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Interconnecting tunnels/shafts

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Jack Barry

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Can anyone shed some light I know that there are shafts which connect other lines for vent and substation purposes but what about connections to other tunnel systems BT, Power and others.
I have these to list Charing Cross/Liverpool Street/Green Park.
 
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bramling

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Can anyone shed some light I know that there are shafts which connect other lines for vent and substation purposes but what about connections to other tunnel systems BT, Power and others.
I have these to list Charing Cross/Liverpool Street/Green Park.

I'm not sure there's actually many tunnels which connect elsewhere.

St Paul's used to have a connection to the CEGB, however as far as I know this is long gone. There's a blind tunnel way down in the depths of the station which is presumably the old access.

Mystique surrounds the connection at Charing Cross station with the Whitehall tunnel system, although I have it on good authority that this is more than an urban myth.

There's plenty of connections between the various lines, either ventilation or cable tunnels, although most of these are certainly not really suitable for man access. It's possible to reach the Northern Line tunnels from Lambeth North station, although you wouldn't want to be actually doing it! In many cases any man access takes the form of rudimentary ladders through confined spaces.

As far as I know none of the deep shelters nowadays have any connection into their adjoining LU stations.
 

Jack Barry

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I'm not sure there's actually many tunnels which connect elsewhere.

St Paul's used to have a connection to the CEGB, however as far as I know this is long gone. There's a blind tunnel way down in the depths of the station which is presumably the old access.

Mystique surrounds the connection at Charing Cross station with the Whitehall tunnel system, although I have it on good authority that this is more than an urban myth.

There's plenty of connections between the various lines, either ventilation or cable tunnels, although most of these are certainly not really suitable for man access. It's possible to reach the Northern Line tunnels from Lambeth North station, although you wouldn't want to be actually doing it! In many cases any man access takes the form of rudimentary ladders through confined spaces.

As far as I know none of the deep shelters nowadays have any connection into their adjoining LU stations.
Was the St Pauls one where the control room was in the old lift shafts although there must have been a cable connection. There was mention in a book about WW2 connections Beneath the City Streets and there was also later ones. As I understand the Charing Cross connection is a walk through so not just cable ducts, I did hear that there is a connection not far from Westminster station but don't have anything further.
I think all the deep shelters have connections to the stations but they are now sealed?
 

bramling

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Was the St Pauls one where the control room was in the old lift shafts although there must have been a cable connection. There was mention in a book about WW2 connections Beneath the City Streets and there was also later ones. As I understand the Charing Cross connection is a walk through so not just cable ducts, I did hear that there is a connection not far from Westminster station but don't have anything further.
I think all the deep shelters have connections to the stations but they are now sealed?

My memory of St Paul’s is a little hazy as it’s been a good few years now since I was there. However from what I remember at least one of the disused lift shafts has a manhole in the bottom, leading down via a ladder to a number of further levels, which are encased in thick concrete. This I presume was the CEGB control room. Leading off from the original base of a lift shaft was a blind heading (presumably leading to the running tunnels), and at right-angles to this was another smaller blind heading leading to a solid wall, with evidence that cables once passed through. As I say, it’s been a few years so I may have his slightly mixed up, but the general gist of the above is sound.

Not sure about Westminster. There’s certainly nothing in the Jubilee Line tunnels. The only features of note are the intervention shaft at Storey’s Gate, vent shafts at both ends of Westminster platforms, and further towards Waterloo a feature on the left-side of the EB tunnel which I believe to be the remnants of the construction working site at Jubilee Gardens, which was reached via a lengthy temporary heading which I believe was backfilled when no longer required. Certainly there’s no way into it if it is still there. LU tunnels are littered with such construction remnants if one knows exactly where to look and what to look for!

Correct about the deep shelters. The access points can be seen in many cases, but completely sealed up. Camden Town is probably the most conspicuous.
 
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Jack Barry

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My memory of St Paul’s is a little hazy as it’s been a good few years now since I was there. However from what I remember at least one of the disused lift shafts has a manhole in the bottom, leading down via a ladder to a number of further levels, which are encased in thick concrete. This I presume was the CEGB control room. Leading off from the original base of a lift shaft was a blind heading (presumably leading to the running tunnels), and at right-angles to this was another smaller blind heading leading to a solid wall, with evidence that cables once passed through. As I say, it’s been a few years so I may have his slightly mixed up, but the general gist of the above is sound.

Not sure about Westminster. There’s certainly nothing in the Jubilee Line tunnels. The only features of note are the intervention shaft at Storey’s Gate, vent shafts at both ends of Westminster platforms, and further towards Waterloo a feature on the left-side of the EB tunnel which I believe to be the remnants of the construction working site at Jubilee Gardens, which was reached via a lengthy temporary heading which I believe was backfilled when no longer required. Certainly there’s no way into it if it is still there. LU tunnels are littered with such construction remnants if one knows exactly where to look and what to look for!

Correct about the deep shelters. The access points can be seen in many cases, but completely sealed up. Camden Town is probably the most conspicuous.
I am almost sure that they connected the shafts at St Pauls for use by the CEGB. I think what you say about the running tunnels on the Jubilee extension is right, perhaps the other tunnels like vent shafts alos provide for others as well, I must admit I was not aware of a vent tunnel towards Waterloo where does this surface at street level? I am sure there are lots of bits that have been left over the years I seem to remember that a sheild was left and I'm sure there were more.
 

Taunton

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You want "Beneath the City Streets" by Peter Laurie, published about 30 years ago, an extraordinary yet fascinating book that describes the detail of these London tunnels - and beyond.
 

Jack Barry

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You want "Beneath the City Streets" by Peter Laurie, published about 30 years ago, an extraordinary yet fascinating book that describes the detail of these London tunnels - and beyond.
I did mention in post 3 about this book, you are right there is a lot of detail although some has been questioned.
 

bramling

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I am almost sure that they connected the shafts at St Pauls for use by the CEGB. I think what you say about the running tunnels on the Jubilee extension is right, perhaps the other tunnels like vent shafts alos provide for others as well, I must admit I was not aware of a vent tunnel towards Waterloo where does this surface at street level? I am sure there are lots of bits that have been left over the years I seem to remember that a sheild was left and I'm sure there were more.

The Jubilee Gardens shaft appears to have been backfilled. The JLE had two working sites which didn’t survive to be permanent intervention or vent shafts, the other being at Old Jamaica Road between London Bridge and Bermondsey. The site of the latter is innocuously conspicuous at track level in the form of a short section of SGI lining in an otherwise long pre-cast concrete section of tunnel.
 

Cesarcollie

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I am almost sure that they connected the shafts at St Pauls for use by the CEGB. I think what you say about the running tunnels on the Jubilee extension is right, perhaps the other tunnels like vent shafts alos provide for others as well, I must admit I was not aware of a vent tunnel towards Waterloo where does this surface at street level? I am sure there are lots of bits that have been left over the years I seem to remember that a sheild was left and I'm sure there were more.

There's a shield at the over-run end of one of the two GN & City Line tunnels at Moorgate (can't remember platform number - but NOT the one where the 1975 disaster occurred).
 

bionic

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There are tunnels from SJP to various non LU tunnels in the area. At least that's what I've been told by someone who worked there.
 

Jack Barry

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The Jubilee Gardens shaft appears to have been backfilled. The JLE had two working sites which didn’t survive to be permanent intervention or vent shafts, the other being at Old Jamaica Road between London Bridge and Bermondsey. The site of the latter is innocuously conspicuous at track level in the form of a short section of SGI lining in an otherwise long pre-cast concrete section of tunnel.
Jubilee Gardens yes now I remember and they had some barges on the Thames which took all the spoil away and I think there was a shaft just by Waterloo Road which was back filled. I think I have seen more sections of SGI lining.
 

Jack Barry

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There's a shield at the over-run end of one of the two GN & City Line tunnels at Moorgate (can't remember platform number - but NOT the one where the 1975 disaster occurred).
That's right and somewhere there are other shields which were just left perhaps this is the norm after completing tunnels.
 

Jack Barry

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There are tunnels from SJP to various non LU tunnels in the area. At least that's what I've been told by someone who worked there.
When you say SJP do you mean the park? What other tunnels BT? or something else and where exactly.
 

DelW

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That's right and somewhere there are other shields which were just left perhaps this is the norm after completing tunnels.
I think it's common to leave shields in the ground unless the tunnel ends in a shaft big enough to crane the shield out. By definition the shield is bigger than the tunnel behind it, and most of the value in TBMs is in the equipment behind the head, so the usual aim is to recover as much as possible of that but leave the rest behind.
 

Jack Barry

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I think it's common to leave shields in the ground unless the tunnel ends in a shaft big enough to crane the shield out. By definition the shield is bigger than the tunnel behind it, and most of the value in TBMs is in the equipment behind the head, so the usual aim is to recover as much as possible of that but leave the rest behind.
I think you are right as to dismantle the sheild would not be worth it. If the chamber is larger then taking out the shield would be easy.
 

bramling

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Showing my ignorance but what is an intervention tunnel or shaft?

It’s an access point into the tunnels for use by emergency services, in particular fire crews. In the most recent practice it’s a “way in” completely segregated from any escape facilities - so that conflicting flows don’t impede each other.
 
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