The following information and photos are from Paul Rohrbacher from Scotch Grove, Iowa. Iit is another fine example of County officials, volunteers, bridge experts and preservationists coming together to preserve and protect some American history. Thanks for the information!!
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“The very small town of Hale, located in Jones County, Iowa has a three span, “King Iron Bridge & Manufacturing Co.”, Bow String Bridge, built between 1877 and 1879 over the Wapsipinicon River. The longest span is 100 feet and the two shorter spans are about 80 feet each. The enclosed photos show the three bridge spans, name plate, and some of the problem areas. As you can see, the bridge is closed to traffic.
Jones County is in the process of contracting to build a new bridge and remove the three old King Iron Bridge bow string spans, starting about October ’02.
The Jones County Historical Preservation Commission, of which I am a member, is in the process of trying to save the bridge. We have secured a place to dry dock the three spans until repairs can be made and the piers are built at the Jones County Central Park Lake, the bridge’s final location. At the park, the bridge will become part of a foot path around the lake.
As part of the new bridge construction project, the three bow string spans will be lifted off of the piers by a crane and placed on the river bank. From that point on, it is up to the Jones County Historical Preservation Commission to save the bridge. The plan currently is to use helicopters from the Iowa Air National Guard to fly the three spans from Hale to the Jones County farm for dry dock and repair.
These are some of the areas we need your company’s engineering/technical help: (NOTE: The wood deck and wood stringers will first be removed prior to lifting the spans off the piers by the crane.)
a. How can the bridge spans be stabilized to safely permit the crane to lift them off of the piers?
b. How should the bridge be supported after it is lifted off of the piers and set down along the river bank and at dry dock?
c. Is additional stabilization required for the flight to the dry dock farm, about 18 miles away?
d. Can bow string spans be moved by helicopter?
e. Where are the lifting points on a bow string span to prevent it from folding like a jack knife and/or twisting?
f. The iron work needs repair. There is pocket rust between the “U” channels and the side plates. The rust has caused the side plates to bulge and pop some of the rivets. There are some stress cracks in the side plates. There may be some rust through at the bearing points at the ends of the 100 foot span.
1) We need information on how to replace the failed rivets, what tooling is required and a source for new rivets.
2) We need information on welding cracks and repairing rusted out areas.
The Jones County Historical Preservation Commission would also appreciate copies of historical records that the King Bridge Co. may have on the original contract, design and building of the Hale Bridge. “
