76 — By Tim Clark
— February 2002
Sculpting the Sea
|Ferretti's latest design carves a shapely wake and a new niche in the Italian builder's series of motoryachts.|
Last October The Ferretti Group's display at the Fort Lauderdale International Boat Show was a thriving affair. A maze of slips flaunted the broad, stylish spectrum of the corporation's holdings--retro runabouts, advanced express cruisers, decked-out sportfishermen, and beguiling motoryachts. Every vessel had a pretty face stationed on the stern, and the tented areas swarmed with an army of bright young things eager to sing the fleet's praises in Italian-accented superlatives. What's more, on one side of the exhibit there was a cafe where you could get an espresso "corrected," as they say in San Giovanni, with a splash of grappa.
It was amid this glitzy hubbub that I met with Andrea Frabetti, head of nautical engineering for the group. The subject of our tete-a-tete was Ferretti's new 76, unveiled last fall at another suitably glamorous yachting hub, Cannes. But although it was impossible to discuss the yacht without touching on her comely looks, the core of our discourse was devoted to technical matters: We examined the 76 from an engineer's point of view.
On this yacht Ferretti has made significant modifications to a hull form already proven to perform well on existing models in the builder's line. Ferretti's fundamental goal regarding the hull has always been to combine performance standards such as speed, range, and economy with a ride that is smooth, quiet, and graceful. The first half of this equation is not hard to determine during the design stage through tried and true calculations and tank-testing. But effective means of predicting the latter have only recently been developed. Using Computerized Fluid Dynamics (CFD) software to foresee how the pressure of the water would be distributed over the hull's surfaces, Ferretti engineers were able to fine-tune the 76's design to enhance the ride.
The shape of the wake a hull creates is important for onboard comfort. A wake that runs too close can make for a wet ride and can create noise that carries through the vessel. With CFD simulations Ferretti can identify specific forms on a hull that aren't distributing water properly and change them. "We modify the design of the hull in order to model the wake, to give the wake the right shape," says Frabetti. Thus, for the well-being of its clients, the Italian builder sculpts the sea.
In addition to an optimum hull form, Ferretti engineers have developed other design standards that contribute to the right balance of speed, range, and comfort on the 76. Engine installation and engine room and systems layouts have been especially well devised.
Coupling the 76's twin 1,300-hp MAN D2842-LE 404s to V-drives allows Ferretti to locate the engine room farther aft. In addition to increasing below-decks living space, this contributes to noise control. Because bearings that keep propeller thrust from the engines are integral to the V-drives' design, Ferretti can set the MANs on soft, vibration-isolating mounts that greatly reduce structure-borne noise. Placing the fuel tanks athwartships just forward of the engine room further insulates living areas from sound. And since the tanks rest at the hull's center of gravity, trim is less affected by varying fuel levels, and the consistency of the yacht's performance underway is enhanced. Frabetti says the MAN diesels deliver a 27-knot cruise and bring the yacht to a maximum speed of 30 knots. A 1,585-gallon fuel capacity is said to provide a cruising range of more than 400 NM.
The 76's technical layout also considers quality of life at rest. All pumps, air-conditioning handlers, and other auxiliary equipment have been organized well aft, just below the transom. With the boat on anchor or at the marina, their operation should register as little more than a murmur.
This article originally appeared in the January 2003 issue of Power & Motoryacht magazine.