International Dredging Review

International Dredging Review

By Judith Powers
Manson Construction Company’s newly launched dredge Robert M. White began work on July 21 to place 2 million cubic yards of sand on Cat Island in the Gulf of Mexico 15 miles south of Gulfport Mississippi.
The project is part of the U.S. Army Corps of Engineers’ Mississippi Coastal Improvements Program (MsCIP).  
The $14293598 contract was awarded to Manson on April 28 four days after the White was launched at Halimar Shipyard on the Gulf Intracoastal Waterway (GIWW) in Morgan City Louisiana. It is named for Robert M. (Mitch) White a lifelong dredgeman and Manson employee who was a leader in marine industry safety. 
The dredge is digging sand from Ship Shoal a stable bar approximately two miles east of Cat Island and pumping to shore through a mile and a half of pipe. The borrow area is not in the littoral system. Water depth in the area is no more than 6 feet and recreational boaters are warned of the pipeline’s presence on the bottom by buoys and lights.  
The project is an ecosystem and barrier island restoration project that will restore the eastern shore of Cat Island to its 1990 configuration said Susan Rees program manager for the Coastal Resiliancy Program at the Mobile District. A secondary benefit of the project is hurricane and storm protection. Rees explained that as the material is placed shore-based equipment shapes it into dunes and beach. The design template ties into the existing dune line. In November the completed dunes will be populated with native plants Rees said. 
The land encompassed by the project and all but 70 acres of the island is owned by the U.S. National Park Service and the State of Mississippi whose intent is to preserve the island forever as a natural habitat. 
Dredging is scheduled for completion in the middle of September.
Manson’s Decision
Building a new dredge “was an organic decision” said Rachel Odell Manson communications director. “Manson continually maintains and invests in our fleet seeking opportunities to strengthen our capabilities to better serve our clients” she said. The company is headquartered in Seattle Washington and has dredges throughout the U.S.
The White joins the cutter suction dredges H.R. Morris Leonard J Frank Bechtolt and Bob Lofgren in Manson’s fleet which also includes 20 derrick barges/clamshell dredges and four hopper dredges.
The White is a “brown water dredge” designed to work the inland and near shore waterways along the Gulf Coast. 
Manson chose to build the dredge at Halimar Shipyard because it is close to the company’s Houma office yard and staff who were instrumental with its build. The Manson team on the build included Mike Warwick vice president Dredge Estimating; Shawn Hillis vice president Equipment; Monty Logue port engineer Special Projects; Zach Chester CSD assistant operations manager Engineering; Kyle Allen Gulf and East Coast controls manager Equipment; and Jake Maltby Gulf and East Coast design manager Equipment.
IHC-America formerly Dredge Technology Corporation provided design and dredge components.
Though ABS Class certification was not 
required Manson chose to obtain it.  
“The primary benefit of it is that it ensures and requires a certain level of quality control in design and materials. It also keeps us adhered to maintaining the equipment to a certain standard and to have the dredge dry docked periodically” Odell said. 
As the White worked its first project Hurricane Harvey passed to the south making landfall on the Texas coast and devastating the area surrounding Houston. Hurricane Irma one of the worst storms recorded in the Atlantic in history was passing to the east but avoided the coasts of Alabama and Mississippi allowing work on Cat Island to continue in safety.

Specifications: Robert M. White
30-inch ABS cutter suction dredge
Length: 270 feet / 82.3 meters
Suction diameter: 30 inches / 0.76 meters
Discharge diameter: 30 inches / 0.76 meters


In this view looking north on Cat island Manson land
equipment is shaping sand to create a beach and dune
system. The dredge Robert M. White is pumping the
sand from a bar two miles distant. Cat Island is a barrier
island in the Gulf of Mexico 15 miles south of Gulfport
Mississippi. (Photo by Sam St. John)