At Heerema Marine Contractors, we do something new every day. We operate the world’s largest crane vessels and with them we transport, install, and remove offshore structures for the offshore energy markets. Our projects range from installing wind turbines, removing retired offshore oil and gas platforms, and installing platforms up to 50,000 metric tons. By joining us, you will play an important part in our unique maritime adventure.
Heerema Marine Contractors Nederland SE (HMC) has won a Contract for the transportation and installation of the 111 Foundation (FOU) Jackets offshore Taiwan. HMC has installed nearly 30 FOU jackets till today. The installation activities are performed by the Heavy Lift Vessel (HLV) Aegir.
The main Installation activities of FOU Jacket are summarized in the following steps:
- Most of the FOU jackets are transported from South Korea to Taiwan by HTV; some of them are transported from a Taiwanese fabrication yard;
- The HTV moor to pre-laid anchor when they arrived to the field;
- The HLV Aegir moor alongside the HTV, install Jacket Lifting Tool on top of Jacket and remotely engage lifting plates;
- Lift jacket from HTV and sail to jacket installation location;
- Set-down the jacket on previously installed, cleaned pin piles.
The FOU jacket is lowered through the water column till the three jacket legs are in contact with the pin piles. The load of the jacket is transferred from the crane to the pin piles. During the load transfer, the stabbing cones of each jacket leg are in contact with the soil within the pile slowing down the final set-down. The objective of the study is to investigate the physics involved during the final set-down of the jacket installation, with special attention to the influence of soil resistance.
Research questions:
- What are the set-down loads derived from the As Built data?
- Do we see large differences in set-down loads between Jackets? How can those differences be explained?
- How do the set-down loads compare to the loads computed using the OrcaFlex model in the Project preparation phase? How can the differences be explained?
Data available:
- As Built data: From each individual already installed FOU Jacket, environmental conditions, motions of the different bodies are logged from different measurement devices, in addition video footage and activity logs are available;
- A study performed by the Foundation Department on soil resistance is available;
- Time domain analyses are performed for this load transfer of the different FOU jacket using different lowering velocities using OrcaFlex.
The scope of work is to:
- Extract field data;
- Derive set-down loads;
- Tune available OrcaFlex model to replicate different installations.
Who will you work with?
As working student you will be be come part of our Marine Engineering department and assigned to our business unit Wind. Furthermore you have a strong collaboration with our Foundation department.