Merrimack Inlet Dredging-Safety Update

The 320-foot dredge barge will be operating on the Merrimac River until early October. Photo by ## Capt. Scott Maguire##
Area of dredging operation.

Boaters navigating the mouth of the Merrimack River on the North Shore of Massachusetts over the next 2 to 3 weeks will need to keep clear of the 320-foot dredge barge “Illinois”. Great Lakes Dredge & Dock Co. is using the giant barge to dredge the channel to a depth of 17 feet between the jetties and out to buoy C“3” (which has been removed, along with buoy C“5”). The dredged sand will be deposited directly onto portions of Salisbury Beach and Plum Island, under a $5.5 million contract with the Army Corps of Engineers. No word yet on whether the notorious shallow “hump” inside the north jetty will be removed, but there seems to be no plan to deviate from the main channel.

Mariners are being asked to maintain a distance of 150 feet from the dredge.

Boaters should observe the following when navigating the inlet:

  • This illustration shows how to safely navigate around the dredging equipment in the Merrimack River. Courtesy, J. Libby, Site Manager

    2 black balls, one over the other, will be placed on the side of the dredge barge exhibiting an obstruction (e.g., pipe lines, suction lines or a cutter arm). At night, the barge will display 2 red lights in a vertical manner on the obstruction side.

  • On the opposite (non-obstruction) side, the dredge will display 2 diamond shapes during the day, one over the other. At night, the vessel will display 2 green lights, one over the other, to indicate the safe side on which to pass.
  • The dredge barge will move among 5 separate anchors during dredging operations, swinging back and forth in a 200-foot arc as it digs. The position of each anchor will be marked with a buoy displaying flashing amber lights.
  • A high-pressure discharge pipe trails behind the dredge. The pipe comprises 1,700 feet of floating 30”-diameter rubber hose attached to 3,000 feet of submerged metal pipe. The floating line is marked every 120 feet by flashing amber lights. A red light marks the end of the floating line, at the point where it attaches to the submerged section.
  • Boaters should remain south of the marker lights when navigating the river.