Along the North Pacific US-coast there are plenty of small harbours and marinas. The Port of Astoria, located on the Columbia River, is one of them.
This marina not only receives large cruise vessels, but is also quite active in accommodating fishing boats, commercial and recreational vessels.
The marina off the Columbia River has not been dredged for the past decade. The current dredging work – removing some 79.500 m3 (100.000 CY) – will be done in three consecutive seasons.
The dredged material is discharged in the flow lane of the Columbia River – during flood tide only – at a discharge distance of some 915 m (3000 ft). The maximum dredging depth is -5.5 m (17 ft).
During the dredging activities in Q1 2021, the Damen DOP250 dredge pump was mounted on an Deere 470G excavator with long-reach boom and stick. The excavator itself was placed on a sectional barge platform which was moved around the harbor with a small tug.
The DOP unit was powered via a hydraulic power pack originally designed for a vibratory piledriving hammer. This powerpack was mounted on the counterweight of the excavator.
Real-time control of depth and location was provided with GPS equipment mounted to the excavator and synchronized with DredgePack® software.