Tug Harbour Breakwater is now complete up to 2 metres above zero tide level. From this point, over 220 reinforced concrete precast units will be placed as breakwater capping and wave deflection walling. The road level for the breakwater will be 3.2m above zero tide level and the wave wall will have a top level of +4.1m to port datum. The facility has been designed to cater for future sea level rises due to "Green House" effects.
A large piling barge has now commenced installing steel piles within the harbour. Due to shallow and very hard bedrock these tube piles will be spun into the bedrock to an embedment depth of 3.5m. High strength cutting teeth are welded to the rim of the pile and the pile is lowered to the sea bed and rotated through the overlying soil. When the bottom of the pile reaches the top of the bedrock it is spun/ drilled into the bedrock and high pressure water pumped down the pile to clear drillings.
The piles are set strongly 3.5m into the bedrock. There are a total of 18 steel piles to be installed. These include pontoon support piles, crash fender support piles and navigation tower piles.
Fabrication of the 2 large steel pontoons is now complete. There are 2 pontoons to be initially installed in the tug harbour to cater for up to 4 tugs. In the future a third pontoon to cater for an additional 2 tugs will be installed. These large steel pontoons are up to 80 tonnes in weight and are 30m long with the widest being over 7m wide. They are expected to be delivered to site in mid September.
The 220 large reinforced concrete precast units are being manufactured off site in Unanderra by local company Obnova Concrete. To date 106 of the 220 units have been cast. Work has also now commenced in installing these breakwater capping units with work commencing from the outer end of the 265m long breakwater and working shoreward.
Other works also underway are the installation of the high voltage power conduits and cables to the site and the manufacture of the high voltage transformer that will provide all future site power requirements. The site stormwater drainage systems are also being installed. This system will incorporate a large pollution control unit called a "Humeceptor" that will filter out all solid and oily pollutants before the stormwater is discharged into the harbour. The site sewerage pumping station will be installed in the near future. Once all underground services are installed the heavy duty pavements will be constructed.
At this stage the Tug Fleet base is expected to be complete in November 2011.