Commissioning the design of a custom yacht or workboat is a major commitment. My main design goal is to ensure that the final product suits the end user, the owner. As the owner knows his/her requirements best, it is critical that he/she is actively involved the design process — which needs to be an enjoyable experience. The boat must perform as well as possible, whether that is speed under sail for a trimaran or excellent fuel efficiency for a power catamaran that operates as a ferry. Certainly the boat has to be strong, safe, and attractive.

Another important task is the consideration given to the building process. The way the boat is laid out structurally must take into account the ease of construction. In the end, human hands, skilled ones of course, will be performing the final assembly. As the designer, one of my responsibilities is to make that task as simple as possible, consistent with the budget and goals of the individual project.

I am a firm believer in thoroughly modeling the boat using 3-D solid modeling. I want to figure out the problems before the boat is built, not during the construction process. At Walworth Designs we use Aerohydro Multisurf for the original shaping of the hull shape, then it is exported to CREO (formerly called Pro-Engineer) for the solid modeling. Thoroughly modeling the boat provides multiple benefits. It allows the project to be seen in 3-D mode, which is easier to understand. Very importantly, it shows what works and also shows conflicts in how pieces of the boat fit together. Drawings are created directly from the actual 3-D model, so as the model is updated, the drawings are automatically updated to reflect the changes. When it comes time to start building the boat, the pieces of the 3-D model are used to create the files a CNC (Computer Numerically Controlled) router uses to cut the parts. This saves time in the building process, as the parts fit together with little to no trimming required. As the boat nears completion, the 3-d model can be rendered to see how different paint schemes work. While the creation of the 3-D model takes time up front, in the end it is an invaluable asset.

Stability Analysis:

The stability characteristics of any boat are important, and WD can provide this service for all boats. Part of receiving a Certificate of Inspection to operate a commercial boat in US waters is obtaining a stability letter. Calculating the stability of the boat requires familiarity with the USCG regulations, coupled with sound naval architectural knowledge. The tool we use is GHS, specialized software developed to analyze the hydrostatic characteristics of boats, both intact and damaged. This is the same software used by the USCG and many other government agencies and naval architecture firms, so compatibility of the computer models is assured. WD has much experience with the procedures, helping to streamline the process. As David is a licensed Professional Engineer in Naval Architecture and Marine Engineering, there is the added benefit of being able to take advantage of the P.E. expedited review procedure at the USCG.

Structural Design:

WD can engineer the structure from an existing conceptual design (see Abigail, for example). It is also not uncommon that the owner of an existing boat will want to make changes that require engineering design. For example, the owner of a large sailing catamaran here on St. Croix wanted to add a small aft deck and crane for the dinghy. WD engineered the laminates for the new aft deck and the installation of the crane.

Boat Parts:

In many ways a subset of the structural design services, the design of individual components for boats is another service we provide. Examples of this include rudders, daggerboards, passerelles, trim tabs, etc.

Structual Analysis:

WD has supported surveyors and provided analyses and guidance for sound repair of damaged boats.

For more information on our services, contact us:
[email protected]

Walworth Designs
PO Box 3792
Kingshill, St, Croix,
US Virgin Islands 00851

Mobile: 340 227 1220