r/Glasgow Tools

Title
Author	eenbiertje
Comment	Sorry, just saw this reply. No, sorry... we're possibly talking past one another here. A simple cap between the Mitchell Library and Charing Cross, which is what's being explored currently by the council, will cost around £50m. Because it is just a simple cap about a city block in size, with no additional works necessary to allow it to happen. Just a roof over one small section of the existing motorway. Easy. To cap the rest of the city centre M8 though, you'd have to factor in 1) the railway line that runs underneath Kent Road next to the Mitchell. It's quite shallow, creating a hump in the motorway, meaning you couldn't have a flat "cap" at this section. You'd need to lower the railway to be able to lower the motorway, to then cap it. You'd probably need to lower and rebuild Charing Cross station too, as it's so close. And 2) If you wanted to get rid of the motorway viaducts and bury the motorway in a tunnel instead between St George's Cross and Townhead, you'd need to figure out what to do with the subway line that runs underneath New City Road. It was built in the cut-and-cover style in the 1890s, and is very close to the surface (only 10 feet or so) in this location. You'd need to lower the subway here, or I suppose alternatively you could make the motorway dive underneath the subway line, but that would also come with costs. Might work out to be the better option though. Regardless, my point is just that there's more to the idea of tunnelling/capping the entire city centre M8 than just adding the roof/cap itself. You'd need to factor in these additional issues and figure out how to mitigate them as part of the overall plan. That's not to say the idea shouldn't be explored (I think quite the opposite, that it's something which very much should be explored). Just that the costs will be in the billions rather than the millions. That's just fact when you consider what's required.
Reddit Link	https://www.reddit.com/r/glasgow/comments/vjkl29/glasgow_council_launches_50_million_bid_to_build/ih94rpj/
Created	Sat 23rd Jul 2022 12:01am
Status	normal ()

Sorry, just saw this reply.

No, sorry... we're possibly talking past one another here. A simple cap between the Mitchell Library and Charing Cross, which is what's being explored currently by the council, will cost around £50m. Because it is just a simple cap about a city block in size, with no additional works necessary to allow it to happen. Just a roof over one small section of the existing motorway. Easy.

To cap the rest of the city centre M8 though, you'd have to factor in **1)** the railway line that runs underneath Kent Road next to the Mitchell. It's quite shallow, creating a hump in the motorway, meaning you couldn't have a flat "cap" at this section. You'd need to lower the railway to be able to lower the motorway, to then cap it. You'd probably need to lower and rebuild Charing Cross station too, as it's so close.

And **2)** If you wanted to get rid of the motorway viaducts and bury the motorway in a tunnel instead between St George's Cross and Townhead, you'd need to figure out what to do with the subway line that runs underneath New City Road. It was built in the cut-and-cover style in the 1890s, and is very close to the surface (only 10 feet or so) in this location. You'd need to lower the subway here, or I suppose alternatively you could make the motorway dive underneath the subway line, but that would also come with costs. Might work out to be the better option though.

Regardless, my point is just that there's more to the idea of tunnelling/capping the entire city centre M8 than just adding the roof/cap itself. You'd need to factor in these additional issues and figure out how to mitigate them as part of the overall plan.

That's not to say the idea shouldn't be explored (I think quite the opposite, that it's something which very much should be explored). Just that the costs will be in the billions rather than the millions. That's just fact when you consider what's required.