Is electrifying a Newark-style flat crossing technically possible?

[brad465]

Looking at images of Newark crossing got me wondering about this; the ECML is obviously electrified here while the Nottingham-Lincoln line is not. While no proposal to electrify the latter exists AIUI, I imagine electrifying this bit is much harder than a typical diamond crossover, as two different lines are crossing almost perpendicular to each other, coupled with them being fed by different power supplies. Can the wires physically interact, even if the whole crossing has to be a neutral section, or would one line's wires have to break for the crossing? Are there examples in other countries of fully electrified flat crossings?

(Apologies if this has been discussed before, I couldn't find anything on this specific aspect amongst the many discussions about grade-separation of this site)

 

[The Pelican]

There are certainly both Tram-Tram and Tram-Train examples in Melbourne- the first are extremely common, at least 20 plus in Melbourne's very grid based centre and south eastern suburbs, while the latter are rarer, but have the power at two voltages. This article gives some information on these: https://www.hawthorntramdepot.org.au/papers/lvlcross.htm

 

[Transilien]

There are certainly both Tram-Tram and Tram-Train examples in Melbourne- the first are extremely common, at least 20 plus in Melbourne's very grid based centre and south eastern suburbs, while the latter are rarer, but have the power at two voltages. This article gives some information on these: https://www.hawthorntramdepot.org.au/papers/lvlcross.htm

From this, I see no problem in crossing two 25Kv AC lines. But the flat crossing should be removed anyway considering that the ECML has to slow down for it and the safety and capacity issues arising from the flat crossing. Near Poissy in the Île de France, there is a flat crossing next to a depot that is electrified at 25Kv AC. It is shown in this cabride video at 19:50

 

[The Pelican]

The USA has a huge number of the world's operational flat crossings between lines, because it uniquely has a very dense network often built before petrol earth moving equipment, including duplicate lines to lots of places. America has relatively little 25kv electrification, on the other hand, outside the North East Corridor. Russia has plenty of 25kv electrification- I wonder if there are any flat crossings there?

(New post)

I've finally found the best answer so far for Newark- the "Linea dei Bivi" which was a Venice-Maestre-orbiting freight route, seems to have had a double track crossing double track crossing, with both parts electrified at 3000 V DC. The following link has two great pictures of it: https://www.trainsimhobby.net/forum/viewtopic.php?t=1987

I found it via a reddit thread on flat crossings in Europe.

 

[HS2isgood]

Yes. El Berrón in Spain proves it's possible.

 

[The exile]

There used to be a tram/ train flat crossing somewhere in the northern suburbs of Dortmund. The tram was obviously electrified and I think the railway was too. Fairly sure the tram line concerned has been superseded by a Stadtbahn in tunnel.

 

[Paul AC]

Yes. El Berrón in Spain proves it's possible.

(Image shows the overhead wiring at the double-track flat crossing at El Berrón in Spain) my photo, taken 19 November 2023. 1500 V dc.

Not really suitable for any decent line speeds - here at El Berrón there are station platforms immediately 'beyond' the flat crossing, so permitted speed can be low. ECML speeds? No.

 

[yoyothehobo]

There is a crossing between the local railway line and a tram line in Matsuyama, just outside Otemachi station

 

[zwk500]

as two different lines are crossing almost perpendicular to each other

The angle is actually about 134 degrees, from a quick google earth measurement of a triangle formed from the western and Northern arms. Obviously the narrower angle would be about 46 degrees as both lines are very straight here.

It's probably not enough to wire it as a conventional crossover though.

coupled with them being fed by different power supplies.

Why would they necessarily be fed from different power supplies? There's a Feeder station for the ECML at North Muskham, a few miles north of Newark. It would be very possible to have the ECML interaction all part of the same Feeder area, with Neutral Sections between the Crossing and Newark Castle for a section fed from the Nottingham end and somewhere around Winthorpe or further east for a separate section fed from the Lincoln end.
The individual track sectioning arrangements for isolations around the Newark area might be quite complicated, but that's different to being fed from different supplies.

And Static Frequency Converters may make different supplies interacting much less of a problem anyway. Not sure, would need a proper electrification engineer to say more.

(See @GraphitProjekt's excellent diagrams on these posts: https://www.railforums.co.uk/threads/ecml-power-supply-upgrade.190071/page-13#post-7428740, https://www.railforums.co.uk/threads/ecml-power-supply-upgrade.190071/page-13#post-7431187)

FWIW, if the Nottingham-Lincoln line were busy enough to justify electrification, I highly suspect it'd be busy enough to require grade-separation.

 

[HST43257]

FWIW, if the Nottingham-Lincoln line were busy enough to justify electrification, I highly suspect it'd be busy enough to require grade-separation.

Double sided question: Does Notts to Lincoln require its new-ish 2tph? Does 2tph not quite comfortably justify electrification?

 

[The Pelican]

Looking at the third rail network of the old Southern Reigon, the obvious way to electrify the Nottingham Lincoln line would be with a through-wired multiple unit, say at least 4 coaches long, and a device for ensuring a pantograph on the front carriage raised it's pantograph before the back carriage dropped it's pantograph.

But in the modern age of batteries on multiple units, even that sort of trick is unnessecary!

 

[jfollows]

Why would they necessarily be fed from different power supplies? There's a Feeder station for the ECML at North Muskham, a few miles north of Newark. It would be very possible to have the ECML interaction all part of the same Feeder area, with Neutral Sections between the Crossing and Newark Castle for a section fed from the Nottingham end and somewhere around Winthorpe or further east for a separate section fed from the Lincoln end.
The individual track sectioning arrangements for isolations around the Newark area might be quite complicated, but that's different to being fed from different supplies.

I agree, it’s just a slightly more complicated arrangement than a normal junction, I understand no requirement other than to have a single feed for the entire arrangement. Beyond the neutral sections in all directions, they would probably be different feeds, but not for the crossover.

 

[zwk500]

Does 2tph not quite comfortably justify electrification?

Not quite comfortably, no. Especially with 2-car trains, the case would be marginal at best.

And it's not 2tph Lincoln-Nottingham only, it's 1tph Lincoln-Crewe, 1tp2h Lincoln-Matlock and 1tp2h Cleethorpes-Matlock. With a couple of early morning peak extras to St Pancras and the 1tp2h LNER Lincoln-King's Cross on the Northgate-Lincoln section.
Electrifying Nottingham-Lincoln would still require BEMUs for Cleethorpes-Lincoln, Nottingham-Trent Jns, the Matlock line, and North Staffs Jn to Stoke.

 

[GraphitProjekt]

The angle is actually about 134 degrees, from a quick google earth measurement of a triangle formed from the western and Northern arms. Obviously the narrower angle would be about 46 degrees as both lines are very straight here.

It's probably not enough to wire it as a conventional crossover though.

Why would they necessarily be fed from different power supplies? There's a Feeder station for the ECML at North Muskham, a few miles north of Newark. It would be very possible to have the ECML interaction all part of the same Feeder area, with Neutral Sections between the Crossing and Newark Castle for a section fed from the Nottingham end and somewhere around Winthorpe or further east for a separate section fed from the Lincoln end.
The individual track sectioning arrangements for isolations around the Newark area might be quite complicated, but that's different to being fed from different supplies.

And Static Frequency Converters may make different supplies interacting much less of a problem anyway. Not sure, would need a proper electrification engineer to say more.

(See @GraphitProjekt's excellent diagrams on these posts: https://www.railforums.co.uk/threads/ecml-power-supply-upgrade.190071/page-13#post-7428740, https://www.railforums.co.uk/threads/ecml-power-supply-upgrade.190071/page-13#post-7431187)

FWIW, if the Nottingham-Lincoln line were busy enough to justify electrification, I highly suspect it'd be busy enough to require grade-separation.

I hath been summoned!
I've since made better illustration of ECML power supplies through the area showing much more info. (I was going to post on the ECML PSU thread once I'd finished maps for the whole line but I need to refind my motivation to do the next few)
View attachment 010426_east mids south yorks.png
(I am aware that I have not drawn every single diesel line in the area, I only did the ones that have an actual passenger service, so no Sheet Stores - Trent!)

To the best of my knowledge the new supplies from Essendine and Potteric Carr supply most of the line now with several older grid connections (Bytham, Grantham, Retford) only used as backup in N-2 scenarios as the 132kV infrastructure in this region is just not strong enough to handle the railway's disbalance especially for the new timetable. And because of that the main sources (Essendine, Potteric Carr) are from 400kV Supergrid or SFC connections both of which manage the disbalance by brute force of power electronics. Similarly, the old Newark FS's supply survives (now piped further to Muskham) which I think is because the 132/25kV transformer is tapped off the 132kV switchboard at Staythorpe which is being directly fed by lots of 400/132kV transformers so that swamps the disbalence better or something, idk just my speculation. But perhaps those older connections Grantham and Retford could be used for the diesel lines that pass by them.

But yeah, I don't think anyone would want to build a 25kV installation for the crossing - it would be a "never before done" for the GB industry and probably be quite a maintenance burden especially at 125mph. I agree that if the route could justify full electrification it would get a flyover too. Since discontinuous is all the rage these days, any wiring scheme without a flyover would is simply have this as a pan down location.

 

[High Dyke]

A similar fitment, as shown in post #7. They would be fed from the same feeder station, so it can be done. Other countries manage it. Whether it's worth it, then probably not. At the moment Network Rail tell us they have little funding available to repair faults, never mind provide electrification on a secondary route.

 

[Snow1964]

If each track of ECML is on a separate feed, and a potential secondary crossing route on a different (third) feed, then the crossing track would have to have short neutral section.

I suspect going to need a fixed bar type conductor in a cross with the insulating section rigid too. The conductors would have to be at exact same height and almost certainly a very shallow V shape at the sides to ensure any pantograph on the crossing train cannot snag.

I do not think it would be possible with cables on higher speed line because any movement might cause the crossing train (in any direction) to hit the cable of other route if it was tilted due to wind or recent train. The surface the pantograph runs along would need to be dead level because whole width of the flat section would touch the route running across.

 

[HSTEd]

Double sided question: Does Notts to Lincoln require its new-ish 2tph? Does 2tph not quite comfortably justify electrification?

It might have justified it in the old days when electrification was comparatively cheap and the choice was all diesel or all electric, but these days I think you would need several times that traffic level to produce a sensible business case.

 

[eastwestdivide]

probably be quite a maintenance burden especially at 125mph

Pretty sure Newark flat crossing is currently 100mph for the ECML. Trains certainly slow down for it

 

[MadMac]

If each track of ECML is on a separate feed, and a potential secondary crossing route on a different (third) feed, then the crossing track would have to have short neutral section.

I suspect going to need a fixed bar type conductor in a cross with the insulating section rigid too. The conductors would have to be at exact same height and almost certainly a very shallow V shape at the sides to ensure any pantograph on the crossing train cannot snag.

I do not think it would be possible with cables on higher speed line because any movement might cause the crossing train (in any direction) to hit the cable of other route if it was tilted due to wind or recent train. The surface the pantograph runs along would need to be dead level because whole width of the flat section would touch the route running across.

Is there a speed limitation on a conductor bar installation?

 

[HSTEd]

Is there a speed limitation on a conductor bar installation?

The highest speed I am aware of one being rated for at present is 250kph, so in the context of the UK classic railway, not really.

 

[Bald Rick]

Pretty sure Newark flat crossing is currently 100mph for the ECML. Trains certainly slow down for it

Yes, 100mph on the ECML; that’s due to standards regarding rail discontinuity.