DNVGL - DNV-OS-C104
STRUCTURAL DESIGN OF SELF-ELEVATING UNITS (LRFD METHOD)
|Publication Date:||1 October 2008|
This standard applies to all types of self-elevating units constructed in steel.
All marine operations shall, as far as practicable, be based upon well-proven principles, techniques, systems and equipment and shall be undertaken by qualified, competent personnel possessing relevant experiences.
A self-elevating unit is designed to function in a number of modes, e.g. transit, operational and survival. Design criteria for the different modes shall define and include relevant consideration of the following items:
- intact condition, structural strength
- damaged condition, structural strength
- fatigue strength
- accidental damage
- air gap
- overturning stability
- watertight integrity and hydrostatic stability. Limiting design criteria when going from one mode to another shall be established and clearly documented. Watertight integrity and hydrostatic stability shall comply with requirements given in DNV-OS-C301.
For novel designs, or unproven applications of designs where limited or no direct experience exists, relevant analyses and model testing, shall be performed which clearly demonstrate that an acceptable level of safety is obtained.
Requirements concerning riser systems are not considered in this standard.
Structural design covering marine operation sequences is not covered in this standard and shall be undertaken in accordance with the requirements stated in Rules for Planning and Execution of Marine Operations.