Portage Lake Lift Bridge

The Portage Lake Lift Bridge (officially the Houghton–Hancock Bridge[3]) connects the cities of Hancock and Houghton, in the US state of Michigan. It crosses Portage Lake, a portion of the waterway which cuts across the Keweenaw Peninsula with a canal linking the final several miles to Lake Superior to the northwest. US Highway 41 (US 41) and M-26 are both routed across the bridge. It is the only land-based link between the north (so-called Copper Island) and south sections of the Keweenaw peninsula.[4]

Portage Lake Lift Bridge
Coordinates47.123768°N 88.574706°W / 47.123768; -88.574706
Carries US 41 / M-26 / LSCT
CrossesPortage Waterway arm of Portage Lake
LocaleHancock and Houghton, Michigan
Official nameHoughton–Hancock Bridge
Maintained byMDOT
ID number3380
Characteristics
DesignVertical-lift bridge
Total lengthapprox 500 feet (150 m)
Widthboth decks: 4 lanes with no shoulders
lower deck: single-track railroad was abandoned 1982.
Height180 ft (55 m)[1]
Longest span250 ft (76 m) clearance
Clearance below4 ft (1.2 m) fully lowered
32–36 ft (9.8–11.0 m) raised to intermediate position
About 100 ft (30 m) fully raised)
History
Opened1959
Statistics
Daily traffic>20,000[2]
Location

This moveable bridge is a lift bridge with the middle section capable of being lifted from its low point of four feet clearance over the water to a clearance of 100 feet (30 m) to allow boats to pass underneath. The bridge is the world's heaviest and widest double-decked vertical-lift bridge.[5] More than 35,000 tons of concrete and 7,000 tons of steel went into the bridge, which replaced the narrow 54-year-old swing bridge, declared a menace to navigation on the busy Keweenaw Waterway.[6]

Hancock and Houghton hold an annual celebration called Bridgefest to commemorate the opening of the bridge which united their two communities.[7]

History

The original bridge on the same site was a wooden swing bridge built in 1875. The bridge was built by James P. Edward of Fox and Howard Inc. of Chicago. Three local men raised $47,000 in stocks for the toll bridge. Construction began in the spring of 1875 and was finished in the spring of 1876.[8] This was replaced by a steel swing bridge, the Portage Canal Swing Bridge, built by the King Bridge Company in 1895. The Portage Canal Swing Bridge was damaged when a ship, the Northern Wave, collided with it in 1905. The center swinging section of the bridge was replaced and a similar incident almost occurred again in 1920, but the ship was able to stop by dropping its anchor, which snagged on the bottom of the lake. In 1959, the Portage Canal Swing Bridge was replaced, at a cost of about $11-13 million (sources vary), by the current bridge. The Al Johnson Construction Company was the general contractor.[9] The American Bridge Company built the superstructure and the Bethlehem Steel Company provided the structural steel.

The Portage Lake Lift Bridge at night from north of Hancock, MI

The original 1959 design by Hazelet and Erdal of Chicago of the bridge's liftspan had roadways constructed on both levels with rails embedded in the road surface on the lower deck. This allowed the span to be partially raised to allow small and medium boat traffic to pass underneath without disrupting vehicular traffic. From this middle position, the span would then only need to be raised for large ships or lowered to allow trains to cross. With the end of rail service in 1982, the lowest position is no longer needed to allow trains to pass so the bridge is not lowered below the middle position during the summer boating season except for periods of maintenance or repair. In the winter after the lake freezes, the bridge is placed in the lowest position to allow the lower deck to be used by snowmobile traffic.[3]

Images
  • Frozen Keweenaw Waterway at night
  • The Portage Lake Lift Bridge at night
  • Looking north while crossing bridge
  • Elevated to let boats pass underneath
  • The Copper Country Limited crossing the Portage Lake Lift Bridge in 1967
  • Veiw from Houghton
  • View showing lower deck looking toward Hancock

See also
  •  Transport portal
  •  Engineering portal
  •  Michigan portal

References
  1. Hyde, Charles K. (1993). Historic Highway Bridges of Michigan. Great Lakes Books. Detroit: Wayne State University Press. p. 159. ISBN 0-8143-2448-7. Retrieved September 7, 2019 – via Archive.org.
  2. "MDOT Unsure About Cause of Stuck Lift Bridge". The Daily Mining Gazette. Houghton, MI. August 5, 2010. OCLC 9940134. Retrieved August 5, 2010.
  3. Michigan Department of Transportation (May 10, 2002). "US 41 – Portage Lake". Michigan's Historic Bridges. Michigan Department of Transportation. Retrieved August 4, 2010.
  4. "Virtual Adventures". Keweenaw Convention and Visitors Bureau. Archived from the original on July 21, 2011. Retrieved August 4, 2010.
  5. Federal Highway Administration. "Copper Country Trail: Portage Lake Lift Bridge, MI". America's Byways. Federal Highway Administration. Archived from the original on October 9, 2007. Retrieved August 4, 2010.
  6. Forgrave, Mike; Forgrave, Tricia. "Portage Lift Bridge". Keweenaw Free Guide. Retrieved August 4, 2010.
  7. "Welcome to Bridgefest!". Bridgefest. Retrieved August 4, 2010.
  8. Smith, D (1986). "Houghton–Hancock Crossing". Michigan Tech Archives & Copper Country Historical Collections. pp. 1–13.
  9. Hyde (1993), p. 152.
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