SPLASHMONSTER

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The SplashMonster JIP is aiming at investigating the wave loads on and dynamic behaviour of complex structures in the splash zone. In particular the JIP is aiming at sub sea structures which are lowered and hoisted through the wave surface.

BACKGROUND

Many offshore structures have to be installed sub-surface by means of lift operations. Such operations are traditionally conducted by semisubmersible crane vessels but nowadays more and more of smaller monohull vessels with relatively large crane capacities are deployed. Solid workability criteria are crucial for both the safety and the feasibility and economy of the operation, especially in harsh weather climates where the work has to be completed in a narrow time window. Operational limits today are often set in terms of statistical wave height based on vessel response and sometimes on a lift dynamics analysis with multi bodies.

For the above water phase and the deeply submerged situation, multibody lift dynamics can be simulated and these computational methods have proved to work well [1]. The phase where the structure is passing the splash zone requires special attention. In the upper wave zone, however, the structure is subject to non-linear wave action including non-linear viscous effects. Although some work is reported on the computational approaches [2], [3] and scale model verification, a thorough full scale validation is required to understand the possibilities and limitations of computational models and to provide input for further developments.

OBJECTIVES

SplashMonster JIP’s aims are as follows:
  • Monitor dynamic lift behaviour, loads and motions in combination with the vessel motions and detailed
    wave and current action,
  • Investigate the effect of leeway of the vessel and ship/lift interaction on lift dynamics,
  • Correlate measured data with model tests and computational models,
  • Formulate Best Practice for engineering & workability units.

Contact

Contact person photo

Henk van den Boom

Senior Project Manager

SCOPE OF WORK

  • Preparations,
  • Monitoring campaign,
  • Model tests,
  • Correlation with simulation models,
  • Evaluation & Best Practice.
JIP MEMBERS ONLY