The Royal New Zealand Navy (RNZN) regularly patrol the waters of the Sub-Antarctic Islands and the Southern Ocean in support of the Department of Conservation and Ministry of Primary Industries. Operation in these waters includes the potential presence and threat from ice, and RNZN Offshore Patrol Vessels are protected against ice with a belt of thicker steel about the waterline. Excessive pitch and roll of vessels can however result in thinner and more vulnerable areas of the hull being exposed to sea ice.
Defence Technology Agency were tasked by the RNZN to evaluate whether there was potential to enhance the level of ice protection on vessels through the use of a polyurethane cored steel faced sandwich panel system that has recently been offered by commercial suppliers. This report summarises mechanical testing undertaken to explore the viability of this type of sandwich panel system. Testing included shear, flexure and impact testing across the likely temperatures that the system would be operationally exposed to, as well as fatigue and corrosion testing.
Results of the tests indicate that a polyurethane cored steel faced sandwich panel system is a viable solution for hull reinforcement, and raised a number of recommended questions that should be answered by any prospective supplier of a solution to the RNZN.
Read this report [PDF: 2.58 MB, 31 pages]