I have quite a bit of experience building custom automated assembly and inspection equipment, a good bit of which went overseas to customers using 50 cycle power. I know from experience that a 50 cycle transformer will work OK on 60 cycles, and that a 50 cycle synchronous motor will run on 60, although faster. It isn't a good idea to run 60 cycle motors and transformers on 50, however; they would get hot.

So, I'm asking a hypothetical question here, that I'm sure some EE will have an answer for. What would happen if a transformer built for 25 cycles were fed 60 cycle power? Would that be too big a jump?

The reason I ask is this: my understanding of the PRR electrification is that the wires at the top of the cat poles carry 100,000 VAC 25 cycle three phase power. Each section between phase breaks is fed by a single phase transformer. Would it be possible to change that 100,000 K distribution to 60 cycles, and use the existing transformers and distribution system? I know it might have some effect on the signal systems, and any synchronous motors, perhaps running compressors at interlockings, would need replacement. But could this be a lower cost way to convert the NEC to commercial frequency? Just asking-

I'm surprised none of our electrical gurus have weighed in yet, but...

First off, we need to keep in mind that 25 hz was chosen not because it was somehow different than commercial power, but specifically because it was the dominant form of heavy industrial power during the years these systems were being developed. As Roger Mitchell mentioned above, the lower frequency made the use of series wound motors practical; this was just as important for starting heavy industrial loads, such as rolling mills and large crushers as it was for railway work back in the days when the only way to slowly accelerate the load was by varying the voltage. At one time most the Northeast was all wired for 25hz distribution; I believe one of the last plants was Niagara Falls, which I believe is closed now.

As an aside, as a young man in the seventies, I spent a bit of time dismantling Chicago's trolley bus system, the abandonment which was a direct result of Commonwealth Edison's desire to get out of the "25 cycle" power business. This had caused the CTA to upgrade the entire rapid transit power system to solid state substations, but the funds were not there for the surface system.

As far as I know transformers are rather frequency dependent. Military and avionics systems use very high frequency AC, 400 hz, because it allows much lighter motors and coils. Discussions I've read about using VFD's, Variable Frequency Drives, to generate three phase power for home shop use inevitably raise the question about stepping the output up to 480V, and the people who seem to know what they are talking about suggest if the drive is to be used for speed control, to step up the primary side and use a 480V drive. Apparently the mass of the iron core in a transformer is pretty much matched to the frequency it is intended to run at. If 60hz. transformers aren't happy running at 120 hz, I doubt 25 hz transformers will be happy on 240% of their design frequency.

The high voltage distribution system along the NE Corridor is two phase, not three phase.

I believe that Amtrak is working on a plan to replace the overhead contact system on the NEC. From what I have heard, the OCS is limiting its maximum speed. I do not know if this limitation is due to the design or its condition.

As I recall the New Haven OCS was replaced from New York or New Haven when the electrification was was extended to Boston. I always thought it was short sighted to place the poles so close to the track limiting the future operation to just two tracks, at least as far as New Haven.

There was some 25 cycle OCS converted to 60 cycle in the 1980s. I recall IEEE papers on the conversion saying that the relay protection on this converted electricfication was a major problem, to the extent that some felt the converted lines had lost protection. Apparently the diffcutly is with trying to protect a moving load. There has been a lot of development in power line protection in the last 35 years and this may no longer be an issue.

As far as getting a GG-1 to run again, which ever locomotive was chosen, it would have to be overhauled from the ground up. The problem with doing this, as many of in railway preservation know, is there is no supply industry to support the project. Every part needed would have to be hand made one at a time.

That's cool. If any of the auxiliaries in the substations (blowers, air compressors, etc.) are powered from the same source, this must be some of the last two phase equipment anywhere. I seem to recall there was a lot of 60hz two phase industrial equipment in the Philly area, but all gone now.

From what I've read, it might be a bit of both. Seems the wire that's up has been there a while and shows wear (contact wire), and there is also the problem of the catenary developing too much sag in hot weather due to expansion. This wouldn't have been too serious a problem at 80 mph, but like track, imperfections that are unnoticed at normal speeds cause serious problems at over 100 mph, in this case pantograph bounce. For modern catenary, the design incorporates devices (the ones I've seen incorporate weights and pulleys at intervals) to keep the wire tension constant at varying temperatures. This is something the old system lacks.

http://cs.trains.com/trn/f/111/t/179488.aspx

http://web.mta.info/mnr/html/catenary.html

https://en.wikipedia.org/wiki/Overhead_line#Tensioning

https://en.wikipedia.org/wiki/Overhead_ ... G10010.jpg

Cameron

Dammit you are making me work to answer you

First - There are two distinct sets of Engineering Landmarks: Historical Civil Engineering Landmarks are designated by the American Society of Civil Engineers (ASCE) and the Historic Mechanical Engineering Landmarks are designated by the American Society of Mechanical Engineers (ASME). There is no 'National' designation (some are not even within the United States) and there are no statutory protections derived from the designation. Landmark number 76 of the ASME list is the New Haven's original AC electrification from Harlem River to New Haven. A plaque commemorating this designation was placed at Cos Cob power plant in 1982. The Plant was decommissioned in 1986 and demolished in 2001. I believe the plaque was moved to the nearby commuter station. The plant had also been listed on the National Register of Historic Places in 1990 (As Brother Mitchell has pointed out this is very different from engineering landmark status) but they knocked it down anyway.

Before I go further a little bit of background so that this makes sense. Prior to electrification New Haven commuter trains went to a terminal in The Bronx at the Harlem River where passengers transferred to ferries, horse cars and what have you. Some long distance trains went into Grand Central and after the New York Central electrified they provided a locomotive at Woodlawn. Penn Station was not completed until 1909 and the New Haven's through trains did not use Penn Station until the New York Connecting Railroad was opened in 1917. Prior to this the few through trains went the long way around using the Poughkeepsie Bridge, the Leigh and Hudson River and the Belvidere and Delaware to Trenton. The New York Connecting was not electrified until 1927 so prior to this point the New Havens through trains used steam as far as Sunnyside Yard where they would change engines. The majority of the New Haven's long distance trains (Boston, Springfield, and Pittsfield) did not run through and terminated at Grand Central.The New Haven used the Harlem River Terminal until the early 30s after which all of the commuter trains used Grand Central.

Second - Cos Cob was absolute state of the art when it opened. The New Haven had already been experimenting with various voltages and transmission systems (They had a near monopoly on trolley lines in Connecticut and over the years tried almost every known system of electrical distribution including a very British 4th rail. At least some of the trolley freight service lasted into the 1960s.) They electrified for one very simple reason – money. The New Haven was required to comply with the New York City Smoke Ordinances, the commuter zone, even then, extended far into Connecticut and, in case anyone here has failed to notice, steam locomotives not only tend to produce great quantities of that black air we call 'Smoke' but they are also expensive to operate. Very expensive. The need for engine changes to enter Grand Central, the Smoke Ordinance creeping its way toward Harlem River Terminal in The Bronx and the fact that Cos Cob represented a far more efficient (meaning net cheaper) method of converting dead dinosaurs and their contemporaries into the energy needed to move trains all militated toward electrification. They went with the 25 cycle system because that's what was known at the time. They built their own plant because there was insufficient reliable commercial power and there was absolutely nothing resembling the grid we have now. Cos Cob also provided some power to the New York Centrals Port Morris Substation in exchange for the power used by New Haven trains into Grand Central and it powered the New York Westchester and Boston.

The New Haven had always been financially weak. When Patrick McGinnis ousted Frederick Dumaine in a 1954 proxy fight he made the line appear more profitable by cutting maintenance. I do not believe that he generated a single dime in additional revenue. One of his first targets was the commuter service. Freight, even on the electrified lines had been morphing to diesel haulage because of the diesel's ability to run beyond Cedar Hill, or for that matter anywhere else on the system without an engine change. By eliminating electric freight haulage and then purchasing the FL-9s for the long distance passenger trains he was able to write the entire cost of operating the electrical system against the suburban service. He spent as little as possible to run it including cutting maintenance. (To be fair here, unsubsidized commuter services have rarely paid their way since the dawn of the automobile and forcing the railroads to run the services on their own dime was in my view a blatantly discriminatory form of corporate taxation.) Mr. McGinnis lasted less than two years on the New Haven before leaving it in a financial shambles. It was left a physical shambles by a lady named Hurricane Diane who wreaked havoc on her trip up the East Coast. Dieselizing the freight services and acquiring the FL9s were sound financial decisions. Pretending that lack of maintenance was profit and putting the difference in his pocket was not. The New Haven never recovered and finally entered bankruptcy in 1961.

Mr. McGinnis then went to the Boston and Maine where he performed the same financial magic until 1963 when the United States Attorney for the District of Massachusetts said, “ENOUGH!” and helped him find employment in the kitchen at a Federal Country Club.

The Interstate Commerce Commission forced the New Haven into the Pennsylvania New York Central Transportation Company in 1968. In the meantime the railroad, including the electric traction system, was quite literally falling apart.

Penn Central was a financial disaster in its own right, of a size that Mr. McGinnis could only dream of. It did not have the cash to keep itself running, never mind fix anything on the New Haven. Maine's potato crop rotted in Selkirk yard and PC itself entered bankruptcy in 1970. There really was no cash. (We need not discuss the Flying Bordello here.) Then somebody dropped a fussee on the Poughkeepsie Bridge...

Cos Cob finally just wore out. Amtrak, Connecticut DOT and Metro-North all put lots of money into keeping an outmoded, failing, dilapidated plant that had seen little maintenance and few if any significant upgrades (other than the change of fuel) running. Funding the 60 cycle conversion as part of the North East Corridor Improvement Project finally allowed it to be put out of its misery. The alternative was a complete rebuild as a new power station. No machinery is perfect. It does not last forever and it needs to be maintained. Like union labor, if you do not spend money on it, it goes on strike.

After I finished law school I took a job with a firm which was ultimately involved in the PennCentral bankruptcy. That precipitated moving my family (two daughters, a son, a Lab mix, a German Shepherd, three cats, and my wife) back to Princeton. It also resulted in regular trips back to Boston and to New Haven and to Providence The weekday morning routine was choreographed to WOR Radio's morning show - Rambling with Gambling – John Gambling (who happened to be a railfan) and Peter Roberts controlled suburban mornings from Bridgeport to Bucks County. Besides the music, news and patter they did detailed traffic and suburban transit reports. The New Haven's electric lines seemed to always be failing and we knew it in New Jersey. Johnny Carson, who had taken over the Tonight Show (broadcast from New York in those days) in 1962, regularly used the New Haven's unreliability in his monologue. Commuting in Connecticut on the New Haven had become a bad joke. Much of the time it was a failure in the plant. Until Amtrak took over and finally got its act together if we were going to New Haven or beyond by train we made sure that we went out of Penn Station because those trains tended to have the FL9s which were not dependent on Cos Cob.

Sidenote – Complaints about the condition of the Corridor are clearly not limited to Brother Wolk's generation. The more I think about that last paragraph the more I realize that I have been hearing them from the time my family emigrated from New Zealand – just before the Second World War.

Cos Cob was worthy of every accolade it and its builders ever received. It was a good design. It did what it was intended to do quite well as long as it was taken care of. Operated with perfection? Never, and after the abuse it took during financial debacle of the 50s and 60s, operated just barely.

GME

^An excellent history, GME. Thank you.

I spent about a decade living in New Haven as a graduate student and have ridden the electrified portion of the former NYNH&H many, many times. While I miss the visual and historical interest of the triangular catenary, for the sake of reliability at least I'm glad the old copper is gone now.

(Now that the power transmission issue is taken care of, Amtrak, Metro-North and Connecticut DOT can move on to the next New Haven legacy engineering problem, namely the bridges -- some of which actually predate electrification.)

-Philip Marshall

Since we listed the Landmarks programs of Civil and Mechanical engineers. I thought I'd check what Electrical Engineers have. Their organization, the IEEE, honors "Milestones". For main line (not street railways) their Milestone is:


Mainline Electrification of the Baltimore and Ohio Railroad, 1895
Baltimore MD, U.S.A., Dedicated 21 June 2012 - IEEE Baltimore Section
On 27 June 1895, at the nearby Howard Street Tunnel, the B&O demonstrated the first electrified main line railroad, and commercial operation began four days later. The electrification involved designing, engineering, and constructing electric locomotives far more powerful than any then existing and creating innovative electric power generation and distribution facilities. This pioneering achievement became a prototype for later main line railroad electrification.

Prior to the Penn Central's transfer of passenger services to Amtrak I do recall a former engineer tell me that the farther they got from Cos Cob the lower the voltage showed on the G's ammeter. Around New Rochelle it was recorded only 9,000 volts compared to Bridgeport's standard 11,000. They would regularly have trouble with the steam generator as there was not enough power to go around and the NH's EF-4 motors would occasionally have to be "reset" due to the lack of proper traction. Yes there has always been trouble but in my mind it seems there was definitely less trouble than there is today (inexcusable delays, power failures) but that's another story.
I always like to say if it works don't fix it; in the case of railroads if it can do what you need it to do don't retire it's not worth the cost. I've seen enough of the MTA's blunders to know what happens when you retire a perfectly good piece of equipment regardless of how old (GP-38s) and replace it with something completely untested. This does not need to happen with the 25 Hz system and honestly it shouldn't have happened with Metro North.
When I lived in Brazil our system (3,000 DC) was and still is well over its planned longevity being almost 100 years old to date and somehow no matter the issue is kept up to its potential. I asked an worker once at a substation and he told me as long as you have the love and dedication to care for your work anything can compete at today's demands. Maybe here in America we lack this type of craftsmanship perhaps we've actually forgotten it but what do I know. What I'm getting out of this and I mean no disrespect to some of our older members is that we actually don't know to how care for our older operating equipment. If the 25 Hz system itself was built as such a simple and efficient transmission why is it getting harder for our railroads to maintain let alone expand it?

Cameron

That system was state of the art...in 1907. Why keep an obsolete system running, let alone expand on it? There was a battle, almost 150 years ago, over currents and to some extent frequencies, between Westinghouse, Edison, Brush, Houston, Thompson and a few others. Guess what? For general usage AC won, and eventually the standard frequency became 60 cycles here in the US. 25 cycle and DC were kept in use for some very specialized applications.

I worked for a company that built rectifiers on behalf of ConEd in NY. There was, may be still is, a lot of DC power distributed in Manhattan, used for elevators and building fire pumps. ConEd wanted to shut down that part of the business, as it was getting expensive to maintain a duplicate system. They were very heavily subsidizing these rectifiers, to go into individual buildings and convert good old 208 VAC into 250 VDC. One more obsolete system out of the way-

And by the way, ammeters measure current, VOLTMETERS measure voltage; big difference.

Hi,

First, I recall a b1g news story about 10 years ago that the last of the ConEd DC system was taken out of service.

Second, When the Great Northeastern blackout occurred about 1964-5, PRR kept running using its own coal fired plants. Family working for PRR said the stations were black but the trains ran. FWIW. I do not know if they were back-ups or primary source.

Third, the cost to convert the entire 25-cycle system to 60 cycle (in my uneducated opinion) is extremely expensive. The move to put in the original 25 cycle system (PRR was about 1930 for the overhead) was not a cheap proposition. If diesels had come on the economic scene 10 years earlier, I think PRR would not have electrified (much to my sadness). I think the idea is "If it ain't broke, don't fix it" attitude fits here. Today's valid attitude of many to keep something "up to date" has to depend on who's paying for the upgrades.

Forth, I am a degreed electrical engineer but design and test computers. I was at the Hayes Modems bankruptcy auction. The auctioneer did not know what he was dealing with. Many times he said he had a "Mul-tim-eter" (like an airplane altimeter) instead of a multi-meter.

Last, the PRR E44s were set up for easy conversion to 60 cycle and one that went to Amtrak was converted for testing and then scrapped. IIRC

Opinion: I find no personal issue with using a 25-cycle motor (that could be replaced with a 60 cycle at need) to run a generator and diode back for 600VDC for the GG1 motors. I am in the minority for that. I also have believed that the 600VDC can come from anywhere including a diesel power unit with 600VDC generation capability to run a GG1. I catch a lot of "not historical" flack for the position.

Doug vV

I know, let's install solar panels along the entire NEC and run the trains off the sun!

From my readings, I have gathered that there are still some technical advantages to 25 Hz which, while insufficient to merit new installations, are enough to warrant keeping existing plant in operation. I do not pretend to understand it entirely but I think it's more than just the fact that the conversion systems will load the incoming 3Φ evenly because you could do that with 60 Hz as well though that would mean costly conversion systems whose avoidance was one major advantage of 60 Hz.

There's are some interesting articles in the 1997 IEEE/ASME Joint Railroad Conference proceedings (some libraries have this). Besides one about the Amtrak 25 Hz system, there is one from a manufacturer of rotary converters touting their ongoing advantages over static (electronic) converters.

As I remember from EE classes many year ago, early high horsepower AC motors required lower frequency electricity because they had too much inductance to operate on 60 Hz power. It wasn't until later that ways were invented to build motors with lower inductance that would also produce the magnetic flux required to make the motor operate. Thus early railway electrification required lower frequency power. Even after the problems were solved, so much equipment was already in use that replacing it all would have cost too much money.

It may not be the frequency, but rather the number of phases. In a post last week or so, David Johnson made the statement that the distribution system on the corridor is 25Hz TWO PHASE. This is a four wire (plus ground) system that is long obsolete, compared to the three wire (plus ground) three phase system, but the issues I see are:

Using three of the existing four conductors yields undersized conductors, so the system has less capacity.

The sections are currently connected with every other section connected to alternate phases to balance the load. This would need to be changed to every third section.

We still haven't gotten a definitive answer if the 25Hz transformers are suitable for use with 60Hz, I suspect not.

So to upgrade the transmission system requires totally rebuilding it.