Starting to get a little interested in Pennsy’s GG1 electric locomotive. Might even put one on my HO layout, once I figure out how to build believable catenaries. I’m curious. Why did the GG1 have TWO pantographs? (is that the right word?) What determined which one they raised at any given time? Also, could a GG1 move at all without overhead power? i.e. batteries for short movements?
Almost all electric locomotives in the US had two pantographs. There wasn’t really a need for two (PRR’s MP54 MU cars only had one), but the security factor of having a second, along with the operating factor of having the pantograph in the same relation to the engineer (for timing on section and phase breaks) made the practice almost universal. PRR practice was to raise the rear pantograph. Some other electric railroads used the front, a few allowed both to be raised at the same time, some even used bus jumpers so multiple electrics could share a pantograph. Amtrak still uses the rear pan by preference, though both pans are located on the same end of many newer locomotives. SEPTA uses the front pan.
GG1’s did have some batteries for lights and such, but not enough to operate the motors. A few interurbans (North Shore, Illinois Terminal) and a couple of larger railroads (New York Central, Lackawanna) had locomotives that could operate off batteries for a short period. IT, NYC and Lackawanna engines had small diesels to charge the batteries away from the third rail or overhead wire.
I am surprised SEPTA uses the front pantograph. The reason the rear was used by PRR, N&W, GN, Virginian, NYNH&H, B&M, CSS&SB is that there is a possiblitiy (obviousliy not likeliy at high speed) that if a problem with the wire and pantograph develops, the front one has already passed the problem location and can be raised to power the loomotive. The CSS&SB regularly used both on the “Litte Joes” when hauling heavy long trains, for additional power handling and reducing of sparking. Similarlyl, on occsion, the North Shore used two trolley poles when long trains were hauled by its ex-Oregon Electric locomotives.
PRR’s (and LIRR’s) B-1 electric 0-6-0 switchers had only one pantograph. All its other electric locomotives had two.
The gallery MU cars on IC and South Shore have only one pantograph each. On the first IC Highliners, the pantograph is at the same end as the motorman’s cab. On the current IC and South Shore gallery coaches, the pantograph and motorman’s cab are at opposite ends.
The old IC Wickerliner motor cars had two pantographs but only one was raised at any one time. All trains would run with the leading pantograph up for six months and on a given date it would be lowered and the trailing pantograph raised and used for the next six months. This was done to equalize wear on both pantographs.
Mark
DL&W MU’s had two pans on the motor cars…usually the westend pan was used with the eastend pan for winter use. But often in summer the eastend would be used for a day or two to assure they worked ok. I believe the east end pans had a higher or stronger pressure to contend with ice and snow. I am not sure, however, about the GG1’s having seen them with either pan up at any given time but never two at a time. I don’t believe with the DL&W cars or the GG1’s that two pans up were allowed because of either overpowering the motors or shorting them out. NH was able to raise and drop pans as needed while in motion. Today’s NJT dualies must be stopped when raising or lowering pans at Dover or MSU and I believe a trainman or conductor must observe from the platform.
The timetable note for use of the front pantograph applies to the ALP44s only. Like the similar Amtrak AEM7s both pantographs are on one end. Reading often ran with the front pantograph, and had bus connectors on all of the 1930-era cars.
There wasn’t any reasaon for GG1’s or any 11000-volt or 25000-volt electric locomotiove to use both pans. Any of othe GG1’s or New Haven electrics could, but there was no reason to do so. At 11,000 vots or higher, currrents are moderate. Remember, watts equals power equals horsepower times a fixed conversion factor. Double the voltage and you halve the current for the same power. Well, actually, there were cases of GG-1’s using both pans at the same time during very rare ice storms, where one pan was equipped with a sleet cutter and the other, behind, relied on for power transmission.
Even the doubling of voltage from 1500 to 3000 for the Milwaukee was enough to eliminate the need for use of pantographs on long freights up mountains. Doubling the volage means one-quarter the current for the same power.
Ah, there is always an exception. Pennsy’s FF2 motors, which were second hand from the GN, had to keep both pantographs raised while in use. http://www.rr-fallenflags.org/prr/prr6.jpg I read somewhere that they had two motor generator sets and each one was tied to its own pantograph.
GN had used a power bus on the roof of its Y and Z class units. I know PRR removed it between units, but removing it between halves of a single unit seems excessive! Photos of units in GN service usually show only one raised pantograph.
MP54’s, 1 pantograph for each car, jumpers connecting all cars; bad order pantagraph results that allow other cars to feed thru the jumpers to the B.O. pantograph.
Why two pantographs on each GG1?
Trailing pantograph, only, up: yes, structural front 'graph failure might take- out the trailing one. It was a GG1 insurance policy?
Two pantographs up makes sense when heavy duty winter storms ice up the wire.
Topping the list of my railroad images, experiences… Milw electrics, all pantograghs on all four units, climbing to Snoqualmie Pass, I watched along side and from above, from the NP’s Mainstreeter heading through heavy blowing snow to Stampede Pass,…watching the pans bounce on the wire’s ice, striking huge arcs, it was a ground level magnificent Fourth of July-type fireworks display: 1964 near 600 am in late November. I don’t cry about it, but I’m sorrow(very)ful that I had no way to preserve on film that spectacular event. for us…I apologize, I can’t say I could have…had not enough money…Army Private…$70 a month…/
Au contrare. PRR had a double pan operation rule when icing was probable. In theory the front one cut the ice and the second powered the train. In reality a great deal of arcing occured from both. Arcing also occured in heavy rain from hydroplanng.
A spare is useful in case one of them snags. Usual practice on the Pennsylvania was to raise the rear one. That way, if it snags it doesn’t carry the other one away. But running the risk of the front one snagging and carrying the rear one away was worth it if there was ice on the wires.
MP54’s NEVER had 11 KV jumpers. Against PRR practice. only the READING MU’s had a spring loaded shoe on the roof like the Great Northern. if a ICE patrol train was called for, (usually at least 5-6 cars) then the lead MP54 was run as control unit with the MCB open. That way the 1st pan would scrape most of the ice off without drawing flaming arcs. 2 A-men & a carknocker would be assigned along with 2 spare Pan shoes. also the up Button an all the cars would be “pinned” in with a cotter key to keep the up cylinders charged to reduce bouncing. as per CT-290 instructions. they also had a cutter shoe that was all steel and not the usual copper strip ones like as built or the later carbon strip ones to knock off heavy ice. they would run back and forth on all tracks in the affected area until told otherwise. got this duty several time when I came on in 1977-1980 as a lineman out of Wilmington. and we didn’t do the freight track unless we needed a escape route from wire down or for the OJ train that ran with 2 G’s or 3 E44’s. Mike, Amtrak lineman and power director for 37 yrs.
thanks
When South Shore first started operating unit coal trains to NIPSCO facilities at Burns Harbor and Michigan City, the Joes raised both pantographs to draw enough current to move the trains. Even with that, South Shore had to operate the unit trains in two cuts from Burnham since the substations and other electrical infrastructure couldn’t provide enough current to move 100 cars of coal in one train.
ALL:
The thread on GG1’s has been interesting.
How many were painted Tuscan vs. Brunswick Green? Were both colors used on freight and passenger?
What were the numbering series between freight and passenger?
I saw a GG1 at the Green Bay museum.
Ed Burns of Anoka, mn
5 were tuscan 4907 for sure. The others were random #s in the system. They were briefly painted silver for use with the four sets of stainless Budd cars for the Senators and Congressional limiteds. The grease and carbon from the pantographs quickly made them dirty so they were painted tuscan. One for each train and a spare.
They were also all used in either service except for 4800 permanently assigned to freight service due to its riveted body. Toward the end several had their gearing derated to 70mph max. As passenger service was in decline and more wound up on freights.
The gearing was changed from 100mph to 90, not 70mph, because physical constraints prevented more radical change. However, their top speed may have been limited to rule book 70mph to further reduce maintenance requirements. Also, the regearing process began with a few in WWII. But these kept their steam boilders and were used occasionally in passenger service, mostly through trains from the south at Washington, DC. I do not know if the boilers were removed from the later conversions.