North Downs line electrification

[Domh245]

Siemens AC Desiro stock is lighter than their DC stock

How do they do that then? Is there some kind of extra equipment that is needed on the third rail units but not on the OLE?

 

[Philip Phlopp]

How do they do that then? Is there some kind of extra equipment that is needed on the third rail units but not on the OLE?

I'd guess so. The mass of the Siemens Desiro stock is one of life's great mysteries. They're unbelievably heavy.

 

[QueensCurve]

An unshielded 800v conductor inches from the ground seems a dangerous insanity to laymen. Hence the embarrassment for any railway professional advocating more of it,even if just short fill in. Yet our third rail DC is less dangerous than AC. The most fervent AC advocate on this thread promised to come back with the stats proving DC killed more than AC,adjusted for pop density etc. He never came back. He couldn't as there is no evidence,just hearsay.. So it is no more dangerous. True, DC faces the inevitable heat losses due to ohm's law. But these are reduced through the lower weight of DC trains,& a better aerodynamic profile,both of which reduce the demand for IxV. Three rail born AC transformers per AC train designed to withstand the shock of rail bounce are ten times more expensive per kW than static transformers that sit on a level concrete floor in a DC substation. A failed organisation like Network Rail( despite some great people who work for it) can barely run the railway structure let alone supervise within time & budget a massive AC wiring programme. The facts prove it. True, DC can't do 125mph & heavy freight up long inclines,but otherwise its failings are far less disruptive than the regular dewirings across the AC network. With limited cash DC infill is a no brainer. And it is not true there is an absolute ban on it. The rules say a case has to be made. See above.

And of course, freed from the shackles of the EU, all the safety regulations will in any case be swept away, losses will no loner be proportional to I squared R and electric shocks will never be fatal.

 

[GRALISTAIR]

Why not use a very effective proven system where the inadvertent risk is far lower, performance is consistently better and safe maintenance of infrastructure can usually be executed without power shutdown. Yes, that's right, HV ac OLE. All the technology is understood, available and for mainline use, has a lower through-life cost than any other rail electric power delivery.

Oh, and a huge chunk of the rest of the world uses it too.

 

[HSTEd]

That would give rise to transformers with very large inductances which in turn would be very difficult to screen. There would be difficulty providing a smooth continuous supply for motors without considerable energy storage on board, (think capacitance or even batteries), and there would be problems in ground coupling to anything ferrous. Of course, all the safety issues inherent with 3rd rail power still exist.

Why would you require considerable energy storage?
Motor power smoothing would provided by the kinetic energy of the train that keeps your universal motors turning through the drop offs in motor current. There would be no onboard rectifiers or transformers or anything like that for traction use. And lighting and air con are hardly a significant load in power terms.
After all a train has rather significant mass and is directly coupled to your motors through a hard mechanical drive.
Universal motors function perfectly well on 16.7Hz and there seems to be little to suggest they would not function well at lower frequencies, until you reach truly ridiculous levels.

Why not use a very effective proven system where the inadvertent risk is far lower, performance is consistently better and safe maintenance of infrastructure can usually be executed without power shutdown. Yes, that's right, HV ac OLE. All the technology is understood, available and for mainline use, has a lower through-life cost than any other rail electric power delivery.

Because AC OLE stops a railway dissapearing into the background, requires massive and disruptive works on its deployment and looks nasty.

These are all significant issues.
Additionally what fraction of the railway is a "main line" for these purposes?
And "through life" cost is entirely dependent on the price of capital available - at higher rates as found in certain circumstances the enormous dinstallation costs of HV AC will overwhelm any operational savings later on.

 

[TheKnightWho]

Because AC OLE stops a railway dissapearing into the background, requires massive and disruptive works on its deployment and looks nasty.

These are all significant issues.

Two of those are the same thing, and is, frankly, a very small issue outside of national parks and AONBs.

The large works required are more than made up for by the cost savings afterward.

 

[QueensCurve]

AC OLE... looks nasty.

You think it looks nasty, I think it looks nice. At least it did until NR deviated from the BR designs.

 

[Philip Phlopp]

You think it looks nasty, I think it looks nice. At least it did until NR deviated from the BR designs.

It's difficult to tell if a railway is electrified or not when you're more than a few hundred metres away, and the entire railway line becomes difficult to spot if you go a couple of miles away.

Motorways like the M25 around Heathrow, M6/M74 through the Lune Gorge or the M8 in Glasgow are huge and much more obvious sights which you will struggle not to notice.

 

[najaB]

Motorways like the M25 around Heathrow, M6/M74 through the Lune Gorge or the M8 in Glasgow are huge and much more obvious sights which you will struggle not to notice.

Here you go...

 

[AM9]

Why would you require considerable energy storage?
Motor power smoothing would provided by the kinetic energy of the train that keeps your universal motors turning through the drop offs in motor current. There would be no onboard rectifiers or transformers or anything like that for traction use. And lighting and air con are hardly a significant load in power terms.
After all a train has rather significant mass and is directly coupled to your motors through a hard mechanical drive.
Universal motors function perfectly well on 16.7Hz and there seems to be little to suggest they would not function well at lower frequencies, until you reach truly ridiculous levels.

Universal motors are large cumbersome devices being developments of DC motors with all the reliability issues of commutators and brushes as well as heat generators.
Compared to a modern synchronous ac motors, they are also quite inefficient. So to use moderm motors in passenger vehicles (as in EMUs) they need conventional control electronics fed by heavy low frequency transformers.

... Additionally what fraction of the railway is a "main line" for these purposes?

Virtually everything with actual operating speeds over 60mph, i.e. not including genuine metro lines.

And "through life" cost is entirely dependent on the price of capital available - at higher rates as found in certain circumstances the enormous dinstallation costs of HV AC will overwhelm any operational savings later on.

As has been made clear both in this thread, the installation costs of 3rd rail vs OLE of similar traffic capacity and performance is very similar. The maintenance cost and the energy costs are much higher for 3rd rail. The cost of finace does not change the actual costs significantly.

 

[The Ham]

Here you go...

That's a bit unfair, the road is relatively lightly used whilst there is a fairly bright train on most of the length of track visible, as such the road would for much of the time be more obvious than it is!

 

[najaB]

That's a bit unfair, the road is relatively lightly used whilst there is a fairly bright train on most of the length of track visible, as such the road would for much of the time be more obvious than it is!

Didn't want to be accused of stacking things in the railway's favour!

 

[reddragon]

A typical scene here of a stray current issue with the 3rd rail. Even the 3rd rail is buried in the ballast and just look at the arcing damage between the 3rd rail and the ballast stones!

To top that, the area was scattered with dead animals that hadn't even touched the 3rd rail. Losses here must be huge, as is the damage to the surrounding metalwork & pots.

Composite aluminum & copper 3rd rail does not have such high losses as iron

 

[najaB]

A typical scene here of a stray current issue with the 3rd rail. Even the 3rd rail is buried in the ballast and just look at the arcing damage between the 3rd rail and the ballast stones!

That looks a little odd (might just be the way the photo is taken) as it appears that the running rail is higher than the contact surface of the 3rd rail.

 

[steevp]

That looks a little odd (might just be the way the photo is taken) as it appears that the running rail is higher than the contact surface of the 3rd rail.

Ah so that's the problem then......

 

[swt_passenger]

That looks a little odd (might just be the way the photo is taken) as it appears that the running rail is higher than the contact surface of the 3rd rail.

This problem of ballast against the third rail; how widespread is it and how often is it completely neglected like that.

I 'put it to the court' that it occurs in such trivially small areas (in terms of distance as a proportion of the SR network) that it hardly worth mentioning.

 

[QueensCurve]

Here you go...

The railway looks great there with Mk3b OHLE.

 

[Bald Rick]

Here you go...

It wasn't sunny there this morning...

 

[najaB]

That's a bit unfair, the road is relatively lightly used whilst there is a fairly bright train on most of the length of track visible, as such the road would for much of the time be more obvious than it is!

Okay then, how about this one:

And yes, there is an electrified railway in that picture!

(Source: The Tebay Gill Skyline - view over the railway and M6)

 

[The Ham]

Okay then, how about this one:

And yes, there is an electrified railway in that picture!

(Source: The Tebay Gill Skyline - view over the railway and M6)

Thank you

 

[Deepgreen]

Thank you

This is all very well, but catenary spoils railway photographs!

 

[QueensCurve]

This is all very well, but catenary spoils railway photographs!

It certainly makes composition interesting.

 

[Mikey C]

Okay then, how about this one:

And yes, there is an electrified railway in that picture!

(Source: The Tebay Gill Skyline - view over the railway and M6)

To be fair, in those sorts of distant shots the motorway looks attractive as well.

 

[HowardGWR]

To be fair, in those sorts of distant shots the motorway looks attractive as well.

Oh no it doesn't.

Also remember the continuous drone.

 

[Mikey C]

Oh no it doesn't.

Also remember the continuous drone.

That's my I said distant shots

But motorways can look attractive, the M6 in Cumbria in particular

 

[Deepgreen]

That's my I said distant shots

But motorways can look attractive, the M6 in Cumbria in particular

No, sorry - can't agree. Their land take is hugely more than railways and as a result their visual impact is always far worse. They also tend to be black or grey whereas railways look brown and blend in far better. Anyhoo - back to the North Downs line?

 

[GRALISTAIR]

It can be argued for North Downs that 3rd rail would be "prettier", but even if 3rd rail safety case etc could be made I just can not see it going in the HLOS early 2017 for CP6. I can see in the electrification RUS refresh which is supposed to be out in the late Autumn-early winter, it coming midway in priority for the rolling program - but to my mind there are quite a few higher priorities.

 

[edwin_m]

continuous drone.

Is that what took all these delightful pictures?

 

[Philip Phlopp]

It can be argued for North Downs that 3rd rail would be "prettier", but even if 3rd rail safety case etc could be made I just can not see it going in the HLOS early 2017 for CP6. I can see in the electrification RUS refresh which is supposed to be out in the late Autumn-early winter, it coming midway in priority for the rolling program - but to my mind there are quite a few higher priorities.

Mid table might be too low - I'd go with Europa League qualifying spot area.

It releases relatively modern DMU stock though, and combined with Western Rail Access to Heathrow (WRAtH) could provide a rail connection between Heathrow and Gatwick which could come into play for either of the two options for additional runway capacity.

The timescales for WRAtH and the new runway mean there's no urgent priority to electrify the route - mid CP7 (2026-2027) would be fine which is hopefully when one would want to add more DMU capacity to the West of England by cascading yet more Turbos.

 

[Domh245]

Mid table might be too low - I'd go with Europa League qualifying spot area.

It releases relatively modern DMU stock though, and combined with Western Rail Access to Heathrow (WRAtH) could provide a rail connection between Heathrow and Gatwick which could come into play for either of the two options for additional runway capacity.

The timescales for WRAtH and the new runway mean there's no urgent priority to electrify the route - mid CP7 (2026-2027) would be fine which is hopefully when one would want to add more DMU capacity to the West of England by cascading yet more Turbos.

Would North Downs electrification be timed to coincide with the wiring of other Thames Valley Branches in order to release all of the fleet to the west?