National Power lines have come into contact with OLE - Berwick (13/10)

[najaB]

Not quite! For a fixed resistance, as V gets larger, I gets larger too.

I think what you meant is that for a fixed power, the current is less and so the losses are less. Power= V*I so, if V is greater then, for the same power, I is less. The (resistive) losses are I^2 * R, so increase with the square of the current. (With alternating current the impedance is not just the resistance, but that's another matter!)

Yes, sorry. I lost that when I edited the post. For a given value of R, as V increases I decreases to transmit the same power.

 

[HSTEd]

Posted above that it was just 11kV - I think 132kV would be on pylons not wooden poles.

132kV wooden pole lines do exist, indeed you get a great view of one going towards Cornwall outside of Exeter station.

They look a bit strange but have a huge set of splayed insulators on the top of the pole, often referred to as "Tridents".

 

[D365]

Daft question time what does DNO stand for?

Not a daft question, in fairness, that abbreviation is used all too often in railway-land without being fully explained!

 

[ABB125]

OpenInfraMap is my new favourite map! I love maps like this, I could spend hours looking at this.
It's fascinating looking at my local area - plenty of wooden poles are 66kV - I'd always assumed all wooden poles were 240V! My only criticism is that it only has high-voltage stuff on it, but I suppose including every power line in the country would be rather too much work.
Interestingly, the University of Birmingham has its own 132kV supply from Selly Oak substation - I wonder why they need this?

Apologies for perpetuating this fascinating but off-topic topic.

 

[ainsworth74]

Any chance of some pictures for those of us that missed the LNER tweet?

 

[_toommm_]

Any chance of some pictures for those of us that missed the LNER tweet?

I've not found much, but here's one or two links:

Significant delay to rail services after power line damage

A Scottish Power cable has fallen onto the overhead lines which power electric rail services at Scremerston on the East Coast Main Line.

www.networkrailmediacentre.co.uk

https://twitter.com/NetworkRailKGX/status/1316028065961533441?s=20

And incase these tweets/articles get deleted, I'll post the photos below (DESCRIPTION: The photos are of the damage to the Overhead Line Equipment at Berwick-upon-Tweed, 13/10/20):

 

[crablab]

Any chance of some pictures for those of us that missed the LNER tweet?

They did retweet the images again in that thread, so I suspect it was just correcting a typo (since you can't edit tweets)

 

[HSTEd]

Is the conductor/catenary wire on that section copper or steel reinforced aluminium?

 

[plugwash]

They did retweet the images again in that thread, so I suspect it was just correcting a typo (since you can't edit tweets)

Do you have a link?

 

[_toommm_]

Do you have a link?

See my photos above in post #36.

 

[1978NWUK]

Is the conductor/catenary wire on that section copper or steel reinforced aluminium?

7/3.95 AWAC, 5 strands alu, 2 strands steel.

 

[HSTEd]

7/3.95 AWAC, 5 strands alu, 2 strands steel.

The difference in colours between copper grid cables and the railway ones is really is striking in some of the images!

 

[swt_passenger]

This type of incident can’t be that common, I would have thought?

It’s just the sort of random snag that would usually result in the sort of discussion we‘re having, but I don’t recall a previous similar fault.

 

[Elecman]

I’m wondering what brought the DNO cables down in the first place

 

[oldman]

This type of incident can’t be that common, I would have thought?

A similar thing happened in Northumberland on a very windy day in the mid-1990s. Went down to York for a meeting but going home the message at York for Edinburgh passengers was don't bother; in fact they had one line open for diesel traction by mid-evening. I ended up on the Eurostar-connecting HST coming up from Waterloo - I don't suppose it often carried so many passengers.

 

[1978NWUK]

I’m wondering what brought the DNO cables down in the first place

This type of incident can’t be that common, I would have thought?

It’s just the sort of random snag that would usually result in the sort of discussion we‘re having, but I don’t recall a previous similar fault.

I can recall a few happening over the last few years. The distance between the DNO OLE and railway OLE is specified in ENA (Energy Networks Association) documents although I imagine its not a simple affair to manage when you throw in wayleave agreements......

There are some locations with ample clearance between DNO and railway which allow for nets to be installed to help reduce the potential for de-wirements.