File opening in Hydromax is window specific, i.e. Hydromax will automatically look for compartment definition files when you are in a Compartment Definition window and a loadcase in a Loadcase window.

To open a design for analysis, ensure that the design view window is active, then select Open Design from the File menu. Choose a Maxsurf design file (.msd).

The following dialog will appear:

Choosing Calculate Sections will calculate the specified number of sections through the hull. These will then be used for the Hydrostatics calculations.

The meaning of (ignore existing data, if any) is explained in Opening an Existing Hydromax Design File.

At this stage, any surface thickness specified in the Maxsurf Surface Properties dialog may be included.

If the Maxsurf model has trimmed surfaces, the Use Trimmed Surfaces item should be ticked.

When calculating stations, you may select how many stations should be used. Reducing the number of stations will speed up the analysis time but reduce the accuracy, conversely increasing the number of stations will increase the analysis time but lead to higher accuracy results.

The first option allows you to use the station grid created in Maxsurf. This is extremely useful for hulls that have features such as keels or bow thrusters that need to be accurately modelled and may need a locally denser station spacing to do so. It also allows designs with significant longitudinal discontinuities in their sectional areas to have stations specified either side of the discontinuity, avoiding any errors inherent in the integration of evenly spaced stations. For example, if it was known that a design had a significant discontinuity in its sectional area curve at amidships, by specifying one station 1mm aft of amidships and one station 1mm forward of amidships this discontinuity can be modelled very accurately.

The upper limit for the number of stations is 200.

The Surface Precision options has two functions:

§   Setting for calculating the hydrostatic sections

§   Setting used to form new compartments or tanks.

The precision at which the design was saved in Maxsurf is included in the Maxsurf design file (.msd). Hydromax recognises this precision setting and will and set the Surface Precision button accordingly.

Note:

Maxsurf surface trimming information may vary for different precisions. Therefore it is recommended not to change the precision setting when opening the Maxsurf design file in Hydromax.