An emergency evacuation of an offshore petroleum installation must be carried out in the environmental conditions that prevail at the time of the emergency. The presence of ice can limit the utility of conventional evacuation systems. The performance capabilities of a conventional lifeboat were investigated experimentally at model scale in an ice tank. Tests were done in a range of ice concentrations, piece sizes, and thicknesses to determine how these factors affect the lifeboat's ability to launch and sail away from the platform. In the thinner ice and smaller floes, the lifeboat was able to progress through ice concentrations of up to 7/10ths coverage. In the thicker ice and larger floes, ice concentrations of only 5/10ths were passable. Additional tests were done with different propulsion power to check if this improved the lifeboat's performance. Significant increases in installed power led to only modest extensions in the boat's utility. Results of the experiments are presented, along with the calibrations, environmental matching, and analysis procedures. The results are a first step toward establishing operational performance boundaries for conventional lifeboats in ice.
National Research Council of Canada. Institute for Ocean Technology
St. John's, Newfoundland
Technical Report (National Research Council of Canada. Institute for Ocean Technology), no. TR-2003-03 (2007).