Built in 1981 for the U.S. Army Corps of Engineers, the Dredge Wheeler is the Corps’ largest “trailing suction” hopper dredge. This dredge is primarily operated in the Southwest Pass of the Mississippi River by a staff of 38 and is capable of removing 100,000 cubic yards of material, or about 7,000 dump truck loads, from a project site each day.
Operating like a giant vacuum cleaner, the Dredge Wheeler lowers three drag arms to the channel bottom and powerful pumps suck a slurry of mud and water from the channel bottom, which is then routed to the hopper.
In an emailed statement today from Caterpillar Marine, they note that this vessel has recently been through a complete refit of her power systems at Signal Ship Repair (SSR) including the installation of a pair of Cat C280-16 marine engines rated at 4600 bkW @ 900 rpm for propulsion and a pair of Cat 280-12 engines rated at 3700 bkW @ 1000 rpm to operate the variable speed dredge generators.
Tim Booth, Caterpillar Defense and Federal Products Marine Program Manager comments, “A key deliverable of the C280 engines is the efficiency and maintenance cost savings they provide the Wheeler as an EPA Tier 2 compliant power solution in an ideal power node.”
“In addition to providing a fully integrated package with components at a great value, we were also able to offer installation support and technical design services during the planning and installation stages of the repower,” added Booth.
|Drag arms||2 overside @ 28″ diameter
1 centerwell @ 42″ diamter
|Full load capacity||8,256 cubic yards|
|Overall length||408 feet, 3 inches|
(keel to top of mast)
|Loaded displacement||19,030.9 L. tons|
|Gross tonnage||10,164 tons|
|Loaded draft||29 feet, 6 inches mean|
|Propulsion||Twin diesel with bowthruster|
|Total horsepower||10,400 main, 800 on bowthrusters|
|Shafting||Twin propeller, controllable pitch|
|Top speed at full load||14.4 knots|
|Crew||38 total, divided into 2 working tours|
|Date Launched||18 February 1981|
|Date placed in service||17 September 1982|
In an emailed statement, Signal International notes the repowering contract consisted of replacing the Cooper Bessemer main propulsion and dredge generator engines as well as the installation of new shafts, hubs, reduction gears and hydraulics. The ship’s three service generators were replaced and the bow thruster received a new ABB variable frequency drive. The ACOE had EMS Marcon on-site to upgrade the propulsion control and monitoring system.
SSR worked closely with Ship Architects, Inc. to detail the major equipment removal and installation plans for the repowering project. SSR and Ship Architects also teamed to perform an ABS witnessed incline experiment and revised the Dredge Wheeler’s stability documentation.
Throughout the project, SSR worked closely with the Wheeler’s home ACOE office in New Orleans, Louisiana and the ACOE Marine Design Center in Philadelphia, Pennsylvania.