Utilizing Legacy Data

Hydrodynamics data set in file format of an old Hydro application can be imported via the FILE / IMPORT / HYDRO menu item.

The file has the extension hyd and contains only the data required for hydrodynamics calculations - it does not contain the results of the calculations.

The seakeeping calculations require the definition of various hull sections. This was accomplished in Hydro by importing a Britfair of Facet file. The name of this file (including full path) is stored in the .hyd file. Therefore, if such a filename is specified in the Hydro file, the Import Hydro File function shall try to import this as a Geometry file. If this is successful, then it is up to you to specify the imported geometry as the new Mainhull.

Since the filename is stored with the full path name, then problems may occur if the Britfair or Facet file have been moved or deleted from their original positions. In such a case, the remaining data is imported, but the new geometry will not be set. If required, it is then up to you to import the new Geometry as normal.

In early versions of Hydro, the names of the britfair and/or facet file were not stored, in which case it is not possible to automatically import the geometry file. However, if seakeeping calculations were performed, a file (known as the seakeeping database - <filename>.sdb) is also stored with the .hyd file. If this is available, then the body sections can be read from this file and are imported as a new geometry file. Once again, it is then up to you to set this as the mainhull prior to performing any Seakeeping calculations.

When a Hydro file has been imported, three new nodes are created

• Hydro Powering

• Hydro - Manoeuvring

• Hydro - Seakeeping

These, of course, can be renamed.

A number of loading conditions could be created within Hydro. These conditions are then combined to give one Powering Calculation sub-node. However, a separate Manoeuvring Calculation and Seakeeping Calculation sub-node is generated for each loading condition, thus allowing the calculations to be performed at a number of draughts.

Finally, it should be noted that importing a file will automatically update some of the General Ship Data values - namely LPP, Beam, Design Draught, water density and temperature, and Appendage data that has already been defined.

Dynamic Positioning data set up for use with the DOS based application - DPDAS can also be imported via the FILE / IMPORT / DPDAS menu item.

DPDAS required the input of a simple ASCII data file containing vessel particulars, thruster locations and positions, rudder information and possible overrides for the various default data used within the Dynamic Positioning calculations. Using the import facility, a new Dynamic Positioning node is created and the DPDAS file read to set data under this new node.

Some information, for example, percentage thrust available was input interactively when running DPDAS. This is therefore not stored in the DPDAS file and so HYDRO defaults are used.

As with importing Hydro data, it must be noted that this will update the general particulars with values read from the DPDAS file.