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  • 21-06-2010 2:14pm
    Registered Users Posts: 9,092 ✭✭✭

    I came across this powerpoint presentation on another site. It's an alternative method for tunnel boring that is apparently used in Barcelona and is being considered for Los Angeles. Instead of using two TBMs to bore in parallel, it uses one larger TBM which creates two vertically separated tubes for the trains to use.

    I don't fully understand it -they say it reduces the size of stations and the impact of building them on the traffic above. I also don't understand how crossovers work but those are technical details.

    I wonder if it's a candidate for Metro North and what impact it would have on it.


  • Closed Accounts Posts: 108 ✭✭eia340600

    I'm afraid that this cheaper method of tunneling is definitely not a canditate for MN.

    One huge reason why it's not is that millions and millions of euro have already been spent on the design and specification of the line.The entire project would essentially have to start from scratch.

    The RPA used safety as a grounds to explain why they would not use a single bore tunnel. I have heard that single bore tunnels are illegal in Ireland but amn't 100% on that.The reason that one could be built in Barcelona is, apparently, because they have lower fire safety standards than us.