Bruce and all, as an additional note ...
The 'roof rib' style hatch rests are included in Red Caboose kits of wood sheathed PFE reefers that come without the full wooden hatch walkways around the hatches.
---In STMFC@..., <smithbf@...> wrote :
As Bill has already noted, these are hatch rests. They kept the hatches from damaging the roof and the roof from damaging the hatch, especially the latching and grab iron hardware on the hatches. Careful examination will show that these are on most refrigerator cars, especially those with steel roofs. “Our Companies” (FGE, BRE, WEF, National) had a unique design that is quite recognizable if you know it. These PFE hatch rests appear to be simply extra height ribs.
Bruce F. Smith
"Some days you are the bug, some days you are the windshield."