Amtrak Gateway Tunnels

Greg Moore wrote:Though, I'm not 100% sure they're boring or doing a tube like the present tunnels.
That said, to an extent some of these projects really are projects where if you wanted to, you really could throw more people and equipment at it and speed things up. (That said, there's a point where you just can't shorten the timeframe.)

Like the present ones, it would be a combination- a bore through the bedrock of Bergen Hill, then a tube through the sediment under the riverbed. Staying in bedrock all the way would involve too steep a grade to be practicable: it's very deep under the Hudson.

Okay, I've done a bit of research, primarily on Wiki (which we KNOW is always right. Right?). At a minimum, it's interesting background:

https://en.wikipedia.org/wiki/New_York_Tunnel_Extension" onclick="window.open(this.href);return false;

https://en.wikipedia.org/wiki/North_River_Tunnels" onclick="window.open(this.href);return false;

https://en.wikipedia.org/wiki/Marmaray" onclick="window.open(this.href);return false; (included as an example of recent rail tunnel construction).

What amazes me is the tunnel profile that's shown on the first link. The river channel, obviously, is deeper at certain points than others; not a uniform depth. So the gradient profile of the crossing is a bit of a roller coaster. I wonder in comparison how the depth and profile of the Bosphorus Strait compares to the Hudson. I could NOT find what the width of the Hudson (North) River is at the crossing point, and what length the tunnel sections are. The immersed tube of Marmary is slightly less than a mile at 4551'. The George Washington by comparison is 4760'.

What I'm getting at is if the tunnels are to be built beneath the sediment/silt at the bottom of the river, but if the river is of sufficient depth that an immersed tube, assembled in sections to account for the depth profile, sitting on the surface of the river, is sufficiently deep for shipping, why not just "drop" a tube on the river bottom similar to Marmary?

We know Amtrak has spent money on access on the NY side (the "box") and preliminary design. We know NJT started construction for the discontinued ARC tunnel on the NJ side, albeit to line up North of Penn in a deep cavern, much different than the Amtrak NY Penn expansion. How much more design work remains to be done for the project to be "shovel" ready? What can they start NOW while waiting for funding to materialize (Cuomo did much of the replacement TZB project similarly, getting it started and then adding to it as funding was "kind-of" identified)?

To me, this should be a "start digging now for what we know" type of project, because it could turn out much like ESA for the LIRR; delays, delays, delays. Again, Cuomo's approach to the TZB got it started quickly, and it will finish in 2017). If you at least get increments started, the tough stuff will be in preparation already.

Study Amtrak's proposed tunnel profile. There are some misconceptions here.
1. In sediment tunnel construction the tunnel had pressurized, but now only the tunnel boring face but still requires workers in that pressurized location.
2. Pressure means the problem of the bends unless the workers at the tunnel face are breathing helium - Oxygen mixes..
3. When in sediment soils there is always the possibility of a blowout and / or major leak into tunnel. Di the east river tunnels have some blow outs ?
4. The documented movement of the present tunnels due to tidal back up will be eliminated by rock boring.
5. Tunnel slope to the bottom elevation should not be much trouble as trains will be slowing for the entrance to NYP. As well the slope westbound will give a very fast head start to climb the easier grade slope to the Palisades. The one problem will be a train stalled at the bottom elevation of the new tunnels
6. Many of the disabled trains in the present tunnels are due to Pans snagging the CAT. There now has been developed reliable power rails instead of CAT wire which. .Don't believe that they can work in the present tunnels due to their tidal movements.

Jeff Smith wrote: why not just "drop" a tube on the river bottom similar to Marmary?.

They dig a trench, sink the tube and then cover it up so it doesn't get the urge to bob up to the surface again.
We don't do that any more because we've been dumping toxic chemicals into the river sediment since we started to make things along the banks of the river. It's not a good idea to stir them up. If you do want to stir them up you have to deal with them as toxic waste not stuff that can be barged out to ocean and dumped like they did decades ago.

There was a reference upthread to the "bulkhead" that separates Manhattan from the Hudson and how the Gateway tunnels will have to pierce it.

I haven't been able to find much details on this but: the last entry on this page I believe references it.

It's a quick read with 2 pictures.

Greg Moore wrote:There was a reference upthread to the "bulkhead" that separates Manhattan from the Hudson and how the Gateway tunnels will have to pierce it.

I haven't been able to find much details on this but: the last entry on this page I believe references it.

It's a quick read with 2 pictures.

Here is a direct link to the NYT article:
http://www.nytimes.com/2008/05/25/nyreg ... ref=slogin&" onclick="window.open(this.href);return false;

Thanks. That's a much better link.

It is sad that this country can not build any worthwhile public infrastructure in anything close to time and budget. Here is another example of how this work is done abroad in Hamburg, Germany. I am familar with this city since my now wife and then girlfriend went to school there. Anyway, they added a new line to the U-Bahn service that connects the center of Hamburg to a new neighborhood (HafenCity) on one of the semi artificial islands on Elbe. This addition is less complicated than Second Avenue subway but it is far from simple. They had to build tunnels under water, used tunnel borning machine, etc. Total cost? Unbelievable €324m. !!! And it has taken five years:
http://www.railwaygazette.com/news/urba ... ncity.html" onclick="window.open(this.href);return false;

Here is a more detailed report in German sounding English:
http://www.tunnel-online.info/en/artike ... 80345.html" onclick="window.open(this.href);return false;

And that in the country that also has unions, labor protections and is very strict about overtimes. This is not China or India, no one in Germany is paid $2 an hour. CEOs of German construction companies are also paid well though perhaps a little less that their US counterparts.

Any idea how they did it. How much do you think this work will cost in the US and how long will it take? Maybe we are really a country in decline...

The US has higher civil construction costs than pretty much everywhere else, and New York has higher construction costs than anywhere in the United States. Even in highly developed first world cities they can get things done dramatically cheaper than New York.

At the end of the day, I simply can't see how this project is worth $20,000,000,000. Maybe $10,000,000,000, but at some point, if building a new tunnel is so expensive it becomes so much more sensible to tell Jersey commuters to ride the bus.

Here are my thoughts on the several previous posts, in no particular order:

I’ve got some pretty good sketches of the bulkhead in my office, I’ll look for them on Monday if someone reminds me…..

Compressed-air tunneling is hardly ever done anymore, its pretty much pressurized-face TBMs now. The construction workers would work in free air (atmospheric pressure) while the front of the TBM is sealed by a pressure bulkhead.

Immersed tubes assembled in sections? Tubes thru sediments? Blowouts?? Leaks?? This is the current thinking:

It will be a shallow-cover tunnel, with a minimum cover of less than 20 feet between the tunnel crown and the river bed. Low-cover tunneling beneath a river presents numerous challenges, including the risk of a blowout, which wouldn’t be the geyser or waterspout that occurred in the East River back in the day, but excessive settlement or heaving.

The bulkhead won’t be pierced, it can’t be. The TBM would pass just beneath it. But there will still be the issue of numerous timber pilings that would need to be removed first….

Don’t get hung up on any maps or profiles that you might see. They’re for illustrative purposes only. They aren’t engineering drawings remember…..

As for construction costs, I wish I had an answer. I read somewhere that the TBM for the Gotthard Base Tunnel is operated by a crew of 2 or 3 guys. Here its probably 20?

Mr. Awe, the first thing to note is that if one tells the Jersey commuters to start riding busses, then a fourth Lincoln Tunnel will be needed; somehow, I think that a vehicular tunnel, considering the monoxide evacuation systems needed would be more wampum than a rail tunnel.

On Wednesday, The Times had a strong editorial suggesting that Gov. Cuomo's position that NY would get little benefit is simply weak:

http://mobile.nytimes.com/2015/08/20/op ... board.html" onclick="window.open(this.href);return false;

Earlier Editorial:

http://mobile.nytimes.com/2015/08/17/op ... unnel.html" onclick="window.open(this.href);return false;

Does it require another tunnel, or can space simply be reallocated towards more space-efficient modes? I understand that the Lincoln tunnel already has an exclusive bus lane.

Something simply has to be done about the unreal costs of infrastructure that the rest of us are expected to put in for. The amounts being thrown around would pay for all of Crossrail in London, which is itself an expensive project by global standards. It would pay for more than a third of California's High Speed Rail project.

I'm always in favor of more transit and rail infrastructure, but we can't have the system we need if we end up spending vastly more than anyone else would on a similar project to get less

bdawe wrote:Does it require another tunnel, or can space simply be reallocated towards more space-efficient modes? I understand that the Lincoln tunnel already has an exclusive bus lane.

No it can't.

What I think a lot of people are forgetting is that it isn't just NJT. It's Amtrak too, and with it, all of NYC's rail connections to places south/southwest of it. If Cuomo is willing to give those up, I don't know what's wrong with this country. You're severing the NEC at its midpoint for crying out loud (yes, there will be one tube open, but I really doubt that that will be enough to maintain full NEC/LD schedule even if you eliminate 100%of NJT w/o some sort of service cuts)
The fact is, people will have a REALLY REALLY hard time getting to work, and it will, in some way or another, harm NYC's economy.
How much service would have to be cut to run all trains into Hoboken, and say, turn some (or most? Or all?) RVL, NJC, NEC at NWK?

An article from Bloomberg on the current tunnel issues.

The damage may be merely the toll of 80 years on copper wire encased in lead, paper, cooling oil and rubber, Magliari said. It may be the work of corrosives deposited in 2012 by Hurricane Sandy floodwater. It may point to a design vulnerability: Built 105 years ago on riverbed silt, the tubes rise and sway with the Hudson’s tides, even as trains zoom through at 70 miles an hour.