Lifeboats are important for safety of passengers and crew on floating vessels and offshore platforms. They need to be designed so that evacuation can be performed quickly and safely in case of emergency. This requires that the lifeboat is not damaged during water entry, that it moves afterwards away from the dangerous area, and that accelerations experienced by occupants do not exceed allowable limits. In this paper, the use of numerical simulation is proposed as a tool for design and optimization of lifeboats. While experimental studies will still be needed to validate the final design, the use of simulation can greatly increase the number of parameters relevant for structural integrity and wellbeing of occupants that can be studied in the design process. In a simulation, full size and realistic operating conditions can be realized, and the computational effort is affordable even for a small design group. The comparisons with experimental data performed so far indicate that the accuracy of simulation is comparable to that of an experiment.

Lifeboats are important for the safety of crew on oil platforms and marine vessels. Their design has so far been mostly based on experimental studies. However, the large number of factors which influence the loads on the lifeboat structure and its occupants makes optimization studies by experimental means both time-consuming and expensive. Besides, many effects cannot be studied at laboratory scale due to the inability to match all similarity parameters, and certain conditions cannot be realized in a laboratory. Numerical simulations based on modern computational fluid dynamics (CFD) methods could complement experimental studies if proven to be sufficiently accurate and efficient. The aim of this study is to demonstrate that this indeed is the case: comparisons between experimental data and simulation results performed by the authors so far indicate that the achieved accuracy in numerical simulations is comparable to the accuracy of experiments. It is also shown that a simulation of one drop test can be performed with sufficient accuracy in one day on a single core of a personal computer. Together with a computational method which uses overlapping grids to simplify the handling of lifeboat motion and specification of initial and boundary conditions, parametric studies of lifeboat water entry have thus become practicable.

Through use of state of the art tools for flow analysis the aims to establish a methodology to determine the performance of a high speed planing craft both in calm water and in waves. Verification against full scale measurements is conducted. The ability to maintain speed in waves is of great interest -both with respect to added resistance and with respect to safe operation and loads on the crew from accelerations. Full scale measurements and CFD (Computational Fluid Dynamics) were conducted on a Norsafe Magnum 850fast patrol boat. The measurements have been conducted during a boat challenge along the Iberian coast. The challenge was run in advance of the HSBO (High Speed Boat Forum) which was held in Lisbon, Portugal, May2015.CFD simulations at similar conditions to the measurements are used for validation. It is further shown how CFD can be used to expand operational envelopes beyond the point where full scale measurements are applicable. This is especially relevant for the acceleration loads on the crew which is often the limiting factor of small HSC (High Speed Crafts). Pressure loads are extracted from the CFD and are evaluated against the current standards for life boats. Various criteria are discussed and the most relevant are analyzed for the measurement results and the CFD simulation. An operational envelope where the different criteria are combined is suggested.

Despite the political objective of decreasing road transport and transfer cargo to road and sea, short sea shipping is struggling. There is therefore a need for development of new short sea Ro-Ro vessels which use significantly less fuel per ton transported which can be built at a modest cost. This feasibility study has: First mapped the main characteristics of the current fleet, i.e. dimensions, capacities, installed power and designs speeds; Second investigated alternative combinations of main measurements to enable more slender hull forms which require less power and hence give fuel consumption and fuel cost per transported unit; Third, performed a case study to compare the economic and environmental performance of these slenderer designs, with traditional designs and road only solutions. This study shows the advantage of investigating a large number of alternative dimensions and capacities to identify the designs which reduces cost and fuel consumption. And that the best option is to design and build more slender vessels.