IHD fact sheet - Dredging methodology January ... - Fremantle Ports

Factsheet: January 2010Loose sand is picked up by a trailer dredge with the materialdischarged into a self-contained hopper within the dredge.Material from the hopper is pumped into the reclamation areafrom offshore via a pipeline.Hard underlying limestone is broken up by a rotating cutter head by a cuttersuction dredge. It is then then picked up by a trailer dredge.Hard material is transported in the hopper of the trailer dredge to the designatedoffshore disposal area. The bottom doors open and the material falls to the seabed.Dredged Material ManagementAround two thirds of the dredged material will be placedbehind a seawall to create further reclamation at Rous Head.As the reclamation fills, the solid sediment settles and theremaining water is returned back into the sea via a weir box.A silt curtain will surround the weir box on the seaward sideto further reduce the extent of sediment plumes.At the offshore disposal area, the hopper will dischargeits material through doors that open at the bottom of thevessel. The solid sediment particles drop through the watercolumn to the bottom of the seabed.Project contact informationIf you have any queries about the project, or would likefurther information, please contact Ainslie de Vos orLisa Rae on 08 9430 3555.1 Cliff St Fremantle, Western Australia, 6160Tel: +61 8 9430 3555 Fax: +61 8 9336 1391Website: www.fremantleports.com.auEmail: mail@fremantleports.com.au