My understanding when I worked for Amtrak in the corridor as an LSA in the late 80s and early 90s was that there was still a difference in voltage or phase or cycles between the former PRR part of the corridor and the NH (Metro-North) line. This came up the hard way. I was working the old Montrealer and when we got onto Metro-North the HEP circuit blew and we ended up running in the dark to New Haven. I was told that at that time only certain AEM7s were equipped for Metro-North territory and we had inadvertently been given one that didn't have the dual circuit equipment (it might have been an E60, at different times #60/61 got either one for power). Anyway, not every Amtrak motor could handle the different power levels all the way from DC to NH at that time.

Interesting. Metro-North converted the NH line to 60Hz in 1986-1987 and Amtrak converted the Hell Gate Line in 1987. So it may have been that not all of the AEM-7's had 60 Hz-compatible HEP converters right away.

Phil Mulligan

I held a regular position on #60/61 a couple of times, from late '86 until the washout north of Springfield, MA in late Winter '87 suspended the service, and from late Summer to late Fall of '89 after they rerouted it via New London, CT. It happened one of those times, and from what you are saying, it probably happened the first time I held it in '86-'87. E60s and AEM7s were pretty interchangeable for that train, since it carried Heritage cars and couldn't go over 110 mph, and it was long and heavy enough that if they assigned AEM7s to it, it needed two of them, vs. one E60. It might have been an E60 it happened with, since if it had two AEM7s you'd think they might have been able to change the HEP to the other unit, that is if one of them was properly modified. Maybe neither of them were. I know they had a list of the ones that had been modified, one of the crew lamented to me that someone in the power bureau didn't look it up before they assigned the motors to the train that night.

Sounds about right. After 10 years of experimenting with unsuccessful AC electric passenger locomotives, PRR finally tested a NH EP-3 motor on its own lines. No modifications were needed except it had to stay away from high wire. [The resulting GG1 used the NH running gear with a lengthened carbody based on the P5a (modified)]

In 1970, after taking over NH, PC moved all the NY-Boston trains from GCT to Penn Station. GG1's ran to New Haven and had no electrical problems except the pans reached too high for NH's air gaps at some movable bridges. I'm sure there was a phase break separating PRR power from NH going onto the Hell Gate Bridge at the PRR end. [still is one but now separating 25 Hz from 60 Hz]

Phil Mulligan

"Lectricity, they've been studying it for years, nobody knows how the heck it works,,,,"

Yes, the PRR and NH had different Lectricity from the beginning, Amtrak tried to make some loco's work on both, but it's harder than it seems. Gotta flip all the switches just right and not blow the fuses,,,,

Kevin, BSEE 1980, MSEE 1981....

PRR and NH used the same AC electrification at the contact wire: 11 kV 25 Hz single-phase AC. The equipment supplying the power may have differed, but the voltages and frequencies were the same.

Some PRR wire was higher than any NH wire which led to difficulties when GG1's began running under NH wire in the PC era and the PRR pans reached too high to catch the recovery wire at some open air gaps on NH. PC raised the wire after pans were torn off and wire pulled down.

When some NH EP-5's were used as E40 freight motors on ex-PRR lines, they each got a new, high wire pan; also NH's ex-VGN EF-4's, now PC E33's, each got a new high wire pan to run on ex-PRR lines.

The phase break at "HAROLD" was to separate NH's power source from PRR's to avoid interference. PRR had multiple phase breaks on its own lines to separate power sources.

The big expensive stuff was compatible but the details differed.

Phil Mulligan

Oh, since I last visited this subject, camed a lot of replyes.
1) Modern locomotive can cope with a lot of different frequncyes and voltages. The older one, with no electronic conversion, only at different voltages and maybe A.C. - D.C. It was also about the transformes, becaude a transformer for let's say 25 Hertz haves a different lenght of coil wire (I don't know exactly how to say it in English) then 60 Hertz (cycles) trasnformer for the same power. An old home radio transformer can probably work bot for eg at 50 and 60 Hz., but that's a small power transformer, probably no more then 200 Watts, when a locomotive transfomer needs more at least 30 times that power;

2) Why 2 difference between the hight of the wires of P.R.R. and N.H.?
Of, we talked about differnces: in Romania (West side of the country) of the rail ring line of Town of Arad level crosses the Arad - Ghioroc interuban streetcar line (the streetcar line is part of a former larger system of interurban electrified narrow gauge railroad, the 1st electrified passanger line in actual Romania). Since the railroad have a 25,000 or 27,000 Volts voltage and the streetcar have 550 Volts (formaly the line had 1,500 Volts, but when the streetcar and interuban line where unified, all the system was put to 550; the poles of the narrow gauge rail also carried 3 wire for 15,000 Volts, for suplying both the trains and the villages along the route) there must be an electric sepration, so trains have to gain speed because there is a no-voltage zone. If they don't, you got a train stucked;

3) If at 25 Hz. an electric motor can be more easely controled then at 50 or 60 (that's why in Germany, Austria, Switzerland they have 16 2/3 Hz., which is 1/3 of 50), why they still used motor-generators for A.C. to D.C. conversion?
Did there where motor-generators or convertres for cars lighting, because at 25 Hz. the classic light bulbs does flicker;

4) Trains do make you to learn geography.
I remeber when I could not write Pennsylvania and Massachusetts (still the number of t's gives me a confusion);

5) Did ever in U.S.A. was tested Europeanen rail stock, besides locomotives?;

6) In a U.S.A. train there where ever stores? Like to buy clothing, beach articles, paper + pencils + fountain pens, newspapers, photographic films;

7) Off-topic question:
Some 3 phase electric motors have what is called a Star-Delta connection. I've seen in schematics that this type of connection is depending on how the coild for induction (stator) are connected. But since I'm not an expert on electricity, I can't understand how physically this connection are made in the motor, like what is the route of the wires between the induction coils, the route of the wires from the coils to the power suplly. Where I can find a drawing of such connection.
I do appologize I've I misspled some technical terms.

5: French Turboliners on Amtrak, Channel Tunnel sleeping cars on Via Rail Canada.
6: Food and drinks, playing cards, tobacco, simple medicines, pillows, blankets. The examples you suggest are more often for sale on tourist and museum trains.

At various times Amtrak cafes sold some of those items, especially playing cards and small pocket games (like checkers and backgammon). Also Amtrak logo blankets, which took up too much storage space in the long run for how many sold.

6) But in the older days, pre-"Amtrack"?

> 1) Modern locomotive can cope with a lot of different frequncyes and voltages. The older one, with no electronic conversion, only at different voltages and maybe A.C. - D.C. It was also about the transformes, becaude a transformer for let's say 25 Hertz haves a different lenght of coil wire (I don't know exactly how to say it in English) then 60 Hertz (cycles) trasnformer for the same power. An old home radio transformer can probably work bot for eg at 50 and 60 Hz., but that's a small power transformer, probably no more then 200 Watts, when a locomotive transfomer needs more at least 30 times that power;

Conversions can be confusing. Generally speaking, a transformer designed to operate on 25 hz can be operated successfully on higher frequencies. The reverse (a 60 hz transformer on 25 hz) cannot be done without being derating it or it will overheat (this has to do with the amount of iron in the transformer's magnetic circuit).

2) Why 2 difference between the hight of the wires of P.R.R. and N.H.?

Since the NH electrification preceded the others, it was essentially the test bed, and the lessons learned from it ware applied to subsequent installations, of which the PRR was one. Wire heights are dictated by the various States; there is no US Federal standard, although the States pretty much all specify the same standards: 21 feet minimum if your RR transports freight cars and 19 feet if it's 100% light rail (as in "streetcars"). There can be waivers for certain situations.

>3) If at 25 Hz. an electric motor can be more easely controled then at 50 or 60 (that's why in Germany, Austria, Switzerland they have 16 2/3 Hz., which is 1/3 of 50), why they still used motor-generators for A.C. to D.C. conversion?

In the early days, like 100 years ago, most traction motors were series wound, and 50 or 60 AC (single phase) causes inductive problems in the connections between the commutator bars and the armature windings (the connections overeat will overheat to the point of failure). This was solved by using german silver resistance wire, a copper-nickel-zing alloy (now called nickel silver). This was made obsolete with the introduction of compensating windings in the motor field structure. 25 hz was selected (then) because it would act as AC in the transformer and DC in the traction motor. Around the same time as the construction of the PRR electrification, it was discovered that 16 2/3 hz is the optimum frequency when taking into account the transformers, the traction motors, and inductive losses in the iron (steel) rails.

>4) Trains do make you to learn geography.
I remeber when I could not write Pennsylvania and Massachusetts (still the number of t's gives me a confusion);

Don't feel bad, I frequently have to look up the spelling of Massachusetts myself, and I've lived in the US all my life. Massachusetts is/was the name of a local Native American tribe. "Pennsylvania' is a contraction of "Penn", William Penn's last name, and the Latin word "sylva", meaning "forest".

5) Did ever in U.S.A. was tested Europeanen rail stock, besides locomotives?;

The Tago trains. The problem is that European designs don't meet US compression standards.

6) In a U.S.A. train there where ever stores? Like to buy clothing, beach articles, paper + pencils + fountain pens, newspapers, photographic films;

These were usually in the larger urban stations. What was sold on a train depended on the operating RRs policies, including Amtrak.

7) Off-topic question:
Some 3 phase electric motors have what is called a Star-Delta connection.

Delta or star, this has to do with the way the transformer windings are connected.

>I've seen in schematics that this type of connection is depending on how the coild for induction (stator) are connected.

In an induction motor, the field coils, called the "stator", are connected in a way that the changing electrical direction of the mains produces a magnetic field which rotates (around the stator frame). As it rotates, this field induces currents in the rotor (the AC armature), and the magnetic fields which arise from these induced currents chase the stator's rotating magnetic fields. This causes the rotor to spin.

> Where I can find a drawing of such connection.

Try here: https://www.explainthatstuff.com/induction-motors.html

As to high wire, when the RR's first electrified, it was normal practice for brakemen to ride on the tops of boxcars etc. to pass hand signals and set handbrakes. The high wire was to give them clearance to do so. As high cars got higher and some brakemen were electrocuted, employees were prohibited from going on top of equipment while under any wire. To water a steam locomotive, you were not to climb over the coal pile but to climb down from the cab, go to the rear of the tender and up the ladder.

25 Hz was a common US industrial frequency so equipment was readily available in the first quarter of the 20th century. I associate 16 2/3 Hz with Central European railroads (DE, CH, AT) Some US interurban electric railways started with 25 Hz AC traction power, but they converted to DC power.

As an observation, MU cars with 25 Hz AC motors would buzz and vibrate at low speeds then appeared to smooth out as they turned faster.

Phil Mulligan

So, getting back to the 6,600V York Rys. interurban car that started this branch of the discussion, this explains how the high voltage AC car could share wires with streetcars. The interurban had 660V series wound traction motors, and carried a transformer to drop the 6,600VAC voltage on the catenary to 660VAC for the motors. In the streets it just ran on 600VDC.

1) Pretty heavy with a transforme inside. But I guess since the motors where winded in series, I didn't need to drop the voltage too much, so it was a smaller transformer then if you would have had a 6,600 to 660 Volts transformer.
2) On an vintage audio-video forum I've read something about the fact the a lower frequncy transformer can work on a higher frequency with almost no problems, but the other way around is problematic. They made some 25 Hz. (Cy.) radios for Canada, because Niagra? power plant deliverd 25 Hz. electricity.
3) As for the delta - star connection, still I don't figure it out.
4) Pennsylvania ryhms with Transilvanya. Transilvany means "to the forrest". Some Scottish guy made a story and ... you know, people associate Transylvania with a certain fellow.
5) Why Europeanen rolling stock couldn't cope so good with U.S.A. and Canada? It's also the other way around, U.S.A., Canada rolling stock would be generally to big and to heavy for Europe. Romania have some pretty large rail clearances (large, not tall) compared to some Western Europe clearences.

> 1) Pretty heavy with a transforme inside. But I guess since the motors where winded in series, I didn't need to drop the voltage too much, so it was a smaller transformer then if you would have had a 6,600 to 660 Volts transformer.

"Series wound motor" means the armature and field coils are connected in series. On DC interurban cars, the motors were then connected in series-parallel and parallel to obtain two running positions on the controller (locomotives also could have a third position: full series).

With the Westinghouse two-motor AC system, the motors were wound for 250 volts and connected in parallel because every point on the controller was a running point. The taps on the transformer varied the motor voltage between about 175v and 295v. The four motor system was slightly different: two sets of two motors connected in series, with each set connected in parallel. Transformer output voltages were probably double the two-motor values, but the voltage across each motor stayed the same.

The 3,300 and 6,600v installations used auto-transformers, while the 11kv and up used isolation transformers. Higher voltage main line RR installations used an isolating transformer, although 6,600v installations could have also used isolating transformers.

The PRR GG1s had 330v traction motors, 12 of them, and used some buck-boost connections, which is in a sense a throwback to WH's first AC control system (1903-1904), which used a induction regulator to obtain voltage control by buck-boost.