FreeCAD-Ship s60 tutorial

In this tutorial we will work with Serie 60 ship, from the Iowa University. The tutorial is aimed to show how to work with a symmetric monohull ship.

You can learn more about FreeCAD-Ship here

Introduction
FreeCAD-Ship works over Ship entities, that must be created on top of provided geometry. Geommetry can be a set of surfaces or solids, but following criteria must be taken into account:


 * Only symmetric ships are supported yet, so only half starboard geometry must be provided.
 * Starboard geometry must be included at negatives y domain.
 * Origin (0,0,0) point is the Amin frame and base line intersection.

FreeCAD-Ship sign criteria

Loading Serie 60 geometry
In order to help new users FreeCAD-Ship includes an example geometries loader.

Example ship geometries loader icon

Executing the tool (Ship design/Load an example ship geometry) a task dialog will shown. Select Serie 60 from Iowa University and press Accept. Tool loads new document with s60_IowaUniversity geometry.

Create ship instance
In order to create a Ship instance select s60 geometry and execute the ship creation tool (Ship design/Create a new ship).

Ship creation tool icon

Creating ship task dialog and some annotations at 3D view will shown. The annotations will removed when you close Ship creation tool, so don't take care about this.

Ship creation has two blocks, ship data and discretization data.

Ship data
Main dimensions must be introduced here:


 * Length: Length between perpendiculars, 25.5 m for this ship.
 * Beam: Total ship beam, 3.389 m for this ship.
 * Draft: Design draft, 1.0 m for this ship.

Length annotations.

Ussually Length between perpendiculars depends on design draft, so if you don't know what is the length of your ship you can set draft, and fit length in order to get bow and draft intersection.

Beam annotations.

Same process is valid for Beam fit. Note that is total beam, so symmetric hiden ship part must be taken into account.

Discretization data
FreeCAD-Ship use for basic calculation process a transversal cuts discretization version of the geometry, so discretization data must be provided. Depending on geometry discretization process can take some time, but future calculations are not heavily affected. If you don't need great results and don't want waste a lot of time, you can get default values, but you can consideer increase the values in order to improve results.

We will select 100x20.

When you press Accept button the program start discretization process, that may take less than one minute (More complex geometries can take hours, take care about this). The program can seems hanged, but if you executed FreeCAD from terminal you can follow progress, and cancel pressing Ctrl+C (Ship will not created).

When discretization ends you have your new Ship instance called Ship at Tags & Attributes dialog. We don't need geometry anymore, so you can hide it.

Ship instance icon.

Until now Ship must be selected before execute any FreeCAD-Ship tool.

Outline draw
FreeCAD-Ship provides a tool in order to make easy exporting ship outline draw.

Outline draw tool icon