The Rock Island District spends a majority of its annual appropriations operating and maintaining the expansive lock and dam system on the Upper Mississippi River. Much of the maintenance performed on this infrastructure is planned and scheduled while some comes as a surprise. An incident in July brought about some maintenance needs in the form of the latter when a roller gate at Locks and Dam 14 was damaged.
A concrete-filled barge collided with the roller gate causing damage that required swift action from offices throughout the District, as well as outside agencies like a contractor and a towing company. “It was a coordinated effort,” said Dan Guise, Plant Facilities Manager at the District’s Mississippi River Project Office (MRPO).
The first step in that effort, according to James Frederickson, Engineering Technician with the MRPO, was getting the barge cleared from the dam. Frederickson said commercial towboats worked in tandem to pull the barge away from the dam, fighting heavy current.
“It was an amazing thing to see,” Frederickson said. “There was probably as much as 20 thousand horse power pulling through a lot of suction because of the river flow.”
Once the barge was free of the roller gate, an analysis was performed. The roller gate is 100-feet wide and plays a significant role in regulating the river’s water level. Guise said the analysis performed by District engineers determined that the damage to the gate would not prevent it from being raised or lowered in-place.
“Once we found that the gate could be raised and lowered, bulkheads were set to block the flow of the river,” Guise said. “At that point personnel from multiple organizations could begin to develop a repair plan.”
The first challenge was to assess the damage and determine what material could be removed without causing the entire roller gate to crumple. Working closely with District engineers, Guise said MRPO’s Structures Maintenance Unit found they could remove the gate’s skin plate and develop a process to move forward with the repairs.
Once repair plans were in place, another challenge was presented – safely accessing the roller gate to perform the work.
“Getting a work platform into that space (around roller gates) was pretty difficult,” said Justin Carter, Crane Operations Supervisor. “There was only four feet of water in the area so none of our tow boats would fit. We had to get creative with work barges.”
With a suitable work platform in place, repairs were ongoing, seven days a week from Oct. 1 through Nov. 7. Some of the initial lead time, according to Guise, was material availability and delivery. “We had complete confidence in the contractor,” Guise said.
The contractor he referred to was J.T. Cullen of Fulton, Illinois. J.T. Cullen was solicited by the District to perform the plate and structural shape rolling that was needed to repair the damaged section of the roller gate.
“We used them (J.T. Cullen) for their capability and expertise,” said Frederickson.
Bob Castro, who is at MRPO on a temporary detail, said he was impressed with the precise capability of the contractor.
“All we gave them was a flat plate with holes (for bolts) and told them what specification to roll it,” Castro said. “To get it rolled to those precise specifications, and have everything match up perfectly, was pretty amazing.”
The work on the damaged gate was finished on Nov. 7 and according to Guise that deadline was firm because the crews working on those repairs had to depart for Lock and Dam 20 which is scheduled for dewatering. Guise said a full operational inspection of the repaired roller dam gate at Locks and Dam 14 will take place before the project is complete.
Both Guise and Frederickson agree that the repair work was an efficient process from the start. Not only did the crews work to repair the damaged gate but they also used the opportunity presented by the work platform already in place to make other routine repairs to the dam system. Guise described the repairs as a combined effort pulling resources from the District’s engineers, contract of ficers and the craftsmen performing maintenance.
“A lot of people have been involved and everyone worked well together,” Guise said. “There were very few lulls or delays and that is a credit to everyone staying on the same page.”