Weeks Marine and Cottrell Contracting kick off the New Year in 2020 full throttle ahead at Thimble Shoal and the Norfolk Inner Harbor Channels. Recently, Weeks installed a new Liebherr crane assembly and clamshell bucket for the job. According to the Army Corps of Engineers, Cottrell Contracting began dredging the Norfolk Harbor Inner Channel and channel to Newport News on Saturday (December 28th).
In October, the Port of Virginia executed a contract with New Jersey-based Weeks Marine to begin the deepening of the western side of Thimble Shoal Channel. The work includes dredging the shipping channels to 55 feet — with deeper ocean approaches — and widening them up to 1,400 feet in specific areas.
The dredging project will enhance accessibility to the Port of Virginia while providing significant benefits to the national economy and national security. The deepening effort got under way in 2015, when the U.S. Army Corps of Engineers and the port agreed to share the cost of evaluating the benefits of dredging the Norfolk Harbor to a depth beyond 50 feet.
Weeks Marine is utilizing a clamshell bucket dredge 551 with a huge scooping capacity. The dredge operator works the levers from a crane control room dropping the bucket, scooping the material and then placing it into a dump scow barge. Weeks’s clamshell dredge 506 is on the way with the new Liebherr crane and bucket assembly. In the Spring, Weeks Marine will enlist its new trailing suction hopper dredge the TSHD MAGDALEN on the project to clear out the middle of the channel.
Last week, reporters from the The Virginia-Pilot visited Weeks Marine’s operations. Weeks Marine will be digging down to about 56 feet. The port will also widen the channel to 1,400 feet to allow for two-way ship traffic. Currently, the channel allows just one large ship transiting at a time.
During interviews aboard the clamshell dredge 551, Weeks Marine’s Project Manager David McNeill told the Virginia-Pilot, “Weeks Marine will dig up about 5.2 million cubic yards of material -enough to fill an estimated 654,125 dump trucks.”
The Virginia-Pilot also posted a short video where Joe Harris, Sr. Communications Director for the Port Virginia explained: “The depths we were in today were in the 50 foot range, scooping up big pieces of the bottom and putting the material on to barges.”
Harris further explains, “when one barge gets to a certain fill level, it goes out to the dump site that has been pre-approved by the federal government – about three miles off the coast.” He continues, “that barge opens up and drops the material that was dredged earlier, and then it heads back.”
On a typical clamshell dredging project, dredging companies will use two or more dump scow barges rotating in cycle from the dredging site to the dredging disposal area.
“There are two barges, so they are always in cycle,” Harris points out. With respect to the dredging operations, Harris continues, “the width of the channel is mapped out, and the barge works back-and-forth between two points, and as they finish loading up they move the bucket back and they start all over again – it’s almost like mowing grass – up and back, up and back,” he finished.
On the inner harbor, the U.S. Army Corps of Engineers, Norfolk District announced this week that it will manage the operations and maintenance project as part of an effort to remove shoaling, allowing safe and unrestricted navigation for the largest commercial and military vessels transiting into and out of the Port of Virginia. Officials expect Cottrell’s dredging operations to take about five months to complete the work.
The contract, awarded in August to the Chesapeake-based Cottrell, permits the dredging of 1.1 million cubic yards of sediment from the federal channel. Cottrell will pump dredge material by pipeline to Craney Island Dredged Material Management Area in Portsmouth. The type of dredge being used is a cutter suction dredge.
Steve Powell, Norfolk District project manager, said Cottrell is dredging to a depth of 52 feet below mean lower low water, a formula based on the lowest tide’s average height measured over a 19-year period.
“This dredging depth ensures that as the channel shoals in between maintenance cycles, the shoals will still be below 50 feet, the depth required to keep commerce flowing in the Port of Virginia,” he said. “It will be performed in a manner that ensures the continued safe and unrestricted navigation in the harbor.”
The Port of Virginia’s six cargo terminals constitute a driving economic force for the state, citing Joe Harris, citing a College of William & Mary study of the port’s value during fiscal year 2018.
The port is responsible for more than 397,000 full-time jobs across Virginia and $23 billion in labor income. In addition, there are an estimated 530,000 jobs in the maritime industry, including shipbuilding and repair, coal and private terminals. Harris said the port also generates $92 billion in output sales, $39 billion in Virginia gross product, and $2.1 billion in state and local taxes.
“Deep, safe and well-maintained navigation channels are vital to the long-term economic health of Virginia’s economy,” Harris added. “We understand that our customers and the cargo owners want to move their big ships and cargo across ports that are growing, modern, efficient and safe. The investments the port is making in its terminals, combined with the deepening and widening of Norfolk Harbor and its commercial channels, will drive business to this port and have a positive effect on job growth and economic investment in Virginia for decades to come.”
The Army Corp’s Powell says “safe and unrestricted navigation” is the objective of all Norfolk District dredging operations in federal channels.
“It’s the engine that drives the economy for the Port of Virginia,” he said. “The commerce that flows through the port ensures a healthy economy for the commonwealth of Virginia and nation as a whole. In addition, unrestricted navigation is critical to meeting the needs of the military, so it’s critical to our national defense.”
Maintenance dredging is required every 12 to 15 months in Norfolk Harbor Channel and every three to four years in the channel to Newport News, he added. Without it, the high rate of shoaling would severely restrict vessel movement within the port.
“Severe shoals could require ships to transit only during high tides, which would cause costly delays for the ship and employees who work at the many port facilities in Hampton Roads,” Powell said. “Also, if a ship ever ran aground, commercial and military vessel transits would be impacted until the vessel is freed from the shoal and the shoal is removed by a dredge.”