Re: PRR X29 and B&O M-26 roofs


Tim O'Connor
 

Interesting point Dennis -- Do you know whether "XF" box cars had wood lining
above the load as well? I never heard of the sweating problem before but lined
ceilings make a lot more sense now. The N&W B-18 PS-1 box cars were not insulated
but they had plug doors and lined ceilings -- just to name one car for which I
happen to have an interior photo scan from the Virginia Tech web site.

Tim O'

Slightly different discussion, but sweating was a big problem with ANY all steel roof, given the proper conditions. Jim Dick of the NPHS sent me copies of a considerable amount of correspondence generated in the Minneapolis milling district concerning this. It seems, during cold weather cars loaded with warm flour would have the moisture condense on the car roof as the load cooled, and rain back down on the load. This did not occure on older cars with outside metal roofs, since they had a layer of wood under the roof panels, or cars with inside metal roofs, because the outer board covering allowed the roof panels to warm with the load.

There was really no good solution to this, as the railroads had a lot of compelling reasons to go with the new all steel roofs. In later years, when bunkerless refrigerator cars (RB's or more commonly RBL's) became more common, these became the preferred car for flour loading, as they had a wood lining under the roof.

As a side note, one has to keep in mind that as long as the railroads were the only game in town for bulk shipments, they were not particularly responsive to customer complaints, often choosing to pay a certain amount in damage claims rather than spend additional capital funds on improving the car fleet.

Dennis Storzek

Join main@RealSTMFC.groups.io to automatically receive all group messages.