• 25 kV 60 Hz AC on the entire Northeast Corridor

  • Discussion related to Amtrak also known as the National Railroad Passenger Corp.
Discussion related to Amtrak also known as the National Railroad Passenger Corp.

Moderators: GirlOnTheTrain, mtuandrew, Tadman

  by D.S. Lewith
 
Back in the late 70s, Amtrak had plans to have the entire Northeast Corridor electrified by 1981 (which meant electrifying between Mill River, New Haven and Boston), and at 25 kV 60 Hz. The former was accomplished in 1999-2000 but between Washington DC and Mill River, New Haven the electrification still stands at 12.5 kV AC (25 Hz between Washington DC and the Sunnyside Yards, 60 Hz between the Sunnysize Yards and New Haven).

As 12.5 kV AC is a nonstandard voltage, Amtrak (and NEC-based commuter agencies) has to add custom modifications to its electric fleet whenever it orders from international railcar manufacturers. Converting the entire NEC (plus the Keystone Corridor between Philadelphia and Harrisburg) to 25 kV 60 Hz AC would make things easier for electric train orders, but it would have to be carried out in stages due to infrastructure complexities (such as in New York Penn Station).
* Stage 1: Between the Sunnyside Yards and New Haven Union Station, and between Washington DC and Wilmington, Delaware. This also would motivate MTA to convert the electrification between Pelham and New Rochelle to that voltage (and maybe extend it a bit further south, eventually reaching Grand Central)
* Stage 2: Between Wilmington, Delaware and the Kearny/Waterfront Junction. This also includes the Keystone Corridor between Phildelphia and Harrisburg, and would also motivate SEPTA to convert the approach tracks to 30th Street Station to Temple University (eventually converting the entire network as well), and NJT to convert the North Jersey Coast Line between Rahway and Matawan and the Princeton Dinky, to that voltage.
* Stage 3: Between The Kearny/Waterfront Junction to the Sunnyside Yards.
  by STrRedWolf
 
You're missing MARC and their HHP-8's. (They're mostly diesel though, so not that bad)

That said, just how much money will it take to undergo that conversion?
  by Greg Moore
 
Ultimately, I think it makes sense. But that said, given how little we seem to be willing to spend on rail infrastructure, I'd rather see money go elsewhere.

But in a perfect world, yes, I having a single standard on the NEC would simplify things greatly.
  by mtuandrew
 
Low-clearance areas still need 12.5kVAC (doesn’t matter how many Hertz), otherwise 25kVAC 60Hz across the board would be ideal. Would be very nice to replace the Safe Harbor(?) 25Hz generators over a few long weekends.
  by bdawe
 
At the very least, converting Long Island through New Jersey to 60 hz from the present 25 hz voltage would greatly simplify NJT-MTA through running options. An M8 would be regionally universal in this scenario, presently unable to run over 25hz power
  by WhartonAndNorthern
 
D.S. Lewith wrote: Tue May 26, 2020 3:08 am Back in the late 70s, Amtrak had plans to have the entire Northeast Corridor electrified by 1981 (which meant electrifying between Mill River, New Haven and Boston), and at 25 kV 60 Hz. The former was accomplished in 1999-2000 but between Washington DC and Mill River, New Haven the electrification still stands at 12.5 kV AC (25 Hz between Washington DC and the Sunnyside Yards, 60 Hz between the Sunnysize Yards and New Haven).

As 12.5 kV AC is a nonstandard voltage, Amtrak (and NEC-based commuter agencies) has to add custom modifications to its electric fleet whenever it orders from international railcar manufacturers. Converting the entire NEC (plus the Keystone Corridor between Philadelphia and Harrisburg) to 25 kV 60 Hz AC would make things easier for electric train orders, but it would have to be carried out in stages due to infrastructure complexities (such as in New York Penn Station).
We've had many discussions here about converting just to 12.5kV/60Hz and sticking points included:
  • signals that ran off of 25 Hz possibly even motor generators designed to produce 91 2/3 or 100 Hz signal current.
  • impedance bonds designed to block 91 2/3 or 100 Hz signal current (creating signal blocks) but allow DC and 25 Hz traction current to return may not allow 60 Hz to pass
  • Amtrak runs a single phase/ 2 wire distribution system with no phase breaks while utilities provide 3-phase service to heavy loads. The grid would need to be redesigned to have phase breaks and load splitting, or you'd still need converters: instead of a 3ph 60 Hz to single phase 25 Hz static or rotary converter (or dedicated plant) you'd need a three phase to single phase converter of some sort at each grid entry point.
Lastly to address your concerns about nonstandard voltages: the European standards are 1.5 kV and 3 kV DC, 15 kV 16.7 Hz AC, and 25 kV 50 Hz AC. None of those are used in the US so we're already ordering "nonstandard." In reality, the only thing we need to order are custom wound transformers with the right number of taps and winding ratios. That isn't that hard. The iron core size varies based on input frequency and a transformer designed for 16.7 Hz would work at US frequencies at the cost of being heavier than required for US 25 Hz. Notionally the tap ratio for a 25 kV transformer works whether its 50 Hz or 60 Hz so yes, I could see some commonality there. But transformers aren't the hardest part of a locomotive to design and US transformers can be smaller than 16.7 Hz European ones so "standardization" is a false economy. The real "magic" in an electric locomotive happens after the incoming power is transformed and rectified to the desired DC Link voltage which, if you design your transformers correctly, can be universal.
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bdawe wrote:At the very least, converting Long Island through New Jersey to 60 hz from the present 25 hz voltage would greatly simplify NJT-MTA through running options. An M8 would be regionally universal in this scenario, presently unable to run over 25hz power
One of the few advantages of doing this conversion would be allowing M8's (that have variable voltage taps but don't have 25 Hz transformer cores) to access Penn without the extra miles of 3rd rail installation over Hell Gate that is proposed.
  by D.S. Lewith
 
WhartonAndNorthern wrote: Tue May 26, 2020 9:28 am Lastly to address your concerns about nonstandard voltages: the European standards are 1.5 kV and 3 kV DC, 15 kV 16.7 Hz AC, and 25 kV 50 Hz AC. None of those are used in the US so we're already ordering "nonstandard."
The Metra Electric District and the South Shore Line use 1500 V DC, and the historic Milwaukee Road electric used 3000 V DC. The NJT Erie Lackawanna electric lines also used 3000 V DC but were converted to 25 kV 60 Hz in 1984. The Deux-Montagnes line in Montreal, Canada was originally 2400 V DC, then converted to 3000 V DC in the 1980s, then 25 kV 60 Hz in 1995, and now it's being converted to 1500 V DC for the REM. Those are all European-Standard voltages (they use 50 Hz for 25 kV because Europe is PAL whilst 60 Hz is used for the likes of the US, Canada, Mexico, Japan and South Korea as they are NTSC countries; they're more or less the same, really). Also to mention, the Ottawa O-Train Confederation line, the Seattle Red Line, and the upcoming Maryland Purple Line are in 1500 V DC (and Denver RTD, San Francisco Caltrain, and Mexico's Tren Surburbano and Mexico City-Toluca train use 25 kV 60 Hz AC).
bdawe wrote:At the very least, converting Long Island through New Jersey to 60 hz from the present 25 hz voltage would greatly simplify NJT-MTA through running options. An M8 would be regionally universal in this scenario, presently unable to run over 25hz power
One of the few advantages of doing this conversion would be allowing M8's (that have variable voltage taps but don't have 25 Hz transformer cores) to access Penn without the extra miles of 3rd rail installation over Hell Gate that is proposed.
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They still have to use the third rail to gain access to the West Side Yard though since LIRR doesn't want overhead wires on it (but if I'm going to be honest, LIRR should start converting to 25 kV 60 Hz on most of their routes (ditto with MNCR on at least the Harlem line), but that would require either modifying their existing rolling stock to run on overhead wires or buying something like the M8s because 63rd Street Tunnel clearances are so tight that not even 14 ft 6 in bilevel cars are allowed).
  by Ken W2KB
 
mtuandrew wrote: Tue May 26, 2020 8:06 am Low-clearance areas still need 12.5kVAC (doesn’t matter how many Hertz), otherwise 25kVAC 60Hz across the board would be ideal. Would be very nice to replace the Safe Harbor(?) 25Hz generators over a few long weekends.
Agreed. I wonder how many low clearance spots there are, and how difficult mitigation of them would be. The difference in phase to ground clearance of 12.5 kV vs. 25kV is only about 6 inches if I recall correctly.

Replacing the two 28MW water turbine generators at Safe Harbor would likely require a complete outage of at least a few weeks each, including time for testing under load, etc. Loss of 28MW at a time is probably not a significant concern, about 8% of peak load. I would hope Amtrak does not operate that close to the edge.
  by bdawe
 
D.S. Lewith wrote: Tue May 26, 2020 12:20 pm

They still have to use the third rail to gain access to the West Side Yard though since LIRR doesn't want overhead wires on it (but if I'm going to be honest, LIRR should start converting to 25 kV 60 Hz on most of their routes (ditto with MNCR on at least the Harlem line), but that would require either modifying their existing rolling stock to run on overhead wires or buying something like the M8s because 63rd Street Tunnel clearances are so tight that not even 14 ft 6 in bilevel cars are allowed).
The thing to do with that sort of capability wouldn't be to pile more trains into the West Side Yard, it would be to run them to New Jersey. Similarly, with a short stretch of electrification you could run Hudson Line trains to Long Island

Here though, the primary beneficiary of power-standardization would be commuter rail riders and agencies, rather than Amtrak, though moving everything to 60 hz would allow some meaningful weight and space savings for Amtrak electrics.

I don't think it would be advisable to move LIRR to overhead, both because of ESA and because re-electrifying the LIRR is such a gigantic job for fairly marginal benefit when reasonably good DC/60hz AC dual power EMUs already exist and roam the region
  by charlesriverbranch
 
D.S. Lewith wrote: Tue May 26, 2020 12:20 pm (they use 50 Hz for 25 kV because Europe is PAL whilst 60 Hz is used for the likes of the US, Canada, Mexico, Japan and South Korea as they are NTSC countries; they're more or less the same, really).
NTSC and PAL were analog TV standards; NTSC specified 30 frames per second, while PAL and SECAM specified 25 frames per second. There were 2 fields per frame, so NTSC could take advantage of the 60 Hz AC power frequency in the United States, and PAL and SECAM could take advantage of the 50 Hz frequency in most of the rest of the world.

But the line frequencies were in use before TV was invented; they influenced the creation of the TV standards, and not the other way around. Most countries use digital TV systems now, such as ATSC (United States) or DVB-T(Europe); analog TV is fast going the way of steam locomotives.
  by Backshophoss
 
You have 3 different power grids on the NEC,The Amtrak/PRR(12.5kv,25hz) grid,the NH/MN (12.5kv,60hz)grid,and the "New Build" Amtrsk(25kv,60hz)grid.
SEPTA 'a RDG grid is still at 11kv,25hz and thru operates on to the Amtrak grid. Conversion to 25 kv would be very expensive on the PRR grid requiring Bridge rebuilding/replacement
for the air gaps needed,,replacing Safe Harbor generating,going to capy,going to 12.5kv would be less $$$$$ but you still replace Safe Harbor's capy and tick off SEPTA due to two seperate Voltage Fleets.
NJT will grumble about changing over the Arrow III's,and MN /ConnDOT barefoots a bunch of M-8's for NY Penn service
Amtrak has invested into the PRR grid,rebuild converters and added static inverters in NJ/
  by west point
 
There are several inaccuracies in the above posts.
1. Correct it is 25 Kv 60 Hz Bos to east of New Haven.
2. MNRR took some 2 weeks to convert from 11 Kv 25 Hz to 12.5 Kv 60 Hz. The New Haven fixed CAT supports do not have clearance for 25 Kv 50 Hz Nominal . Remember the voltage variations are actually + / - 10 %. So 25 Kv actually means 27.5 Kv Max 22.5 Minimum voltages. That 10% applies thru out the whole NEC.
3. Now we near NYP the voltage is 12.0 Kv 25 Hz (not 12.5 ) with max 13.2 Kv. Converted in stages by PRR from 11.0 Kv to 11.5 Kv. . Then Amtrak converted from New Rochelle - WASH in the 1980s from 11.5 to 12.0 Kv. NYP does not have clearances for 25 Kv nominal.
4. Amtrak a few years back converted from New Rochelle to Gate the Hell Gate line from 12.0 Kv 25 Hz to 12.5 Kv 60 Hz. I never found a reason but suspect that it was to eliminate the frequency change at New Rochelle ?
5. PRR and Amtrak did the increase of 25 Hz voltages for the whole system. There are phase breaks on the 25 Hz PRR lines even today. That is because even though it is single phase the power is supplied at 69 Kv one leg and the other leg 180 degrees the other way. That way you get 138 Kv leg to leg. Much like your home with each leg 120 V but 240 V leg to leg.
6. A conversion of somewhere west of the North river portals probably could be started to just before Secaucus station.
7. About clearances: To go to 25 Kv you have to double the clearance from the CAT to train cars. Then have to double the clearance from CAT to anything overhead. .
8. The problem locations I am aware are Newark Penn Station. Maybe Trenton in the tunnel. Unknown if PHL 30th street has enough. The Union tunnel north of Baltimore, Maybe the B & P tunnels. Much of WASH Union station will need to be raised. The tunnel to the first ave tunnel leaving WASH is unknown. This poster thinks any location that does not have plate "H" freight may have low bridge clearance problems and other locations.
9. Safe Harbor already has 60 Hz generators as well as the 25 Hz single phase generators. so that is not a problem. Does it have 25 / 60 HZ frequency converters is unknown ?
10. Conversion can only be done incrementally see #2. This poster would see it start at WASH - Baltimore, Baltimore - Aberdeen., Probably beyond the end of SEPTA to Harrisburg, Then it gets complicated NJT would need to finish converting the Long Beach shore line to short of Perth Amboy,
11. South of Newark ( Port Amboy ? ) to north of Trenton.
12. Secaucus to south of Newark. Allows NJT to access its 60 Hz lines.
13. In the meantime all these conversions will require retirements and changes to frequency converters. Also major wiring , Transformers, CBs, signals, Impedance bonds , etc.
14. Then you have the Septa mess, It has its own converter location at Wayne shops and does not use Safe Harbor except in an emergency lurch. SEPTA still at 11.0 Kv How the Amtrak SEPTA grade crossing is done at North PHL am unaware.
15. Can SEPTA convert to 25 Kv ? Unknown clearances especially Suburban Station ? Leave that for another day.
16. Amtrak could convert its PHL area in no special order . PHL - Wilmington would require SEPYA to convert the airport line. Then the. rest of PHL - Harrisburg, Then PHL - Trenton how to solve North PHL ?

All in all suspect a 20 year project. Now if Amtrak just went to 12.5 Kv 60 Hz would reduce complication but you still have the SEPTA problems. Of course SEPTA and NJT would need dual frequency capable equipment for their EMUs..
  by STrRedWolf
 
Needless to say, a big project.

Lets get a few things straight. From what I've seen through the thread, you have to replace the CAT wire to even get 60hz 12.5 kV nominal, update the transformer stations to get 12.5kV down from 138 kV, update the converters along the route in sections, as well as the Safe Harbor dam generating this power. I doubt it's all "flip a switch all at once."

My fear in such a project is that a section would require power to sections of track to be shut down. Since the NEC is insanely busy on a good day, shutting power off to a track needs to be carefully planned and coordinated... and makes me wonder about MARC getting asked by Amtrak to lend a few diesels...
  by bdawe
 
STrRedWolf wrote: Wed May 27, 2020 6:43 pm Needless to say, a big project.

Lets get a few things straight. From what I've seen through the thread, you have to replace the CAT wire to even get 60hz 12.5 kV nominal, update the transformer stations to get 12.5kV down from 138 kV, update the converters along the route in sections, as well as the Safe Harbor dam generating this power. I doubt it's all "flip a switch all at once."

My fear in such a project is that a section would require power to sections of track to be shut down. Since the NEC is insanely busy on a good day, shutting power off to a track needs to be carefully planned and coordinated... and makes me wonder about MARC getting asked by Amtrak to lend a few diesels...
60 hz needs different wire than 25 hz?
  by MattW
 
I don't believe you'd require different transformers. From what I understand, 25Hz transformers can handle 60Hz, but not the other way around.