Nostalgia & History > Time for a little SN

Sacramento Northern is doing some switching at Port Chicago CA on Sept 6, 1952. Ralph Buhr photo.

Thanks for looking,

Tom

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Doing very little switching with both the pan and the pole down.

It looks to me like there is only one pole. If so, I would imagine that running this locomotive as oriented TO THE RIGHT with the pole up would be a recipe for pole breakage (or wire breakage).

So perhaps this photo was taken at a point when the direction of locomotive travel was being reversed. So the pole came down before the pantograph was put up?



Edited 1 time(s). Last edit at 08/19/14 16:57 by chakk.

Great picture, I've got one of those.

Out

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chakk Wrote:
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> It looks to me like there is only one pole. If
> so, I would imagine that running this locomotive
> as oriented TO THE RIGHT with the pole up would be
> a recipe for pole breakage (or wire breakage).
>
> So perhaps this photo was taken at a point when
> the direction of locomotive travel was being
> reversed. So the pole came down before the
> pantograph was put up?


Pole was used primarily to pump up air when starting loco. Air was needed to raise and lower the pantograph, SN653 is currently at the Orange Empire Railway Museum. The pole good see limited use where wire hangers would not allow pantograph operation. The pole could be swung 180 degrees for bi-directional operation.



Edited 1 time(s). Last edit at 08/19/14 20:29 by ATSF429.

><Pole was used primarily to pump up air when starting loco. Air was needed to raise and lower the pantograph,

To clarify a little: air is needed to release the air operated latch which holds the pantograph down. There is no such thing as an "air-raised pantograph"; they are all spring raised. With some air pressure is needed either to release the latch (SN, etc.), others to overcome a hold-down spring (MLLW).

>The pole could be swung 180 degrees for bi-directional operation.

Not really on an SN 650 class because "backwards" it would tend to run afoul the pantograph, not to mention the person trying to raise it.

Here's SN 653 at Orange Empire back in 1970 or 71. It's running with PE 1624, which looks like a Baldwin-Westinghouse but really has General Electric motors and controls very similar to 653.

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Beautiful model scene, impressive elevator.

Awesome juxtaposition of the old car with the motors down near Perris.

Best regards,

Rob L.

EtoinShrdlu Wrote:
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> >The pole could be swung 180 degrees for
> bi-directional operation.
>
> Not really on an SN 650 class because "backwards"
> it would tend to run afoul the pantograph, not to
> mention the person trying to raise it.

I disagree with part of your statement. I had the pantograph drop partially with low air pressure on the locomotive. Also air pressure was used to lower the pantograph. The Key system's bridge units Pantograph were spring operated to raise the Pantograph and used air to lower it. I also ran SN653 using the pole in both directions many times. I cannot remember if the pantograph had been removed for repair or not at this time. regardless the pole's primary purpose was still to get air on the locomotive in order for it to operate as it was needed to raise the pantograph. Not for running.

The pan is currently off 653 for repairs, and when it does run, the pole is used. Right now it's awaiting repairs to the air compressors. The old car is the 1941 Chevy I received as a "hand-me-down" from my folks. I wound up selling it in 1972; for all I know it may be in East LA with chrome rims and a bodacious paint job. I posed it with 1624, because both the juice jack and the Chevy went by my home in Monrovia, the car in the driveway and the motor a short distance away on the PE tracks. My mother got a photo of 1624 about 70 years ago (have to find the scan and post it.)

>The Key system's bridge units Pantograph were spring operated to raise the Pantograph and used air to lower it.

All pantographs are spring raised and air lowered. What causes confusion, particularly here on these forums, is that high voltage applications, like the MILW, had auxiliary spring apparatuses on their pans which held the pan in the lowered position when there was no air pressure in the locomotive. There was an air cylinder attached to this spring which, when pressurized, counteracted the spring's force, allowing the operating springs to raise the frame and contact slider. Air pressure is needed to allow the pan to rise, but air pressure doesn't force the pan up, nor does it hold the contact slider against the trolley wire. The operating springs do this.

>I also ran SN653 using the pole in both directions many times. I cannot remember if the pantograph had been removed for repair or not at this time.

I've heard of this being done at OET from time to time.

>regardless the pole's primary purpose was still to get air on the locomotive in order for it to operate as it was needed to raise the pantograph. Not for running.

If you move the raise/loer valve to "raise", all you have to do is trip the hold-down latch manually (which is what RVJ does). If you don't move the valve to "raise", the pan will go up, but then suddenly come down part way when the MR pressure raches about 50 psi.