Authorities had to redirect traffic from all directions after a large semitrailer carrying a section of a wind turbine tipped over near the intersection of highways 9 and 86. The mishap took place Thursday at approximately 11 a.m. and left the wind turbine segment askew in the southwestern curve of the four-way stop.
Southbound traffic from the intersection was blocked, and a sheriff’s deputy directed traffic coming from three directions. A member of the Iowa State Patrol directed northbound traffic to the east along a gravel lane which circles the nearby Northwood Inn. Several similar trailers carrying other segments of the wind turbine were lined up just west of the intersection.
Dickinson County Sheriff Greg Baloun explained the segments of the turbine base act as their own trailer and are bolted to several axels. The front four axels are rigid, while the four in the load’s rear are meant to steer. Baloun said the truck that entered the ditch was the only model in the convoy of turbine segments that did not have a second driver steering the rear wheels. Instead, the truck’s rear axels relied on a concept truckers call scuff – the wheels turn automatically in response to road forces and friction. The setup became problematic as the truck began to round the curve from eastbound Highway 9 to southbound Highway 86.
“When the tractor hit the crown of the road, it transferred the weight off of the front dollies,” Baloun said. “So the weight went on to the back four axels, which steer. The second that happened, they turned and went into the ditch.”
Baloun said the driver had little say in where the rig was headed once the wheels were turned.
“It’s kind of like being in a zero-turn lawnmower in wet grass on a hill,” he said.
The chances of such a mishap are very low, according to the sheriff.
“The driver’s been doing this for 27 years,” Baloun said. “It was just that the stars and moon were lined up.”
A crane from Raveling Inc. of Melvin was called to hoist the trailer out of the ditch. Owner Bruce Raveling said his company is used to maneuvering large items – scheduled or otherwise.
“We deal with it weekly – things like that,” Raveling said. “We lift transformers, houses. It’s just something different every day.”
Raveling said the crew’s first step is typically to determine the best way to move the load, and the method will generally dictate how large a crane is needed to safely do the job. Thursday’s job needed a 265-ton crane. Baloun said the gross weight of the truck and it’s load was close to 206,000 pounds, but Raveling calculated the crane would only be lifting somewhere in the neighborhood of 100,000 pounds of that total. The sheriff said the trucks following the lead section weighed even more – approximately 246,000.
After initially placing footings in the median and roadway near the trailer’s side, crews repositioned the crane at the rear of the load. The process of rearranging equipment took a little over two hours. The tilted trailer had already attracted the attention of several drivers, bicyclists and other onlookers, who began to exchange theories as to how the crews planned to right the situation.
But by 4:42 p.m. the cables were taut and ready to lift the rear of the rig. Crews did some final checks and pulled on the straps holding the massive white base. Soon after, the rear of the giant section began to rise.
The rear wheels were gradually lifted off the ground, and the crane swung the entire rear of the trailer onto the road before gently setting it down again. The entire load was once again on solid ground just before 5 p.m.
“It was a pretty simple job – a pretty normal job,” Raveling said.
Raveling said the trucking company will be billed for the service but declined to comment on the price.
The driver pulled the oversized load forward – albeit slowly and carefully – to clear the lane.
Normal traffic resumed by approximately 6 p.m., after crews had cleared away the crane and other heavy equipment.
The rest of the convoy passed the curve without incident.
The sheriff’s office was assisted by the Iowa State Patrol, Iowa Department of Transportation and Dickinson County Emergency Management.
|Wind Watch relies entirely
on User Funding