Ship Motion Analysis

For seakeeping calculations Vard Marine typically uses the codes ShipMo PC or PRECAL, depending on the vessel under study.   ShipMo PC is a strip theory based code suitable for seakeeping calculations for displacement monohulls. This code was developed by the Defense Research and Development Canada (DRDC) and is well validated by numerous sea trials. Vard Marine has developed very useful post processing tools to rapidly calculate vessel operability and other seakeeping performance parameters. ShipMo PC can also calculate added resistance in waves and wave bending moments.

As a result of our participation in the MARIN Cooperative Research (CRS) program, Vard Marine has access to some of the advanced panel method seakeeping programs developed by MARIN. By making use of these state-of-the-art 3-D potential flow seakeeping codes, PRECAL and PRETTI, we can offer accurate seakeeping predictions for a wide variety of hull forms including monohulls, SWATHs, and trimarans. These software tools have the capability to calculate the structural loads imposed on ships in a seaway and enable Vard Marine to conduct a completely non-linear time domain analysis of the ship’s motions and structural loads.

For offshore structures, Vard Marine uses AQWA for motion analysis, structural loads and mooring analysis.

Services_AA_shipmotions_image1Each of these seakeeping codes can be used to develop real time visualizations of seakeeping predictions with accurate representations of the vessel motions such as:

  • Vessel motions / accelerations / loads
  • Rates of slamming / propeller emergence
  • Speed loss due to waves
  • Ship operability
    • Helicopter take off/landing
    • Motion sickness rates
    • Irregular waves