Should lines electrified with 3rd rail convert to 25Kv ac

[Trainician]

Hi this thread is for opinions on what should be done about the lines electrified with 3rd rail (not considering London underground).

 

[D365]

Should it be done? Yes. [for the most part]

Is it going to happen? No.

Easy debate tbh.

 

[Trainician]

OK mate

 

[brad465]

Only after a number of beneficial electrification schemes are completed to lines with no electrification at all.

 

[Whistler40145]

Clearances under bridges have to be taken into consideration and all the associated costs

 

[NoMorePacers]

Not until all non-electrified lines are electrified.

 

[30907]

Frequently discussed on these forums over many years

 

[Trainician]

Oh I didn't know it was frequent

 

[Murray J]

Honestly it seems to me to not be worth the effort when all modern third rail EMUs can be converted to run on pantographs and some EMUs can run on both, or can be converted to dual voltage.

 

[Belperpete]

There can be significant problems where DC and AC electrification schemes meet, in preventing the traction return currents from going places they shouldn't, as experienced on Thameslink and West London lines. So unless the DC area was converted to AC all in one go, you would have a rolling programme of significant and expensive to solve problems.

And what benefit would the travelling public see from the massive investment and disruption required (probably dwarfing that being spent on HS2, by the time you have costed in all the bridge and tunnel rebuilding, signalling immunisation work, new rolling stock, etc.)? Particularly when the end result would be a railway that is far more likely to be disrupted by storms and high winds.

 

[RichJF]

You'd have a whole host of infrastructure works to convert 3rd rail to OHLE in association with this.
On my local line there are three tunnels (one that is near 2.1km long) that would require MAJOR works to allow a conductor bar/ wires to go through them. It's much easier/cheaper specifying rolling stock to fit the tunnel & work on the current 3rd rail tbh.

 

[Murray J]

most certainly. not to mention it would require more rolling stock to be converted to pantograph operation, which operators in the south just don't have, except a small fleet of dual voltage 377s with SN, also 2.1KM, that long? I mean it always felt long but I never realised.

 

[Ploughman]

Does the original question apply to Tyneside Metro as well?
I don't think their OHL is compatible with standard 25 Kv.

 

[Trainician]

Honestly it seems to me to not be worth the effort when all modern third rail EMUs can be converted to run on pantographs and some EMUs can run on both, or can be converted to dual voltage.

You mean that some EMUs can run on third rail and 25Kv AC at the same time?

 

[Murray J]

You mean that some EMUs can run on third rail and 25Kv AC at the same time?

yeah, like the class 319 and 700.

 

[AM9]

yeah, like the class 319 and 700.

Well, not quite at the same time, but sequentially on the same journey if required.

 

[duffield]

A few selected lines for specific projects? Probably/possibly.

A mass conversion program? Very, very unlikely. A lot of money for small gains, there will always be higher priorities *except possibly* when 3rd rail infrastructure is life-expired.

If battery technology continues to improve significantly, then 3-way rolling stock (battery/3rd rail/OHLE) may become common and piecemeal changes may slowly lead to less 3rd rail, particularly when 3rd rail infrastructure is life expired.

Summary: Don't hold your breath!

 

[Murray J]

Well, not quite at the same time, but sequentially on the same journey if required.

Ah didn't read the question properly. No they don't operate on both at the same time because I don't think much track exists with both third rail and pantograph exist, although in theory they probably could operate both at the same time.

 

[AM9]

Ah didn't read the question properly. No they don't operate on both at the same time because I don't think much track exists with both third rail and pantograph exist, although in theory they probably could operate both at the same time.

Dual voltage trains have a changeover switch, - indeed, I think the Electrostars need a reboot to go from one system to another. The track from Farringdon to City Thameslink is equipped for both DC and ac running but is both complicated and expensive to operate. I believe that some of the tracks into Euston also have both systems to enble some flexibility in platforming the Overground services there.

 

[PeterC]

The DC Line approaches to Euston are probably the best (or perhaps least worse) candidate for conversion. The line is equipped with dual voltage stock anyway so a switchover at, say, South Hampstead would be no big deal. Only worth doing in the event of major work on the classic station.

 

[HSTEd]

No, waste of precious capital for very small gains.

The 25kV programme has enough problems without trying to generate additional work for it.

 

[ohgoditsjames]

Not until electrification reaches the parts of the country that don't have any wires at all. We've still got major cities without electrified lines.

 

[Meerkat]

Yes, but targeted and no rush/need to do inner suburban. For outer suburban the power and speed advantages, plus reduced icing issues, would be very handy.
Basingstoke-Bournemouth would be the obvious first route (when they did Southampton tunnel did they allow for wires?) to allow for future electrified freight and bimode XC.
Then expand to be Woking-Weymouth (and Salisbury)
Havant-Haslemere would be help for power/acceleration/icing, but the business case would be ugly unless D.C. renewal was needed anyway - particularly as you wouldnt want a sparks effect as there is no room for more passengers!
I would suggest the Brighton line but there are a couple of serious tunnels and the Coastways complicate it.

 

[HSTEd]

Basingstoke-Bournemouth would be the obvious first route (when they did Southampton tunnel did they allow for wires?) to allow for future electrified freight and bimode XC.

Electrified freight does not need AC conversion.

Class 92s exist for a reason.
A class 66 is sufficient to haul many freight trains despite only having 2240kW or so of at wheel horsepower.
Which is about equivalent to a single modern multiple unit.

Even with the third rail power limitations a ten-car 444 draws almost as much power as any reasonable freight train would.

 

[Purple Orange]

Not at all. The biggest issue of our times is pollution and replacing an energy source with zero local pollution with another energy source with zero local pollution is a waste of time and money. Our resources need to go in to generating clean electricity and taking out diesel, petrol and gas usage where we can, across all areas of society.

 

[PeterC]

No, waste of precious capital for very small gains.

The 25kV programme has enough problems without trying to generate additional work for it.

So you are saying that in the event of major work at Euston (remember the rider in the post that you responded to) a mix of 3rd rail and OHLE should be retained.

 

[HSTEd]

So you are saying that in the event of major work at Euston (remember the rider in the post that you responded to) a mix of 3rd rail and OHLE should be retained.

I didn't actually respond to that person, I was technically responding to the OP.

But I would expect no major work at Euston beyond those already programmed for the HS2 works for a very long time.

 

[klass43]

yeah, like the class 319 and 700.

717's. Welwyn Garden City - Moorgate.

377's (some) and 387's when they were used on Thameslink, Bedford/Luton to Brighton/south of the river. Not sure about now as they've been cascaded.

 

[AM9]

717's. Welwyn Garden City - Moorgate.

377's (some) and 387's when they were used on Thameslink, Bedford/Luton to Brighton/south of the river. Not sure about now as they've been cascaded.

All mainline EMUs ordered since the noughties have been either dual system ready or convertible. Look at the DC-only class 375, 376, 377, they have pantograph wells and suspension set up for a transformer. Most ac-only EMUs have passive provision for 3rd rail collection, - fitting of shoes is a minor depot operation. A 750V DC bus is now the norm for system design.

 

[yorkie]

Oh I didn't know it was frequent

Plenty of reading material to be found: https://www.google.com/search?safe=...d+with+3rd+rail+convert+site:railforums.co.uk