Electric Power between Harrisburg and Philadelphia

The idea of deenergising the wire for the duration of the work is an excellent one in my opinion, particularly since it is so seldom used. The process to safely deenergize the wire on an as needed basis can be very time consuming and waste a good portion of the work time.

For those of you who do not realize how time consuming this is, please allow me to give you a brief narration of how long the process can take and how complicated it can be.

For starters, the wire is broken up into sections called “plates.” These plates are the sections of wire between “brakes” where the insulation joints are, thus being able to deenergize only a small portion at a time. These plate are indicated to us (dispatchers and operators) by a diagram of the tracks and the affected plate being drawn in red while the rest of the tracks are drawn in black.

To deenergize the wire safely, first, the power director will talk to the train dispatcher and request the plates he wants to remove power from. Assuming that the dispatcher has time to dedicate to the plate, he then looks the plate up in the book to see which tracks he needs to keep electric trains from operating over. He then calls the operators involved and has them look up the plates. The operators will then apply blocking devices to the switches and signals leading into the affected track and will record those blocks on the train sheet and inform the dispatcher of these blocks, who will repeat them back to ensure accuracy. After the blocks have been established, the dispatcher will dictate a form to the operators instructing them to “Hold electric trains and engines clear or tracks affected by plate No. [what ever the plate number is].” After copying the plate order, the operators must repeat the plate order back to the dispatcher to ensure accuracy. Once the dispatcher is confident that everyone has repeated the plate order correctly, he will issue an effective time, similar to a form D effective time. Now, the dispatcher must give the power director permission to remove the power.

Now that the power director has authority over the wire, the power director calls the person in charge of the catenary switches, which can be operators, and instruct him to open the switches. This is another time consuming process of repeating and verifying. The power director will instruct the operator to open the switch (identified by number), verify it is open with the appropriate light, block it and tag it. The operator must repeat this back for accuracy before he operates it. Once he operates it, he must tell the power director exactly what he did, and power director repeats it back.

I am unfamiliar with exactly happens after this, but I know it involves applying grounding hooks which I believe will protect the workers if the power were to be accidentally reapplied.

This entire process can take up to 15 minutes providing that the train dispatcher and operators involved are able to devote their attention to this process. I have seen it take up to two hours between the time the power director requests the plate until the plate order is in effect. With the AC motor stops in place and the wire out of service for electric moves, this entire process can be eliminated for the 2 or 3 times a day a plate is issued for a territory that sees maybe 2 pantographs a month.

Maybe on the former PRR it took from fifteen minutes to two hours to
de-energize a track but on the former NHRR, we would de-energize the
track, do the work and have it back up in that same two hours time.
The load dispatcher would contact the train dispatcher and tell the
dispatcher what track was wanted and the limits wanted. The load
dispatcher would also tell the dispatcher whether the crossover tracks at
each end of the working limits were still OK or not. The dispatcher would
generally give the track up as requested and from that point on, the load
dispatcher would either handle the necessary switches directly from their
HQ in Cos Cob or through various tower operators on the road. Some
anchor bridge breakers were handled directly and some through manned
towers.
The PRR did thing differently, I guess that is why they were the "sub
standard railroad of the world".
Noel Weaver

I think deenergizing the wires are a good idea because it could lead to MOW people getting hurt etc.

You not only have to depower them, you have to *ground* them. Otherwise, you get inductive pickup from paralleling lines, and an extremely dangerous situation because people think the power's off...but there's still power there.

I hope Amtrak's not getting themselves into a false sense of security here by simply opening the breakers, just because the breakers are open doesn't mean the wires are truely dead...

Nasadowsk wrote:You not only have to depower them, you have to *ground* them. Otherwise, you get inductive pickup from paralleling lines, and an extremely dangerous situation because people think the power's off...but there's still power there.

I hope Amtrak's not getting themselves into a false sense of security here by simply opening the breakers, just because the breakers are open doesn't mean the wires are truely dead...

This is true, on the NHRR, the wire train had a grounded pantograph on
one of the work cars and that was raised whenever people were working
on the wires over the track involved. If it was not the wire train, the work
crew would have a ground stick and the grounding would be done that
way.
Even if the wires were dead and grounded by BO or GO, they would still
have to be grounded before the work could begin.
Noel Weaver

From the various posts on the issue, it appears that the railroads never adopted live line maintenance protocols. Electric utility crews for years routinely make repairs on live wires, even to 500,000 Volt transmission.

Ken - proximity to return paths is why they don't. They used to work on the 3kv system live (I think), and the LIRR/NYCTA/MN still work third rail live. At lower voltages, it's perfectly doable, but at high voltages, clearences become an issue.

Historically, high Kv catenary (in the US) was worked on de-energized, BUT there have been instances where it has in fact been worked live.

Working utility lines hot is a necessity, to a point. Imagine if they had to turn off one of those lines before doing anything to it....

It's pretty easy, actually. Wind turbines are ugly as heck, noisy, very expensive, and don't make much electricity anyway. They're useless for baseload generation, they're too pricy for peaking, and they take up lots and lots of space.

For the money spent on adding a hundred or so peak MW cpacity with windmills, a good combined cycle plant can be built, which will add 1000 or so constant MW, be small and unobtrusive, quite efficient, and exceptionally clean and reliable.

The trouble is, the environmentalists refuse to believe that there's no big conspiracy to squish out these so called 'alternative energy' sources, it's just that in real life, they're too expensive for the tiny gains they achive. NY state needs a few thousand MW of baseline capacity, especially on LI and downstate. A few cute windmills in Westchester and off Jones Beach won't do squat.

If you ignore global warming , then wind Turbines are not worth it . (although Califionia doesnt seem to think so , theyve had them for 20 years or so ) . However if peak summer load is the problem ( caused by airconditioning demand i presume ) , then a government scheme to support households installing solar hot water systems would probalby be the most cost effective answer .