The old tunnel will be repaired, but won’t close down for extensive periods, obviously. The Hudson crossings are critically important, and both tunnels will need to be fully operating, except at slower periods where they can do repairs.
Eventually, NJ will need to build its own tunnel. Unfortunately Christie cancelled the ARC tunnel to fuel his conservative bona fides, and now NJT is stuck with no tunnel. The ARC tunnel would have been operational by now, BTW.
NJT can use the two Amtrak tunnels, and its capacity will soar following the opening of the Gateway tunnel, but that third tunnel will eventually be needed. Amtrak is planning on huge long-term increases in service, and that will eventually crowd out NJT.
I’m not an expert on this matter, but I’m pretty sure these tunnels go entirely underneath the riverbed. So they’re basically like any other underground tunnel completely encased in earth. It’s not like there are fish swimming on the other side of the wall. But I could be completely wrong.
I would think that the tunnel exposed above the riverbed would invite the possibility of sabotage, maybe I’m just paranoid with all that is happening in the world .
It took a little digging but I found this older video posted on the project website. It follows the trains journey on the new segments with elevations. It will be buried under the bedrock like all other river tunnels.
Think Sawtooth replacement is in procurement and the Portal Bridge is about halfway through its construction so it seems that funding for those portions are already there.
The first steel track supports went up on the bridge’s southern (closer to Newark) side and concrete support casting is nearly complete. An additional steel beam is present as well, which indicates to me that the concrete casting is nearly complete and steel laying is going to move likely at a faster pace much like the northern end. The difference in height is also quite evident on this end as well, highlighting the increased vertical clearance under the bridge for marine traffic.
The northern end has 3 segments installed already and the concrete supports have been pretty much complete for a while now except for a couple that seem to be curing in some sort of cocoon.
