I’m guessing the containers were “experimental” because they were transitioning from wood crates.
Photos: Opened Doors Of PFE 5706 (1951)
A photo from the Gateway To Oklahoma History website:
Photos can be enlarged quite a bit.
There is a lot of information in this photo.
PFE 5706 is a Class R-40-23 car, first placed in service in 1947.
Note the stenciling on the doors and the printing on the boxes.
Blue Goose (American Fruit Growers Co-Op) Ventura Maid lemons in cardboard boxes. This 1951 date is a few years before Sunkist converted to cardboard shipping containers. Note the printing "One-Half Standard Box". This was the typical size when the packing houses converted to cardboard shipping containers.
Also note the printing "Experimental Container" on several boxes.
Stencil: "Floor Racks In This Car Not Safe For Lift Truck Operation"
Stencil: "Air Circulating Fans"
Ventura Maid lemons were packed by the Ventura Pacific Company in Montalvo (now Ventura), CA in a packing house served by the Southern Pacific.
Crate label, pre-cardboard box
Railroad Citrus Industry Modeling Group