Waterplane Properties

Waterplane properties are more sensitive to station spacing than are displacement properties. This is because the shape of the end of a waterplane may not be well represented when it falls between stations. Longitudinal KM and LCF are exceptionally sensitive to station spacing.

Transverse stability, which depends on displacement and center of buoyancy, is relatively insensitive to station spacing.

When the accuracy of waterplane properties is particularly important, the hull model can be enriched with additional stations. The FILL command is most useful for this since it uses nonlinear interpolation. FILL requires Model Converter.

The following run illustrates the effect which station spacing has on waterplane properties. It uses the FV.GF model which is distributes with GHS and BHS.

copy c:\ghs\fv.gf fv.gf1
read fv.gf1
report fv.pf
macro g
ghs 4.0, 4.2 ... 9.0
/
.g
fill /maxgap: 2
.g
fill /maxgap: 1
.g
quit

Three graphs of the same hydrostatic properties are produced, the first is with the original station spacing, the second is with stations spaced at 2% of the overall length and the third is with stations at 1% of the overall length.