Maintenance dredging is ongoing at Manasquan Inlet this week, with the dredger Murden performing the work.
Murden is owned and operated by the U.S. Army Corps of Engineers. On Thursday night, the boat was continuing dredge operations at the inlet well after dark, using its spotlight to guide the vessel along the edge of the north jetty in Manasquan. The entire inlet is being dredged as part of regular maintenance before busy summer boating season begins.
This is at least the second time the vessel has been dispatched to clear shoaling from the inlet, which two summers ago made headlines when navigational safety issues were being caused by sand collecting near the south jetty in Point Pleasant Beach to the point where anglers could set up beach chairs alongside the inlet while fishing.
Local residents would be forgiven to mistake the Murden for the Currituck, which is more commonly deployed to New Jersey for inlet dredging activities. While the two vessels look similar, the Murden is a purpose-built, split-hull hopper dredge that was commissioned in 2011. The Currituck was adapted to the dredge role and was built in 1974. Murden stretches 156-feet in length and displaces 639 tons when loaded with dredge sand. Its twin diesel-powered engines are powered by 14,500 gallons of on-board fuel.
A split-hull hopper dredge utilizes a suction pipe which is dragged along the bottom of a shallow channel, essentially vacuuming up sand and silt. The sand flows into the hull of the boat itself – known as the “hopper” – and the water flows back out to sea. When the hopper is filled with sand, the hull mechanically “splits,” dumping the dredged-up sand in a location offshore or on a beach for replenishment purposes.
On Thursday night, Murden could be seen navigating off the inlet and releasing the sand in deep water to the north.
Manasquan Inlet is charted to a depth of at least 9.1 feet, with 13.5-feet of water at midchannel. Shoaling has reduced those depths significantly along the south jetty. Murden, which can operate in depths as low as 5-feet and carry 512 cubic yards of sand at a time, will restore the inlet to its statutory depth. While weather and mechanical issues drive the boat’s schedule, dredging Manasquan Inlet has historically taken between a week and 10 days.