Maintenance of disused tunnels (Thackley)

[ASharpe]

I live near Thackley railway tunnels and walk over them almost every day.

A couple of weeks ago some maintenance work started on one of the air shafts over the disused bore. It looks like a relatively big and expensive project, they have built a large scaffold and put a temporary surface over most of the field.

I am wondering why network rail would spend money on an tunnel that's been out of use for nearly 50 years.

 

[John Webb]

I live near Thackley railway tunnels and walk over them almost every day.

A couple of weeks ago some maintenance work started on one of the air shafts over the disused bore. It looks like a relatively big and expensive project, they have built a large scaffold and put a temporary surface over most of the field.

I am wondering why network rail would spend money on an tunnel that's been out of use for nearly 50 years.

I expect they are legally bound to maintain the structure to prevent damage to passers-by or other things. Not something they could easily sell off, as they've done with other surplus land!

 

[yorksrob]

I'm not sure NR have much to do with these structures. I believe most of them passed to BR residuary on privatisation and recently the Highways agency.

 

[gimmea50anyday]

Old railway formations that came under the remit of property board now come under highways jurisdiction. This included viaducts bridges and tunnels. Requirement to maintain will be due to other structures that may be affected such a road or building etc that may pass over or under the route could be damaged by failure of the formation.

Tiviot dale tunnel for example has a metal frame within the tunnel to prevent the tunnel from collapsing and damaging the church above it. The M63 could also be damaged by the tunnel failure. Ironic given that it was construction of the M63 that damaged the tunnel in the first place causing closure of the route!

 

[Harbornite]

The British Rail board (residuary) was established in 2001 and was one of the relics of the old BR. It was responsible for the maintenance of disused infrastructure, such as viaducts, tunnels and Waterloo International. It was wound up in 2013 and responsibility for maintaining the aforementioned structures was passed on to other authorities, such as the Highways agency (as mentioned earlier).

 

[snowball]

The M63 has been M60 since 1998 and the Highways Agency has been Highways England since April 2015.

 

[mcmad]

Who is responsible for disused routes/structures in Scotland?

 

[DarloRich]

I live near Thackley railway tunnels and walk over them almost every day.

A couple of weeks ago some maintenance work started on one of the air shafts over the disused bore. It looks like a relatively big and expensive project, they have built a large scaffold and put a temporary surface over most of the field.

I am wondering why network rail would spend money on an tunnel that's been out of use for nearly 50 years.

so it doesn't fall down taking the hill with it? NR ( or whoever else the asset passed to) are legally required to maintain these out of use structures in a safe condition.

 

[edwin_m]

Who is responsible for disused routes/structures in Scotland?

I believe this is Highways England also, which doesn't make a great deal of sense. I don't know whether it counts as part of the Scottish government budget.

 

[ASharpe]

Thanks for the replies everyone.

Would the collapse of a tunnel approximately 50m underground have much of an effect on the surface?

 

[Philip Phlopp]

Thanks for the replies everyone.

Would the collapse of a tunnel approximately 50m underground have much of an effect on the surface?

Yes - it'll normally make a ruddy big hole. You will normally lose the height of the tunnel plus any soil flow outwards into the remaining tunnel, so it can make a very deep hole or a shallower but much larger diameter large dip.

If you cast your mind back to 1994 and the Heathrow Express tunnel collapse, it made a large and very very very expensive hole.

 

[DarloRich]

Thanks for the replies everyone.

Would the collapse of a tunnel approximately 50m underground have much of an effect on the surface?

god yes! it will make a MASSIVE hole. There will be lots of places near you in West Yorkshire when mining subsidence a long way below the surface is clearly visible on the surface. That is caused by a similar action to a railway tunnel collapse.

 

[rf_ioliver]

Thanks for the replies everyone.

Would the collapse of a tunnel approximately 50m underground have much of an effect on the surface?

Not 50m, but the collapse of the Tyler Hill tunnel that runs under the University of Kent rendered the computing building useless.

From: http://www.forgottenrelics.co.uk/tunnels/gallery/tylerhill.html

"In 1963, the University of Kent - which was then being established - acquired the structure for £70. An inspection determined that it was safe to build over and part of the campus was subsequently erected on land above it. However a 1973 report found significant defects in the tunnel, including bulging of the vertical sidewalls. Tenders went out for the repair work but it was too late: on 11th July 1974, the Cornwallis Building was affected by subsidence, sinking 18 inches in about an hour. Responsible was a 30-yard collapse, filling the tunnel with brick and clay 260 yards from the north end."

There were remnants of the repairs to the building when I was there back in the late 90s

t.

Ian

 

[edwin_m]

A collapse of a forgotten construction shaft would be even worse. It hasn't happened often but here is one from the 1950s.

http://www.railwaysarchive.co.uk/docsummary.php?docID=944

 

[ASharpe]

A collapse of a forgotten construction shaft would be even worse. It hasn't happened often but here is one from the 1950s.

http://www.railwaysarchive.co.uk/docsummary.php?docID=944

The next shaft to the East has been capped (don't know if it's been filled in) and this time of year there are often teenagers relaxing on top of it - I hope that shaft is maintained from the inside.

 

[edwin_m]

The next shaft to the East has been capped (don't know if it's been filled in) and this time of year there are often teenagers relaxing on top of it - I hope that shaft is maintained from the inside.

The collapse was due to the failure of the tunnel roof underneath where the shaft used to be, allowing the fill in the shaft to fall down into the tunnel and destroying the houses that had been unknowingly built on top. I think the tunnel itself was filled in afterwards, so if the roof failed in the same way under another filled shaft there would be nowhere for the fill to go and therefore much less damage at the surface.