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Post by spsmiler on Sept 22, 2016 19:29:52 GMT
Having seen my website someone has contacted me saying that he suffers from claustrophobia, but only in the single bore (single track) tunnels. He is OK in double track tunnels used by trains travelling in both directions.
He was asking me to tell him which sections of line have single bore tunnels so that he can avoid them.
That set me thinking....
Obviously most of the small profile tube trains mostly use single bore tunnels. The only exceptions which I can think of are the Central Line near Chigwell and the Piccadilly from Hounslow West to Heathrow Central. Plus (I think) also on to T5.
Also the Northern City is single bore Moorgate - Drayton Park.
But what about the subsurface lines?
I think the Met between Baker Street and Finchley Road should be classified as single bore, albeit only in segments.
Also, Kings Cross subsurface is also single bore, albeit very short.
As they are closed the Widened Lines can be ignored.
On the District Line, I think the flyunders used by northbound trains West Brompton - Earls Court and southbound trains High St Ken - Earls Court should be flagged as being single bore.
But what about the western end of Mansion House? Especially the westbound exit? I think this is single bore, albeit only for a short distance.
Even more challenging to classify are the tunnels between Gloucester Road and South Kensington - both the tunnels were originally twin track but...
Technically eastbound is only single track but the tunnel itself remains large enough for twin tracks.
Westbound is a little easier, as it retains two tracks, although both are used in the same direction and it must be very rare to actually have two westbound trains between both stations at the same time.
Have I missed anything?
Simon
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Post by superteacher on Sept 22, 2016 19:32:46 GMT
District line flyunder at Barking.
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Post by spsmiler on Sept 22, 2016 19:37:26 GMT
District line flyunder at Barking. Thanks. Ah, yes, westbound only. |
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Post by crusty54 on Sept 22, 2016 20:13:20 GMT
Think you have missed his point about bored tunnels as opposed to cut and cover sections.
In most of the latter there is quite a lot of space around the train even when there are walls between some stretches of track..
If you really want a full set try the Piccadilly line from Hounslow West to the airport. Open section, cut and cover, a bridge and bored tunnel. Sometimes known as Follenfant's Folly - he was Chief Engineer when it was planned.
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Post by superteacher on Sept 22, 2016 20:27:14 GMT
Think you have missed his point about bored tunnels as opposed to cut and cover sections. In most of the latter there is quite a lot of space around the train even when there are walls between some stretches of track.. If you really want a full set try the Piccadilly line from Hounslow West to the airport. Open section, cut and cover, a bridge and bored tunnel. Sometimes known as Follenfant's Folly - he was Chief Engineer when it was planned. No, I think he meant tunnels with only enough room for a single track. If we take your definition, I don't think there are any true bores on the SSL. |
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Post by Deleted on Sept 22, 2016 20:33:45 GMT
Think you have missed his point about bored tunnels as opposed to cut and cover sections. In most of the latter there is quite a lot of space around the train even when there are walls between some stretches of track.. If you really want a full set try the Piccadilly line from Hounslow West to the airport. Open section, cut and cover, a bridge and bored tunnel. Sometimes known as Follenfant's Folly - he was Chief Engineer when it was planned. No, I think he meant tunnels with only enough room for a single track. If we take your definition, I don't think there are any true bores on the SSL. Baker Street to Finchley Road does still have some single bore sections I believe. The original line was only single track, so it was built in a single bore tunnel. When the line was doubled, I believe they did it with a second lot of single bore tunnels, interspersed by the open (and cut and cover?) sections for the station platforms. |
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Post by superteacher on Sept 22, 2016 20:41:25 GMT
No, I think he meant tunnels with only enough room for a single track. If we take your definition, I don't think there are any true bores on the SSL. Baker Street to Finchley Road does still have some single bore sections I believe. The original line was only single track, so it was built in a single bore tunnel. When the line was doubled, I believe they did it with a second lot of single bore tunnels, interspersed by the open (and cut and cover?) sections for the station platforms. But were they bored in the traditional sense of the word? You can still build a cut and cover single funnel. |
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Post by Deleted on Sept 22, 2016 21:18:57 GMT
Baker Street to Finchley Road does still have some single bore sections I believe. The original line was only single track, so it was built in a single bore tunnel. When the line was doubled, I believe they did it with a second lot of single bore tunnels, interspersed by the open (and cut and cover?) sections for the station platforms. But were they bored in the traditional sense of the word? You can still build a cut and cover single funnel. TfL calls them "single bore tunnels" here, which is what I was thinking when I made my post. I wasn't thinking hard enough to know for certain whether they were built by cut and cover or bored out of the ground, but I think they were bored out of the ground, they look like it and it's a tight fit in those tunnels. According to Video125 certain types of surface stock were banned on the section, although it was big enough for the A stock, and they were the biggest of all those that were left by the millennium. |
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Post by philthetube on Sept 23, 2016 1:37:06 GMT
But were they bored in the traditional sense of the word? You can still build a cut and cover single funnel. TfL calls them "single bore tunnels" here, which is what I was thinking when I made my post. I wasn't thinking hard enough to know for certain whether they were built by cut and cover or bored out of the ground, but I think they were bored out of the ground, they look like it and it's a tight fit in those tunnels. According to Video125 certain types of surface stock were banned on the section, although it was big enough for the A stock, and they were the biggest of all those that were left by the millennium. The tunnels on the met north of Baker Street are nothing like as tight as the tube ones, there is room to walk down the side of a train in these tunnels, that is deff not possible in the tube ones. |
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Post by brigham on Sept 23, 2016 7:46:42 GMT
There are tunnels on the SSLs. Clerkenwell tunnel is probably the oldest and best-known.
Railway parlance generally doesn't accept 'covered way' as being a 'tunnel'. Tunnels are driven through existing obstructions using the technique known, unsurprisingly, as 'tunnelling'.
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Post by philthetube on Sept 23, 2016 11:43:35 GMT
I have been told that the only proper twin track tunnel on the underground is the one on the north curve between Croxley and Ricky. I hav no idea if that is true though.
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Post by bassmike on Sept 23, 2016 13:17:28 GMT
On Central line under Holly- bush Hill E 11
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Post by bassmike on Sept 23, 2016 13:20:01 GMT
Meant to state twin-track tunnel.
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Post by Deleted on Sept 23, 2016 13:28:25 GMT
Between Grange Hill and Chigwell?
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Post by bassmike on Sept 23, 2016 16:24:17 GMT
Already mentioned earlier
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Post by brigham on Sept 23, 2016 16:26:06 GMT
Isn't Clerkenwell Tunnel double track?
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Post by spsmiler on Sept 23, 2016 21:07:07 GMT
Yes.
Dont forget the East Putney Tunnel on the District / LSWR route to Wimbledon.
SWT trains still come this way too!
Simon
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Post by norbitonflyer on Sept 23, 2016 21:14:52 GMT
As far as I recall Cleekenwell Tunnel is double track, but the Widened Lines tunnel now used by Thameslink is two single track bores.
West of Earls Court O think all tunnels are single track except for the westbound towards West Bromptons which has two parallel westbound tracks.
What about the Thames Tunnel? Two tunnels with cross passages every few yards, or a double track tunnel with pillars between the tracks?
There are single track tunnels on the Overground between South Hampstead and the top of Camden bank.
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Post by abe on Sept 26, 2016 6:47:23 GMT
On the sub-surface railway, the tunnels between Finchley Road and Baker Street are cut and cover for both the single- and double-track sections. Clerkenwell Tunnel, between King's Cross and Farringdon was hand-mined from the ends and from now-closed shafts sunk from the surface. Campden Hill Tunnel, between Notting Hill Gate and High St Kensington was also mined. Both the latter two tunnels are double track.
The parallel tunnels between Gloucester Road and South Kensington are both cut and cover, and wide enough for two tracks, although the northern tunnel only has a single track since the changes in the late 1950s. There are some very short lengths of single-track tunnel elsewhere on the SSR (e.g., King's Cross, Tower Hill, Mansion House, Moorgate, Earl's Court) but these are rather connections between the main double-track tunnels because of the more complex layouts at these locations. For example, the flyunder on the east side of Earl's Court - does this count as a tunnel?
Regarding terminology, only Campden Hill, Clerkenwell, and Croxleyhall Tunnels are true tunnels on the Met/Circle lines. All the rest are technically covered ways, although the LU asset classification system uses TL codes for much of the time. They seem to use CW codes for the larger, flat-topped sections, but it would be interesteing to know the true criteria for this.
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Post by superteacher on Sept 26, 2016 10:56:27 GMT
On the sub-surface railway, the tunnels between Finchley Road and Baker Street are cut and cover for both the single- and double-track sections. Clerkenwell Tunnel, between King's Cross and Farringdon was hand-mined from the ends and from now-closed shafts sunk from the surface. Campden Hill Tunnel, between Notting Hill Gate and High St Kensington was also mined. Both the latter two tunnels are double track. The parallel tunnels between Gloucester Road and South Kensington are both cut and cover, and wide enough for two tracks, although the northern tunnel only has a single track since the changes in the late 1950s. There are some very short lengths of single-track tunnel elsewhere on the SSR (e.g., King's Cross, Tower Hill, Mansion House, Moorgate, Earl's Court) but these are rather connections between the main double-track tunnels because of the more complex layouts at these locations. For example, the flyunder on the east side of Earl's Court - does this count as a tunnel? Regarding terminology, only Campden Hill, Clerkenwell, and Croxleyhall Tunnels are true tunnels on the Met/Circle lines. All the rest are technically covered ways, although the LU asset classification system uses TL codes for much of the time. They seem to use CW codes for the larger, flat-topped sections, but it would be interesteing to know the true criteria for this. Thanks - a very informative post. |
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