Amtrak Gateway Tunnels

I thought the plan for Portal was two bridges, 4 tracks total. Has it been cut down to just two tracks now?

No. Portal South is a later add-on to accommodate traffic levels well after Gateway future-proofed for NEC FUTURE and future run-thru commuter rail service from the north to Secaucus/Newark. It's not a construction dependency for Gateway and service levels immediately thereafter because the fixed-bridge replacement for the current span and whacking of the speed restriction is enough of a capacity increase in itself to handle the next 20 years worth of incremental growth. Think 2035 for Portal South, not 2025. The reason they're studying it now, locking down the probable alignment, and making it so the replacement-Portal design can be twinned for Portal South is to shave the pre-planning bureaucracy to a minimum when it's time and give it a quicker path to shovel-ready when it's time.

The Hudson Tunnel Project is:

The Federal Railroad Administration (FRA) and NJ TRANSIT are jointly preparing an Environmental Impact Statement (EIS) to evaluate the Hudson Tunnel Project. The Project is intended to preserve the current functionality of the Northeast Corridor’s (NEC) Hudson River rail crossing between New Jersey and New York and strengthen the resiliency of the NEC. The EIS is being prepared pursuant to the National Environmental Policy Act of 1969 (NEPA). As appropriate, FRA and NJ TRANSIT will coordinate with Amtrak and the Port Authority of New York and New Jersey (PANYNJ) on the EIS.

Click on the image for a higher resolution view: Click here for the actual pdf, which allows you even greater visibility.

http://www.hudsontunnelproject.com/index.html" onclick="window.open(this.href);return false;

Oversight corporation created: Reuters

Oversight body approved for Amtrak's $24 bln Gateway project

A regional transportation authority for New York and New Jersey on Thursday approved the formation of a municipal corporation to oversee construction of Amtrak's massive $24 billion Gateway rail transportation project.

The Gateway Program Development Corporation will be an entity within the Port Authority of New York and New Jersey to oversee the project, which stretches from Newark to Manhattan and includes digging new train tunnels beneath the Hudson River which separates the two states.

The corporation, first proposed in 2015, is being led by John Porcari, an executive at consulting firm Parsons Brinckerhoff and former deputy secretary of the U.S. Department of Transportation.

The Portal project timelines are more complicated than we first thought. Reading the whole project you will find that the swing bridge will not be removed until Portal south is operational. Remember that when the new Tunnel bores are operational that Amtrak hopefully plans to just have to rebuild one of the old bores at a time ( subject to condition of other bore at that time) . That way there may be 3 bores operational so the swing bridge track may be needed. All that assuming Amtrak can keep the swing bridge operational until Portal south is built.
Suspect that Amtrak and NJ Transit will build schedules so if other old bore is shut down can easily divert to Hoboken. Once one of the old bores is rebuilt then permanent schedule changes can be implemented. Must wonder how the 1/2 hour Acela schedules will be implemented.

Portal south is planned to replace the swing bridge

Why does the new tunnel swing south so much? That is adding to its length.

According to the Preferred Alternative Summary (1.3MB PDF), it's the minimum-impact, minimum-risk routing:

As part of the Preferred Alternative, the new tunnel would follow the same route in New Jersey as the previous Access to the Region’s Core (ARC) project, a tunnel alignment that was found to have the least potential for construction delays; minimal impacts to existing transit and other transportation services; and the least impact related to displacement of active uses, since NJ TRANSIT has already acquired a number of the needed properties.

Also, keep in mind, on the New Jersey side, a longer route isn't necessarily a bad thing, it means a reduced grade.
Also, given the location of proposed ventilation shaft, that's probably a bit easier/cheaper to build there.
Making it directly parallel to the tunnels wouldn't give room for a ventilation shaft as easily.
Also on the NJ side, the "box" is built. This shows up on the PDF above as "Amtrak R.O.W. Presevation. So you'd already have to zig a bit to line up with that.

It's sort of a shame that what's marked as "New Surface tracks" can't curve sooner and do a straight shot into the proposed alignment. Save some distance and probably a bit faster.

bostontrainguy wrote:Why does the new tunnel swing south so much? That is adding to its length.

The original ARC alignment looped that way because it had to get deep enough to go under the existing Hudson River tunnels. It may be that when they built the tunnel box below the new Hudson Yards project the only thing they could base it on was that ARC plan. The tunnel box definitely points toward the south so the new tunnels will have to loop at least a bit in order to hit it.

The curves in the new tunnel should be compensated for by less stiff grades and don't look much worse than the curve already present west of the existing tunnels anyway. My understanding from this board is that the speed on that curve is 75 mi/hr, and 60 mi/hr in the current tunnels. My bet is that, once ESA and the whole Gateway program is through, whatever minor speed penalty, if any, is incurred on the curves in or just west of the new tunnels will be more than offset by the travel time savings from the following factors:
1. Conversion of Portal to a fixed bridge will eliminate a 60 mi/hr speed restriction on an otherwise 90 mi/hr segment.
2. ESA will take a hefty chunk of LIRR traffic out of NYP, freeing platform slots and circulation space.
3. Incremental circulation improvements called for under Moynihan, even without Penn South, will enable at least some of the platforms to be cleared more quickly.
4. Quad-tracking NYP-NWK will significantly alleviate the current bottleneck.

After reading the information online, I understand that the new tunnel (2 tracks) will connect to the southwest side of Penn Station.

I'm speculating that the connection would come thru the current retaining wall at 10th Avenue, south of the track leading to/from the Empire Connection tunnel, in the vicinity of existing yard tracks 1A, 2A and 3A.

Is that accurate?

Basically yes.
Trying to find some good diagrams.
This shows a bit: https://www.amtrak.com/ccurl/930/618/Am ... 13-105.pdf" onclick="window.open(this.href);return false;

This shows more: https://nec.amtrak.com/content/hudson-y ... on-project" onclick="window.open(this.href);return false; (scroll the photos).

The scary-mongering has begun: http://www.reuters.com/article/us-new-y ... SKBN1410CE" onclick="window.open(this.href);return false;

Look for the project cost to double from here as more and more is done to "minimize" disruption.

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

...
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.
...
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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