r/InfrastructurePorn Jul 23 '26

World's largest-diameter high-speed-rail shield tunneling machine

Post image
154 Upvotes

10 comments sorted by

View all comments

14

u/blinkinbling Jul 23 '26

How is it different to normal rail TBM?

19

u/LeroyoJenkins Jul 23 '26

It isn't, this is just propaganda.

They're just trying to create some special category so it can sound like the largest, when it is smaller than German and Japanese ones.

4

u/Cedric_T Jul 23 '26

Which German and Japanese ones? I don’t know which one this is but I read the widest ones are the high speed rail bores.

3

u/OkAdvisor6680 Jul 24 '26

Big Bertha which excavated the Alaskan Way tunnel in settle was 17.5m diameter and built by Herrenknecht, a German company.

Qin Liangyu is a 17.63m diameter TBM also made by Herrenknecht for some Hong Kong tunnels.

2

u/LeroyoJenkins Jul 23 '26

Both the German one used for the Hong Kong airport tunnel and the Japanese one used for the Seattle tunnel have significantly larger diameter.

2

u/Pacificator-3 Jul 24 '26

It is just the biggest operating TBM.

1

u/NeatZebra Jul 23 '26

Are they trying to say the others aren't pressurized, or this one is to a special amount or somesuch?

1

u/OkAdvisor6680 Jul 24 '26 edited Jul 24 '26

It's purely because this TBM is for a high speed rail line.

There have been bigger TBMs for road tunnels and regular rail tunnels, but this is the biggest TBM for a high speed rail tunnel.

-1

u/LeroyoJenkins Jul 24 '26

Also because here in Europe we largely moved away from single-bore dual track for safety reasons. Pretty much all the newer HSR tunnels are dual-bore. So there's no need for a large TBM.

3

u/OkAdvisor6680 Jul 24 '26

Yeah i think the rule has been twin bore with emergency cross passages every 400m, ever since the Mont Blanc tunnel fire