International Dredging Review

International Dredging Review

The stern of the cutter suction dredge Marion worked on the James River on ‎September ‎15 ‎2016.

Cottrell Contracting Corporation of Chesapeake Virginia reports that its dredge Lexington has been working on a contract known as Maintenance Dredging Wilmington Harbor Anchorage Basin and 42-Foot Project Brunswick and New Hanover Counties North Carolina Contract # W912PM-I6-C-0012 with the U.S. Army Corps of Engineers. The Lexington is an 18-inch cutter suction dredge with 4250 installed horsepower and is 200 feet long and 38 feet wide. The contract was awarded in August 2016 and the project started at the end of September 2016. All work will be completed by the end of February. 

The Cape Fear River which is the access channel to the Wilmington Harbor is being dredged to a depth of 42 feet with a 2-foot allowable over-depth. The material being dredged is comprised of clean silty sand. In general the project was running smoothly but natural events in the form of Hurricane Matthew did have an impact and caused some delay in dredging on the river. 

Matthew made landfall mid-morning on October 8 at Cape Romain National Wildlife Refuge near McClellanville South Carolina. The storm traveled northwards along the coast reaching North Carolina soon thereafter. According to Devon Carlock Cottrell’s director of corporate safety “Concern over the track and uncertainty of Matthew’s strength caused Cottrell’s management to take action early and crew and equipment were wisely moved to a protected safe harbor in Southport North Carolina. Although this resulted in approximately a one-week delay in the dredging schedule the safety precautions that were taken resulted in zero injuries and no damage to dredge barges and associated equipment. The storm did cause debris to float into the Cape Fear River and stronger than normal tides. At one point the crew reported seeing a roof from a home float by the dredge.” 

In total the job in Wilmington Harbor involves dredging approximately 1.4 million cubic yards. Despite the week’s delay back in October the expectation was that the job would be delivered right on time. And indeed that is the case as Carlock reported at the end of February the Wilmington Harbor dredging was completed and “the dredge Lexington was demobilized and as of February 28 she was under tow to the Eastern Shore.”  


In another important maintenance dredging project Cottrell’s dredge Marion has been working on a continuing U.S. Army Corps of Engineers multi-year contract on the James River Virginia. The Marion is a cutter suction dredge with 2000 installed horsepower. She is 130 feet long and 26 feet wide. The contract known as SATOC Maintenance Dredging Contract #W91236-15-D-0053 was awarded in September 2015. The first task order was issued in October 2015. Carlock explained: “The contract is for three years but task orders are issued at the discretion of the Corps of Engineers and then executed. We have done multiple task orders in the same year for instance 0002 and 0003 were issued in 2016. How many task orders are issued in a year is up to the Corps.” 

CSD Marion returned to the James River to execute Task Order 0004 in autumn 2016. The work encompasses dredging river sediment to a depth of elevation of -25 feet Mean Lower Low Water with 1-foot of allowable over-depth. Depending on the location and area of dredging material is pumped into a confined placement facility. Material can also be transported outside of the navigational channel into predetermined in-water placement areas. 

For the James River contract the quantities dredged vary from location and task order. For instance task order 0002 was approximately 200000 cubic yards. But importantly as Carlock explained “In view of environmental value of the area the work can only be executed during times of non-restrictive environmental windows. Nonetheless this part of the contract has just been completed as planned and the cutter suction dredge Marion has now been demobilized from the James River and arrived back to the Eastern Shore as of February 27.” 

The photo here shows the stern of the cutter suction dredge Marion working on the James River and was taken ‎September ‎15 ‎2016.