To identify potentially critical areas of a ship’s design, we simulate and evaluate the loads and resulting stress flows through the hull structure. Highly stressed areas are assessed for risk of permanent deflection and buckling failure. Details within areas of pronounced stress concentration and exposed to large dynamic stresses are checked for sufficient fatigue life.
Projects
› Offshore rig reduction analyses (CFD) – 2015
› OHT – Hawk modification with sponsons – 2013
› OHT – Albatross ship conversion (Tanker to HLV) – 2013
› Master Marine – Global re-assessment of jack-up hull – 2008-2011
› BOA – BB29 hull stern modifications – 2011
› Jotun – FPSO 3rd party verification – 1997-1998
› Refer: Topsides float-over and installation
Areas of competence
› Modification of ships
› Hydrostatic/Hydrodynamic analyses of ships
› CFD analyses of hulls
› Local and global structural analyses of ship structures
The Haven Jack-Up vessel has been on a 4-year charter with Conoco Phillips for the Ekofisk renewal project as an accommodation platform. The vessel was modified for this purpose adding 3 additional accommodation modules and an office module to give a total of 447 beds. It was also outfitted with workshops and the two existing cranes were replaced by a smaller one. Additional footings (add-ons) were added under the existing spud cans to provide the necessary additional stability to withstand a 10.000 year wave.
Semar has been involved with the concept development, detail design and construction of the vessel. Semar had the responsibility of verifying the capacity of the hull for the temporary and in-place conditions that the modified vessel might experience operating as a living quarters at the Ekofisk field. Hydrostatic and hydrodynamic analyses have been made for the wet tow to the Ekofisk field and structural analyses for the dry tow, wet tow, and in-place conditions including a 10.000 year wave, earthquake and sudden drop condition caused by settlement of the seabed. Semar has also been responsible for the design, analysis and production of drawings for the structural modifications required including Helideck and lifeboat support structures, module supports, and miscellaneous outfitting. Semar personnel worked in the project team and had responsibility for the marine operations required for the installation of the jack-up at Ekofisk, including the dry tow from Batam, the installation of the add-on foundations, the wet tow to Ekofisk and the final installation.
Scope of work summary
› Global verification of hull in temprary and in-place conditions
› Global ULS assessments
› Fatigue verification of hull
› Global and local ALS assessments: Seabed sudden drop, explosion loads, earthquake, dropped object
› Calculation of modules interface loads
› Hired out personnel to manage marine operations and assistance in engineering coordination and construction follow-up
Key figures
| Client | Master Marine |
| Operator | Conoco Phillips |
| Project duration | 2008 – 2011 |
| Project characteristics | Modification of multipurpose service jack-up to accomodation jack-up |
| Construction in Indonesia, UAE and Norway | |
| Successful offshore installation in 2011 |