RSSB looking at possible extension of 3rd rail electrification

[corfield]

You do understand that the Bournemouth snap-change was done with just one platform in each direction. Even then there were commonly four services an hour east of there. The only shame about the old arrangement was the changeover was done at Bournemouth, not Poole, and so the electric service only covered half the conurbation.

Vs now that involves one driver doing exactly what they do at any other station? Why on earth would you do this when you can avoid it so easilyv
Even then they saw this was so inefficient they went to the considerable effort to electrify all the way to Weymouth to get rid of doing it.

 

[Taunton]

Not familiar with Bournemouth in that sense but even if the trains existed now I would be surprised if either signalling had changed to its deteriment or the safety standards changed or both. Today I would consider 20 minutes the bare minimum (and its probably more) to complete such a move. Just look at long it took for Class 67s to attach to Mark IVs to drag them off the East Coast Main Line via the alternative unwired routes.

If you go to Switzerland you find such snap-changes of power in a few minutes are a constant event.

 

[The Ham]

Not familiar with Bournemouth in that sense but even if the trains existed now I would be surprised if either signalling had changed to its deteriment or the safety standards changed or both. Today I would consider 20 minutes the bare minimum (and its probably more) to complete such a move. Just look at long it took for Class 67s to attach to Mark IVs to drag them off the East Coast Main Line via the alternative unwired routes.

SWR can still split EMU's within a minute if needed although normally the timetable is that they have 3.

The reason for the timetable is so that the passengers on the train can get off before the split is undertaken and there's still time after to allow more passengers to board the service.

If done on a late running service it appears that, train stops, second driver enters cab, quick safety check, front portion moves forwards to divide then stops, quick safety check before door release and then as per normal. There's a noticeable delay in the train doors opening, yet not so much that people start getting worried that the doors aren't going to open.

If you had to move a loco into place or had to enter the platform slowly with a logo in place it would probably add a bit more time, but not all that much (especially the latter).

 

[yorksrob]

The problem is the much bigger AONB without a railway through it...

I'm not sure where you're referring to. The Dungeness branch continues to where Romney Junction used to be, then is taken over by a fairly hefty service road up to the perimeter of the power station. These should enable a cable to reach the wider network quite easily.

 

[Ashley Hill]

It does seem that each side just advances their own arguments here, of course. But one thing that cannot be denied is that Southern is already 95% DC installed, 5% diesel, and it does seem crackers to now say a different, incompatible system should now be used for the remaining 5%, lines that if BR had a bit more money in the 1960s-90s would have been converted to DC long ago.

I agree here. The Southern is DC land why change it. To put OHLE BSK-SAL seems pointless when everything else is DC unless OHLE is going to be expanded throughout the Southern.

 

[edwin_m]

I agree here. The Southern is DC land why change it. To put OHLE BSK-SAL seems pointless when everything else is DC unless OHLE is going to be expanded throughout the Southern.

If this scheme goes ahead at all then it will be in the context of a wider programme of electrification. This potentially includes making it part of an AC route for freight between Southampton and the Midlands, taking the freight off the busy line via Winchester. I agree that third rail is the right choice for infills within the existing third rail network where there is little likelihood of freight, I believe it would be short-sighted to expand the third rail outside its existing limits.

 

[D365]

To put OHLE BSK-SAL seems pointless when everything else is DC unless OHLE is going to be expanded throughout the Southern.

It has to start somewhere...

 

[hwl]

I'm not sure where you're referring to. The Dungeness branch continues to where Romney Junction used to be, then is taken over by a fairly hefty service road up to the perimeter of the power station. These should enable a cable to reach the wider network quite easily.

This isn't anything to do with Dungeness which a red herring as it is already well connected to the grid (and also due to close in 2028). The main issue is the rather much larger High Weald AONB to the North and West of Rye, adding extra hurdles to Grid to DNO to Rail supply connections. As the is a AONB and also nearby SD National Park, there are large areas without much new development or extra electrical demand, which creates headaches for the DNO to deal with increasing demand (e.g. greater Brighton).

 

[yorksrob]

This isn't anything to do with Dungeness which a red herring as it is already well connected to the grid (and also due to close in 2028). The main issue is the rather much larger High Weald AONB to the North and West of Rye, adding extra hurdles to Grid to DNO to Rail connections. As the is a AONB and also nearby SD National Park, there are large area without much new development or extra electrical demand.

Would you not just go along the railway line ?

 

[Domh245]

This isn't anything to do with Dungeness which a red herring as it is already well connected to the grid. The main issue is the rather much larger High Weald AONB to the North and West of Rye, adding extra hurdles to Grid to DNO to Rail connections. As the is a AONB and also nearby SD National Park, there are large area without much new development or extra electrical demand.

There is a transmission line from Dungeness to a substation at Ninfield, so you could piggyback of that if it can take the additional power requirements. It then continues from Ninfield and passes 1.5mi south of Uckfield station, so you could get even closer to get a grid substation to feed the railway from.

Would you not just go along the railway line ?

Would be a difficult route to get from Dungeness/Marshlink to Uckfield without running all the way up to Croydon and back!

 

[yorksrob]

There is a transmission line from Dungeness to a substation at Ninfield, so you could piggyback of that if it can take the additional power requirements. It then continues from Ninfield and passes 1.5mi south of Uckfield station, so you could get even closer to get a grid substation to feed the railway from.



Would be a difficult route to get from Dungeness/Marshlink to Uckfield without running all the way up to Croydon and back!

Ah well, there's a solution to that

 

[JohnElliott]

Ah well, there's a solution to that

Several -- were you thinking of going via Isfield, Groombridge or Mayfield?

 

[hwl]

There is a transmission line from Dungeness to a substation at Ninfield, so you could piggyback of that if it can take the additional power requirements. It then continues from Ninfield and passes 1.5mi south of Uckfield station, so you could get even closer to get a grid substation to feed the railway from.

Correct (Hoathly 1.5 miles south of Uckfield as I previously suggested 2 pages ago) and the transmission line continues west to Bolney where most of the DNO supplies in West and a lot of East Sussex come from.

A GSP for electrifying Uckfield is over kill but an extra GSP to feed the south eastern patch of the Bolney area (East Brighton and along the coast to Lewes -ish) where usage is increasing would make sense but that wouldn't be at Hoathly and would better the the Local DNO network but further away.

Usefully UKPN have some local upgrades to the Uckfield supply pencilled in which might enable the southern bit of the branch to be electrified with the new local spare capacity but that still leaves most of the northern end of the branch to sort as well (which is in the area fed exclusively by Bolney GSP as is the East G. line)

 

[GRALISTAIR]

It has to start somewhere...

And a very good place to start.

 

[Journeyman]

...don't a lot of the DC EMUs have a dead weight to simulate transformers anyway so the suspension etc can be identical?

Yes. DC-only Electrostars carry three tons of ballast to ensure they weigh the same. A former boss of mine worked out that removing these and altering the suspension would improve performance and pay back the cost pretty quickly, in terms of reduced energy use and lower track access charges (part of which is calculated on axle loading).

 

[HSTEd]

Aside from capital cost, it seems you’re deliberating ignoring the fact that 25kV is much more efficient when it comes to power delivery.

Electricity consumption is not a large portion of the railway's cost base.
So saving it is not going to save much money proportionally.

EDIT:

Also note that on the Merseyrail network, DC losses are only about 11%, compared to ~3.8% on the AC system.
Far better than the 20% often quoted, which was based on selective reporting of certain sections of the DC system to generate the result Network RAil wanted.

Given new third rail lines will be far more similar in character to Merseyrail than to the Brighton Main Line, this is important.

EDIT#2:

DUKES puts annual rail electricity use at 4.5 million megawatt hours per year.
So about £500m worth of electricity.
Not a huge portion of the railway's costs.

 

[yorksrob]

Several -- were you thinking of going via Isfield, Groombridge or Mayfield?

Well, I was thinking Isfield, but I wouldn't be against Groombridge or even Mayfield either !

 

[corfield]

Electricity consumption is not a large portion of the railway's cost base.
So saving it is not going to save much money proportionally.

EDIT:

Also note that on the Merseyrail network, DC losses are only about 11%, compared to ~3.8% on the AC system.
Far better than the 20% often quoted, which was based on selective reporting of certain sections of the DC system to generate the result Network RAil wanted.

Given new third rail lines will be far more similar in character to Merseyrail than to the Brighton Main Line, this is important.

EDIT#2:

DUKES puts annual rail electricity use at 4.5 million megawatt hours per year.
So about £500m worth of electricity.
Not a huge portion of the railway's costs.

A 20% difference is 100million per annum.

Enough to pay for a Wisbeach every other year.

Businesses spend far more than that to save a fraction of 20% level efficiencies. A freind of mine in the aero engines industry is overseeing a multi billion project to achieve a 2% improvement in a key turbine technology. It will take years to do and the company may not get there first - but offering an engine 2% more efficient is a “no brainer” for the decision makers.

 

[edwin_m]

Also note that on the Merseyrail network, DC losses are only about 11%, compared to ~3.8% on the AC system.
Far better than the 20% often quoted, which was based on selective reporting of certain sections of the DC system to generate the result Network RAil wanted.

Given new third rail lines will be far more similar in character to Merseyrail than to the Brighton Main Line, this is important.

Merseyrail is right at one end of the spectrum on this. I doubt there is anywhere else on Network Rail that has such low speeds and frequent stops over the entire journeys of most of the trains that use it. Any that come close, such as the inner lines of the Southern and the Underground, are electrified already.

The infill candidates like Uckfield line are far more rural with a lower train frequency, longer trains and a longer stop spacing. Basingstoke to Salisbury is similar, probably higher frequency but higher speeds as well. Neither are remotely comparable to Merseyrail. So I stick with my view that third rail would be fine for the infills but isn't the right answer elsewhere.

 

[D365]

I've got absolutely no qualms about Merseyrail remaining third rail. It's a heavy rail metro in every sense.

As @edwin_m points out, Uckfield and Basingstoke are two completely different kettles of fish.

 

[HSTEd]

The infill candidates like Uckfield line are far more rural with a lower train frequency, longer trains and a longer stop spacing. Basingstoke to Salisbury is similar, probably higher frequency but higher speeds as well. Neither are remotely comparable to Merseyrail. So I stick with my view that third rail would be fine for the infills but isn't the right answer elsewhere.

And far lower traffic density!

Uckfield and Salisbury is going to have a comparative handful of trains, each with comparatively low power draw, running on it.
It won't get pounded by an endless succesion of 12-car 700s or anything like that.

In that respect it is much more like Merseyrail than the regular south-of-London network as it exists now.

A 20% difference is 100million per annum.

Even if it is 20%, and I am skeptical it is, that is peanuts.

Enough to pay for a Wisbeach every other year.

Or you could buy a dozen, or two dozen, or more Wisbech lines right now by not spending the extra money on a 25kV installation.
The enormous savings from not installing 25kV will pay for an awful lot of lost electricity.

Even Network Rail admits that Marshlink line electrification being third rail instead of 25kV dramatically reduces costs.
Indeed the difference between their estimates is almost enough to buy Wisbech by itself.

 

[pompeyfan]

Yes. DC-only Electrostars carry three tons of ballast to ensure they weigh the same. A former boss of mine worked out that removing these and altering the suspension would improve performance and pay back the cost pretty quickly, in terms of reduced energy use and lower track access charges (part of which is calculated on axle loading).

Southern didn’t remove the ballast from their electrostars because their 377/2s often work on DC routes, so they needed to ensure all units behaved the same from a driving perspective. SWR Desiros don’t have any ballast because They don’t interact with AC units even though they could. I can’t answer about SEs 377s or 375s but I would imagine as some retained their OHLE equipment that all kept their ballast.

 

[DJ_K666]

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.

Reigate to Guildford is another one. Juice rail only goes Redhill to Reigate

 

[Philip Phlopp]

I agree here. The Southern is DC land why change it. To put OHLE BSK-SAL seems pointless when everything else is DC unless OHLE is going to be expanded throughout the Southern.

Basingstoke to Salisbury is very complicated.

The most important question to ask on that particular route is whether there will still be third rail from Basingstoke to Worting Junction when electrification to Salisbury is authorised, how that would then impact on what electrification system is chosen, and how the feeding arrangements could work.

The other important question to ask is what rolling stock will Salisbury TMD be expected to maintain when electrification to Salisbury is authorised, given Express Sprinters won't last forever but aren't quite ready for scrapping just yet.

 

[DelW]

Reigate to Guildford is another one. Juice rail only goes Redhill to Reigate

... and Wokingham Junction to Aldershot South Junction.

 

[si404]

I agree here. The Southern is DC land why change it. To put OHLE BSK-SAL seems pointless when everything else is DC unless OHLE is going to be expanded throughout the Southern.

Though the Reading-Basingstoke route might bring OHLE to Basingstoke, complicating things.

 

[Dr Hoo]

Basingstoke to Salisbury is very complicated.

The most important question to ask on that particular route is whether there will still be third rail from Basingstoke to Worting Junction when electrification to Salisbury is authorised, how that would then impact on what electrification system is chosen, and how the feeding arrangements could work.

The other important question to ask is what rolling stock will Salisbury TMD be expected to maintain when electrification to Salisbury is authorised, given Express Sprinters won't last forever but aren't quite ready for scrapping just yet.

Surely any strategic (rather than purely short-term/tactical) consideration of electrification around Salisbury, via both Andover and Romsey, has to allow for multiple heavy freight trains carrying containers, aggregates and other commodities, hauled by electric locomotives that will operate under 25kV for much of the rest of their journey.

Unlike another poster who considers that: "...Salisbury is going to have a comparative handful of trains, each with comparatively low power draw, running on it. It won't get pounded by an endless succesion [sic] of 12-car 700s or anything like that", this area needs to be seen as at least a secondary main line.

 

[HSTEd]

Surely any strategic (rather than purely short-term/tactical) consideration of electrification around Salisbury, via both Andover and Romsey, has to allow for multiple heavy freight trains carrying containers, aggregates and other commodities, hauled by electric locomotives that will operate under 25kV for much of the rest of their journey.

A Class 92 on third rail has only 4MW of power draw, which is less than a 12-car 700.
It's about equivalent to a 10-car 444.

Given that many of these trains operate perfectly happily with a single Class 66, which has an at rail power of about 2.2MW, I think the power supply issue is somewhat overblown.

 

[Philip Phlopp]

Surely any strategic (rather than purely short-term/tactical) consideration of electrification around Salisbury, via both Andover and Romsey, has to allow for multiple heavy freight trains carrying containers, aggregates and other commodities, hauled by electric locomotives that will operate under 25kV for much of the rest of their journey.

Yes. The 'Electric Spine' plans have Worting Junction to Basingstoke East Junction converted to 25kV AC OLE with change of traction power from DC to AC at Basingstoke. That's where things get complicated if you try and electrify west to Salisbury on DC. There may be three miles of third-rail missing between Worting Junction and Basingstoke.

A Class 92 on third rail has only 4MW of power draw, which is less than a 12-car 700.
It's about equivalent to a 10-car 444.

Given that many of these trains operate perfectly happily with a single Class 66, which has an at rail power of about 2.2MW, I think the power supply issue is somewhat overblown.

It's sadly not as simple as comparing rated power - a Class 92 consumes more energy than a Class 700 despite having the same rated power, it's simple physics, the mass of a container train is considerably greater than a fully laden Class 700 and the drag is vastly greater. If you're in the business of working such things out, you can calculate the amount of power needed to move one tonne of train one mile which will give you a kWh figure. The idea of retaining and strengthening the existing DC supply between Basingstoke and Southampton was considered, given the complexity of converting the route to AC OLE (remembering it's being planned for freight purposes, so the route clearance needs to remain unchanged or be improved) but couldn't be made to work.

 

[mr_jrt]

The obvious thing to do is convert Basingstoke to Southampton to OHLE as phase 1, then continue the project along to Weymouth as phase 2a, whilst firing off phase 2b to string up the OHLE from Basingstoke to Southampton via Salisbury. You're all set then to continue on in a follow up project from Salisbury towards Bristol, either all the way to meet the planned GW project limits at Thingley Junction (which we can hope will eventually get extended to Bristol proper via Bath), or as far as Westbury to meet a project to wire up Newbury to Thingley.