GRALISTAIR
Established Member
Glad you pointed this out - I did a double take and decided to sleep on the OP rather than comment. Your understanding is exactly mine.
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Scottish Electrification updates & discussion
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Just a gentle reminder this thread is to discuss updates regarding what is happening in respect of Scottish electrification projects.
If anyone wishes to discuss anything else, please post in the appropriate section.
For ideas/suggestions please create a thread (if there isn't one already) in Speculative Ideas.
Thanks!
If anyone wishes to discuss anything else, please post in the appropriate section.
For ideas/suggestions please create a thread (if there isn't one already) in Speculative Ideas.
Thanks!
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chiltern trev
Member
Re the battery EMU for WHL - it would also need one small genset per unit for hotel power winter contingency - no good getting stranded out in the wilds with bad weather.
https://www.railforums.co.uk/threads/scottish-electrification-stock.207146/
check out my post #12 in the speculative section.
Altnabreac
Established Member
A topic which frequently comes up on this thread is whether it is possible to electrify the Forth Bridge.
Was interesting to see on Twitter that the question "Can the Forth Bridge take electrification equipment?" was raised in response to the Alloa - Kincardine feasibility work and Alex Hynes gave a one word answer of Yes.
https://twitter.com/AlexHynes/status/1303057076298690570?s=20
Was interesting to see on Twitter that the question "Can the Forth Bridge take electrification equipment?" was raised in response to the Alloa - Kincardine feasibility work and Alex Hynes gave a one word answer of Yes.
https://twitter.com/AlexHynes/status/1303057076298690570?s=20
Yes is the answer but the clearances on the bridge will need to be increased significantly. Its also a listed structure and the work may not be allowed.
Could be cheaper just to admit defeat and look to sinking a tunnel or putting tracks on the old road bridge.
Philip Phlopp
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That's because Alex is well briefed...
That would be basically the same tunnel that was costed at £800m in 2006 prices, wouldn't it ? How is that going to be cheaper ?
The Forth Road Bridge can't (easily or cheaply) take train tracks - suspension bridges have significant issues with train tracks and I don't really know if the Forth Road Bridge is structurally designed or capable of withstanding the specific loads imparted by trains.
Clearances aren't a particular issue and whilst there is an engineering challenge to deliver electrification, it will not remotely be insurmountable. The recent developments around modelling for pantograph uplift under limited clearance structures, and the array of new technologies which can be deployed to provide the necessary electrical clearances make life considerably easier than it once would have to electrify the structure (and its cousin, the Tay Bridge).
The UNESCO World Heritage designation included clauses concerning the upkeep, improvement and enhancement of the structure for operational purposes, and in terms of heritage/listed structures, electrification has taken place on/over/through equally important sites. The bridge itself isn't actually an issue for visual disruption, it's the approach viaducts which will need careful design work, but with things like Brunel's bridges on the GWML and the Royal Border bridge being sympathetically wired, doing the Forth Bridge won't be an issue.
There have been various schemes to sink a tunnel. Not necessarily at the same point as the bridge. There are shorter crossing points available.
The road bridge is currently due to have its cables replaced. So no doubt higher specification cables could be used.
In its road days the road bridge was cleared for the heaviest loads. Whereas the rail bridge carries load restrictions.
Clearances on the rail bridge are significantly tight. Both horizontally and vertically. It may be possible to redesign the vertical struts to gain clearance. That would be quite costly. However horizontal clearances would be another probable problem to gain pantograph clearance. Many years ago an employee was caught by a train and lifted over the side into the waters below. That was at the point at which hv vesta were fitted with velcro tabs.
So perhaps not just as simple a yes as Alex has given. The approach viaducts to the Rail bridge are the least problem of any electrification project. It was a similar difficultly at the Royal Border bridge at electrification.
The problem isn't the total amount of load - it's the way that suspension bridges respond to the load application.
I’m not sure how many times it needs to be said, but the Forth Bridge is not a big problem for OLE.
And even if it was, it would be cheaper to provide every train that goes across it with a short range battery or Diesel engine than to dig a tunnel, or build a new line to the Forth Road Bridge and convert it to rail use (which, I assume, would need some seriously heavy engineering to deal with the point loads and total dynamic loads of 2000 tonne freight trains passing each other).
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paul1609
Established Member
Is this "Electrifying the Forth Bridge is not a problem" like "Electrifying the Severn Tunnel is not a problem"?
Agreed but it won't stop people believing in myths!
The biggest issue is likely to be the extra caffeine consumption to get people though all the discussions on heritage paperwork.
No a bit more like running LU D Stock through the Ryde tunnels on the IoW isn't a problem!
nlogax
Established Member
In 2019 Network Rail submitted the planning paperwork for a pedestrian walk and viewing platform atop the bridge which could be fairly disruptive and needed those sorts of heritage permissions. Submission to approval took about a year.
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GRALISTAIR
Established Member
Well Scotland are on the ball with this sort of stuff so I don't have any concerns.
GRALISTAIR
Established Member
Yes and I bet you a tenner it will need restating by experts again and again before fizzy knitting trains run across it.
Yes it is! It's a 2, 476m long problem last time I checked. I agree it's not difficult though.
Glenmutchkin
Member
technically true, Kincardine, Alloa and Stirling to give some example.
Helpful, no. Practical, no.
but truthful..... yes.
Philip Phlopp
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Technically, we've already electrified two bridges across the Forth.
The current one can’t cope with that as it is. Before SAK opened, Longannet was supplied using 29 HAA (or other 4 wheel hopper) sets, long after pretty much every other power station had switched to HTAs or other high speed bogie hoppers. Even at that they crawled over at 20mph IIRC.
Pretty much as soon as SAK opened, the Hunterston to Longannet trains swapped to long strings of HTAs
Philip Phlopp
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Didn't they crawl over at 20mph because any more and the coal was blown out of the hoppers and on to the houses below the bridge ?
Nope, that’s the speed limit for freight on the bridge. 50 for pretty much everything else, hence getting the MGRs diverted opened up a lot of extra paths. I know what you’re thinking of though - there used to be a glue sprayer thing in Inverkeithing yard for southbound trains to stop the dust, again IIRC.
d9009alycidon
Member
A few replies back someone mentioned a tunnel, there already is (or was) one https://www.scottishfield.co.uk/culture/the-forgotten-tunnel-that-crosses-the-river-forth/ considering the short time that took to dig, could it not be surveyed, drained, opened out and used?
Read the article and work out why it couldn’t be !
GRALISTAIR
Established Member
There are others - including that it is currently flooded. Look what happened on Manchester - Preston electrification that went through mining areas. TOTAL NON STARTER!
d9009alycidon
Member
For many years I was one of the naysayers when anyone suggested extending the Glasgow Underground, citing the difficult geology that the Victorian engineers had to endure, then they drove a 4.7m Dia Sewer for 3.1 miles across the South of Glasgow from Craigton to Queen's Park in around two years - if there is a will there is a way.
Oh that goes without saying. But the "way" is usually to throw a large enough pile of cash at the problem to make it go away. As @Bald Rick says, given that you'd be talking many hundreds of millions of pounds, if it were impossible to electrify the Forth Bridge, it would be cheaper to either buy hybrid rolling stock, or invest in banking engines (bridging engines?) to haul electric stock across the bridge.
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GRALISTAIR
Established Member
I agree. Time, money and political will and almost anything is possible. But I am sure the Scottish government will all go for the low hanging fruit of other decarbonisation-electrification stuff way way before this is considered. The existing tunnel is a non-starter - it really is.
Even just taking into consideration that it would be a 12km or so diversion on either side from the existing Forth Bridge.
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