Construction and outfitting

Saltwater Engineering was contracted by one of our clients to design a project specific installation system to be used for cable pull in from an offshore installation vessel to an onshore installation. During the cable pull in operation, the cable needed to transition a certain mid span point. On the shoreside of this point, the cable could be buried by means of land-based equipment. On the seaside of this point, the cable would be buried using a specified trenching tool.

Saltwater Engineering offers tailor-made cable handling solutions.
Saltwater Engineering offers tailor-made cable handling solutions.
Saltwater Engineering offers tailor-made cable handling solutions.

The installation system was to be used on the mid span point where the cable transitioned from floating with floatation devices to rolling on pre-installed rollers. A barge was planned to be beached to provide a fixed platform to house the installation system and providing access to personnel to remove the floatation devices from the cable. Due to the tidal effects in this region, the entire system had to be elevated above the deck of the barge because the barge would be completely submerged during high tide. This enabled the operation to continue during high and low tide.

Saltwater Engineering offers tailor-made cable handling solutions.
Saltwater Engineering offers tailor-made cable handling solutions.
Saltwater Engineering offers tailor-made cable handling solutions.

Upon completion of the cable pull in operation, the cable had to be removed from the system to land the cable on the seabed. Therefore the entire system was designed to be capable of tipping by 90 degrees to enable the cable to be removed from the system. The tipping was achieved by system of winches making the design rugged, reusable and capable of being used in multiple configurations on other vessels.

Project information

Scope of work

  • Scantling check for the laboratory
  • FEM calculation to check structural integrity of the laboratory during lifting
  • Calculation of the lifting pad eyes
  • Production drawings of deck house, outfit and winch foundation
Category
Mobilisation Engineering