Performance under wire—different systems

RC '75 wrote:I had a few questions regarding electric current on NJT.

Does anyone know what the voltage is for each line on NJT?

Is the voltage the same in NYP as it is at Sunnyside Yard?

Are all Arrow III's leaving NYP set for the same voltage, (if that is the correct term) or are they set to a specific line?

25,000 Volts used on the M&E (Morristown Line/Gladstone Branch) as well as on the Montclair Line.

On the NEC, it is 11,000 Volts.

On the NJCL, it is 11,000 volts to Aberdeen Matawan, but just west of the station there is a voltage change to 25,000 volts.

Yes, the voltage is the same at Sunnyside as it is in NYP.

All Arrow IIIs leaving NYP are the same voltage (11,000 volts.) So thus, the Arrow IIIs are used out of NYP for NEC trains. On rare occasions, the Arrow IIIs may find use on South Amboy or Aberdeen/Matawan Locals but cannot go further than that because they cannot change voltages on the fly like the ALPs can. The Arrows used on the M&E and Montclair Lines are set at 25,000 volts and used on Hoboken trains only and not on MidTowns because they are not capable of changing voltages on the fly.

What happens if an ALP is supposed to change on the fly and doesn't. I am sure this has happened. If it fails from going from lo to high there must be a breaker that pops. If it fails going from high to lo then do you get a power loss or total stall ?

Don't know about the locomotives, but electric utility equipment, in many ways similar, have both overvoltage and undervoltage and overfrquency and underfrequency relays set to activate breakers and prevent damage. It would seem to make sense that the ALPs would be relayed in a similar fashion, at least for the voltage sensing.

ALPs have a main circut breaker. It is located on the roof, and is between the pantograph and the main transformer. When going through a phase gap, magnets on the ground will be detected by a sensor underneath the locomotive. This will make the MCB open. After the phase gap will be another set of magnets, which will close the MCB. The locomotive can detect the power entering the locomotive, and if the transformer is not properly set up to operate on that voltage, the MCB will not close.

All (I assume) of the Arrows are marked with an orange triangle "12" or "25" indicating the voltage they run on. PRR voltage was 11 kV but maybe is a bit higher now?

25 means 25kv/60hz
12 means 11kv/25hz or 12.5kv/60hz (12 is the avg. rounded up).

RC '75 wrote:I had a few questions regarding electric current on NJT.

Does anyone know what the voltage is for each line on NJT?

The NEC, it's tunnels, and NJCL north of South Amboy are all 11.5kv@25hz, the old Pennsy standard. The NJCL south of South Amboy down to Long Branch, as well as the entire Hoboken electrified division and the Midtown Direct connection west of the phase gap (ride the NEC, you'll see the signs and insulators) are all 25kv@60hz. The Hoboken electrified division used to be 3000 volts DC, but in 1984 was converted to 25kv with the expectation that Amtrak would follow suit.

RC '75 wrote:Is the voltage the same in NYP as it is at Sunnyside Yard?

Yes, the NEC from Washington DC to SHELL interlocking in New Rochelle is all 11.5kv@25hz. As noted above the New Haven used to be 11.5kv to the end of their system as well, but the MTA changed the system over to 12kv@60hz.

RC '75 wrote:Are all Arrow III's leaving NYP set for the same voltage, (if that is the correct term) or are they set to a specific line?

Yes, the Arrow's transformers can only be changed between 25kv and 11.5kv systems while in the shop. You can see stickers in the corners of the car stating "12kv" or "25kv" and indicating which system the car is set up for. It's likely that NJT didn't feel automatic tap changing was neccesary since at the time the M&E was completely separate from the NEC and it was expected that by the time MidTown Direct came to be the NEC would be 25kv anyway.

Oddly enough some of SEPTA's Silverliner IVs were delivered with automatic tap changing transformers, in addition to factory dynamic brakes. This was likely for the same reason NJT chose not to have Automatic Tap Changing in the Arrow IIIs. SEPTA was likely planning on Amtrak changing over the 25kv@60hz, but SEPTA likely would have retained some branches at 11.5kv@25hz rather than spend the money on upgrading the entire ex-Reading network. In the mid 1990s with the prospect of Amtrak changing standards on the NEC looking less and less likely and the environmental impact of PCBs lining up the transformers were swapped for non-tap changing units with more environmentally friendly units.

These days thanks to modern power electronics it doesn't even matter which power source the train uses. The only consideration would be the efficiency of transmission and the power delivered. 1.5kv is pretty piss-poor when it comes to delivering watts, while 50kv@60hz is superb, but has issues with clearance and leakage. Germany has the same low-frequency high voltage AC power that the Pennsy used, yet they have low floor LRVs that are capable of operating off a 750vdc trolley overhead or a 15kvAC@17hz with roof mounted high frequency transformers.

These days you wouldn't even have needed to reelectrify the M&E from 3kvdc to 25kvAC for Midtown direct. The French have had dual-voltage 1.5kv+25kv locomotives for years, and with the coming of the EU other countries have adopted increasingly versatile electric locomotives, some of which can travel on all the electrical systems on the continent. The quadrivoltage Class 189 locomotives and ICE 3M can run under 1.5kvDC, 3kvDC, 15kvAC@17hz, and 25kvAC@50hz. The Class 189 is not too far removed from the Class 185 which formed the basis for the ALP46. If the M&E had stayed 3kvDC and the ALP46 had been based on the Class 189 then the push pull's ontime rating likely would have suffered more compared to their operation under 25kv. The Class 189 develops 6400kw under both 15kv and 25kv, but only 6000kw under 3kv, and an abyssmal 4200kw under 1.5kvDc power. It wouldn't have been a great difference, but since people seem to lose it when a train loses 2 or 3 minutes on an unfavorable schedule.

For more on the class 189:
http://www.br146.de/revisionen_daten/
technische_Daten_BR_189.htm

So the NJ Coast is 25 kV timetable-west of South Amboy now? I remember the change west of Aberdeen being mentioned here, but I missed the south Amboy-to-Aberdeen increase. When was that?

timz wrote:So the NJ Coast is 25 kV timetable-west of South Amboy now? I remember the change west of Aberdeen being mentioned here, but I missed the south Amboy-to-Aberdeen increase. When was that?

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I had the same question, timz.

I thought the original South Abmoy to Matawan electrification was 11k, and the extension to Long Branch was 25k

^No no no. When they extended the electrification to Long Branch back in the 80s, it was 12,000 volts. This is why up to a year ago Arrows could travel down to Long Branch. But about a little over a year ago, they changed the voltage west of Matawan/Aberdeen to 25,000 volts. So when travelling through the phase gap just west of Matawan/Aberdeen station, the train switches voltages. So now, with the exception of the Aberdeen/Matawan trains and South Amboy trains, all electric trains on the Coast Line must be ALP hauled for the voltage change.

Incidentally, there is also a Perth Amboy Local (in the morning only- Jt told me about it once and I was suprised as the dickens to hear about it) but this train is always a push pull ALP as it comes from Hoboken and Hoboken operates under 25,000 volts.

The 1/03 timetable shows 12 kV all the way to Long Branch, the 1/04 shows 12 kV changing to 25 kV at Aberdeen. So no question about any of that-- but this is the first I heard about the change now being at South Amboy, and I was wondering when that happened.

The timetable doesn't list a phase gap at South Amboy; is that an easy thing to install?

There is no voltage change at South Amboy. The change is just west of Abredeen-Matawan.

Irish Chieftain wrote:

Nick11A wrote:Are the benefits of 25 kV really a big deal vs the 12 kV?

Half the substations IIRC...I remember reading that with the 25kV 60Hz system, you only need a substation every 20 miles.

Amtrak did themselves intend to convert the former PRR to 25kV 60Hz but never got the funding to do it.

...

There are at least two more benefits of a 25kV 60Hz system if it came to pass:

1. NJT could then avoid having frequency converters in its substations. It is my understanding that frequency converters are expensive…which would mean we are paying for them in our NJT tickets and our NJ State taxes. Same for any railroad.

2. The locomotives and MU power supplies would need less hardware if built to only one voltage and frequency. They would cost less, and would have less hardware to break down and less to maintain. And fewer parts usually means more reliability (as in getting to the station on time).

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.

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.

Ken -- is that rotary unit trackside near Lincoln or in that substation by US1 and Amboy Ave.? (where the three trolley lines met)