This is an interactive 2-track bridge based on the PRR span over the Baltimore River
at 18th Street in Chicago, Illinois. This version is interactive to close the bridge at the approach of a train. No water
bourn traffic interactivity in included. Horizontal clearence = 270 ft. Vertical clearence = 165 ft if the water level is
set half way up the concrete piers. Many thanks to Mike Kiehl (Etrains48) for the pics and info.