SPUI wrote:http://www.tmk.com/books/hmdinner/plate18.jpg shows four tracks between the two junctions, while http://nycsubway.org/nyc/path/path-trackmap.html only shows two. Which is correct?
Both
There are short pieces of tunnel on both the upper and lower levels, which would have gone directly from that junction to Hudson Terminal (now the WTC). The only pieces that were built (for this route) were those short stubs; pieces where the planned tunnels crossed under Tunnel E downtown; and the bellmouths at Hudson Terminal.
You can see a signal shed in the tunnel mouth. The short piece of tunnel behind the shed is reportedly full of junk, mostly pipe from the ejector pump system on the lower level.
To answer another question in this thread, there was a plan in the mid-20's to convert the H&M system to 4 tracks, but after the Holland Tunnel opened, ridership fell, and then the Great Depression started. I had drawings of the 4-track plans at my Hoboken Historical Museum exhibition a few years ago (they weren't on display - you had to ask me to see them - as we had far more material than space at the show).