Tunnel Box

Well, it appears that Amtrak will begin work on the Gateway Tunnel Box very soon. http://www.fra.dot.gov/eLib/details/L04571

Thanks, excellent find. The FRA finding and Environmental Assessment documents at the FRA website answer questions I had about the concrete casing box that is now going to be built to protect access for new Hudson River tunnels to NYP. For those who are not going to read the documents: the concrete box will extend from 10th to 11th Avenue, will be approximately 800 feet long, 50 feet wide, 35 feet tall. From a quick read of the EA document, it looks as if it will be built basically using a cut and cover approach through part of the LIRR West Side yard, requiring demolition of part of the MOE building and temporary removal of shop tracks to the MOE building. The project will excavate approx 83,000 cubic yards of soil and bedrock.

If the link works correctly, this should show the Enviromental Assessment documents for the Hudson Yard Concrete Casing filed in March, 2013.

I also read that the tunnel box would be 60 feet bgs near 11th avenue. Does this mean that the top of the tunnel would be at 60 feet bgs, or the bottom?

Thomas wrote:I also read that the tunnel box would be 60 feet bgs near 11th avenue. Does this mean that the top of the tunnel would be at 60 feet bgs, or the bottom?

Check the profile drawing on page 53 of Appendix A, the Final Report from Tutor Perini Corporation and Parsons Brinckerhoff. Looks like the tunnel box will drop about 20' from 10th Avenue to the end, ~150' west of 11th Avenue. The top of the box will be about 45' below 11th Avenue and 30' below ground level as it goes under 11th Avenue. The profile shows the tunnel box will pass well above the No. 7 Line tunnels, which are pretty frigging deep under 11th Avenue at that point (~110 ft).

Edit: west of 11th Ave, not east...

1. I also looked at Page 53. How are you able to understand that diagram? I am not able to fully read it.

2. Are you saying than that bottom of the tunnel box will then be about 63 feet below 11th avenue since the box is supposed to be 18 feet tall?

Design work is well underway. I have a submittal due on June 4th.

That's good to know. Would you by any chance know how deep below the street the current tracks are at Penn Station, and if Amtrak is looking into studies for the trans-hudson tunnel segment?

I'll take a look tomorrow if I remember.

Thomas wrote:1. I also looked at Page 53. How are you able to understand that diagram? I am not able to fully read it.

2. Are you saying than that bottom of the tunnel box will then be about 63 feet below 11th avenue since the box is supposed to be 18 feet tall?

The bottom half of the profile chart on page 53 is not that difficult. The two green lines are the top and bottom of the tunnel box, the dashed lines are the top of the bedrock for the left, right, center of the tunnel, the vertical bars are the test borings where the solid part is where the bore found rock, the X and Y axis are in feet although on different scales.

The tunnel box as stated in the documents is to be about 25' high. The tunnel will emerge into the NYP "bathtub" at the same level as the existing tunnels which looks to be about 45' below 10th Avenue. It looks from eyeballing the profile that the top of the tunnel box will be about 45' below 11th Ave and the bottom, thus about 70' under 11th St. The bottom of the tunnel box will be approximately 50' about the top of the new No. 7 Line subway tunnel with ~50' of rock between them.

The profile shows that there will be a lot of Manhattan schist to be drilled and blasted for the box tunnel. Scheduling the blasting around LIRR Hudson Yard train moves, street traffic, other construction activity, Empire tunnel traffic, possibly NEC and No. 7 line traffic could prove to be an interesting challenge.

That's good to know. I was not trying to offend the people who drew the diagram. It is just that my diagram, for whatever reason, was blurred on my computer. But let's not forget that the tracks between 10th avenue and 9th avenue actually descend a grade, which means that the Penn Station tracks are actually "below" 45 feet...

I wonder how long it will take to prepare tunnel documents for the trans-hudson segment and the NJ segment. Does anyone have an estimate?

Amazing - I guess all the problems that NJT encountered with ARC (the bulkhead, the subway line, the grade) which required the station BELOW PSNY, and eventually under 34th St. - aka Macy's Basement, aren't going to be an issue with the Gateway Tunnels. Wow, how things change when different people get involved........

Jtgshu wrote:Amazing - I guess all the problems that NJT encountered with ARC (the bulkhead, the subway line, the grade) which required the station BELOW PSNY, and eventually under 34th St. - aka Macy's Basement, aren't going to be an issue with the Gateway Tunnels. Wow, how things change when different people get involved........

JT,

I've been trying to figure that one out for a long time. I'll let you know.....

Don31 wrote:

Jtgshu wrote:Amazing - I guess all the problems that NJT encountered with ARC (the bulkhead, the subway line, the grade) which required the station BELOW PSNY, and eventually under 34th St. - aka Macy's Basement, aren't going to be an issue with the Gateway Tunnels. Wow, how things change when different people get involved........

JT,

I've been trying to figure that one out for a long time. I'll let you know.....

It just seemed like ARC was sabatoged in a way by restrictions and requirements that apparently weren't as cast in stone as made out to be. Its not like NJT's first choice was to end up in a cavern under 34th St. There were issues with ARC in the end, and what it developed in to, but the bigger question is how did it evolve into what it became and what was ultimately its demise......

And the even BIGGER question is, are these hurtles that faced ARC and NJT going to happen to Amtrak with the Gateway project, if the wrong person gets PO'ed or left out???

That being said, im glad they are looking forward and planning and building this tunnel box while the land and space is available before construction over West Side yards begin.

I think in several dozen years, we are going to have a very juicy political story come out about ARC and Gateway and all the various people and organizations involved, that would probably put some people in jail if the story came out now....so we will have to wait until they are all dead and what THEY wanted to be built, built.

Jtgshu wrote:

Don31 wrote:

Jtgshu wrote:Amazing - I guess all the problems that NJT encountered with ARC (the bulkhead, the subway line, the grade) which required the station BELOW PSNY, and eventually under 34th St. - aka Macy's Basement, aren't going to be an issue with the Gateway Tunnels. Wow, how things change when different people get involved........

JT,

I've been trying to figure that one out for a long time. I'll let you know.....

It just seemed like ARC was sabatoged in a way by restrictions and requirements that apparently weren't as cast in stone as made out to be. Its not like NJT's first choice was to end up in a cavern under 34th St. There were issues with ARC in the end, and what it developed in to, but the bigger question is how did it evolve into what it became and what was ultimately its demise......

And the even BIGGER question is, are these hurtles that faced ARC and NJT going to happen to Amtrak with the Gateway project, if the wrong person gets PO'ed or left out???

That being said, im glad they are looking forward and planning and building this tunnel box while the land and space is available before construction over West Side yards begin.

I think in several dozen years, we are going to have a very juicy political story come out about ARC and Gateway and all the various people and organizations involved, that would probably put some people in jail if the story came out now....so we will have to wait until they are all dead and what THEY wanted to be built, built.

I have a couple of things to tell you about the political story. I'll shoot you a PM over the weekend.....

Please do.