Amtrak Gateway Tunnels

Jeff Smith wrote:Brief, fair-use quote per forum policy from above article:

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Contractors may also have to bore through a historic century-old granite bulkhead along the river shoreline, the documents show. Reuters also reviewed public records and conducted interviews with transportation officials and industry sources.
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Of two main ideas taking shape, the more intrusive one calls for contractors to dig up a partially renovated section of New York's Hudson River Park under a "cut and cover" concept. This would limit public access and lead to lane closures on the West Side Highway, a major thoroughfare.

Contractors will likely also need to stabilize the ground for tunnel boring using so-called freezing methods that involve permanently hardening the ground because parts of Manhattan sit on landfill.
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Contractors will also likely build an underwater concrete encasement for the tunnel to come up through the New York side of the river.

The encasement, itself larger than a football field, would counteract buoyancy and protect the tunnel from anchors, grounded ships and other risks. It is expected to remain hidden below the waterline. Work in the water could span two years and encompass 224,000 square feet.
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I think the article is pretty alarmist. Of course, everything is subject to change as the design advances, but the current thinking is as follows:

Cut-and-cover in Manhattan was being considered, but the current thinking, if possible, is to use the TBMs between the NJ and NY shafts. At the Manhattan shoreline, it should run about 60 - 70 feet deep, but nobody knows how deep the historic bulkhead runs. Ground treatment (freezing) would be required between the shoreline and the shaft site, but it would only clip a small piece of the park just south of the heliport, and wouldn't be permanent.

In the river, with the exception of an approximately 550 foot low cover area, the tunnel would be well below the mud line, so buoyancy and anchors wouldn't be a problem. The low cover area does require grouting of the riverbed to make it capable of sustaining the pressure of the TBMs from within and the water pressure bearing down on the tunnel to prevent collapse of the tunnel face. It's likely that the grouting would be done from barges, with sheet pilings to protect the work from the currents. These would be removed at the end of the work. An underwater concrete encasement in the river? This is the first I'm hearing of this.

Don31 wrote:In the river, with the exception of an approximately 550 foot low cover area, the tunnel would be well below the mud line, so buoyancy and anchors wouldn't be a problem.

Will the new tubes be deeper than the existing North River tunnels then? Buoyancy actually is an issue w them, isn't it? Think they shift a fraction of an inch w the tide.

I believe they will be deeper, but I'd have to check. And yes, the existing tunnels do indeed shift slightly.....

That's typical of a lot of water crossings past a certain length. A river bottom usually isn't bedrock until hundreds of feet below the silt layers that have been channeled over millennia, so any practical tunneling depth is likely to be above the bedrock and have to deal with very slow liquefaction flow over many decades. It's rarer to actually have the available bedrock that close to the surface to anchor a fully fixed tunnel than it is to have to go through a silt layer. The current does cause extremely long-term incremental flow to soil layers deep below the water level, and when tides are involved that incremental movement can 'flex' gently in 2 directions.

Completely standard 'feature', not bug, of most underwater bore techniques ever since crossings under large bodies of water first became a civil engineering thing in the late-19th c. There's tunnels older than these that were purposefully built to move, and tunnels older than these that are engineered to move more over time than this because of the properties of the particular body of water they have to cross. It was one of the big engineering advances that enabled practical lengthy underwater tunneling in the first place.

If you go on Amazon or iTunes, search for "The Rise and Fall of Penn Station". It's from PBS' and WGBH's American Experience documentary series. The video describes how the tunnels were initially dug out, and how the tides in the Hudson make the tunnel flex. It's worth a rental at least. I think I'll sync it back to my iPad and watch it again.

Mr. Wolf, hate to deprive "Mr. B" or "Mr. C" of "desperately needed" sales;

https://youtu.be/ewaSvAJAoZ4" onclick="window.open(this.href);return false;

Mr. "GBN",

Sorry for the silly "A" thing when referencing a company we all know, but my wife insists. When discussions get to a certain level, a much lower level than you would think, they become strictly confidential. I asked my lovely, totally out of my league, wife how I could reference the whole package-by-rail discussion and was told, rather curtly, to not mention by name "the company".

Just respecting the wishes of a loved one, much like some of the railroaders on here refuse to mention what rail line they work for for fear of reprisal.

And no, not a single DC/FC/MC or whatever a warehouse is this week is rail served. Trucks are so much faster and so much more reliable that rail service stands basically no chance of ever being a real part of "A"'s logistics systems.

There might be, and that is a very big MIGHT, be one or two little niches where I could see the idea advancing, but I would imagine it would be upon third party logistics providers to move the idea forward. I know of one HUGE opportunity to do so, but I lack the millions in capital to see it through, so it'll sit in my brain until Mr. "B" is looking for a rising star in the company to come up with an idea to trim 1 or 2 percentage points off the movement of high volume products and then I'll print out my writeup on it, slip it to my lovely, beautiful, young, and totally out of my league wife and she can forward it to Mr. "B" and he can then read it, be impressed, promote her, give her a huge raise and even huger office in some awesome city somewhere and...damn...probably make her way too far out of my league. Mrs. "SF" will become Ms. "Ex-SF".

D'oh! Anyone know a good attorney?

Edit: Just realized Mr. "GBN" was referencing something I said in a topic about Mail and Packages on Amtrak and that this is a forum about the Gateway Tunnels. I will get back on topic with my next post, apologies to all who had to read my whimsical idiocy.

PS- If anyone wants to start a 3PLP with me shipping huge quantities of material in boxcars (yes, real freight cars!) for "A", just drop me a PM and I will approach my wife, in a manner most courteous and with great decorum most resectful of her beauty, intelligence, youth, and her rating as totally out of my league...and also with my flak jacket on and rifle both locked and loaded, and humbly request her permissiom to take initiative on my own.

Gateway appears on Trump's list of priority projects:
http://www.mcclatchydc.com/news/politic ... 164.html#0" onclick="window.open(this.href);return false;

I hope this isn't an 'alternative fact'

I am curious as to how it is supposed to generate 15 000 "direct jobs". In the header it mentions "job years", so perhaps this is 1500 jobs for 10 years, which still seems rather high. The 19 000 "indirect jobs", are probably easier to justify, or rather more difficult to prove they don't exist.

Obama's administration last action on Gateway: http://www.reuters.com/article/us-new-y ... SKBN14W30W" onclick="window.open(this.href);return false;

The board overseeing the $24 billion Gateway Program to rebuild portions of Amtrak rail lines through New York City voted on Thursday to enter the first phase of construction into a federal program, a critical step to accessing billions of dollars of financing.

The Gateway Program Development Corporation agreed to put the first phase onto the federal "emerging projects" roster. That will allow it to apply for an estimated $6 billion of federal low-interest loans.

From our good friends at the Star Ledger of New Jersey:

http://www.nj.com/opinion/index.ssf/201 ... iver_index" onclick="window.open(this.href);return false;

Apparently, President Trump is cutting a key grant that was required for the boring of the Gateway Tunnels and replacement of Portal Bridge.

Btw: I was always of the mind that President Trump would be an ally of this project, no matter my political differences with the man.

You would think someone with sizable real estate holdings in NYC would be supportive of infrastructure that would increase the value of those holdings.

I have come to take a lot of what the Ledger says with a grain of salt. In reading their article, they speculate, saying "It could", no positive proof. I would like more data/information before saying it's dead.

I feel this bears posting......
http://www.nj.com/opinion/index.ssf/201 ... iver_index" onclick="window.open(this.href);return false;