Re: Car capacity vs load limit, was Late 40's to mid 50's military rail movements
Gatwood, Elden J SAD
Thanks, Bruce, for the clarifications.
I obviously blew it in relating in this case, the pucker is for the High & Wide guy who has to guarantee it fits within the clearance diagram. There were many cases where that went wrong!
From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io>
On Behalf Of Bruce Smith
And I want to stress another thing... even loading a car to the Load Limit is not "pucker" inducing. That's the SAFE maximum load. As with all engineered structures, there is an additional safety margin. Elden Gatwood has shared correspondence regarding the overloading of PRR's heavy duty flats (eg. F38) and the subsequent discussion of repairs previously.
Finally, most rail cars, including most flat cars, cannot take the entire load limit on the center of the span. Thus the steel box beams on the T43 load (no wood there, in spite of what some have posted) are longer than the treads to help spread the load away from the center of the car. So while there was no issue what so ever with the weight, there appears to have been a concern about the weight at the center of the span.
BTW, the dunnage in the T43 photo is the first time I've even seen a tank loaded in that manner.
main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> on behalf of Thomas Evans via groups.io <tomkevans@...>
So Bruce, let me paraphrase what you are saying & see if I've got it right: