Iluka Boat Harbour Dredging

Navigational Channel Maintenance Dredging

Principal: New South Wale Department of Finance and Services for Trade and Investment

Location: Iluka Boat Harbour, New South Wales

Contract Value: approx. $350,000

Completion Date: January 2016

Iluka Boat Harbour Dredging – 2015/16

Neumann Contractors was engaged by the New South Wale 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 the dredging of 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, maintenance dredging was required to remove the accumulated sediment from both the navigation channels to the Iluka Boat Harbour.

The Nu Discovery (cutter suction dredge), a land based booster pump and support vessels were used for the project. The Nu Discovery is a new 250mm Cutter Suction Dredge and is ideally suited to this type of dredging working. It can be easily transported to remote sites, when dismantled the entire unit can be transported in 2 x 40' open top shipping containers.

Nu Discovery - Drawing.jpg
Nu Discovery, a 250mm Cutter Suction Dredge

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 (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 in the 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 is capable of dredging 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 distance.

The Nu Discovery is manoeuvred by a three wire anchoring system and can be setup to cut the entire width of a channel 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.

Iluka Boat Harbour Dredging - Video

Scope of Work

  • 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.

Challenges

  • Strict environmental limitations on noise and turbidity.
  • Maintaining suitable access for the marine traffic to and from the Iluka Boat Harbour.

Google My Maps Link

Iluka Boat Harbour DredgingLink to Google MyMaps showing the channel dredge area, pipeline and deposition area