Inaugural Project for Barracuda Class Dredger

J.F. Brennan Company, Inc., based in LaCrosse, Wisconsin, recently completed the inaugural project for its newest, fully customized Barracuda Class dredger from DSC Dredge.

The Quad Cities Generating Station, a two-unit nuclear power plant located on the Mississippi River near Cordova, Illinois, requires biennial dredging of siltation near the secured water intake area of the plant.

The newly commissioned 12-inch by 12-inch swinging ladder cutterhead Barracuda Class “Victor Buhr” was ideal for this project, which began in late April and was completed in late May 2015.

The Barracuda Class dredger is a swinging ladder dredger that can also be operated conventionally by locking the ladder in place and pivoting on the stern spud, using swing wires and anchors, which increases the cut width and dredging efficiency. The Victor Buhr has been customized to allow for dredging depths of up to 36 feet.

For the Quad Cities project, the dredger was required to work at depths that reached 15 feet.

According to Del Groth, J.F. Brennan Superintendent for the project, “Quad Cities Nuclear requires a defined amount of water to be available for emergency purposes. If it goes out of spec, through too much sand or silt coming close to the secured intake for the plant, then it needs to be cleaned out. Quad Cities has worked with us to do this about every other year for the past 20 years. This year, we worked seven days a week to finish the project within a month.”

Groth said that the project typically entails dredging approximately 37,000 to 40,000 cubic yards of sand and silt.

At the Quad Cities site, the material was transported 5,000 feet via pipeline from the dredger to one of two onsite containment areas. A DSC booster pump was placed 2,000 feet from the dredger (3,000 feet from the containment area) to ensure consistent production rates and save wear and tear on the dredge pump.

“Quad Cities contracts with another company to spread the material 2 to 3 feet thick in the containment area,” Groth said. Although this is considered to be a remediation project, the dredged material is not toxic.

“Because this is a highly secure area, the material stays onsite to support ease in running the plant,” added Groth.

In January 2015, the Victor Buhr joined eight other DSC dredgers in J.F. Brennan’s fleet – including two additional Barracuda Class dredges and six Moray Class dredgers. All of J.F. Brennan’s nine DSC dredgers are convertible from swinging ladder to conventional design, and all are extensively customized.

As the namesake of J.F. Brennan’s Environmental Division Manager Vic Buhr, this newest Barracuda dredger is similarly designed. And Vic Buhr played a large part in the customization of the dredger.

“Vic has been instrumental in designing our equipment since the beginning,” said Tony Binsfeld in March 2014 as J.F. Brennan signed the dredger order during CONEXPO-CON/AGG in Las Vegas. “We have been naming dredgers after the projects they are designed for. This one is strictly different,” he said.

Special features, which Buhr was active in designing as he worked with the engineers at DSC and J.F. Brennan, include:

• High-viscosity cutterhead;
• 12-inch by 12-inch discharge pipe;
• Articulated ladder that allows the cutterhead to operate parallel to the bottom surface;
• Maximum dredging depth of 36 feet, with 24-foot dredging depth in the articulated, swinging “surgical” dredging mode;
• Wing tanks on the pontoons for added stability;
• Hydraulic systems relocated to the dredger deck;
• Front spuds with gates to eliminate the need for removing the spuds from the sockets, and instead pulling the dredge from side to side;
• Custom cab area, built to order to accommodate additional circuitry and computer hard drives;
• Customized PLC controls;
• Custom thrusters for deep river work.

The Victor Buhr’s next project – a U.S. Army Corps of Engineers project near Guttenberg, Iowa, along the Mississippi River – will require some additional re-outfitting of the dredger, including adding the custom-built thrusters for work along this section of the river.

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