west point wrote: ↑Mon Apr 24, 2023 1:17 pmM-8s do not work on 25 Hz. Why not just convert the CAT to 60 Hz 12.5 kV into the location at NYP that 3rd rail ends on the Empire corridor?
That's what I said. The 11.5kv/25 and PRR third rail would meet (with PRR third rail overlap for transition) the 25kv/60 that the M-8s can run off of.
Jeff Smith wrote: ↑Mon Apr 24, 2023 1:57 pmM-8's are an expensive option; you'd probably have to double the fleet. I would expect that they are also more maintenance-intensive. Then there's the cost of catenary, and it's maintenance, on a line that already has power. I've also heard, on here, that the FRA would likely not approve dual electrification; it's one or the other.
There are three key advantages to switching the Hudson line to 25kV/60 at Highbridge and along the Empire Connection:
1. Amtrak could electrify and run AC power all the way to Albany.
2. MN could eliminate dual-mode operations with 25kV/60 run to Poughkeepsie and Danbury.
3. Switching at Highbridge provides an unimpeded freight route from Selkirk to Oak Point and Fresh Pond with no third rail.
Switching at Highbridge preserves access from the Harlem Line to Yankees Stadium on DC power.
Yes, the M-10 fleet would need to be big, but if combined with adding tracks south of NWP on the Harlem and increasing the substation capacity to full acceleration with 12-car sets all the way to Southeast, the Harlem could soak up about 2/3 of the Hudson Line M-7 fleet, the rest could be rebuilt for LIRR, as they'd soak up those cars plus hundreds more with electrification to Port Jefferson, Oyster Bay, and Patchogue, not to mention reactivating the Central Branch further into the future.
MN should really get AC EMUs that can run on 25hz and handle low level boarding but not third rail and pool those with CDOT for electrification to Springfield and SLE to Westerly, which would allow for all-AC operations into NYP from POU and NHV, but that's a different issue.
Then there's design and clearance issues. It would be great if you could get High(er) Speed Rail on the Hudson, but you still need that DC for last mile through the Park Avenue Tunnel. You're adding a lot of weight just to provide a solution in search of a problem.
At one point I recall seeing a map that showed 19' Autorack clearance to the GM plant at Tarrytown from the North, which is no longer there, so the only clearance issues for Plate C clearance under 25kV/60 would be for 18mi south to Highbridge. The M-8 design is proven on the New Haven Line, and yes, it is a bespoke solution for NYC, but it has a lot of benefits, and combined with 25kV/60 to Danbury/New Milford would eliminate the kludgy dual-mode diesels, so it's a worthwhile trade-off.