From today's "Scotsman" newspaper:

"ALEX Salmond was facing a parliamentary backlash last night over his controversial plans to invest in roads at the expense of trams.

The First Minister was accused of ditching projects where the Scottish National Party has little grassroots support and using the funds saved to favour schemes in his heartlands. Mr Salmond has "deep misgivings" about the £600 million Edinburgh tram scheme and this is likely to be one of the first victims of the new government's transport agenda.

At the same time, the Executive's new transport minister, Stewart Stevenson, has announced plans to dual the A9 from Perth to Inverness at the same cost, £600 million. The road runs through three SNP constituencies...."

Full article:
[news.scotsman.com]

So, if you had to choose, which would you prefer?

I would have to opt for "Dual the A9" as I think it has greater benefits to the whole of Scotland with regard to usage, safety and tourism. In addition, it would make good commercial sense as it "open up the highlands" to more business....

Discuss.

I'd keep the tram project with it's Airport - Haymarket link up and ditch the absurd £600m plus Edinburgh Airport Rail link, there is certainly no need for both and the Tram system offers a lot more for the Cash.

As for the A9, a unique opportunity is about to be squandered with the Beauly to Denny power line. If we want a more sustainable future and an example of joined up government, change the route of the powerline to follow the rail line/A9 corridor and go for undergrounding, improving the A9 while dualling the Highland Rail Line to a high speed electrified line, the undergrounding can follow the new rail alignment and the underground capacity requirement could be reduced by coupling the overhead train lines with a proportion of the grid distrubtion.

I make A9 trips & airport trips, with about same frequency. - I agree the airport could have a more cost effective link than is proposed. Airport access for those outside the city is also critical. Tram to a new rail halt would be good. - I could leave my car at home.

Work on certain parts of the A9 would save lives, and that is important, whatever your politics.

alan Wrote:
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> and the underground
> capacity requirement could be reduced by coupling
> the overhead train lines with a proportion of the
> grid distrubtion.


I'm not sure how that would work? The new power lines are 400KV - you wouldn't want that anywhere near the trains. The problem with long cable runs is volt drop, so I'm not sure if reducing the voltage of the overhead power lines (to a safer level) would work.

Another problem is maintenance. Overhead lines and all their paraphenalia need to be maintained. This would mean closing the rail line when the work needs to be done. Not a good idea (I've had to shut down rail lines for this reason for just an hour or so and it costs a FORTUNE). Another problem is faults. A fault on the overhead line would require switching off the railway whilst it was fixed.

An underground 400kv line would need an excavation similar to that of a motorway and would need to be far enough from the road to ensure that any cable faults could be fixed without causing disruption (jointing 400kv cable is not an easy task - at least 3 days work).

I'm convinced that undergrounding the line is the best way forward. But it costs money - and that is the ONLY thing stopping it happening.



Edited 2 times. Last edit at 22.09hrs Wed 30 May 07 by William.

William wrote:
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>jointing 400kc cable is not an easy task - at least 3 days work.

Aye aye, I bet thats wit u say tae yer boss and goes on the paperwork, 10 min pronto mair like then ya go and cruise aboot town eyeing up the burds..





Edited 1 times. Last edit at 21.52hrs Wed 30 May 07 by growwild.

Attachments: quickfix.jpg (8kB)  

(my estimate was waaaayyy off. I'm not a 400kv cable-jointer, I have only joined oil-filled 33kv cables. One joint takes 3 days)


"One of the most critical points of a 400-kV XLPE cable installation is that jointing must be performed in an environment free from dust and with controlled temperature and humidity. So, jointing was undertaken in special containers that were placed on a 2.5-m by 15-m (8.2-ft by 49-ft) concrete foundation that was positioned before the cable was installed. The foundation consisted of five specially designed concrete elements that were placed on sand bedding and then waterproofed. After the cable was laid and placed inside the foundation, three purpose-designed 6-m (20-ft) containers from NKT Cables were placed on top of the foundation, providing a jointing area in which they could be installed in the final position. At the beginning of the installation, it took five weeks to complete three single-core joints, but with the jointing area, that time was greatly reduced to three weeks by the final stage."

Definitely the A9 for me - far more important as part of the whole transport infrastructure. The airport and Leith are already well served with buses and while it would be a fantastic thing for Edinburgh to have, I don't think the costs can be justified.
As for the pylons, according to an S&S engineer pal of mine, unfortunately to build the 400kv cables underground - due to the size of the insulation and the distance required between them - would mean a width excavation of more than a dualed A9. The resultant cost would be 5-7 times that if done with pylons.

Forget the A9, waste of money ... there's plenty of opportunities to overtake there anyway.

How about a three-lane A82(M) motorway on a flyover just off the shore of Loch Lomond the foundations for which could sit on those old crannogs the clans left behind for us.

Here here!

That roads awright(A9), the A82 is shocking. Though they have done a bit of work to the surface between Ardlui and Tarbet, but that will last the summer if that afore it starts tae pot hole back up.. And this is the main road out west, though its cools as it is, well good for hammering it up, but thats probaly wit makes it a bit dangerous too, ya just cannae win!

A bridge wi a glass surface ower the loch would be cool!

>As for the pylons, according to an S&S engineer pal of mine, unfortunately to >build the 400kv cables underground - due to the size of the insulation and the >distance required between them - would mean a width excavation of more than a >dualed A9. The resultant cost would be 5-7 times that if done with pylons.

Forget the cost - just think of the environmental damage of building the equivalent of a motorway accros a large swathe of delicate upland ecology. The pylons will create much less environmental damage than putting the cable underground though they will be visually intrusive in places.

not true!

The landscape could be returned to the same state it was in before the cables were buried - and there is NO need whatsoever to lay the cables in environmentally sensitive areas. They could go anywhere! Once the cables were laid, you would never ever know where they were.

No problem.

Scottish & Southern Energy have shit loads of money. Profits announced today - a cool billion quid. They are also tight as a nun's chuff. They don't like spending money - that is why they want to have the cables overhead. No other reason. Forward thinking countries (Scandinavian countries for instance) are gradually undergrounding their grid. It's cleaner, less obtrusive, there are less faults. It's the way to go.

I don't want pylons marching over my mountains. There is no need for it at all.

How big are these cables? and how are they joined, are they melted/fused into one or a big bit of barrier strip/connector block and some tape?

Depends on the type of cable!

Modern XLPE cable isn't that big - about the the diameter of your arm. The cross section area of a conductor is dependent on the current it is carrying, not the voltage - which is (one) reason transmission lines use high voltages. To keep the size of the conductors as small as possible, and keep costs down.

There are two (main) types of cable. Modern XLPE and older oil filled. Simply put, the XLPE cable is joined by bolting the conductors together and then sealing the joint with a special resin.

However it is difficult, because the joint has to be done in spotlessly clean environments, measurments when cutting back the various layers of the cable have to be exact. Any non-perfect joins, debris, slight niks in the sheaths will quickly break down at such high voltages and the joint will break down.

Oil filled is a nightmare...

Attachments: xlpe.jpg (30kB)  

I'm all for dualling the A9. It'll be that much easier for those from the central belt to get up to CM to use the new dry slope!! Seriously though..it is a death trap road and the removal of the need to cross carriageways to exit the road at junctions such as those to the south and north of Aviemore can only be a good thing.

Regards
Olderalan

William the last time I saw the aftermath of something similar - the oil or gas pipeline near stonehaven there was a large amount of damage that is taking several years to return to something approaching its prior state and that wasn't in the much more delicate upland situation for the powerline.