Sparking Pantographs?

I spent a lot of time on and around the Gs during the later stages of their careers with Amtrak, Conrail and NJ Transit. You are correct in you recollections that, under normal operating conditions, arcing and/or sparking was minimal. Arcing became more frequent during inclement weather particularly when ice formed causing the pantograph to make intermittent contact with the overhead. Other than that, I found it to be negligible in my experience.

 

I hope this helps.

 

Bob   

I'll second this. Growing up in New Jersey during the 1940s & 1950s, I witnessed a lot of PRR electric operations around Elisabeth and South Amboy, and rarely ever saw "sparking" at the pantographs on ANY of the PRR electric locomotives. I also remember that during severe winter storms, the PRR generally operated with both pantographs up, with the forward one not "energized" so as to break any ice that may have formed on the contact wire, thus that leading pantograph did NOT spark. 

A year ago I rode an Amtrak Keystone Service train from New York to Harrisburg. The trip was at night. There were flashes from sparking pantographs during the entire trip, but easily noticed in the darkness of rural Pennsylvania. The arcing created the illusion of blue flash bulbs going off every 30 seconds or so; it was bright enough to see passing foliage. Weather was damp, with occasional rain.

 

 

Wonder if that has anything to do with the voltage now being 25,000 volts at 60 Hz vs. the original 12,500 volts at 25 Hz?

I also grew up along the PRR mainline in NJ in the 60's. The GG1 did spark a little every now and then, not very much.

 

However, real sparking occured during the Metroliner era. In the wooded areas near my home you'd see sparking light off the trees at night and the attendant arcing sound well before the train passed.

 

 

Hot Water - Halving the voltage would double the current assuming the power being used stayed the same. Doubling the current has the potential to create bigger sparks.

I fool you not my Z scale overhead does.. And it's not simulated at all.



Seriously you turn off the lights and they spark. A little blue zap! It's cute

Thank goodness for the "keep alive"

Pans down on the RE4/4 shows my fine scale z Swiss overhead. An experiment but it does not function.

Seriously everything here is DCC with sound and the Transalpinen Eisenbahn layout gains current/signal from the overhead.


And..... It is this small...

I can't speak for the GG1 or metroliner eras, but I do recall seeing regular arcing along a number of SEPTA's regional lines when I lived in that area in the 20 years ago.

I used to see the GG1's running up and down the North East Corridor and their pantographs were sparking alot.  Same with the Metro liners and the current fleet of electrics that travel through here.

Agreed.  One night many years ago I happened to be waiting for a train at Princeton Junction in NJ.  While I was waiting on the station platform, a Metroliner came cruising along on one of the inside tracks (i.e., not stopping at the station), and it was a sight to see.  Very impressive in terms of speed and arcing.  Made an impression I'll never forget.

 

At York today, Lionel demonstrated the new VL GG1.  Arcing is apparently simulated with strobe-like LEDs on the pantographs.  I thought the effect was very well done, but there's only so much I'm willing to pay for this "extra" feature beyond what we have on the JLC's thus far.  And I suspect Lionel will push the envelope of reasonableness once again for GG1 pricing.  Unfortunately, no details were provided on price, and we may have to wait for the catalog in late Jan 2016 for that minor piece of information. 

 

Until then, the Conrail bicentennial scheme has a couple of months to call my name.  Perhaps that's Lionel's strategy...  Get folks interested in the product... Then hit them over the head with a 2x4 for the pricing details.  By then it'll be too late to say no.  

 

David

Though not a GG1 here is the link to a YouTube video of my favorite electric locomotive, IORE with pantographs sparking. The video was taken at the depot in Narvik, Norway, inside the Arctic Circle, in winter.

These are just my opinion,

Thanks,

Naveen Rajan

in my travels on the PRR in 1950's,  never noted any sparking, nor on the Lackawana from the Oranges to Hoboken.

 

mikeg

It is a lot more visible in the dark than daylight.

Naveen Rajan,

Excellent!

Thank you for that 'Sparkling' presentation video.

Ralph

Sparking pantos on GG1's?....yepper.

 

When I was a kid (late 40's/early 50's) growing up in D.C., Dad would occasionally take a drive to a street that overlooked the Ivy City yards and paralleled the PRR tracks heading north out of Union Station.  There was lots to see, especially the variety of motive power types and colors serving the busy yards.

 

But the most exciting moments were when a Pennsy passenger train would be hitting its stride as it raced by heading north/south.  And the occasional spark(s) at the pantograph shoes added to the show. 

 

Also, my junior high school 7th grade science teacher, Miss Hill, was famous for arranging a class trip to the museum in Philadelphia....for which we rode the Pennsy from D.C. and back.  And the plethora of GG-1's lurking the passing yard and corridor tracks with their nighttime return trip occasional light show was greeted with Ooooohs and Aaaaahs from my classmates. 

 

Love the opportunity on this forum to 'spark' a memory or two!!

 

 

KD

More prototype sparking and arcing.

 

That's an interesting detail.

 

I seem to recall that third-rail systems (London Underground and others) sometimes have a lot of sparking, perhaps because it's lower voltage higher current with lots of breaks at switches and platforms where the third rail starts/stops or transfers to the other side. It was certainly noticeable at night.

 

Are overhead wires still mostly copper or are other alloys used? Would that be a factor in sparking? Otherwise, section breaks probably have the most potential for sparking as already mentioned.

 

When a French TGV hit 357mph in 2007, some of the video showing big sparks on the overhead wires. They boosted the voltage from 25Kv to 33Kv for that run.

 

 

 

Other than ice, most pantograph sparking has to do with the pantograph shoe not being able to stay in contact with the wire.  To keep the shoe in contact with the wire the wire has to well built, tight and properly supported.  The track also has to be smooth so the locomotive is not bouncing around.  The pantograph has to be in good condition so it can move up and down fast enough to be able to follow the wire and respond to loco bounce. The S-500 series pantographs used on the GG1 is actually two pans.  The large one we are all familiar with, and a smaller pan just below the shoe which allows the shoe to respond to small variations in the wire without the entire pantograph respond to the minor changes. Arcing can also reduced by increasing the vertices up force the pan places against the wire.  The S-500 series pan typically puts a force of about 30 pounds up on the wire. I think the PRR used a much higher force up, maybe as much as 60 pounds.  It is hard to design a wire system that will work with this much force.  There is more arcing when the current draw is higher.

 

It is my understanding that the PRR contact wire system had to be modified early in its life to reduce arcing.  A second wire was hung just below the original contact wire but with twice as many support points, reducing the sag between support points.  That upper original contact wire is 4/0 hard drawn grooved trolley wire.  It is made by Phellps Dodge here in the US.  The presence of that upper original contact wire is the only reason that trolley museums can still get this original style of wire.  The lower contact wire is a high strength phos. bronze wire, used in all new trolley construction.  

 

I watched the sparking pantograph at the Lionel booth at York.  The one problem I had was there are two lights making the arc simulation, one on each side of the pantograph shoe.  In real life the arc occurs at the contact point between the shoe and the wire, which is usually near the center of shoe, 

David,

Thanks for the explanation. I wasn’t at York but I can speculate why Lionel might have gone for 2 sparks. In India, as in many other countries around the world, the contact wire is not exactly centered over the track. It zig-zags to the left & right at each support (around 300 – 400 mm, each side from center, according to this book), about the track center so that the graphite insert at the top of the pantograph head wears uniformly. I am not familiar the Pennsylvania railroad overhead contact lines but if a hobbyist expects the simulated arc only in the center, then a real world pantograph would end up with a groove worn in the middle. Also unlike the track which can curve, the contact wire can only be tensioned as a straight line between successive supports. So 2 lights on the Lionel GG1 alternatively sparking could be relatively more realistic than just 1 light sparking intermittently in the center.

These are just my opinion,

Thanks,

Naveen Rajan

http://www.irfca.org/gallery/o...g2_imageViewsIndex=2

 

Pentrex put out a VHS tape on constructing a catenary called 995 days.

http://pentrex.com/bcr995.html

 

Maybe Jeb at Mega Steam will brew up an O-zone scented smoke fluid for the new GG-1s to compliment the sparking pantographs.

Any particular reason why the front pantograph was not energized?

So that it would not produce huge arcs and damage the contact shoe plus burn the wire. The front pantograph was thus, only mechanically clearing the ice formed on the wire without drawing any current. Pretty simple idea, when you stop to think about it.

Arcing once or twice maybe every minute or so is understandable.

 

Lots of arcing is a very bad thing. It blows chunks out of the pantograph and pits the overhead wires. Seeing this much in a dry environment would mean that there is a pantograph defect, or the overhead wire is slack.

I had the same thoughts. I was also thinking two energized pantographs would share the load and possibly spark less but I assume PRR tried this and found one energized and one clearing ice was the way to go. 

Does running at 60Hz spark less than running at 25Hz?

 Impressive.