Methods Used

The methods employed in Hydro for the calculation of Dynamic Positioning are very simple. Environmental forces and moments are calculated for current, wind and waves. These forces are based on default environmental coefficients for either a Supply, Drill or Tanker ship type. Alternatively, you may supply their own environmental coefficients. These forces must be matched by the vessels thruster units to maintain station. Thus, it is simply a case of finding the maximum thrust required to hold station in a known environment, or iterate to find the maximum environment at which the given thruster units can hold station.

A propeller-rudder combination is treated internally as a steerable thruster with a barred zone. Details of this are given in Representation of a Fixed Propeller and Rudder.