THE PERFORMANCE OF A SYSTEMATIC SERIES OF ICE-CAPABLE HULL FORMS IN OPEN WATER

A systematically varied series of ice-capable bow forms fitted to a common stern were designed and tested to characterise each hull's open water performance. Testing was completed in calm water for bare hull effective horsepower performance and in head seas for pitch, heave, added resistance due to waves, and relative bow motion performance. Flow visualisation studies of the forebodies were conducted. In addition, performance in ice was estimated for each hull form using current empirical methods. The paper also presents analytic estimates of open water performance characteristics using such tools as SMP, standard series EHP estimates, and the ADDRES code for added resistance in waves. The results of these predictions are compared to the measured model data to provide a measure of the effectiveness of these tools in analysing these extreme hull forms. The results also allow the examination of open water performance degradation which might occur in each of these areas (seakeeping, calm water EHP, and added resistance in waves) with varying levels of icebreaking capability. Final various voyage scenarios are played out to determine how the tradeoffs between open water and ice capabilities might affect the selection of hull form for a particular mission.