Challenges with Free Fall Lifeboat Performance in Rough Weather; Analyses, Improvements and Operational Risk Reducing Measures for Use of Free Fall Lifeboats on the Norwegian Continental Shelf

Abstract

Abstract Full scale testing and model testing of Free Fall Lifeboats (FFLB) have revealed weaknesses in performance of existing SOLAS certified lifeboats on the Norwegian Continental Shelf (NCS). The weaknesses vary between the different lifeboat types, but are generally related to safe use in rough weather. It is not possible to perform full scale testing in rough weather conditions, thus new methods for analysis of performance in severe wind and wave conditions have been developed. These analyses have provided new knowledge for design development and safe use of FFLBs. The analyses of the Free Fall Lifeboats (FFLB) are mainly concerned with the following issues: –Accelerations on the human body (G-forces) during drop–Structural strength, slamming loads and behaviour in submerged mode–Forward motion capability and manoeuvrability after surfacing–Release mechanisms, testing and improvements The analyses have been compared with new design requirements to FFLB on the NCS. Performance standards for lifeboats on existing offshore units have been established, and limitations for use combined with risk reducing measures have been operationalized for Statoil's units. The paper will present: –Experiences and lessons learned from testing and analyses of FFLBs–Methods for analyses of performance of FFLBs in various weather conditions–Performance standards for important safety parameters–Operational risk reducing measures implemented to ensure safe operations–Considerations related to modification/change-out of lifeboat systems offshore The knowledge and solutions developed will improve safety and functionality of FFLBs used in harsh weather conditions. The paper will give examples of how the new knowledge has been operationalized in Statoil.