Re: Bridge girder on three PRR FM flat cars

Claus Schlund \(HGM\)

Hi Bil and List Members,
Interesting insights there Bill!
From the flat car's point of view, this would appear like it is a point load, since the flat carries the full load at the spot where the load bolsters (is there a more correct term for this?) are installed on the flat. Puting the point load right in the middle of the car would make the load stress the worst it could possibly be, and moving it closer to the trucks would help with this.
Claus Schlund

----- Original Message -----
Sent: Saturday, December 21, 2019 1:42 PM
Subject: Re: [RealSTMFC] Bridge girder on three PRR FM flat cars

OK. Here is my take on why the girder was not mounted to pivot on the longitudinal center of the end flat cars… 

Placing the pivot point closer to the truck would result in less overhang inward on curves. Also doing so may reduce the outward overhang at the ends of the girder. In short, there may have been operational restrictive reasons for what appears to perhaps be an odd loading.

Also, a long shot idea here, loading closer to the trucks would perhaps allow for a heavier load to be carried than what would be the limit if loaded at the longitudinal center of the car. 

Both of the above are just food for thought.

Bill Keene
Irvine, CA

On Dec 21, 2019, at 7:20 AM, Claus Schlund &#92;(HGM&#92;) <claus@...> wrote:

Hi Brian and List Members,
Thanks Brian for calling our attention to this.
I find it interesting that the bridge girder is NOT mounted on the exact center of the trio of PRR class FM flat cars, and the bridge girder is instead somewhat closer to the camera. This does two things that I find somewhat puzzling...
(1) It imbalances the load on the trucks on the two flats at the ends - for each of these two cars, one truck will be carrying more load than the other truck
(2) It required the brake wheel on the flat closest to the camera to be removed. Had the load been placed so it was in the center, that car maybe could have kept its brake wheel in place, as is the case on the flat furthest from the camera. Note there is a removed brakewheel mounted to the deck of the flat closest to the camera, and another removed brakewheel mounted on the deck of the flat furthest from the camera - presumably this last one came off the midle flat car
Any thoughts on this?
Claus Schlund
----- Original Message -----
Sent: Saturday, December 21, 2019 10:08 AM
Subject: [RealSTMFC] Bridge girder on three PRR FM flat cars

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