What's the shortest tunnel in Britain?

[The Barlow Boy]

Conversely the Long Bridge on the Euston - Watford DC line under the City Goods Lines at Willesden is 147 yards long.



This difference between a tunnel and a bridge has more than one answer, as it depends why you are asking the question a bit like 42 and the meaning of life etc.

The list of tunnels in the Sectional Appendix is a list of those structures the operating department wanted their train drivers and signalmen to carry out the rules relating to working in tunnels.

The length qualification usually derives from structures inspection, where over a certain length the inspection is carried out in sections rather than as a whole. Different companies and regions had different standards, so what would be a tunnel to one works section would be a bridge to another.

A more pure Civils definition is based on how the structure was formed.
A tunnel is bored (or tunnelled) through an existing feature.
A bridge is a built structure that spans over something.
A covered way is where a hole is dug and a structure built that is then buried when the hole is backfilled.

But the bottom line is, that for railway operating purposes if it's listed in table "A" as a tunnel it is one. Otherwise it's a bridge or covered way.

 

[route:oxford]

Are they still that length since part of them collapsed a few years ago?

Take a look at them on google maps. Can't really go much shorter with the canal going over the top.

 

[Flamingo]

Glad to see that nobody mentioned that car-park over the main line at Ealing Broadway that Quails insists on calling a tunnel.

 

[LE Greys]

Glad to see that nobody mentioned that car-park over the main line at Ealing Broadway that Quails insists on calling a tunnel.

Covered way, although the Railway Performance Society insisted on calling it a tunnel in one of their mileage charts.

 

[Flamingo]

It's one of the trick questions on our route exam - How many tunnels are between London and Reading? If anyone says one, then they get told to use the Sectional Appendix, not Quail's!

 

[mbonwick]

Looking at the Baseline Declaration from April 2009, there is a tunnel marked as Birdswood Tunnel just north of Weaver Jcn on the WCML marked as 22yds.

Anyone know where I can find the Baseline Declaration these day? Network Rail appear to have deleted the page....


Thanks

 

[OxtedL]

Yup, they've removed it, you know need to have some kind of account with them to view, it seems.

I'm sure various people will have copies of what was there though. [Activates Don't-Look-At-Me field].

 

[Flamingo]

Do bridges count as an answer ?

If you mean to my question, then no, they are bridges, not tunnels - therefore one can lay detonators under them whilst doing emergency protection if the distance so indicates!