Total mileage is x4 because 4 separate bores contemplated with the duck under bore probably more expensive.
SRich wrote: ↑Thu Feb 23, 2023 2:39 pmThat extra 2 feet translates into a considerably larger volume of spoil to be dug and removed from the tunnel, which would affect the design and construction of the tunnel walls and invert, which would increase costs even further. STrRedWolf indicated that the B&P Tunnel will be retained for freight use, and it can be rebuilt for double stack once its catenary is removed during the reconstruction of the tunnel.Bob Roberts wrote: ↑Thu Feb 23, 2023 1:16 pmGotthard Base Tunnel consist of 2 separate tunnels with an total length of 70 mile did cost € 8.9 billion or €128 million per mile. In 2011 €1 was $1.3924.TheOneKEA wrote: ↑Thu Feb 23, 2023 11:00 am Where was that 50 kilometer tunnel built? This tunnel is being built in a heavily developed urban environment with lots of obstacles in its way; was the 50 kilometer tunnel in Europe built in a similar geological environment? It doesn't excuse the high cost of the Frederick Douglass Tunnel but it offers useful context and explains one of the reasons why the cost is so high.Yea, it is certainly easier to dig beneath a mountain than Baltimore. A better comparison of baseline costs might be the new tunnel built to allow HSR through service from Madrid Atocha to Chimartin -- this runs beneath an urban area not much different (but certainly more fragile) than central Baltimore (but I can't comment on soil / rock). My calculations are that this Madrid tunnel was built for $78.5 million USD per mile. The base tunnel mentioned above (Gotthard?) was $193.5 usd per mile (if my conversions were kosher). The Spanish (and the Swiss) know a thing or two about tunneling.
https://railway-news.com/new-tunnel-and ... in-madrid/
So the price per mile in $ 178 million.
But Amtrak is making a wrong choice in my opinion, that the new tunnels aren't prepared for double stack under catenary. Its only 2 feet or 60 centimeter more depth to dig and the double stack under wire is done.