Monday, March 17, 2014

WSDOT to the rescue with Bailey bridge

By Alice Fiman

Starting today, our workers will be installing a unique structure designed for use during wartime to keep traffic moving in rural Thurston County.

Thurston County requested use of part of our Bailey-style bridge to temporarily replace a bridge out of service on Littlerock Road, south of Olympia. Once our crews get out there later this morning, they should have the bridge pieces together, up and open to traffic within two days. The plan now calls for it to be in place by Friday, March 21.

And yes, you did read that correctly – they are just borrowing part of it.

That’s because a Bailey bridge isn’t a whole thing, but actually just pieces, or panels, for those who may be more familiar with that sort of thing. You can see the full Wikipedia description here. The panels are made to be light, portable and not require any special tools or equipment. But they are strong enough to carry tanks. The Bailey bridge design is close to 75 years old, but can be installed to handle 21st century travel.

We own enough Bailey bridge parts to build close to three, 150-foot-long Bailey-style bridges. These are built by assembling various parts, similar to a large tinker toy set. Bailey bridges were designed for soldiers to build the structure using only manpower, no cranes or heavy equipment needed.  We keep these bridge parts stored in the Tacoma Narrows Bridge anchor gallery for safety and protection from the elements.

For what’s known as the L-4 bridge on Littlerock Road, our crews will install what they call a “triple single,” which will be one stack of three panels on each side of the roadway (the same configuration as the first picture). The bridge will be designed to carry most loads including cars, school buses and fire trucks. Check with Thurston County for more information on traffic control.
Bailey Bridge used on SR 142 in Klickitat County in 2012

We own a Bailey bridge for the reasons you may think – we have lots of water in Washington (and other stuff you may need to cross). If something happens, we are ready to assemble these pieces to keep traffic moving. In 2007, crews put up a 180-foot bridge in six days over the Chehalis River near SR 6 in Lewis County. And, more recently, we put up a Bailey bridge in Klickitat County in 2012.

1 comment:

Anonymous said...

DOT - Thank you, thank you, thank you!!!

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