Emerson Zooline Railroad, Saint Louis Zoo

At the Saint Louis Zoo is a 2-foot narrow gauge railroad with a 1.5-mile loop around the zoo with 4 stations. This is the Emerson Zooline Railroad. I spoke with some of the staff (mostly elderly retirees) and a mechanic to learn the technical aspects of the railroad. Technical Facts: -Gasoline motor and transmission box turn a drivetrain that gives traction to the pilot axles and trailing axles, which must be capable of handling a fully-loaded 57-ton train up and down the steep hills. -While standard gauge trains increase air pressure to release the brakes, these narrow gauge trains bleeds air to release the brakes.