Saturday, October 24, 2009

Yacht design with Delftship

The following video from Youtube shows how a racing yacht moves at sea. It uses sails as prime mover. To have a faster speed, the yacht must have smaller block coefficient with streamlined hull that minimizes water resistance.

The design of ship and boat is now easier due to the availability of such computer aided ship design software as Delftship, Maxsurf, Autoship and etc. In today's post, I am going to explain how to design the main deck of a yacht using Delftship. If you haven't got the software, just go to and download it. You need to register yourself first before being able to get the free version of the Delftship.
The boat that I am about to design is the default hullform given by Delftship when I first launch Delftship's new file. The principle dimension is Length: 12 meters; Beam: 3.7 meters and the draft: 0.5 meters. After launching the new file, we will get the yacht design plans as shown on the following screenshot:
Choose the Perspective view so that we can visualize our steps of hull design in 3D form.
With the perspective view of the Delftship screen as the main window, while holding Ctrl key, please, click the edge of the boat. After that, highlight the Edit button. The pull-down menu will show up. Then select the Edge and click the Crease button. This will prevent the curving along the edge of the deck and the side hull.
After clicking the Crease, while the yellow line along the deck edge is still active, click the Edge again at the pull-down menu of the Edit and then select the Extrude option. You will be asked to enter some value.
Because we need to extrude the deck line to the centre line of the boat, we fill -1.75 meters as the half value of the yacht's breadth in the Transverse direction form.
As a result, we will get the following hull form in Plan View Window of the Delftship.
Now, we need to move the yellow edge of the deck line until it really in one axis as the center line. To do this, with Plan View of the Delftship Window is activated, click the Control points of the deck line while holding the CTRL key.
As you will see on the computer screen, the Delfship will show X Y Z coordinates. Fill in 0.00 in the Y form to move the points of the yellow deck line to the centerline of the yacht. When you have done it, press Enter, finally you will get the hull form of the yacht as shown below.
If you still haven't seen the 3D view of the boat, select Window which is located next to Help option menu. Then choose the Perspective view. After that Click the Show both sides from the pull-down menu of the Display. The remove the red lines and the control net, just click it. Now, your yacht design should look like the one above.
For those who are interested in learning yacht design, please, read Yacht Design According to Perry. It presents detailed information related to yacht. As an experienced designer, Perry explains the art and science of yacht design with many of its technical challenges in an easy to understand book. by Charles Roring