4 ms·
Two of everything, ventilation, electrical, water, telecoms,you name a system, and then name it again. Chances are that set backs required for engineering and
by metalman 2y ago
Two of everything, ventilation, electrical, water,
telecoms,you name a system, and then name it again.
Chances are that set backs required for engineering and existing infrastructure will be
challenging, with two parallel sytems.
edit: there is an assumption that the space required undergroud is free and infinite, when in fact two tunnels with set backs and spacing will require more total space than one larger tunnel
and will then limit the availible area for deep building foundations and anything else.
Then we get to interchandes, and emergency access.
And there is a ready market for any material removed from the dig, which will be a very routine operation.
And while the volume of fill removed will be greater, the internal volume per cubic foot of tunnel wall will also be greater, allowing for more generous alotment of space for future systems and untilities, bigger wider lanes, etc.
Somewhere I came across a journal, just for tunnel makers, and there equipment.
And recent reports have tunnels bieng completed
ahead of schedule and on budget, so they are infact, taking care of business.
- rsynnott 2y agoOh, yep, I’ve no doubt that if they can ever actually get planning through for the damn thing, they’ll be able to build it. In Ireland it’s generally the planning that’s the problem. What I’m curious about, though, is what, if anything, changed to make this single-bore approach suddenly popular. A lot of new metro lines seem to be built that way, but old (and not, like, 19th century, even most 20th century stuff) always seem to be double-bore.
- ianburrell 2y agoOne big factor for single-bore subway is that can fit the stations inside the tunnel. That saves a lot of money digging out the stations. I think Barcelone Line 9 is the one that popularized it. I suspect the other factor is that they figured out how to make large TBM.