Scottish Electrification updates & discussion

[InOban]

How often does Alex Hynes have to repeat that there is no problem in wiring the bridge?
There is a problem with Kinghorn tunnel, and there may be an issue with the high girders on the Tay bridge, but I've not seen a definite statement on that.

 

[mcmad]

Kinghorn Tunnel would benefit from being rebored to remove the kink in the middle. Would mean diversions via Dunfermline for an extended period of time but would then remove the significant speed reduction (20/30 from memory)

 

[GRALISTAIR]

---- it would be cheaper to either buy hybrid rolling stock, or invest in banking engines (bridging engines?) to haul electric stock across the bridge.

Yes a la Lickey. You would have an electric shunter - ( battery and overhead) either side - one for north and one for south bound and they would be on charge when not in use with a little headshunt for stabling. Much cheaper than the tunnel idea. But as has been said ad nauseam - electrification across the Forth Bridge is not insuperable.

 

[edwin_m]

I think we can take it that the diagonal bracing above the Forth Bridge rail deck allows enough clearance for the wires and the pantograph, so all the various "solutions" offered on this forum over the years are unnecessary. Just need to find out if they still make those red insulators...

 

[GRALISTAIR]

It would be easier - bespoke admittedly- to add red iron oxide pigment to the polymeric insulators I think. Red-brown Ceramic would also work of course.

 

[marks87]

Even once the wires are up and electric trains happily running across the Forth Bridge this forum will still insist it can’t be done

Either that, or the Tay Bridge will become the new focus. Presumably a conductor bar will considered for the high girders, while the open sections will need a nice strong design to withstand the “challenging” weather that comes with an exposed firth.

 

[najaB]

Either that, or the Tay Bridge will become the new focus.

To be honest, I've never doubted that the Forth can be wired - the Tay Bridge has been the one that concerns me. The high girders section is a bit tight on clearance, and the low girders will be more challenging than the Forth approach spans to do sympathetically.

 

[marks87]

To be honest, I've never doubted that the Forth can be wired - the Tay Bridge has been the one that concerns me. The high girders section is a bit tight on clearance, and the low girders will be more challenging than the Forth approach spans to do sympathetically.

A Royal Border Bridge-style bespoke solution will almost certainly be required.

The challenge will be in balancing robustness with visual impact.

 

[najaB]

A Royal Border Bridge-style bespoke solution will almost certainly be required.

The challenge will be in balancing robustness with visual impact.

Yeah, the Tay is the opposite of the Forth in that the part of the Forth that has the greatest cultural icon status is the cantilever section, the approach spans are almost an afterthought.

(Image from Wikimedia showing the Forth Bridge seen from the West)

Where with the Tay Bridge the high girders section isn't as iconic of the city as is the graceful curve of the low girders section away from the waterfront.

(Image from Wikimedia showing the Tay Bridge seen from the north)

 

[Meerkat]

Apart from the history I don’t really see the attraction of the Tay Bridge - not in a form that normal OLE is going to really spoil (obviously the GW stuff spoils even ugly places!)

 

[59CosG95]

It would be easier - bespoke admittedly- to add red iron oxide pigment to the polymeric insulators I think. Red-brown Ceramic would also work of course.

I believe the red insulators were part of the UK1 (West Coast Route Modernisation) range, so could probably be used again depending on the design.
Then again, it's such a small number of insulators by comparison to most electrification schemes that going for a bespoke colour pigment in the silicone probably wouldn't be that different in price to buying light grey ones off the shelf.
I can't remember who supplied the insulators for UK1, but if a ROCS solution is used, the supplier for that might not warm to changing the colour.

Besides, when you're at ground level, it's difficult enough to see them 110m above!

The start of the cantilever spans would be the ideal place to transition to ROC, if that does get used - failing that, contenary. The approach spans are also spaced 51.2m apart, so it's a pretty reasonable assumption to put an OLE structure at every approach pier. No idea what setions would be used, as that largely depends on wind modelling and strength of the piers.

 

[GRALISTAIR]

The start of the cantilever spans would be the ideal place to transition to ROC, if that does get used - failing that, contenary. The approach spans are also spaced 51.2m apart, so it's a pretty reasonable assumption to put an OLE structure at every approach pier. No idea what sections would be used, as that largely depends on wind modelling and strength of the piers.

That is useful information - I did not know that. Thanks for posting.

 

[ABB125]

I believe the red insulators were part of the UK1 (West Coast Route Modernisation) range, so could probably be used again depending on the design.
Then again, it's such a small number of insulators by comparison to most electrification schemes that going for a bespoke colour pigment in the silicone probably wouldn't be that different in price to buying light grey ones off the shelf.
I can't remember who supplied the insulators for UK1, but if a ROCS solution is used, the supplier for that might not warm to changing the colour.

Besides, when you're at ground level, it's difficult enough to see them 110m above!

The start of the cantilever spans would be the ideal place to transition to ROC, if that does get used - failing that, contenary. The approach spans are also spaced 51.2m apart, so it's a pretty reasonable assumption to put an OLE structure at every approach pier. No idea what setions would be used, as that largely depends on wind modelling and strength of the piers.

What's a ROCS solution? Rigid Overhead Conductor?

 

[marks87]

Apart from the history I don’t really see the attraction of the Tay Bridge - not in a form that normal OLE is going to really spoil (obviously the GW stuff spoils even ugly places!)

It's a category A listed building so any electrification will need to go through various processes to ensure it doesn't have a significant impact on the appearance etc. (as with the Royal Border Bridge, as mentioned).

 

[59CosG95]

What's a ROCS solution? Rigid Overhead Conductor?

It certainly is. AFAIK, all of these are bespoke solutions and not part of any standard design range.

 

[nlogax]

I believe the red insulators were part of the UK1 (West Coast Route Modernisation) range, so could probably be used again depending on the design.

These?



As seen on Argos Unipart's electrification catalogue - https://www.unipartrail.com/wp-content/uploads/2020/07/overhead-line-catalogue-listings.pdf

 

[59CosG95]

These?

View attachment 83416

As seen on Argos Unipart's electrification catalogue - https://www.unipartrail.com/wp-content/uploads/2020/07/overhead-line-catalogue-listings.pdf

Yes, those ones - although from memory the quoted 9-digit no's are from the standard Mk3 range, so might be Mk3d. Then again, these parts can be ordered from a number of suppliers, so different colours are not uncommon.

 

[Bald Rick]

Re red insulators - can’t they just be made out of steel? Then they’ll rust over time.

 

[najaB]

Re red insulators - can’t they just be made out of steel? Then they’ll rust over time.

Can't see anything wrong with that plan at all...

 

[Bald Rick]

Can't see anything wrong with that plan at all...

Well there’s been no resistance so far.

 

[ABB125]

Well there’s been no resistance so far.

Ohm my goodness! What a terrible joke!

 

[najaB]

Ohm my goodness! What a terrible joke!

I know. Positively shocking.

 

[ABB125]

I know. Positively shocking.

I don't have much capacitance for these jokes, but unfortunately resistance is futile! (Yes, I know that one's been done before, but I couldn't resist (sorry once again!) it!)

 

[Bald Rick]

Ohm my goodness! What a terrible joke!

At your service.

 

[edwin_m]

Re red insulators - can’t they just be made out of steel? Then they’ll rust over time.

That's a really stupid suggestion.

Don't you know they paint everything red on the Forth Bridge to stop it rusting?

At your service.

You'd better get your coat and go ohm.

 

[ABB125]

At your service.

Sorry, I just can't work out if there's a joke in here or not; would you mind enlightening me?
Having said that, we seem to have gone off on a stray current... earth bonding required!

 

[alangla]

I hope everyone angsting over the look of electrification on the Forth & Tay bridges never looks at Sydney Harbour Bridge. 1500V DC OHLE, overhead gantry signs on the motorway, big fences on the footways. Still an iconic structure & one of the key images of Sydney.

 

[McRhu]

Oh electrification o’er the silvr’y Tay


Wi fiendish storm and tempest blast a’ the way


How the wires would tremble and sway


If the Series 1 components they did give way

 

[najaB]

I hope everyone angsting over the look of electrification on the Forth & Tay bridges never looks at Sydney Harbour Bridge. 1500V DC OHLE, overhead gantry signs on the motorway, big fences on the footways. Still an iconic structure & one of the key images of Sydney.

If you look at Street View images you can see that the OHLE was able to be naturally fit in on the lighting structures. https://goo.gl/maps/PEet8bErPWV7gJu2A

Unfortunately, the designers of the Tay Bridge didn't think to include any.

 

[nlogax]

If you look at Street View images you can see that the OHLE was able to be naturally fit in on the lighting structures. https://goo.gl/maps/PEet8bErPWV7gJu2A

Slight nuance.. but weren't those gantry structures actually designed for DC OHLE right from the start? There used to be two pairs of lines when the bridge opened, one either side of the bridge and both sets of gantries remain today as per the photo.