Development of a Methodology for Quick Seakeeping Assessment of Warships for Helicopter Operations in Rough Weather

Helicopter operations at sea are greatly affected by the seakeeping behavior of warships, especially in rough weather. A strategic and tactical advantage can be accrued by assessing the suitability of available warship options before deploying and assigning the tasks of helicopter operations to them. Naval vessels inherently display significant variations in their loading conditions (draught, trim and CoG etc.), having direct impact on their seakeeping behavior. Therefore, it is important to evaluate seakeeping qualities at actual loading condition of the ship. This paper proposes a methodology for a quick seakeeping assessment of available warships to assess their suitability for helicopter operations. At the onset, motion Response Amplitude Operators (RAOs) of the helo-capable ships are calculated for a range of draft, trim, and CoGs combinations using commercial software. These RAOs are stored in a database that can be used to estimate motion RAOs under actual loading condition of a warship. Availability of RAOs database drastically reduces seakeeping assessment time. BMTs Global Wave Statics can be used to represent typical sea conditions of the area of operation to estimate operability windows of available warships for helicopter operations.