TRIVIA. Bored tunnels with more than two tracks.

[Rob F]

What examples can people think of, of single bored tunnels that accommodate more than two tracks? Side by side bores do not count. All I can think of is maybe the approach to Lime Street but I am not certain if these are bridges across the cutting or actual bored tunnels.

 

[The exile]

Highly unlikely that there would be many truly “bored” tunnels as by definition their height would be correspondingly ( and unnecessarily) great. There may be some excavated ones, but I doubt there are many.

 

[Ken H]

What examples can people think of, of single bored tunnels that accommodate more than two tracks? Side by side bores do not count. All I can think of is maybe the approach to Lime Street but I am not certain if these are bridges across the cutting or actual bored tunnels.

Farnworth is the obvious one. On the manc - Bolton line.
Do places in bored tunnels where there are crossovers count? Think there are 2 on the Channel tunnel. And the Victoria Line has some.

Edit. link to Murphy Construction page where they discuss the farnworth Tunnel, with pictures. https://www.murphygroup.com/projects/farnworth-tunnel

Scheme to enlarge Farnworth Tunnel near Bolton to allow the electrification of the railway line between Manchester and Preston.
Two original 270m-long brick tunnels constructed between 1838 and 1880 at Farnworth were showing their age with water causing the lining of one of the tunnels to deform with open joints and cracking. The electrification project was also an opportunity to ensure that the structure would be secured and safeguarded for the future by Murphy carrying out strengthening works.

Murphy had to fill the up-tunnel with 7,500m3 of foam concrete before re-boring it using the UK’s biggest tunnel boring machine (TBM), Fillie, to create a bigger tunnel housing two tracks with room for overhead electric cables.

 

[The exile]

but Farnworth Tunnel is only twin track, isn’t it? The question is about more than two tracks.

 

[Ken H]

but Farnworth Tunnel is only twin track, isn’t it? The question is about more than two tracks.

should have gone to specsavers

 

[Potterlad]

Birchenwood tunnel, Kidsgrove on the old Potteries loop line (Etruria to Kidsgrove) was originally built to accommodate 3 tracks (2 for the North Staffordshire railway Loop line and 1 for the Birchenwood Colliery industrial line.

Attached is an excellent picture and additional information by Martyn Hearson.

Birchenwood Tunnel, Kidsgrove, Stoke on Trent. | One of the … | Flickr

When I last visited a few years ago you could still walk through it - but don't know if it has since been 'opened' out to prevent any accidents to the local kids. I remember walking through it as a kid when single line to Goldenhill Open cast workings was still in situ (closed 1976) and remember it was quite eerie to see such a wide tunnel with just one line in it.

 

[Watershed]

What examples can people think of, of single bored tunnels that accommodate more than two tracks? Side by side bores do not count. All I can think of is maybe the approach to Lime Street but I am not certain if these are bridges across the cutting or actual bored tunnels.

There's the 118 yard Richmond Hill Tunnel between Leeds and Neville Hill depot, which spans 5 tracks (all electrified, incidentally), but I'm not sure whether that was bored or bridged. It's a very impressive skew brick structure.

Otherwise the closest I can think of is the Gerrards Cross Covered Way - which infamously collapsed during construction. Currently only has 2 tracks but was built to accommodate 4 tracks.

 

[Ianno87]

There's the 118 yard Richmond Hill Tunnel between Leeds and Neville Hill depot, which spans 5 tracks (all electrified, incidentally), but I'm not sure whether that was bored or bridged. It's a very impressive skew brick structure.

Basically just a massive brick overbridge. I think it was originally a 2-track tunnel, but then opened out.

Otherwise the closest I can think of is the Gerrards Cross Covered Way - which infamously collapsed during construction. Currently only has 2 tracks but was built to accommodate 4 tracks.

But not bored I don't think; basically a concrete shell placed over the railway, and then filled over on top.

 

[pdeaves]

Basically just a massive brick overbridge. I think it was originally a 2-track tunnel, but then opened out.

According to http://www.railwaycodes.org.uk/tunnels/tunnels3.shtm, not opened out (declaration of interest: my site but the late Stewart Smith's research). However, the finer points of rebuilding for different formation width may not be apparent.

But not bored I don't think; basically a concrete shell placed over the railway, and then filled over on top

Yes, and it was incorrect filling that caused the collapse in 2005.

 

[Dr Hoo]

I think that Mount Pleasant Depot on the Post Office Underground Railway had more than two (narrow gauge) tracks and a traditional circular bolted segment profile although I am sceptical that a bespoke boring machine was constructed for such short section of excavation; so it may fail the 'bored' test.

 

[S&CLER]

The standard work of reference is Alan Blower's British Railway Tunnels (Ian Allan, 1964). He lists nearly all the longest tunnels and gives the number of tracks. On a quick leaf-through I cannot find any with more than double track in a bored tunnel. but I seem to recall that the tunnel on the approach to Liverpool Central once had three tracks for at least part of the distance.

 

[Dr Hoo]

The standard work of reference is Alan Blower's British Railway Tunnels (Ian Allan, 1964). He lists nearly all the longest tunnels and gives the number of tracks. On a quick leaf-through I cannot find any with more than double track in a bored tunnel. but I seem to recall that the tunnel on the approach to Liverpool Central once had three tracks for at least part of the distance.

A good shout. Most of Blower's detailed descriptions of tunnels are of those over a mile long.

The 'Central' Tunnel in Liverpool was indeed three tracks, around 1,000 yards long in total, albeit actually divided into several distinct sections, with full-width 'shafts' between them. The nature of the rock in Liverpool meant that it was relatively easy to cut by hand rather than being 'bored' in a continuous sense.

 

[Bald Rick]

Yes, and it was incorrect filling that caused the collapse in 2005.

Tesco: You shop, we drop.

although I am sceptical that a bespoke boring machine was constructed for such short section of excavation; so it may fail the 'bored' test.

Of course most bored tunnels in this country did not have a boring ‘machine’; they had a shield and dozens of navvies with shovels. I’m fairly sure the wider tunnels on the P.O. railway were bored.

 

[snowball]

A good shout. Most of Blower's detailed descriptions of tunnels are of those over a mile long.

The 'Central' Tunnel in Liverpool was indeed three tracks, around 1,000 yards long in total, albeit actually divided into several distinct sections, with full-width 'shafts' between them. The nature of the rock in Liverpool meant that it was relatively easy to cut by hand rather than being 'bored' in a continuous sense.

The term "bored" does not imply continuous boring or a rotary device. As Bald Rick points out, a bored tunnel is just one that was never opened out at any stage during construction, but always had earth or rock overhead at each point along its length.

 

[Ken H]

The term "bored" does not imply continuous boring or a rotary device. As Bald Rick points out, a bored tunnel is just one that was never opened out at any stage during construction, but always had earth or rock overhead at each point along its length.

I think you could call Marc brunels Thames tunnels 'bored' as are much of the Yerkes* tubes. All long before TBM's, which are post WW2 technology

*Yerkes was a private developer who built the Piccadilly, Northern and Bakerloo lines in the early 20th century.