This year marks the 50th anniversary of the Portage Lake Lift Bridge, and the northern Michigan communities of Houghton and Hancock celebrated that milestone this past weekend at their annual Bridgefest.
The Portage Lake Lift Bridge is actually the third bridge to span the lake that pretty much divides the Keweenaw Peninsula into two pieces.
The discovery of copper in at tip of the Keweenaw Peninsula in the 1840s drew people to the area, but Portage Lake was an obstacle for traffic headed there from the south.
Ferries moved people, livestock, and goods across the lake much of the year, until the winter when traffic moved along marked paths on the ice.
Increasingly heavy traffic led county officials to green light a plan to raise money and build a bridge at the site in 1871. Problems with pilings on the north side of the lake and the bank panic of 1873 scuttled those plans.
Investors tried again in 1875, constructing a wooden swing bridge with a pivoting center span. That bridge opened for one day, before closing for a year after a land slide from a nearby stamp mill again caused problems on the north side of the lake.
Bridge construction and repairs cost a little over $50,000, and the bridge reopened in 1876.
A second level added to the span facilitated train traffic in the 1880s, a steam-powered steel span replaced the wooden draw portion of the bridge in the 1890s, and a track added to the upper level allowed street cars to cross the bridge.
In 1901, the King Bridge Company replaced the original bridge with a new steel swing bridge with a wooden center span.
In 1905, a steamer crashed into the bridge, knocking a large portion of the center span into the lake. The bridge reopened in 1906.
The fact that the swing section of the bridge was wooden, while the rest of the bridge was steel, caused some unique maintenance problems. The wooden section expanded during very warm weather, requiring local firefighters to wet it down so it would shrink and continue to move correctly. Frigid winter weather caused some of the gears and turning mechanisms to ice up and workers hacked the ice away to allow the swing span to turn.
The Michigan Department of Transportation set plans in motion to build a new bridge in the 1950s. The American Bridge Company, a division of U.S. Steel in Detroit, became the prime contractor to build a double-deck, vertical lift bridge to accommodate increased vehicle, rail, and maritime traffic.
The bridge, started in 1959 and completed in 1960, cost 11 to 13 million dollars to build. It contains more than 35,000 tons of concrete and 7,000 tons of steel. The lift span, suspended between two towers, weighs 2,220 tons. The bridge is the world's heaviest aerial lift bridge, and it is the only bridge of its type in Michigan.
Two decks allowed vehicle traffic to cross on the upper level, and heavier trains to cross on the lower level.
The center span sits as low as just four feet above the water, and operators can lift the span to an intermediate level at 32 to 36 feet above the water, or lift it all the way up to 100 feet above the water to accommodate the largest ships passing underneath it.
An accident just before the new bridge's opening narrowly was a sort of replay of the accident that closed the first bridge in 1875. This time, a ship barely managed to stop in time, snagging some underwater phone lines and disrupting phone service in the area for several days.
Train traffic dwindled to nothing over the years, and the last trains crossed the bridge in 1982, almost 100 years after the first trains crossed over the lake on the original wooden bridge.
Today, the bridge stays in the intermediate lift position nine months out of the year. That allows the smaller boats that make up most of the maritime traffic these days to pass under the bridge without lifting and lowering it. Operators lower the bridge to its lowest position for the winter so snowmobilers and skiers can use the lower level as cars and trucks traveling US-41 and M-26 still cross over on the upper level.
Want to learn more about Houghton County history? Check out Houghton County: 1870-1920 by Richard E. Taylor.
Fascinated with bridges and their history? Check out Historic Highway Bridges of Michigan by Charles K. Hyde.
© Dominique King 2010 All rights reserved
Back in the early '70's, while a student at WMU, I had a roommate who's father was the operator of the liftspan bridge between Houghton and Hancock. I used to have some really great pictures which I had taken from the Houghton side tower top. Unfortunatley, those have been a casualty of time. Beatuiful area.
Posted by: Randy Jones | August 18, 2010 at 06:57 AM
Randy-Thanks for stopping by!
Wow, I bet those photos taken from the tower top were great. I love bridges and taking photos of them from all different angles.
You're right about it being a beautiful area. I wish we were able to get up that far north more often.
Posted by: Dominique King | August 18, 2010 at 06:40 PM