Is there a reason why they can't drill a couple bowling ball sized holes at strategic intervals and put some high speed extraction fans in?
Stations entrances are open to outside so if you create enough negative pressure the hottest parts in the tunnels it'll pull in air. Do that long enough and presumably ambient & clay cools?
Presumably engineers dismissed this already, but why?
They have added ventilation to the tunnels, it's mentioned in the article. It's more than just a couple bowling sized holes, but apparently still not enough
Unfortunately, hydrating clay is extremely hard to do. Clay is what you use as a water-tight material in dams, artificial lakes, waste dumps and stuff like that, because water doesn't really pass through it.
I think people might object to TfL drilling a bowling ball sized tunnel in the middle of their house/garden/park/road/driveway/swimming pool/historic monument.
Remember the deep level network is some 23m down, and runs under buildings. At lot of it doesn’t follow roads, or have any kind of conveniently clear space on the surface above it.
Stations entrances are open to outside so if you create enough negative pressure the hottest parts in the tunnels it'll pull in air. Do that long enough and presumably ambient & clay cools?
Presumably engineers dismissed this already, but why?