• All Things Portal Bridge: Amtrak and NJT Status and Replacement Discussion

  • This forum will be for issues that don't belong specifically to one NYC area transit agency, but several. For instance, intra-MTA proposals or MTA-wide issues, which may involve both Metro-North Railroad (MNRR) and the Long Island Railroad (LIRR). Other intra-agency examples: through running such as the now discontinued MNRR-NJT Meadowlands special. Topics which only concern one operating agency should remain in their respective forums.
This forum will be for issues that don't belong specifically to one NYC area transit agency, but several. For instance, intra-MTA proposals or MTA-wide issues, which may involve both Metro-North Railroad (MNRR) and the Long Island Railroad (LIRR). Other intra-agency examples: through running such as the now discontinued MNRR-NJT Meadowlands special. Topics which only concern one operating agency should remain in their respective forums.

Moderators: GirlOnTheTrain, nomis, FL9AC, Jeff Smith

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  by lensovet
 
if you look at the documents posted on the portal website, all of this information is outlined there. part of the reason to have two bridges is because you can't just blow up the existing bridge while building the new one. so you need to have a new bridge built anyway, clear of the existing bridge, while all the traffic on the NEC continues on its merry way.

there are also redundancy benefits of having two separate bridges.
  by lensovet
 
you need room for the connecting tracks too, putting in new embankments, etc, while still leaving sufficient clearance for existing service.

you also need more $$$ for a bigger bridge. look at how many years it took to just scrape together this cash for a smaller one.
  by photobug56
 
There are groups out there who believe that 4 track is the way to go. Daily News says that the 2 track, since it does not increase capacity, is not eligible for the federal funding they plan to use, funding based on a major increase in capacity. If DN is right, then this circus needs to stop and get redesigned ASAP. Plus, I don't understand why they are not doing the tunnel repairs as per the way NYCTA did - I grant those aren't perfect but ought to stabilize and improve conditions for the existing 2 tracks.
  by ExCon90
 
photobug56 wrote: Thu Dec 17, 2020 10:33 am There are groups out there who believe that 4 track is the way to go. Daily News says that the 2 track, since it does not increase capacity, is not eligible for the federal funding they plan to use, funding based on a major increase in capacity. If DN is right, then this circus needs to stop and get redesigned ASAP. Plus, I don't understand why they are not doing the tunnel repairs as per the way NYCTA did - I grant those aren't perfect but ought to stabilize and improve conditions for the existing 2 tracks.
(You lost me at "if DN is right" ...)
I think the argument has been made somewhere along here that a new double-track fixed bridge not imposing a speed restriction would in fact increase capacity by increasing trains per hour -- the ability of NYP to handle such an increase is a separate issue, but it's a necessary link in the chain. I don't remember reading whether that point has been settled.
  by STrRedWolf
 
ExCon90 wrote: Thu Dec 17, 2020 11:16 pm (You lost me at "if DN is right" ...)
I think the argument has been made somewhere along here that a new double-track fixed bridge not imposing a speed restriction would in fact increase capacity by increasing trains per hour -- the ability of NYP to handle such an increase is a separate issue, but it's a necessary link in the chain. I don't remember reading whether that point has been settled.
For context, what is the current MAS on the Portal bridge right now? (assuming not raised)

If it's 60 mph (same as the tunnels), then rebuilding for a higher speed will be worth it for feeding more tunnels with epic switch action.

If it's over 60 mph already, then the onus would be the current condition of the bridge. The bottleneck is the tunnels.
  by photobug56
 
Is the speed limit in the tunnels slower than possible because of the poor condition of the tunnel? Or just because it was designed and built a century plus ago?

Obviously on the east end of the tunnel you have a huge slowdown as you go through switches and station / yard tracks.
  by lensovet
 
current MAS is 60.

while I do not see an explicit speed mentioned in the documents (which I do find odd), the speed restrictions on both sides of the bridge are 90, so my expectation would be that the new bridge would also have that speed.
  by STrRedWolf
 
lensovet wrote: Sat Dec 19, 2020 6:38 am current MAS is 60.

while I do not see an explicit speed mentioned in the documents (which I do find odd), the speed restrictions on both sides of the bridge are 90, so my expectation would be that the new bridge would also have that speed.
I would expect it to be 90 at least.

Why? I see this tied with Gateway and the Hudson rebuilds. The new Gateway tunnels are expected to be 60 mph. You'll have *four* of them, and you can rebuild one while having three running with an express track. It's a little more capacity until you add another bridge of two tracks and get them full bore.
  by Ken W2KB
 
STrRedWolf wrote: Sat Dec 19, 2020 10:15 am
lensovet wrote: Sat Dec 19, 2020 6:38 am current MAS is 60.

while I do not see an explicit speed mentioned in the documents (which I do find odd), the speed restrictions on both sides of the bridge are 90, so my expectation would be that the new bridge would also have that speed.
I would expect it to be 90 at least.

Why? I see this tied with Gateway and the Hudson rebuilds. The new Gateway tunnels are expected to be 60 mph. You'll have *four* of them, and you can rebuild one while having three running with an express track. It's a little more capacity until you add another bridge of two tracks and get them full bore.
Also, the substantial delays from the all too frequent "disabled train in tunnel" would be significantly reduced by having a minimum of three tracks in service.
  by photobug56
 
3 or 4 tracks would be nice. But the tunnels are said to be in very poor condition, wiring badly needing to be replaced, cement falling. The whole excuse for urgent funding for Gateway is the condition of the tunnels. MTA / NYCTA showed that you can do a lot of what's needed to restore much better running conditions with their tunnel projects, and not take the risk of the regular smaller failures or one big failure. And it costs less. You can start building the new tunnels / tracks while repairs are underway.
  by STrRedWolf
 
photobug56 wrote: Sat Dec 19, 2020 5:07 pm 3 or 4 tracks would be nice. But the tunnels are said to be in very poor condition, wiring badly needing to be replaced, cement falling. The whole excuse for urgent funding for Gateway is the condition of the tunnels. MTA / NYCTA showed that you can do a lot of what's needed to restore much better running conditions with their tunnel projects, and not take the risk of the regular smaller failures or one big failure. And it costs less. You can start building the new tunnels / tracks while repairs are underway.
I think the onus pre-pandemic was to build the tunnels first so that repairs can be made without impacting service.

Now... maybe not so much, but I still think traffic is busier than 6 trains per hour (3 in one direction, 3 in the other).
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