The ILC 40’ class is the most technical and sophisticated of all ocean-going yachts. To be competitive, “Alligator” was designed to incorporate state-of-the-art concepts and using structural and hydrodynamic calculations, which have brought great satisfaction to its illustrious skippers: Francesco De Angelis and John Kosteky.
Alligator is longer and lighter than other competitors, with a notable concentration of weight, achieved through structural use of the cockpit, deckhouse and a revolutionary layout of interior fixtures and fittings. Modelling software has been used to create a hull with low freeboard, the minimum allowed in its category, a very round section with little rake, a high displacement-length ratio and with “terraces” on deck to make the maximum use of the righting moment from the crew. To make the most of the characteristics offered by building the boat in carbon fibre, the overall boat/internal layout has been completely reviewed: the bathroom is now amidships, under the entrance, in order to free the bow completely and create, with the galley/lockers structure to one side, an extremely rigid central structure. This has also made it possible to concentrate all the masses in the centre and the structures, with a Finite Elements program, optimising the laminates, and to create an ultra-light monocoque structure, fore and aft. The specific wheelhouse and cockpit layout has also made it possible to remove all deck reinforcement structures. To increase the rigidity of the mast/bulb, the studio has also developed a system to slot the top part of the bulb into the centreboard case, integrated into the bulkhead of the mast and the engine box.
This notable saving in weight terms and the lowered centre of gravity (thanks to the cutting-edge structure) have made it possible to limit the weight of the bulb, which has been reduced by 600 kg compared to the average for these vessels. Therefore, it has been possible, using Analytical Methods and their fluid dynamics program (VS Aero), to optimise the keel blade and the end bulb to obtain an appendage with great height and a low resistance coefficient at all angles. As far as the deck plan is concerned, and the layout of lines, one important feature has been the elimination of winches on the deckhouse, thanks to an original tightening mechanism below deck, which means that since the deckhouse is not structural, it is much lighter. The other winches are all set in the deck to lower the centre of gravity; the main sheet runs inside the sandwich thickness of a carbon tube and all fine adjustment lines run below deck in special ducts, to leave the deck free and lower moving weights even further. Extremely sophisticated technology is behind the construction, such as vacuum lamination of single parts with oven post curing of the laminated items. All parts of the boat, such as the shroud chain-plates, the boom and the interior furnishings are made in vacuum glass and carbon fibre.
