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?It was probably beyond their imagination to think of semi-trucks carrying more than 80,000 pounds.??John Summerville <p>on early brdige designers in Marion County |
Many of the bridges have load limits of three tons?planned for an era when many farm loads were on wagons pulled by horses. The main transportation in much of the countryside was still horse and buggy, and the early automobiles were just taking hold.
?Now, even a modern pickup truck can carry enough to be over three tons,? Summerville said. ?It was probably beyond their imagination to think of semi-trucks carrying more than 80,000 pounds.?
New needs, old bridges
It seems that even when bridges were rebuilt closer to the modern era, such as one redone in 1940 going into Chase County, the people back then often didn?t anticipate new needs, Summerville said.
The oldest county bridge still in use that Summerville knows of is a stone-arch bridge built in 1887 at 310th and Wagonwheel.
Marion County had double the population it does now in the first half of the 1900s, double the taxpayers to share cost. A much higher percentage of them lived in the countryside.
Summerville said an early challenge that faced settlers in building roads still is a challenge to bridge upkeep today. A look at a map of streams and rivers in the county, not just the roads, puts it into perspective. The waterways are meandering, crooked, wandering. Summerville said south of Marion the creek intersects with the road three times in one mile, necessitating three bridges.
Less use, higher costs
Contrary to what you might think, it?s when the bridges are off the most traveled roads that the costs really go up. Summer?ville said costs of bridges on hard-surfaced rural secondary roads are paid for 70 to 80 percent by the state.
Costs for these go up to some extent because the Kansas Department of Transportation requires them to be inspected once every two years by an outside engineering firm that bids with the county for the work, he said. In Marion County?s case, most of the work has gone to Cooke, Flatt & Strobel of Topeka in recent years.
These rural-secondary route bridges are replaced one at a time under a required five-year plan, Summerville said.
He said the county is responsible for inspecting and replacing the bridges on dirt and gravel roads. Summerville had marked about 44 deteriorated bridges that need to be replaced.
Even the most remote bridges, perhaps ones not even serving a home where someone lives, are virtually assured of deterioration beyond the original rate planned for because of the development of bigger agriculture, he added. The scale of farm equipment and trucks is much bigger than planners would have thought.
Someone has fields, pastures and livestock nearly everywhere there is a road and a bridge, Summerville said. It has been considered necessary for commerce and a right of the tax-paying citizen to have a traveling route to activities.
One positive change
But modern agriculture also has a positive side that will help the county with its bridge maintenance. Summerville said all of the conservation practices done by farmers over the past 50 years are paying off in water control.
Terracing, waterways, changes in tillage practices, new ponds and lakes, and other innovations are keeping more water on the land to soak in, he said. Streams used to carry higher volumes of water, and the violence of uncontrolled flash flooding was worse, he said.
Summerville said he knows of several cases where bridges with spans to cover 30-foot widths of water now cover widths of only 8 feet. This gives the county the opportunity to replace bridges with much less expensive pre-cast concrete culvert boxes.
Replacement options
Summerville and Bridge Foreman Gary Williams already have identified 11 bridges to be replaced with boxes. Road and bridge regular crew can do this work rather than going to an outside contractor, and every two-year inspections will be replaced by an as-needed basis.
?A bridge is anything over a 20-foot span,? Summerville said. ?A box can be done according to need on anything less than a half to a third the cost of a bridge. Instead of a minimal $80,000 for a bridge, you might be talking $10,000 in materials with all the labor done in-house, coming off our own payroll.?
Most of the concrete boxes come from McPherson in 8-foot-long sections, he added. They can be as wide as 12 feet and with heights from 4 to 12 feet.
Another bridge-replacement strategy?low-water bridges?features concrete slabs built right through the stream bed, but those probably won?t become any more common than they are. Summerville knows of ?five or six? in the county that probably will be maintained or replaced as needed.
A local resource
Solutions like this can lead to other problems. Summerville said it is in the county?s interest for a company like Krause Welding, owned by Andy Krause at Hillsboro, to be in business as a local bidder on the gravel road bridges. Krause frequently is the only bidder and does most of the county?s bridge work not done by county crew, he said.
Besides that, Krause is the type of local industry the county commissioners say they want to promote.
Summerville said Krause needs to build two county bridges annually to stay in business. One bridge isn?t profitable for Krause because of insurance and bonding costs.
This year Summerville said he had to tell Krause the county doesn?t have a bridge for him to build to give him a chance to drop insurance and bonding for inactive months.
?Andy could retire or quit if we don?t have the work,? Summerville said. ?There?s no company here to replace him. If we lose Andy, we would have to go to bigger construction companies outside the county and that would increase our costs.?
Summerville said $80,000 is the low-end price for a bridge, and that it is possible to have a structure of up to $400,000 to replace.
?Just one of those could ruin our budget for years to come,? he said.
Inter-county cooperation
In some cases, the decisions of the past are making it necessary for the Marion County Commission to negotiate the fates of bridges with county commissions in neighboring counties that usually have similar budget problems.
Summerville said the bridge mentioned earlier as being rebuilt in 1940 is north of U.S. Highway 50 on Clover Road going into Chase County. At this time, it mainly serves Chase County residents with little benefit to Marion County residents.
For some reason, Summer?ville said, the county commissioners made a deal with Chase County when the bridge was built that Marion County would maintain the bridge if Chase County maintained the road.
Summerville surmised that the commissioners thought they were getting a good deal because it placed the burden of the cost of continually replacing gravel on Chase County. They didn?t foresee that changes in agriculture would bring about overloaded semi-trucks regularly driving over bridges and causing premature deterioration.
?They were looking at bridges being more permanent than they are,? he said. ?It?s easy to think, you build it and it?s there forever.
?When I was growing up, most grain was hauled in pickup trucks instead of these big trucks,? he added. ?You didn?t have such big pot-loads of cattle.?
