Design
We told you this puppy would be fast. The Italia 9.98 Low Noise II designed by Matteo Polli is attractive, commodious downstairs and comfortable to sail and a 2015 ORC World Champion to boot. The latest crop of Italian ORC racer cruisers have a lot going for them as accomplished all-round designs; it would be instructive to see some examples of the breed now being campaigned in IRC. Right: CFD analysis of the reverse T-keel chosen for this mid-sized design
Straight out of the box…
Matteo Polli’s 34-footer was an instant success story
ITALIA 9.98 FUORISERIE Introduction
The concept behind this new 34-footer was a client’s desire to approach new racing challenges by downsizing from his previous 37ft cruiser-racer. What lent the project additional excitement was that the request came from Giuseppe Giuffrè, owner of the M37 Low Noise I, one of the most successful boats ever under the ORCi system, with three world championship titles, two European titles plus many national titles to his credit. The project also presented itself as an interesting challenge from a designer perspective, con- sidering that smaller yachts are commonly disadvantaged in handicap racing. Italia Yachts, a new and rapidly growing boatyard in the fast cruiser sector, embraced the challenge, creating an appealing product around this racing machine. The market requirements imposed by the yard added even more com- plexity to the project, introducing many important cruising and production criteria. Summarising, our brief featured these main points: Overall length <34ft Capable of winning races under ORCi and IRC both inshore and offshore Full crew-oriented cockpit but without precluding shorthanded cruising comfort
42 SEAHORSE
Light and rational interior adequate for weekend cruising ISO cat A CE certification and ISAF special regulations compliant Market price in line with competitors
Performance vs rating
When this project started the ITC was just about to launch big changes to the VPP that led to the new ORCi system. The variations to the hydrodynamic model were such that a new approach was necessary to get the most favourable ratio between real perfor- mance and rating, and much of the experi- ence gained optimising boats under the old IMS system was no longer relevant. Luck- ily, after a lengthy exploration of the new rule, I had the chance to test my ideas in practice since I was in charge of the optimi- sation of the M37 Low Noise I, which I had co-designed with Maurizio Cossutti. The success of this work gave me the basis to start the design of the Italia 9.98 fuoriserie. Following these major changes the ORCi system has proved to be working well, with the first 10 boats in a champion - ship race often covered by a minute on cor- rected time. This shows that all of the parameters are now properly accounted for by the VPP. Therefore, designing a successful boat is now less a matter of finding loopholes in the system than about creating a balanced boat that is really fast in relation to its rated characteristics. Designing for handicap racing is not all about pure performance but the ratio
between real speed and rated speed as the true indicator of value. However, real performance is paramount in these smaller yachts for positioning in clear air at the front of the fleet. Therefore, the primary objective was creating a boat with the highest possible performance to rating ratio in the wind range 8-12kt, while keeping the real performance profile as high as poss - ible. Secondly, I wanted to design a boat that was easy to sail, because a boat that spends more time sailing close to its maxi- mum potential will have an advantage that is not rated by any handicap system. The principal parameter I wanted to investigate was the beam to draft ratio both in upright and heeled conditions, with the ratio between displacement and sail area another key point in my study. After an initial parametric investigation and relating to my previous experiences, I developed three design families with equal sail plans, stabilities and appendage geometries, but differing in hull shape and displacement to explore the new hydro - dynamic model of the ORCi VPP. Cape Horn Engineering, now involved with BAR, provided a full matrix of CFD RANS simulations for what I felt to be the three best concepts; multiple single simula- tions were also run to discard any unat- tractive candidate designs.
These hydro profiles were then analysed using the VPP and compared to the ORCi and IRC ratings. The outcome in terms of W/L performance/rating ratio can be seen
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