South Trees Inlet Pipeline Armouring

Berthing Pocket Anti-Scour Heavy Armour

Berthing pockets alongside wharves and RoRo ramps often suffer from scour caused by thruster jet wash velocities in the order of 5m/s+. In these cases rock protection and lighter weight grouted solutions are either ineffective in mitigating the effects of thruster induced scour or else they are prohibitively large.

  • Available in Heavy Density 3000kg/m3
  • Fully interlocked array for superior stability performance.
  • Stainless steel wire for extended design life.

Subcon recently worked closely with its client, their design house and the installation contractor to implement a cost-effective, heavy scour solution that provides stability equal to an equivalent depth of cover to a ~D1m rock around the berthing pocket.

Firstly, 75mm rock fill was used to rectify the scoured section of the pocket and to provide a competent filter layer over the existing core. Subsequently, 500 mm thick articulated concrete mattresses were used to provide a continuous heavy armour array over the rock to protect the berth and mooring dolphins from the high thruster jet wash velocities and grounding.

The toe of the leading edge of the mattress array can either be trenched or secured with duck bill anchors to prevent against uplift.

Subcon have ongoing research projects at the Australian Maritime College to support the design calculations associated with this solution.