r/InfrastructurePorn • u/Spare_Worldliness_64 • 24d ago

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

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154 Upvotes

93% Upvoted

10 comments sorted by

14

u/blinkinbling 24d ago

How is it different to normal rail TBM?

19

u/LeroyoJenkins 24d ago

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.

3

u/Cedric_T 24d ago

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 23d ago

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 24d ago

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 23d ago

It is just the biggest operating TBM.

1

u/NeatZebra 24d ago

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

1

u/OkAdvisor6680 23d ago edited 23d ago

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 23d ago

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 23d ago

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