In case you ever asked "what happened to the world's first two composite reefer cars?" the answer is they are now essentially a fixture in Stanwood, Washington. These are actually pretty significant boxes that completely changed the game for chill and frozen by rail. The composite part refers to how the aluminum, steel, and fiberglass are specially adhesive bonded together to maintain even thermal expansion across materials, making them very efficient and a couple tons lighter. The height of the current 78 foot reefers developed from these is because of french fries. Fries cube out before they hit max weight, so the new reefers are tall enough to handle double stacks of fry pallets. Also notable for anyone who had to deal with the old reefers from the 60s that these replaced, is that the same car can be optimized for chill or frozen with a few quick adjustments to the floor, no more need for either a chill or frozen car.