Iluka Boat Harbour Channel Maintenance Dredging
Overview of Project
Neumann Dredging was engaged by the New South Wales Department of Finance and Services for Trade and Investment to undertake dredging works to the entrance channels for the Iluka Boat Harbour.
The works involved dredging the two approach channels to the Iluka Boat Harbour up to a depth of -3.0m below Iluka Port Datum. The total volume of marine sediments dredged was approximately 26,000m3.
Due to the depositional environment of the boat harbour, sediments had gradually accumulated in parts of the harbour since construction. Therefore, the harbour and channels required maintenance dredging to remove the accumulated sediment from the navigation channels to the Iluka Boat Harbour.
Scope of Works
The Nu Discovery (cutter suction dredge), a land-based booster pump and support vessel, were used for the project. The Nu Discovery is a new 250mm Cutter Suction Dredge and is ideally suited to this type of dredging works. You can easily transport it to remote sites. When dismantled, you can transport the entire unit in 2 x 40′ open top shipping containers.
- Mobilisation of a 250mm cutter suction dredge, the Nu Discovery, 1 x booster pump and 2 km’s 250mm poly pipeline.
- Dredging of 26,000m3 of marine sediments for the two harbour approach channels.
- Pumping the sediment through 2.0km of pipeline to the deposition site adjacent to Main Beach.
- Management of pumped material in a series of settling ponds.
- Strict environmental limitations on noise and turbidity.
- Maintaining suitable access for the marine traffic to and from the Iluka Boat Harbour.
Nu Discovery CDS used for this Project
The Nu Discovery is a 250mm cutter suction dredge from the Nu Explorer series of dredges. The Nu Explorer series of dredges have been designed and constructed by Neumann Contractors to specifically suit the typical dredging conditions encountered in projects like the Iluka Boat Harbour channels. There are three dredges in the Nu Explorer series that currently complement our fleet (a total of 9 Cutter Suction Dredges):
- Nu Explorer(original dredge in the Nu Explorer Series) has been working in the OTML Mine in PNG for the last two years,
- Nu Discovery has recently completed work in the Iluka Boat Harbour and Entrance Channel Dredging project,
- Nu Investigator is the latest fleet and has just completed initial trials and testing at Neumann Contractors, Corridor Sands plant at Woongoolba.
The Nu Discovery is a 227kW (305hp) 250mm three-wire cutter suction dredge. The dredge can dredge up to 120m3 per hour (in optimal conditions), dredge to a maximum depth of 6.5 metres, and pump the material up to 1,000m in the distance.
A three-wire anchoring system is used to manoeuvre the Nu Discovery, and the operator can set up to cut the entire channel width, including any batters, in just one cut width. The side anchor ropes remain on the sea bed while the dredge is in operation, which will minimise any inconvenience to other boating traffic through the affected channel areas. The dredge can easily move to one side of the channel to allow for vessel movements.