In 2014, Bezemer was involved in the Wheatstone Development Project. The Wheatstone Development Project by Chevron involved amongst other things a trunkline from the Wheatstone and Lago offshore fields to the onshore LNG Plant situated in Ashburton, south of Onslow, along the Pilbara coast of Western Australia. Bezemer was approached by subcontractor De Cloedt Baggerwerken en Zn., nowadays DEME, to provide a linear winch spread for the shore crossing section of this project.  

 An environmental solution for a landfall at a mangrove  

The coastal region near Onslow is characterized by tidal creek systems that have formed narrow drainage channels with mangrove vegetation. To limit the effects on the mangrove, the shore crossing section of the trunkline was installed using micro tunnelling. This involves the creation of a tunnel beneath the dune system at approximately 2 m water depth, minimalizing the need for dredging and trenching in this area.  

Bezemer’s KTC 800 linear winch was used to pull the pipeline, through the tunnel under the mangrove. Linear winches are used since they offer a higher line pull-to-weight ratio than conventional styles of winches. The which used for this project can create a maximum pulling force of 800 mTon with a relatively low footprint.   

The 800 mTon linear winch was placed land inwards at the end of the micro tunnel. The long distance between the pipelaying vessel the Tog Mor and the onshore pulling site was covered by a steel wire rope. As the steel wire rope was pulled in by the linear winch, the pipelaying vessel could weld and give out more pipe.

 Extensive pulling wires  

For this project, 3000 meters of steel wire rope were required. This steel wire had a diameter of 127mm (5 inches) and a minimum breaking force of 1300 mTon. Before the start of the project, the wires were break tested, to make sure the actual breaking force was true to the MBL and exceeded the project-specific requirements. The linear winch was load and function tested at Bezemer’s testing facility.  

In addition to the wires and the linear winch spread, Bezemer provided two RR15.000 storage winches to handle the steel wires. These storage winches, each capable of storing over 100.000 kg of steel wire, were placed behind the linear winch to store all the incoming pulling wire. By combining the above-mentioned equipment and the expertise of all stakeholders involved the pipeline was successfully pulled into place.  

Winches as a solution

Bezemer Dordrecht greatly appreciates the opportunity to contribute to the Wheatstone development project. Working alongside De Cloedt Baggerwerken en Zn. and other project stakeholders, we overcame challenges and delivered a solution that met all project-specific requirements, resulting in minimum disturbance to the nature of the mangrove area.