Although the entire harbor bottom requires periodic dredging to maintain suitable depths, the most critical dredging area is the entrance channel, which is constantly assaulted by a virtual "river" of littoral drifting sand. In this diagram, the dredge sweeps from side to side across the entrance channel ingesting sand and other bottom debris through the suction head.
This material then passes through the suction pump and is discharged through the dredge discharge line, which is routed underwater to the east jetty. The terminal point for discharge of dredged material can be one of two areas -- a beach / surf zone pipeline or an offshore pipeline. These are chosen to best advantage of beach replenishment and odor control of decaying seaweed.
About the Suction Heads
The dredge "Seabright" uses two types of suction heads to remove material from the bottom of the harbor and entrance channel.
During inner-harbor dredging, the small dredge "Squirt" utilizes a suction head, which is assisted by a rotating cutter that excavates the sediment.
In the entrance, the dredge "Seabright" utilizes a suction head assisted by water jets which turn the sediment into a slurry that can be pumped.
In both cases, dredged material passes through the suction head and is discharged through the dredge discharge line.
|Please consider the environment before printing this page. We appreciate your help!|