Amtrak Gateway Tunnels

Thomas wrote:A new Gateway Project PDF was recently released.

If you type in Google Gateway Fanwood PDF, you should be able to find it, page 16 shows the proposed Gateway Tunnel Alignment

Try this link.

According to the preliminary sketch, it looks like the loops (if built) will connect with the new 2-track "ROW" south of the current station. But if the "new SEC" gets built, I suspect a one-seat ride from Bergen is not likely to happen for the foreseeable future. If the loops are built, you would decrease the need for SEC (not increase) and you wouldn't need to build the equivalent of another new station. So a big station which is already built beyond its need possibly getting bigger and more people transferring instead of reaping the hopeful benefit of a one-seat ride. In an ideal world, they could route trains going to SEC to the original "ROW," and keep the loop and the expresses on the new or something of that nature. But in the real world, I guess not everyone can win.

Thanks Greg Moore for the link.

Does that green tunnel alignment on page 16 of the Fanwood PDF refer to new East River Tunnels or the Current East River Tunnels?

Sorry to add to the continuous questions, but one thing has bugged me about Gateway. All the diagrams show it looping a bit south of the North River Tunnels instead of following a closer parallel alignment. Has a reason been released for this or is this simply one of those details to be hashed out later in the detailed analyses?

MattW wrote:Sorry to add to the continuous questions, but one thing has bugged me about Gateway. All the diagrams show it looping a bit south of the North River Tunnels instead of following a closer parallel alignment. Has a reason been released for this or is this simply one of those details to be hashed out later in the detailed analyses?

I recall reading it had something to do with the terrain they were tunneling under. The chosen route would save time and money, but I'm having trouble putting my finger on the source.

Does anyone else recall this tidbit of information?

ThirdRail7 wrote:I recall reading it had something to do with the terrain they were tunneling under. The chosen route would save time and money, but I'm having trouble putting my finger on the source.

I believe the proposed alignment is for two reasons:

1. It actually can reuse some of the ARC Alignment towards Palisades Avenue in New Jersey;

2. It enables a "Northeastern Approach" to meet up with the Hudson Yards' Tunnel Box Segment. If this did not occur, trains would not be able to make the grade if they just proceeded east towards Midtown, Manhattan. (The Tunnel Box heads northeast).

There appears to be a lot of dirt moved (possibly for a future development) just west of Secaucus Junction in New Jersey.

Is this going to make the Gateway Alignment more difficult to construct in New Jersey?

that large pile of dirt has been there for several years. My assumption was it was piled up there and left to sit so it can compact the ground it's sitting on for the future expansion to the future portal bridge replacements.

Steve F45 wrote:that large pile of dirt has been there for several years. My assumption was it was piled up there and left to sit so it can compact the ground it's sitting on for the future expansion to the future portal bridge replacements.

Thus, one can infer that this soil will be removed soon.

However, I know that Amtrak is attempting to move about $300 million around back to NEC improvements. I think Amtrak has their eyes on hopefully beginning the Portal Bridge Replacement Project within the next year or so. I also think that Amtrak has already begun the design process for the replacement of the South Portal Bridge as well as the design process for the second phase of the Tunnel Box (Concrete Casing in Manhattan).

MattW wrote:Sorry to add to the continuous questions, but one thing has bugged me about Gateway. All the diagrams show it looping a bit south of the North River Tunnels instead of following a closer parallel alignment. Has a reason been released for this or is this simply one of those details to be hashed out later in the detailed analyses?

There is more to developing a horizontal alignment than merely drawing a line between Point A and Point B. Amtrak's design criteria must be followed. The track design speed is the critical characteristic that determines which criteria are followed and how they are applied. Variables that need to be considered include horizontal tangents, vertical tangents, curve superelevation, location and length of spirals, maximum effective grade, grade compensation, etc., etc., etc. The location of the ventilation shafts and their criteria must also be factored in to consideration. The intent is to try and utilize the Tonnelle Avenue grade separation structures that were built as part of ARC.

Don31 wrote:There is more to developing a horizontal alignment than merely drawing a line between Point A and Point B. Amtrak's design criteria must be followed. The track design speed is the critical characteristic that determines which criteria are followed and how they are applied. Variables that need to be considered include horizontal tangents, vertical tangents, curve superelevation, location and length of spirals, maximum effective grade, grade compensation, etc., etc., etc. The location of the ventilation shafts and their criteria must also be factored in to consideration. The intent is to try and utilize the Tonnelle Avenue grade separation structures that were built as part of ARC.

Interesting to know.

Any updates on the Gateway Engineering Study Schedule and design criteria for the Block 780 Station?

1. If property acquisition ends up being a big problem in Block 780, what are alternative ways of increasing capacity into and out of Manhattan?

2. If property acquisition ends up being a big problem in Block 780, what are alternative ways of increasing capacity into and out of Manhattan without forgetting the tunnel box?

Thomas wrote:1. If property acquisition ends up being a big problem in Block 780, what are alternative ways of increasing capacity into and out of Manhattan?

2. If property acquisition ends up being a big problem in Block 780, what are alternative ways of increasing capacity into and out of Manhattan without forgetting the tunnel box?

Trebechut.

Seriously, while they're related (increasing capacity) Block 780 isn't necessary for the tunnels. You lose a chunk of the advantage, but even w/o Block 780, you gain a lot in terms of redundancy and simply being able to move more trains in/out of the existing tracks.

I just wonder how deep are the support structures for the buildings in Block 780.

Remember, acquiring property and demolishing buildings in Manhattan is not cheap!

Thomas wrote:1. If property acquisition ends up being a big problem in Block 780, what are alternative ways of increasing capacity into and out of Manhattan?

2. If property acquisition ends up being a big problem in Block 780, what are alternative ways of increasing capacity into and out of Manhattan without forgetting the tunnel box?

Build a deep cavern station under Macy's basement?