5. Operation modes

Simple modes

5.1. Solve with known draft

When selected, this mode finds a solution based on known draft, heel and trim data. Useful when you need to determine the ship displacement at a specific waterline height. This is the fastest mode, and produces almost instantaneous results.

 

5.2. Solve with known displacement

When selected, this mode finds a solution based on known displacement, heel and trim data. Useful when you need to determine the draft at a specific ship load. This mode is based on interpolating functions, and requires a little more time to determine the correct draft that gives the targeted displacement value.

 

Iterative modes

5.3. Iterate through draft

When selected, this mode iterates through a range of draft values, defined in the Iteration range field. It is essentially an automatized Solve with known draft mode. It allows you to see how certain hydrostatics properties change as the draft changes. Useful for building displacement tables, finding optimal coefficients, etc. Please note that large ranges and small steps result in lengthy calculations. Just as any of the Iterative modes, it allows you to output a selected hydrostatics property to a graph. Iteration range field limitations are as follows:

  • Range Start: no less than 0, no more than the height of the hull.
  • Range End: no less than Range Start, no more than the height of the hull.
  • Range Step: small enough to produce at least 2 results.

 

5.4. Iterate through displacement

When selected, this mode iterates through a range of displacement values, defined in the Iteration range field. It is essentially an automatized Solve with known displacement mode. It allows you to see how certain hydrostatics properties change as the displacement changes. Useful for building draft tables, finding optimal coefficients, etc. Please note that large ranges and small steps result in lengthy calculations. Just as any of the Iterative modes, it allows you to output any hydrostatics property to a graph.

  • Range Start: no less than 0, no more than the volume of the hull.
  • Range End: no less than Range Start, no more than the volume of the hull.
  • Range Step: small enough to produce at least 2 results.

 

5.5. Iterate through heel

When selected, this mode iterates through a range of heel angle values, defined in the Iteration range field. It requires a consistent displacement, and allows you to see how certain hydrostatics properties change as the heel angle changes. Useful for producing righting moment tables, determining maximum lateral stability, finding flood angles, etc. Please note that large ranges and small steps result in lengthy calculations. Just as any of the Iterative modes, it allows you to output any hydrostatics property to a graph.

  • Range Start: between -180° and 180°.
  • Range End: between -180° and 180°, higher than the Range Start.
  • Range Step: small enough to produce at least 2 results.

If Auto-trim option is checked, Hydrostatics Calculator will attempt to automatically adjust the trim of the hull to keep the CoG and CoB in the same lateral plane. For this to work, you must type the CoG coordinates in CoG coordinates input fields. Please note that enabling this option will take more time to find each solution.

 

5.6. Iterate through trim

When selected, this mode iterates through a range of trim angle values, defined in the Iteration range field. It requires a consistent displacement, and allows you to see how certain hydrostatics properties change as the trim angle changes. Useful for producing righting moment tables, determining maximum longitudinal stability, finding bow/stern flood angles, etc. Please note that large ranges and small steps result in lengthy calculations. Just as any of the Iterative modes, it allows you to output any hydrostatics property to a graph.

  • Range Start: between -180° and 180°.
  • Range End: between -180° and 180°, higher than the Range Start.
  • Range Step: small enough to produce at least 2 results.

 

Advanced modes

5.7. Simulate natural buoyancy

The most complicated and computationally demanding mode, it attempts to perform a buoyancy physics simulation based on a pre-determined displacement and Center of Gravity coordinates. Model is re-positioned and re-oriented by trial-and-error using interpolating functions, adjusting the draft, heel and trim, until the Center of Buoyancy is above or below the Center of Gravity within an lateral and longitudinal distance error margin specified in the Error margin setting in the Settings window. Hydrostatics Calculator will make a number of attempts to find the solution (configurable in the Settings window), and in case of a failure, terminate the simulation to avoid an infinite loop, displaying a message "No solution found". If you encounter this error, try to run the simulation again - it is likely that the learning algorithm will have gathered enough data to find a solution before reaching the attempt limit. If it still doesn't succeed, try to set the Error margin in Settings window to a higher value, or move the Center of Gravity to a less extreme position. If the simulation is successful, it will analyze the final result, and output hydrostatic properties in the Results window.