Achieving truly high speeds between New York and Philadelphia appeals so much because:
1. There is a high frequency of express trains on the line;
3. Many longer-distance routes ride over this “core section” of the Northeast Corridor and would thus see schedule improvements alongside New York-Philadelphia traffic;
4. And the line is already tantalizingly close to long stretches of high-speed running.
While improvements that themselves save 1-3 minutes might not sound like much, they add up, as others have remarked. Reducing an Acela schedule from NYP to 30th St. down to 45 minutes is not only possible, it’s relatively feasible, and a great showcase for true high-speed rail in the United States.
The two main speed impediments between New York and Newark (Portal Bridge and Sawtooth Bridges) are already slated for replacement. This should increase speed limits on the section to 90 mph for all trains, and the new Acela could possibly run 110 mph over this segment. In 1969, the PRR (well, alas, the PC, but perhaps my Pennsy affections are shining through) was able to run Metroliner 101 from NYP to NWK in 10 minutes. With Acela’s high speeds and tilting I would imagine even reducing this to 8-9 minutes would be possible, but even matching PRR’s 10 minute schedule would be a dramatic improvement for Amtrak.
The portion of the line that would benefit most from speed upgrades, though, is from Newark Penn Station to Zoo interlocking, directly north of 30th St. Station in Philadelphia. Constant-tension catenary, as others have pointed out, is necessary to get the Acela over 130 mph on the NEC. New Brunswick-Trenton (23 miles on 3 tracks) has already been upgraded for 450 million dollars. Assuming similar costs, Trenton-Philadelphia (33 miles) and New Brunswick-Newark (22 miles) could be upgraded for about 1.1 billion dollars.
With constant-tension cat, the only real impediment to constant 160-mph running from Newark to Zoo is 5 curves, 3 in New Jersey, and 2 in Pennsylvania. I would think that 180 mph would even be possible, but I defer to others on what the necessary track centers would be at that speed. (Does anyone know the track centers on Germany’s ICE lines or France’s LGV lines?) The five curves, their current speed limits, and their speed limits once improved are listed below.
1. Elizabeth S-Curve 55 mph-160 mph
2. Metropark S-Curve 100 mph-160 mph
3. Metuchen S-Curve 100 mph-160 mph
4. Torresdale S-Curve 110 mph-160 mph
5. Frankford Jct. S-Curve 35-160 mph
Elizabeth is likely the most difficult of the curves, but is nevertheless worth it when it is the only significant speed limit on the entire NYP-Philadelphia route.
With these improvements, it should take 10 minutes to get from New York Penn to Newark with 2 minutes of padding, and 35 minutes to get from Newark to 30th St. with 2 minutes or so of padding. That is a 25 minute reduction from Amtrak’s current schedule, and would revolutionize travel in the Northeast!