With the help of a 250-ton horizontal directional drilling (HDD) rig from Germany-based Herrenknecht, a 700-meter-long pipeline was installed in Anglesea, Australia, using the sea outfall method under extreme time pressure and strict environmental protection requirements.
In August 2015, a large cliff segment collapsed, impairing the sea outfall pipe of the local water treatment plant on the Bass Strait coast. The affected sewage pipe had to be replaced as quickly as possible to ensure stable wastewater disposal.
Australian drilling contractor, Dunstans Construction Group, employed a crawler-based Herrenknecht HK250C HDD rig. To install the new 14-inch outer diameter polyethylene (HDPE) pipeline, the crew first drilled a pilot hole from the treatment plant to the coast and under the sea, and then reamed the borehole from the land side. At that point, Dunstans faced another hurdle – transporting the product pipe by sea past Port Philip Bay, one of the busiest ports in Australia. Regular shipping was not obstructed by the exceptionally long cargo.
To complete the installation, Dunstans crews pulled the pipeline floating on the sea through the predrilled alignment all the way back to the treatment plant. Thanks to the 250-ton pulling force of the Herrenknecht rig, this task was carried out quickly and cleanly. With connection of the pipeline to the treatment plant, the new infrastructure was successfully installed in just three months.
FOR MORE INFORMATION:
Herrenknecht, +49 7824 302-0, herrenknecht.com