Case Study : a boat hull

Giving a new lease of life to vintage sailing vessels

The engineering office of the CNS-Co Shipyard uses rhinophoto and rebuilds a 3D model of a yacht hull in a record time.

In order to enhance its already exceptional fleet of hire yachts, Escoffier, a well-known professional skipper in St. Malo (France) and founder of Etoile Marine Croisières, decided to do a refit of a mythical and prestigious vintage sailing vessel that he owns. It’s a 14m single-hulled sloop designed by Cornu (an illustrious French naval architect). The interior, the mast and the sails need to be completely renewed. Only the hull will be preserved though it will have to be repaired.

The Project Manager, Patrick Balta, who is a naval architect, needed precise information on the shape of the hull in order to make stability calculations which were necessary to design a new mast and new sails. He confided the digitization of the existing hull to the engineering office of CNS-Co Shipyard based in Port Saint Louis (13). The company is specialized in boat design, construction and repairs and their engineering office uses hi-tech material and software allowing them to model boats in their finest details with the required precision for repairs, manufacture and rebuilding.

Rhinophoto, is an automatic photogrammetry system which allows 3D objects to be accurately digitized from a set of photos. The application is a plug-in for Rhinoceros CAD which is perfectly adapted to the naval construction industry. Within the scope of this project, the aim was to obtain a precise model of the hull geometry which could be read into a computer in order to reconstruct an exact 3D copy of the real hull.

“Laser technology also allows us to digitize a complete boat or particular parts of the boat, but it’s a costly procedure and the resulting data processing can be extremely complex. The problem is that we end up with an enormous mesh which is often difficult to exploit because of the sheer quantity of data that we recover with this type of system. With Rhinophoto, only the points of the object that we are really interested in need to be digitized and this allows us to work very rapidly with a much smaller volume of data which give us full control over the whole operation”, explains Christian Moulin, the Manager of CNS-Co.