Metro-North Penn Station Access Study (PSAS)

[Backshophoss]

Amtrak has over time spent $$$$ on maintaining the ex-PRR power Grid including rebuilding Rotary Converters and adding some
static Inverters into the mix,and pushed the wire voltage in to the 12.5-13 kv level at 25hz.
To redo the entire grid to 25 kv will require replacing many bridges/overpasses for proper clearances around the catenary(air gaps around )
At best Amtrak could upgrade to 12.5 kv 60 hz after replacing EVERY insulator on the catenary,and upgrading the entire power grid.
PC/CR/MN went the 12.5 kv 60 hz route due to the ex-NH Cos Cob power plant was failing and Rotary Converters could not keep up with
the power needs of the then new M-2's
The cost of making 25hz power was not cheap,CL&P in Conn and Con ED in NY kept raising the rate per kw/hr on PC/CR.
After the conversion to Comm power,the mg sets on the M-2's were swapped for inverters,ending the possibilty of M-2's into Penn station
if "barefooted"(no 3rd rail shoes on)

That also ended the use of GG-1's and Metroliners to New Haven.

[bdawe]

lacking extensive knowledge of electrical engineering, why would you need to replace insulators to change the frequency?

[DutchRailnut]

you don't, just circuit breakers and such, not much was changed during MN switchover.

[Jeff Smith]

...
Harlem's the only one shut out of NYP because the Port Morris Branch doesn't join the Hell Gate until after all of the Bronx intermediates, depriving Harlem of most of the new reverse-commute ridership that New Haven's tapping. NYP alone isn't compelling enough for the track miles on the diversion if it can't hit those high-growth spots in the Bronx, so there isn't enough of a "WOW!" hook for bringing Harlem to the party.

In addition to that, Melrose platform was extended over the former connection from the Harlem line to Port Morris, Port Morris has tight curvature which I think was problematic for passenger cars/clearances, and the connections are/were both in the wrong direction. At Oak Point the connection is in the north/easterly direction, and at Melrose, the connection came north from the Mott Haven Wye. Neither were problematic for freight service, but for passenger, both would require a reverse move. I'm not sure if there's room for a connection heading south from the Harlem, but I'm pretty sure the connection at Oak Point would be problematic as the Hell Gate Bridge approach is already fairly elevated over the connection, which passes underneath the NEC.

Now, if you want to get to into fantasy stuff, notwithstanding the curvature/clearance issues and the fact the connection never saw a day of passenger service, reconnecting at Melrose could lead to interesting intra-Bronx service, and if a southerly connection could be made from the Harlem, likewise.

The RPA also has plans for their RxLINK? I think it is to bring service from Brooklyn and Queens (and potentially LGA) over this connection to Melrose and possibly Yankee Stadium. Shorter subway cars might manage the curve, but you'd have to get across the Hell Gate too (which only has room for one more track).

[Backshophoss]

Believe the "given" is CSX will not allow passenger service across the Oak Point Link into "their" yard

[DutchRailnut]

oak point link is a yard track, no signalling pretty much a given that FRA will not allow passenger moves in absolute dark territory.

[jackintosh11]

In that case, the LIRR is gonna have some problems operating the Greenport and Montauk Branches

[ExCon90]

They've been in continuous operation for years--I think they're grandfathered. The Oak Point thing is a startup; a whole new world.

[Ridgefielder]

Thought I posted this yesterday but I guess I didn't... anyway, the only place a Harlem-Penn Station connection would touch Oak Point would be in the Oak Point yard itself. Penn Station access for the Harlem Division would have to use a resurrected Port Morris branch. Remember, the Oak Point Connection joins the ex-NYC Hudson Division at High Bridge to the ex-NH Harlem River branch at the location of the former NH/NYW&B terminal at Harlem River. It passes directly under the Harlem River lift bridge; it's separated from the main into GCT by about 40' in elevation and there's no possible way to connect the two without tearing down a bunch of buildings and moving the Major Deegan Expressway.

[F-line to Dudley via Park]

I think the original PSA studies described how the angle of intersection between the Port Morris and the Hell Gate would be modified for run-thru without excessive destruction. IIRC it wasn't that huge a deal.

Those documents would be on the PSA site in the archives section...oldest scoping study docs on there.