and the east section to Southern for a London bridge to Guilford service?