|A bascule bridge (drawbridge) is the most common type of movable bridge.|
There are 16 bridges along the Milwaukee River from the northernmost point of the RiverWalk — the Humboldt Street Bridge — to the southern end — the Milwaukee Street Bridge in the Historic Third Ward. Along with the standard Fixed bridge, these include different types of movable bridges allowing for boat traffic:
- Bascule bridge (drawbridge), which is the most common type of movable bridge as it opens quickly and requires little energy to operate.
- Vertical Lift bridge, in which a span rises vertically and remains parallel with the deck.
Movable bridges are operated by a combination of bridge operators, who man the bridge houses at each bridge, and off-site operation using remote control cameras and switches. The bridges have different hours of operation and follow varying operating procedures set by the Department of Public Works, including regular opening times and advance call-in guidelines.
The design of bridge operator houses reflects the time period in which the bridges were built, and include Neoclassical, Art Deco and Modern. The bridge houses contain the electrical controls and are characterized by a tower-like profile which provides superior overview of passing vessels.
From the Water Street Bridge in the Historic Third Ward, one can view the Menomonee River Railroad Bridge, one of three nationally significant and rare bobtail Swing bridges in the country. Built in 1904, the bridge is still in use today. In its closed position, the bridge allows both passenger and freight railroad traffic to cross the Menomonee River from the Milwaukee Intermodal Station. When a vessel needs to pass under the bridge, motors rotate the bridge from a center point approximately 90 degrees horizontally. This provides clearance for vessels of any height but restricts the width of the waterway through which the vessel can pass.