Box Tunnel, track lowering, would 3rd rail not have been better?

[PaxmanValenta]

I've just seen on TV that they lowered the track level of the Box Tunnel in Wiltshire to accommodate future electrification.

I'd have thought it would have been too costly and very risky and as this was once done to a tunnel in Scotland which lead to its collapse burying 2 workers who 35 years later still remain buried.

https://en.m.wikipedia.org/wiki/Penmanshiel_Tunnel

Would it not have been a lot safer and cheaper to use 'third rail' for the tunnel and adapted trains with brushes to use third rail for tunnel sections?

That would kill 2 birds with one stone as it would also allow those trains to operate on the South Eastern networks as well as overhead electric sections.

 

[Ironside]

The tunnel you refer to was built in unstable ground, as the article states. If the Box tunnel doesn't have the same problem then 3rd rail not necessary.

Also 3rd rail would require a speed reduction, which would be contrary to one of the main reasons for the GWML electrification project.

 

[swt_passenger]

They had to lower the track level in Southampton tunnel for W10 gauge clearance for containers, it's 'horses for courses'.

Penmanshiel will have highlighted the risks, but realistically it was never going to mean no track lowering would ever be done again.

 

[dggar]

I've just seen on TV that they lowered the track level of the Box Tunnel in Wiltshire to accommodate future electrification.

I'd have thought it would have been too costly and very risky and as this was once done to a tunnel in Scotland which lead to its collapse burying 2 workers who 35 years later still remain buried.

https://en.m.wikipedia.org/wiki/Penmanshiel_Tunnel

.

From the link that you quote:---

The report suggested that the collapse was likely to be the result of over-stressing of the natural rock on which the brick arch rings were founded. It was likely to have happened at some time in any event and there was insufficient evidence to say whether or not it had been triggered by the excavation.

 

[furnessvale]

They had to lower the track level in
Penmanshiel will have highlighted the risks, but realistically it was never going to mean no track lowering would ever be done again.

Many track lowerings in tunnels have been safely completed since Penmansheil.

 

[swtandgw]

The tunnel you refer to was built in unstable ground, as the article states. If the Box tunnel doesn't have the same problem then 3rd rail not necessary.

Also 3rd rail would require a speed reduction, which would be contrary to one of the main reasons for the GWML electrification project.

Not to mention requiring the Class 800/801s to have extra equipment and shoegear for operating on 3rd rail, and also, safety implications of 3rd rail types that are not bottom contact like on the DLR, e.g. SR/Merseyrail-style top contact.

 

[DarloRich]

I've just seen on TV that they lowered the track level of the Box Tunnel in Wiltshire to accommodate future electrification.

I'd have thought it would have been too costly and very risky and as this was once done to a tunnel in Scotland which lead to its collapse burying 2 workers who 35 years later still remain buried.

https://en.m.wikipedia.org/wiki/Penmanshiel_Tunnel

Would it not have been a lot safer and cheaper to use 'third rail' for the tunnel and adapted trains with brushes to use third rail for tunnel sections?

That would kill 2 birds with one stone as it would also allow those trains to operate on the South Eastern networks as well as overhead electric sections.

what on earth are you talking about? This kind of work happens all the time

 

[D365]

750V brushes? I think that says it all really

 

[Carntyne]

Winchburgh on the E&G has just been completed recently with no issues. Not being lowered, but Cowlairs 990m tunnel trackbed also being replaced in March before electrification works.

 

[najaB]

I understand that Box Tunnel requires pumping to remain dry - adding third rail sounds like a recipe for interesting times.

 

[jopsuk]

Whilst I don't agree that 3rd rail would have been good idea (especially somewhere in the middle of a massive OHL project), tunnels that require pumping to remain dry are fine with 3rd rail. The Thames Tunnel, used by the East London Line, has constant pumping to remove the river. I wouldn't be surprised if some of the other old tunnels used by the Underground are actively pumped too

 

[najaB]

I wouldn't be surprised if some of the other old tunnels used by the Underground are actively pumped too

Fair enough, didn't think about that.

 

[Philip Phlopp]

I've just seen on TV that they lowered the track level of the Box Tunnel in Wiltshire to accommodate future electrification.

I'd have thought it would have been too costly and very risky and as this was once done to a tunnel in Scotland which lead to its collapse burying 2 workers who 35 years later still remain buried.

https://en.m.wikipedia.org/wiki/Penmanshiel_Tunnel

Would it not have been a lot safer and cheaper to use 'third rail' for the tunnel and adapted trains with brushes to use third rail for tunnel sections?

That would kill 2 birds with one stone as it would also allow those trains to operate on the South Eastern networks as well as overhead electric sections.

No.

And No, because just No is too short for the software.

 

[route:oxford]

That would kill 2 birds with one stone.

And lots of Badgers and other mammals who touch the 3rd rail too.

 

[61653 HTAFC]

And lots of Badgers and other mammals who touch the 3rd rail too.

Though if a method of scooping up these freshly cooked critters could be devised it'd make up for the lack of a buffet car... It could even be branded as "Local Country Fayre"!

 

[Murph]

The risks in Box should be particularly easy to quantify, since it runs right through the middle of an extensive quarry system (much of which was later used as a massive munitions depot, nuclear bunker, and a high security military computer centre). The strata around the rail tunnel should be very well known, and there's extensive self-supporting tunnels surrounding it.

 

[Philip Phlopp]

The risks in Box should be particularly easy to quantify, since it runs right through the middle of an extensive quarry system (much of which was later used as a massive munitions depot, nuclear bunker, and a high security military computer centre). The strata around the rail tunnel should be very well known, and there's extensive self-supporting tunnels surrounding it.

We have had to be extra careful with the OLE geometry, the strategic steam reserve locomotives have particularly tall funnels fitted for some reason.

 

[Trog]

We have had to be extra careful with the OLE geometry, the strategic steam reserve locomotives have particularly tall funnels fitted for some reason.

Will the carbon deposits from test steaming a 1000 ex BR standard locos once a year not compromise the insulators on the OHLE?

 

[The Decapod]

We have had to be extra careful with the OLE geometry, the strategic steam reserve locomotives have particularly tall funnels fitted for some reason.

That's OK because they had particularly small wheels as well.

 

[DarloRich]

We have had to be extra careful with the OLE geometry, the strategic steam reserve locomotives have particularly tall funnels fitted for some reason.

was worried about the strategic steam reserve secret under ground bunker but apparently the new connection was installed without problem and is hidden behind that in no way odd looking door marked SSR - SECRET about 2/3rds of the way through.
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Oh not sure i am supposed to say that

 

[HarleyDavidson]

The tunnel you refer to was built in unstable ground, as the article states. If the Box tunnel doesn't have the same problem then 3rd rail not necessary.

Also 3rd rail would require a speed reduction, which would be contrary to one of the main reasons for the GWML electrification project.

You can install Furrer & Frey overhead conductor rail which is certificated for use with 25kV.

http://www.furrerfrey.ch/en/systems/conductor_rail.html

--- old post above --- --- new post below ---

They had to lower the track level in Southampton tunnel for W10 gauge clearance for containers, it's 'horses for courses'.

Penmanshiel will have highlighted the risks, but realistically it was never going to mean no track lowering would ever be done again.

The base of Southampton Tunnel was actually at one time a canal.

 

[RichmondCommu]

We have had to be extra careful with the OLE geometry, the strategic steam reserve locomotives have particularly tall funnels fitted for some reason.

Oh my God this is wonderful news! Are there any Midland Railway 3F tender loco's in there? I know it's a long shot but I would love to own one.

 

[snowball]

You can install Furrer & Frey overhead conductor rail which is certificated for use with 25kV.

http://www.furrerfrey.ch/en/systems/conductor_rail.html

But is not guaranteed to remove the need to lower the floor or otherwise enlarge the tunnel.

 

[Philip Phlopp]

But is not guaranteed to remove the need to lower the floor or otherwise enlarge the tunnel.

It's a nice solution even when the tunnel is large enough for conventional OLE as it reduces the maintenance and inspection requirements - no tensioning equipment, no catenary wire, droppers or pairing of the catenary and contact wires in reduced height situations (though the GWML doesn't do that anyway - constant height being the order of the day with the GWML's OLE).

 

[furnessvale]

Whilst I don't agree that 3rd rail would have been good idea (especially somewhere in the middle of a massive OHL project), tunnels that require pumping to remain dry are fine with 3rd rail. The Thames Tunnel, used by the East London Line, has constant pumping to remove the river. I wouldn't be surprised if some of the other old tunnels used by the Underground are actively pumped too

The tunnel under the Mersey used by Merseyrail has massive pumps fitted at both ends which, if both ends failed simultaneously, would flood the tunnel within hours rather than days.

 

[Philip Phlopp]

The tunnel under the Mersey used by Merseyrail has massive pumps fitted at both ends which, if both ends failed simultaneously, would flood the tunnel within hours rather than days.

The only real benefit OLE has in this case, over third rail, is that the OLE is going to stay energised long enough to have a chance of getting a unit out of a flooding tunnel, if the third rail trips, the unit may well be stuck with water rising about it, whilst an AC unit has at least half a chance of getting itself out before the traction motors become submerged or other component failure occurs.

The irony of that statement is, of course, that 25kV AC units 314208 and 314212 may have been the last electric units to suffer flood damage in this manner when Glasgow Central Low Level flooded in 1994.

 

[WelshBluebird]

The tunnel under the Mersey used by Merseyrail has massive pumps fitted at both ends which, if both ends failed simultaneously, would flood the tunnel within hours rather than days.

And I'm sure most here will be aware of the Severn Tunnel, which if the pumps and the backups fail would flood in a matter of minutes.

 

[ainsworth74]

And I'm sure most here will be aware of the Severn Tunnel, which if the pumps and the backups fail would flood in a matter of minutes.

Is that actually the case? It's always seemed a bit hard to believe for me at least. I've been through there in HSTs and conducted some external observation of the tunnel and was half expecting water to pouring out of the roof from what's been said!

 

[najaB]

Is that actually the case? It's always seemed a bit hard to believe for me at least. I've been through there in HSTs and conducted some external observation of the tunnel and was half expecting water to pouring out of the roof from what's been said!

I think it I heard it said that they pump ten million gallons a day!

 

[swt_passenger]

The base of Southampton Tunnel was actually at one time a canal.

Southampton tunnel crossed the route of the former canal tunnel at an oblique angle, the tunnels were on slightly different headings. The canal tunnel entrance was south of the railway at the east end, and north of the railway at the west end, near the BBC buildings.

It wasn't a case of the rail tunnel just re-using the full canal route, but it explains the drainage issues.