Indeed, when I said towards I was meaning a bit in that direction, and was in response to the suggestion of going to Exeter.
Indeed.
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3rd rail infills and extensions may have a future after all…
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Indeed, when I said towards I was meaning a bit in that direction, and was in response to the suggestion of going to Exeter.
Indeed.
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R
RailUK Forums
1&2 are south, 3-5 are north. I wish the station layout images have a compass.
1 being DC makes sense, as it's mostly used by the Basingstoke Stoppers, with the potential for the grade separated junction changing this more.
Likewise platform 5 being AC makes sense.
However other than that, not so much. As you'd probably prefer AC for platform 2 so trains heading south/west start under AC, likewise platform 3 so trains heading towards Waterloo start off under DC.
It's probably better to just remove DC from Basingstoke entirely and have the change over on 4 straight sections of track rather than at the complex station layout.
Are you proposing to only leave 2 tracks for the SWML? Good luck.
daodao
Established Member
In principle, I agree, for the missing gaps in the Southern Region and limited Merseyrail extensions, as it would decarbonise these lines without the extra risk of 3rd rail, but make use of existing 3rd rail electrification. However, there may need to be short sections of 3rd rail where the infill gaps are relatively long to permit in motion recharging to reduce the battery size requirements. However, 3rd rail electrification of Reading-Basingstoke and the lines serving Salisbury would be daft. I would also support 4th rail electrification from Amersham to Aylesbury.
This is another thread with a comment which prompts me to say "What is GBR for then?"
Surely to get away from worthwhile initiatives failing to get off the ground because of such a parochial outlook from one "department" of our national railway.
There is - for the simple reason the 444s, 450s and 458s are allocated. The 158/9s are allocated. If you moved any of those 4xxs to replace the 158/9s then you'need something to do the work those 4xxxs are currently doing - and since there aren't many 3rd rail EMUs sitting unused, that'll be new build, at which point the question again becomes why cascade old stock onto Exeter when if that line were electrified using 25kv OHL, brand new dual voltage stock would be ideal.
But NR wouldn't as that's not one of their standards. That's the London Underground standard - but why would you put 4th rail all the way to Aylesbury? Discontinunous OHL to allow battery charging with hybrid units would make more sense. Aylesbury - Amersham is only 15 miles so well within battery range.
Are they? If the 450s are currently doing work that the 458s are going to do and 701s are introduced in full, then assuming there is no increase in the timetable from current levels, there seems to be a surplus of 450s equal to at least the number of 458s moving to the Portsmouth line.
How does Basingstoke, Alton, the locals and some of the slower services on the Portsmouth and Southampton lines account for 127 450s?
Snow1964
Established Member
There seems to be an obsession by some that the third rail on West of England line should either end at Basingstoke or Salisbury.
Salisbury may traditionally been where a number of services terminate, and has a diesel maintenance depot, but populations change. Until the new census results are published I am having to use estimates, but Andover has apparently grown to about 47,000 population and thus is slightly bigger than Salisbury at estimated 46,000
I would extend the third rail to Andover, have the Basingstoke stoppers extend there. Then go 25Kv west from Andover. At same time I suggest Romsey should become the third rail limit. Remember there are already substations at Worting Junction, Redbridge and Eastleigh so could electrify 2-3 miles of each route using existing substations.
Ideally want overlaps where stopping trains can change systems whilst in the platform, and sufficient extra short dual sections so that freight and non stop trains don’t need to change where they are accelerating or going uphill, you don’t need miles of dual system.
With Andover as the changeover point the 450s on stopping trains can extend there, and only need to consider changing the long distance trains to dual system. Thus save cost of modifying the 444 and 450 fleet to dual voltage.
But a bit of isolated 25kv to Salisbury (or Wilton parkway if built) is fairly useless on its own, but really need to be doing Romsey/Andover - Salisbury - Bath- Bristol -Filton (including Bathampton-Chippenham) as 25kv and then introducing dual voltage bi-modes for both routes via Salisbury (freeing up all the class 158, 159, 165, 166 for use elsewhere). There is already separate thread on speculative new stock for Portsmouth-Cardiff but that seem to recommend a 5 or 6 car dual voltage bi-mode so thinking seem to be same for the Wiltshire area services. I think a virtually identical train was suggested if GBR ordered trains, a 110mph electric (95-100mph diesel) cross country bi-mode to fill gap between intercity and suburban/ local train.
Salisbury may traditionally been where a number of services terminate, and has a diesel maintenance depot, but populations change. Until the new census results are published I am having to use estimates, but Andover has apparently grown to about 47,000 population and thus is slightly bigger than Salisbury at estimated 46,000
I would extend the third rail to Andover, have the Basingstoke stoppers extend there. Then go 25Kv west from Andover. At same time I suggest Romsey should become the third rail limit. Remember there are already substations at Worting Junction, Redbridge and Eastleigh so could electrify 2-3 miles of each route using existing substations.
Ideally want overlaps where stopping trains can change systems whilst in the platform, and sufficient extra short dual sections so that freight and non stop trains don’t need to change where they are accelerating or going uphill, you don’t need miles of dual system.
With Andover as the changeover point the 450s on stopping trains can extend there, and only need to consider changing the long distance trains to dual system. Thus save cost of modifying the 444 and 450 fleet to dual voltage.
But a bit of isolated 25kv to Salisbury (or Wilton parkway if built) is fairly useless on its own, but really need to be doing Romsey/Andover - Salisbury - Bath- Bristol -Filton (including Bathampton-Chippenham) as 25kv and then introducing dual voltage bi-modes for both routes via Salisbury (freeing up all the class 158, 159, 165, 166 for use elsewhere). There is already separate thread on speculative new stock for Portsmouth-Cardiff but that seem to recommend a 5 or 6 car dual voltage bi-mode so thinking seem to be same for the Wiltshire area services. I think a virtually identical train was suggested if GBR ordered trains, a 110mph electric (95-100mph diesel) cross country bi-mode to fill gap between intercity and suburban/ local train.
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The bit you're missing is freight from Southampton - currently that's all diesel hauled and a 3rd rail loco would probably be too much for the 3rd rail infrastructure - as the 92s were - so there is a need to get 25kv south as well as south west. Putting 3rd rail to Salisbury or beyond won't help that.
It's a problem at Ashford too, just one it was decided was worth having to avoid international trains having to switch. Similarly at Euston, where lines B and C are equipped with both systems to allow Watford DC line trains to avoid the need to change.
However having both systems means you have to shield/immunise cabling and return current paths against both DC and AC interferences at 2 very different voltages. You also have increased maintenance requirements as you are maintaining 2 systems over the same track. The costs quickly add up, and at Basingstoke the disruption and interventions required would be much higher than the benefit provided.
Dual electrified stretches are normally kept to a minimum.
Among other things, on a 3rd rail DC line, the running rails need to be kept insulated from earth, otherwise traction current may find an alternative earth path and corrode lineside metal objects. On a high-voltage overhead AC line, the running rails and all nearby metal objects need to be bonded to earth, otherwise trackside metal objects could give an electric shock.
I would argue that everywhere west of Basingstoke should be wired to 25kv overhead, and potentially also east to Farnborough to allow SWML linespeeds to be increased from 100 to 125mph. Beyond Farnborough to London Waterloo would be more complicated due to the need to wire the Alton, Portsmouth and London suburban lines in conjunction, so I would say that area should stay as third rail.
As for the third rail coming into Southampton and Eastleigh from Fareham, you could perhaps have short stretches of dual voltage track in those areas where they meet the SWML.
Raising linespeeds would be a lot of pain for basically no gain, as you'll just be catching up the train in front quicker. I personally can't see any conversion away from 3rd rail until OLE makes its way into Hampshire from the GW area.
If you want OLE for freight, you'll need to wire the whole Southampton area. So you'd either be looking at Dual voltage St Denys to Redbridge, or short sections of OLE extending out to Southampton Airport Parkway and Totton at either end.
I'd love to see the Access planner's face when you asked them to draw up a possession plan to wire Southampton, having just resignalled it!
Wouldn't you do Redbridge - Romsey - Salisbury ? That way the "only" dual voltage bit would be around Redbridge until you then got to Basingstoke.
The reason I put "only" in inverted commas is I appreciate any stretch of dual voltage has its own challenges as helpfully explained on other threads - so I was looking to keep that to a minimum, not underplaying that it does have other issues.
Plus Totton to Hythe if and when it reopens.
I'm not sure about that - if that opens I'd expect diesel or battery to be the way forward. No need for OHL at present - the key to OHL in the Southampton area is to convert the freight being hauled to the Midlands to electric, which 3rd rail isn't really suitable for (in that the current draw of a freight loco will add to the load on the current 3rd rail infrastructure).
Don't think there's much freight coming up from Hythe.
Sorry, I meant third rail as that's what the thread is about.
Even then it depends on how its being served. If it's an extension of a diesel service then no point in going to the trouble and cost of 3rd rail.
It would be very useful if they ran Merseyrail services to Preston. They could have easily path it to have 2 trains per hour with the 2 platforms at rufford for each train to access the 1 track and it will save northern to have to run services to it
It will be a standalone shuttle if it goes ahead. Electrification would be very much a later enhancement.
Why would TfW want 3rd rail electrification?
We don't know what TfW thinks of a change in policy on 3rd rail electrification.
Otherwise a compromise could be made to electrify Bidston-Heswall on 3rd rail and use battery power Heswall-Wrexham
at Ashford it’s a couple of trains an hour each way, with all trains stopping.
at Basingstoke it would be an order of magnitude more trains, with some not stopping.
the Problem with dual electrified AC/DC systems is the amount of electricity that it has to deal with, and at Basingstoke it would be a lot.
25kV east of Basingstoke does not, of itself, allow 125mph. It also needs resignalling, new track, new bridges, etc etc.
If 25 kV is chosen between Basingstoke-Southampton Freightliner terminal there would have to be a changeover point somewhere east of Basingstoke with perhaps two platforms there retaining 3rd rail in case of problems with EMUs not able to use AC power.
Eastleigh would need to retain 3rd rail in the bay platform for Fareham services and access to the works.
3rd rail access will be needed between St Denys and SWR's traincare depot at Northam particularly ECS to/from Fratton.
There'll need to be a changeover point at Millbrook or Redbridge between AC and DC power, unless one or two platforms retain 3rd rail at Southampton Central for emergencies.
The electric spine idea will need careful thought about where dual voltage sections are located.
Eastleigh would need to retain 3rd rail in the bay platform for Fareham services and access to the works.
3rd rail access will be needed between St Denys and SWR's traincare depot at Northam particularly ECS to/from Fratton.
There'll need to be a changeover point at Millbrook or Redbridge between AC and DC power, unless one or two platforms retain 3rd rail at Southampton Central for emergencies.
The electric spine idea will need careful thought about where dual voltage sections are located.
all valid points, but the electric spine is long since dead and not happening.
Bimodes, such as the excellent FLIRT units currently operating in East Anglia, would solve that problem.
Turtle
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To an extent but bear in mind that in terms of efficiency a bimode is a dmu lugging around an electric motor. Simultaneously it is an emu burdened with a fuel tank and diesel engine. It is the short term thinkers pseudo solution to avoid electrification.
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