> a lot of tbm's are special machines that ONLY work for the specific tunnel/project,
Yes, a lot, but not all:
> In December, the TTC bought a banner ad on the Tunnels & Tunneling International website, to list for sale four tunnel-boring machines it used to dig the 13.5-kilometre twin tunnels for the Spadina subway extension to York Region. The TTC had bought the machines in 2009 from Lovat for $58-million. Today the TTC has stored the machines at the Keele Valley landfill site. The machines are nearly good as new, the TTC says. “The TBMs are generally considered to have a useful life of tunneling of approximately 20 kilometres,” reads a TTC tender document. “At the completion of this project, they would have been used between 2.5 and 3.2 kilometres, or approximately 10-15% of their useful life. Accordingly, the TBMs will be capable of significant additional tunneling on other projects.”
Yes, a lot, but not all:
> In December, the TTC bought a banner ad on the Tunnels & Tunneling International website, to list for sale four tunnel-boring machines it used to dig the 13.5-kilometre twin tunnels for the Spadina subway extension to York Region. The TTC had bought the machines in 2009 from Lovat for $58-million. Today the TTC has stored the machines at the Keele Valley landfill site. The machines are nearly good as new, the TTC says. “The TBMs are generally considered to have a useful life of tunneling of approximately 20 kilometres,” reads a TTC tender document. “At the completion of this project, they would have been used between 2.5 and 3.2 kilometres, or approximately 10-15% of their useful life. Accordingly, the TBMs will be capable of significant additional tunneling on other projects.”
* https://nationalpost.com/news/toronto/why-metrolinx-plans-to...