The Southern Pacific heavily weathered car has working hopper doors that a spring holds shut.
Other views: (a) Three Modern Hopper Cars; (b) The BAR hopper following a diesel unit.
Working hopper doors on the SP car — Freight Cars seen on the AP&G
[Miniature Worlds —> Locomotives —> Freight Cars —> Passenger cars —> Buildings —> Scenes on the AP&G —> Next]