Performance under wire—different systems

Ken W2KB wrote:Not to mention that the original (1930's) 25 megawatt rotary converter is still used continuously at the Metuchen, NJ Switching Station. Sooner or later it will fail.

Thanks! I thought frequency converters were rotary.

Aren't they a motor driven by 60 Hz on one end, with a generator for 25 Hz on the other end?

That's exactly what the rotary converters are. The newer Amtrak converters are solid state wihtout moving parts. Metuchen and perhaps other rotaries soldier on as well.

So maybe the NEC will be 25kv/60Hz or 22-25kv/25Hz in near term ?

Doubtful. At this point, the 25hz system sees to be entrenched on the NEC. Amtrak's given up on bothering to convert, regardless of the advantages it'd have. My guess is that Amtrak will likely become the sole operator of a 25hz power system in the world, <b>period</b>. I can't think of any overseas, and AFAIK, only the NYCTA uses 25hz power for anything and they're quickly dumping it (AFAIK, none of the power grid is tied to 25hz, just signalling). It has no industrial use. It's not even required for electric operation, with the exctption of the Silverliner II/III cars, everything in the US right now can switch on the fly for 60hz. AFAIK, the SL II/III cars are shop switchable to 60hz. Heck, by now they may have even been modified for 60hz auto switching.

16 2/3 hz, 15kv is still pretty common in Europe, but they have lots of legacy equipment. 25kv 50hz has been the common standard there for years though. 1.5kv still holds a minority following in France and the Netherlands. The latter is converting to 25kv.

Germany, Austria, Switzerland, and Sweeden are the big 16 2/3 hz user, I think. For them, converting still isn't feasible. But then, Germany alone has about 10,000 miles of electric track, though some is 50hz.

I'll predict it now - unless a minor miracle happens and Amtrak hires and actual engineering staff, you'll see 25hz operation on the NEC 25 years from now. And likely only on the NEC - I'm guessing after the last Silverliner II/III drops it's pan, Septa's gonna make the jump to 60hz, if not before then.

There's no reason whatsoever to run 25hz. It's a historical artifact from before the era of rectifiers and inverters and power electronics. It has lots of disadvantages and few (any?) advantages. 60hz comercial power isn't a flakey idea, it's proven by a few decades of operation in the US, and decades of operation on a 50hz system overseas. Phase balancing, while and interesting issue, hasn't been a showstopper for anyone. And that's so far been the only excuse for 25hz (though I suspect even the PRR's 25hz system is multiphase - the New Haven's was)

At an IEEE meeting I attended a few years ago, Amtrak's engineering department speaker estimated that the 25 to 60@25kV constant tension catenary conversion project would take approximately 10 years to complete because of the need to protect the train operations on the very busy Corridor. I seem to recall that the cost was in the order of magnitude of billions of dollars since it would likely involve close to a total replacement of all the electric infrastructure, even many of the supports are nearing the end of their life.

Boston to NH is 25kV/60Hz ?

NYP to NH is a mix of 11kV/25Hz and 12.5kv/60Hz ?

Ken W2KB wrote:At an IEEE meeting I attended a few years ago, Amtrak's engineering department speaker estimated that the 25 to 60@25kV constant tension catenary conversion project would take approximately 10 years to complete because of the need to protect the train operations on the very busy Corridor.

Well, yeah. But to change to 60Hz, the voltage doesn't need to go up, the catenary doesn't need to be changed. Metro-North went from 25 to 60Hz in the 80's and only recently started doing the wires. They went in stages as the M-2s can swap between 25 and 60hz. It's still 12.5kV. Ok, they bumped it 1500 volts. Whoopie.

Ken W2KB wrote:I seem to recall that the cost was in the order of magnitude of billions of dollars since it would likely involve close to a total replacement of all the electric infrastructure, even many of the supports are nearing the end of their life.

The whole NY to DC overhead is nearing the end of it's life. It's been poorly maintained since the 60's, and it's being run outside it's intended design parameters anyway. It needs conversion to constant tension, it needs many poles replaced. This is independent of the voltage/frequency issue. Most of the substations are near the end of their lives. 25hz transformers are expensive, as is the switchgear - nobody makes it as a regular item anymore.

25kV on the NEC? EVERYONE was ready for it in the 70's. NJT rebuilt the Hoboken division on 25kV in part because Amtrak told everyone that that was gonna be the NEC's voltage. SEPTA's equipment can handle it, AFAIK the M-2s have 25kv taps, the E60s had it (never used!), the AEM-7s have it.
Amtrak cut from Harold over to New Rochelle to 60Hz years ago (12.5kv). I don't know why they stopped.

I question how badly Amtrak needs to go to 25kV, and if it's even possible in some places. But dumping 25hz operation most certainly is - there's no reason 12.5kV/60Hz can't work on the NEC. And it'd save Amtrak a lot of money in the long term. Frequency conversion isn't 100% efficient - static inverters are good, but the rotary jobs Amtrak still uses are maybe 70% efficient at best. 25Hz means much heavier onboard equipment, making a bad situation much worse.

The simple fact is the NEC's power system is shot and rebuilding it for 25Hz operation is without merit.

Certainly agree with what you say. I looked at quite a few photos of the Amtrak infrastructure about a year or two ago, when there were some issues with the reliability of the utility transmission overbuild (Amtrak gets a hefty rental payment for the space above their system) and the photos were not encouraging. Like you, I wonder why they didn't go to 60Hz when they spent a lot of money 3 or so years ago building the large solid state converter in PECO's territory. One would think that new transformers would have been somewhere in the same order of magnitude of expenditures.

Tonight, after the evening super express (from South Amboy to Newark) blew past Perth Amboy, I was waiting for my South Amboy local a few minutes behind it- arrives 7 PM at Perth.

As it was coming across the Raritan way in the distance, I noticed something very peculiar. All of the brake lights wer at the same height and had the same color. Of course, I got excited (ooh goody, a solid set.) But when I realized it was the darker green color not of the Comet IIMs, IVs and Vs, I was confused. As it got closer and the headlight blinded me more and more, I heard that unmistakable horn. It was an Arrow III train.

This was my first time seeing Arrows on the South Amboy local (since of course the voltage change at Aberdeen/Matawan last year). I know they have been used on the S. Amboy trains rarely since but I never thought I'd get a chance to see one or ride one.

On an interesting note, the train seemed to have its safetys on at Perth as the rear brake gave two to go but the train didn't start moving until the conductor shut his trap and closed the door.

I was quite surprised to see that A3 set in South Amboy tonight also, I haven't seen MU's down the coast line to S.A. in about 6 months.

Oh the good ol days - hahahahhaha

Yeah, I'd love to see more Arrows on the S. Amboy (and even Matawan) locals. I'd like to be optimistic and hope that this is a sign of more to come.... but I know better. Just one of those once in a blue moon things. Just happy I got a chance to ride it as it is an extremely rare thing.

What is SEPTA's ex-RDG lines now using for juice ? 11kv/25Hz or other ?