Michigan Central Lot 324-B auto box cars (99500-99999) had Vulcan ends
on one end only. There were seven ribs per side, and had the added interest
in that they were also end doors on the cars. Apparently they didn't hold
up well, and were replaced with more conventional end doors later on.
The ribs on these cars had a "negative" pressing, and from what I've
seen in a number of places this is sometimes associated with the term
"Vulcan", although I don't know if there was any "official" reason for this
One down side of vertically alligned end sheets would be that the car
couldn't have a heavier guage sheet on the lower section where it was more
prone to damage from shifting loads.