PATH loading gauge and tunnel diameter

[jsmyers]

Can somebody tell me what the PATH loading gauge is?

Similarly, after reading a few threads on the board, I think I understand that the uptown tunnels are narrower than the downtown tunnels (which are ~15'). How narrow are the uptown ones?

[R36 Combine Coach]

The Steinway Tuunel on the IRT #7 also have a narrow loading gauge, similar to the H&M.

[Terry Kennedy]

Similarly, after reading a few threads on the board, I think I understand that the uptown tunnels are narrower than the downtown tunnels (which are ~15'). How narrow are the uptown ones?

Here's an original drawing for the south midown tunnel (toward NYC). Click on the picture for the full-size version. The standard inner diameter (in a straight section of tunnel) is 18'. The effective diameter is smaller in the curved sections of tunnel.



I have Jacob's original measurements and drawings for the various sections of the north midtown tunnel (toward NJ). Note that this tunnel has a variety of diameters and is finished in brick or concrete, not rings (the rings start just west of Morton St. in this tunnel). I don't have them online - post a reply here if you need me to dig them out,

[jsmyers]

Hmmm.

Thanks for the reply.

I was under the impression that the downtown tunnels were 15' ID, and that they were larger than the uptown tunnels.

That 18' ID tunnel would easily fit a train of the BMT loading gauge (not that there aren't other conflict points), correct?

What am I missing?

[HBLR]

I believe they used the same iron sections from whatever furnace was doing the molds on the whole system. The rings are used to keep water out, not just the river, but groundwater in manhattan and the fill areas in Hudson county. I'm just guessing here, but I think the concrete/brick sections are put in where they are more concerned about the weight of stuff above slowly smushing the strong, but still ductile, iron rings. There's a lot of compromise here, as can be seen in the water damage at the ends of pavonia newport station, I'm pretty sure that area is fill.

That's just my 2¢. I could be totally wrong.