Base tunnels in North America: how, where, and why

[mtuandrew]

I'm not going far down this rabbit hole, but I dream of the day we can have similar base tunnels through the Appalachians and Pacific Coast ranges (Tehachapi and Cajon.) Glad the EU and Switzerland have embarked on these massive projects - and are completing them.

[mmi16]

I'm not going far down this rabbit hole, but I dream of the day we can have similar base tunnels through the Appalachians and Pacific Coast ranges (Tehachapi and Cajon.) Glad the EU and Switzerland have embarked on these massive projects - and are completing them.

Now if the Swiss and EU will just pay for the massive US projects......

Nobody in the US will foot such a bill.

[Woody]

... this rabbit hole, but I dream of the day we can have similar base tunnels through the Appalachians and Pacific Coast ranges (Tehachapi and Cajon.)

Fantasy time again: If we had the funds, where could we use base tunnels, or just tunnels?
Worcester-Springfield, Pittsfield-Albany. Nah, at this point in time, it's one train a day. LOL.
Harrisburg-Pittsburgh. Probably the #1 need east of the Mississippi.
Charlottesville-Charleston. There's bound to be tunneling opportunities on the Cardinal's core route.
Roanoke-Bristol-Knoxville-Chattanooga-ATL/Birmingham. Twists and turns, but we need 110-mph to make it work.
ATL-Birmingham. Twisting its way thru the south end of the Appalachians, this route will need more and better tunnels to get 110-mph trains and heavy ridership.
Any route CHI-FL will encounter serious hills, or fair-sized mountains, where tunnels could be needed.

And then there's the West. California could use a handful of serious tunnels. But even if we tunnel under the Continental Divide in two or three places, or thru the Sierra Nevadas, nothing we could do could rival the costs of the European base tunnels.

[SemperFidelis]

Port Jervis southeast to cnnection with NYSW? Would make the route up the Delaware a lot more viable for regional passenger rail as well as freight. Not really high on the list, but not having to climb the mountain and fight commuter traffic would probably change NS's traffic patterns significantly.

Agree with above poster(s): a tunnel to avoid the giant doglog on the route between Pittsburgh and Harrisburg would probably be the most important tunnel east of the Mississippi.

A freight tunnel to Long Island would probably be nice, but with so many containers already beginning thier land journey just across the river, it might not be as useful as hoped.

We are kind of blessed by geography in this country. Most of our tunneling needs would be quite small in comparison with Europe's.

[ExCon90]

A freight tunnel to Long Island would probably be nice, but with so many containers already beginning thier land journey just across the river, it might not be as useful as hoped.

I think the problem there would be finding enough land area on Long Island to support a container terminal big enough to justify the tunnel. I doubt that there would be enough carload traffic destined to individual sidings.

[mtuandrew]

Moderator's Note: my fault for going off-topic in the Lyon-Turin Base Tunnel topic, so I skimmed off the foam.

[electricron]

We're not going to see "base" tunnels in America because the Appalachians aren't high enough for them. The Rockies and Sierras are, but there aren't very large cities on both sides of the mountains close enough to make it worthwhile.
Heights of Gotthard tunnels are 1151 meters and 549 meters (3,776 feet and 1,833 feet), Alleghenny Tunnel is 2,167 feet (660 meters), Moffat Tunnel is 9,239 feet (2,816 meters), and Sierra summit tunnel is 7,000 feet (2,133 meters).
Denver may be fairly close to Moffat Tunnel to the east, the closest large city to the west is Salt Lake City, 508 rail miles away. For Donner Passs, Reno is 35 miles away to the east, Sacramento is 125 miles away to the west.

[mtuandrew]

Also, woe unto the engineer who has to tunnel through the fault lines between Bakersfield to Los Angeles (one of the few places it makes some sense in the USA.)

[Jishnu]

Also, woe unto the engineer who has to tunnel through the fault lines between Bakersfield to Los Angeles (one of the few places it makes some sense in the USA.)

Isn't that exactly one the two major tunneling projects involved in the California HSR project? The other one is under Pacheco Pass between San Jose and the Central Valley.

[electricron]

Also, woe unto the engineer who has to tunnel through the fault lines between Bakersfield to Los Angeles (one of the few places it makes some sense in the USA.)

Isn't that exactly one the two major tunneling projects involved in the California HSR project? The other one is under Pacheco Pass between San Jose and the Central Valley.

Yes, if you consider the Pacheco Pass 13.5 mile tunnel a Base Tunnel. While there will be 36 miles of tunnels in Southern California, the lengths of every tunnel hasn’t been determined yet because the route hasn’t been finalized. FYI, the Gotthard Base Tunnel in Switzerland is 35.5 miles long. The longest railroad tunnels in the USA to date is the Cascades Tunnel in Washington at 7.8 miles long, followed by the Flathead Tunnel in Montana at 7 miles long, and the Moffat Tunnel in Colorado at 6.2 miles long. The new proposed Pacheco Pass Tunnel would be the longest railroad tunnel in the USA, but pales in comparison to the Gotthard Base Tunnel in length.

[andegold]

How long is the LIRR East Side Access tunnel from Sunnyside (or wherever it goes underground) to the new terminal? Wasn't that entire tunnel (with the exception of the box under the river which was built many many years earlier) done using a boring machine? I assume you're not counting any subway segments since they contain so many cut and cover segments but how long is the 7 line either from Times Square to it's eastern portal or from it's new endpoint at Hudson Yards? That would seem to be a rather deep bore tunnel at least until somewhere east of the East River.

[electricron]

How long is the LIRR East Side Access tunnel from Sunnyside (or wherever it goes underground) to the new terminal? Wasn't that entire tunnel (with the exception of the box under the river which was built many many years earlier) done using a boring machine? I assume you're not counting any subway segments since they contain so many cut and cover segments but how long is the 7 line either from Times Square to it's eastern portal or from it's new endpoint at Hudson Yards? That would seem to be a rather deep bore tunnel at least until somewhere east of the East River.

LIRR East Side Access Tunnel "Line" per Wiki is going to be 2 miles long. I'm not sure the entire distance of the Line will be underground?
The 7 Line Steinway Tunnel per Wiki under the East River is 1.3 miles long. The initial tunnel length for the rail line was 5.6 miles, connecting the NY Central tracks along the Hudson with the LIRR tracks at Hunterspoint Avenue, with the Queens side portal between 5th Street (now 49th Avenue) and 4th Street (now 50th Avenue).
Both tunnels are far shorter than the 35.5 miles Gotthard Base Tunnel in Switzerland.
Although, when considering the entire 245 miles of MTA subway system, 147 miles (60%) are undergound.

[andegold]

Thanks Electricon. I had no illusions that they would come close to the European tunnels, just thought maybe they'd compare favorable to some western US tunnels. I guess not. I didn't bring up the system as a whole as I didn't want to get shouted down about trying to compare cut and cover with deep bore.

[Scalziand]

The NECFuture inland alignment essentially had a base tunnel through western CT from Danbury to Southington.