 This lift bridge features a middle section capable of being raised from a low point of 4 feet ( 1 @.@ 2 m ) of clearance over the water to a clearance of 32 feet ( 9 @.@ 8 m ) to allow boats to pass underneath . The Portage Lake Lift Bridge is the widest and heaviest double @-@ decked vertical lift bridge in the world . The lower deck of the span was originally open to rail traffic when it was built in 1959 , but this level is now closed to trains and is used in the winter for snowmobile traffic . 
