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Portage Lake Lift Bridge

Houghton-Hancock, Michigan

Portage Lake Lift Bridge at intermediate level

This unusual bridge replaced a 1905 steel swing bridge which had in turn replaced a wooden swing bridge. Designed by Hazelet and Erdal (of Chicago) and built by the American Bridge Division of the U.S. Steel Co., the Portage Lake Lift Bridge opened for automobile traffic in late December 1959 and was formally dedicated with a large celebration on June 25, 1960.

The double-deck, vertical-life bridge originally bore railroad traffic on the lower deck (which could also accomodate automobiles) and highway traffic (US-41) on the upper deck. Rail traffic ceased in 1982. Today the vertical-lift span sits in the intermediate level nine months out of the year while vehicular traffic crosses the old railroad deck, allowing most small boats to pass under the bridge. In the winter the bridge is lowered and made accessible to snowmobiles and skiers, while vehicles cross on the upper deck. Although most boats using the waterway today can pass under the bridge at its intermediate level, it is still raised to its highest level 450 to 500 times during the year.

Length of largest span: 269.0 ft.
Total length: 1,310.1 ft.
Deck width: 53.8 ft.
Vertical clearance above deck: 14.2 ft.

Portage Lake Life Bridge at highest level

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The Robinson Library >> Technology >> Bridge Engineering >> Individual Bridges, A-Z

This page was last updated on May 29, 2017.