Design and operation US 31–Island Lake Outlet Bridge

bridge opening beaver island ferry




bridge closing after ferry has passed

the steel mesh road surface 44 feet (13 m) wide 6-foot (1.8 m) sidewalks cantilevered beyond bridge girders. each leaf of bascule bridge 45 feet (14 m) in length total channel width of 90 feet (27 m). each approach 40 feet 10 inches (12.45 m) long concrete road surface. leaves , approaches supported concrete piers resting on steel piles; abutments supported cyprus pilings.

the leaves opened electric motors , machinery weighs 50 short tons (45 long tons) , each counterweight consists of 73 short tons (65 long tons) of concrete. operator s house @ southeast corner of bridge , transformers located southeast on east bank of round lake. original design included recessed barriers rise block traffic driving onto leaves. these abandoned , removed part of maintenance upgrade in 1990 s. gates descend , flashing lights warn oncoming traffic. when closed, there 17 feet (5.2 m) of clearance below bridge.

the bridge has been rated functionally obsolete due outdated design.

the bridge opens recreational craft on hour , half-hour april through october. april through december, bridge opens on signal between 10 p.m. , 6 a.m. remainder of year, bridge opens on signal when given notice twelve hours in advance. public , commercial vessels , vessels in distress, bridge opened possible.