Felci Yacht Design:
We were asked to design a simple handling, no compromise 33 ft. mono hull conceived to be super-fast in real time while simultaneously offering the chance to achieve excellent results in handicap races such as the IRC, ORC Sport Boat Category and the brand new HPR.
The whole project is aimed at extremely high performances as being the key to enjoying sailing, getting results in regattas, and above all giving this new racer boat a long life span.
This hull gives the double objective of having very little friction resistance and slight wave resistance at lower angles. This ensures excellent performance when sailing downwind in a light wind. Together with an increase in heeling and in righting moment given the power available, allows the ICE 33 high performance levels when sailing upwind.
In order to underline these characteristics the ICE 33 is sailed as flat as possible, taking full advantage of the beamy hull and crew weight until it becomes necessary to further power the torpedo keel and hull shape when the wind increases. The weight of the torpedo comprises 55% of the final weight.
A high modulus Hall carbon mast with PBO Smart rigging, the very latest generation of deck equipment and numerous small but high quality details such as carbon pulpits and stanchions, complete the efficacy and the “look” of this thorough-bred racer that will launch with an over-all weight of 4,200 lbs displacement, of which 2.200 lbs are dedicated to the keel and torpedo.
The sail area upwind with square top mainsail is approximately 775 sq. ft. while downwind it is around 2,260 sq.ft., thanks to a mast head gennaker attached to the 6.5 ft. retractable bowsprit.
The ICE 33 is auxiliary powered by an outboard motor with a concealed lifting system which has undergone detailed engineering so as to render this operation simple and efficacious, enabling the motor to be completely hidden and the hole necessary for passing the engine strut drive closed with a sliding hatch, perfectly flush with the hull.
The innovative hydrodynamic concepts behind this new 33 ft hull had been set aside for a period of time but have now reacquired popularity having been improved by recent CFD studies, were done using the most sophisticated software available and embraced by other famous naval architects design studios.
At Felci Yachts the latest CFD studies have caused us to reassess the potentiality of these hulls that we could define as “high stability form rounded hulls”. Thanks to this project they have evolved even further.
Essentially these new analyses have allowed us to estimate precisely whether the increase in wave resistance generated by the curved topsides that is submerged at a certain heel angle, is nullified by the extra power that becomes available.
However, this specific study remains restricted within a limited cloud of boats characterized by a low relative displacement and a high relative sail area.
The basic concept is that of modelling a hull that at low heel angles and submerged is the slimmest as possible with a low wetted surface area.
With the changes in geometry at high angles, where the chalice shape, offers new supports and a solid increase in the global righting moment.
This hull gives the double objective of having very little friction resistance and slight wave resistance at the lower angle and thus ensures excellent performance when sailing downwind in a light wind together with an increase in heeling, an increase in the righting moment and therefore in the power available that gives high performances when sailing upwind as well as off wind.
In order to underline these characteristics the ICE 33 must be sailed as flat as possible taking full advantage of the beamy hull and crew weight until power supplied by the torpedo and hull shape overtake when the wind increases.
Notwithstanding, the weight of the torpedo comprises approx. 55% of the final weight but in theory it could be further reduced in order to optimize the 33 in conditions of particularly light wind.
The images show how, while maintaining unchanged the principle parameters of the canoe body (volume, CP, RM20 etc), the answers in terms of resistance of the two typologies of hulls developed around different midsections have been analysed: the first, decidedly “roundy”, the second characterized by a boxy-type mid-section .
The first one was further analysed to the point where it became a “roundy” canoe body “cutted” and equipped with chine extended along almost the whole length in order to emphasize the effect coming from the increased RM at high angles.
As previously set out many of the available parameters were left unvaried so the final evaluation was carried out by correlating the increase in RM and the increase in resistance. Crossing these results with a parametric analysis of the prevailing meteorological conditions in the Mediterranean area, we arrived at the answer represented by the hull of the ICE 33.
From the structural and constructive point of view, the choices were made with the objective of creating a composite as light as possible but at the same time one that would meet the minimum laminates imposed by ISO regulations. There has been detailed work in studying the interconnections between the structures, the forestay and shroud fitting attachments, the fin recess and its reinforcement structure.
An interesting element is the fin structure which together with great efficiency and rigidity, offers an ergonomically important element which in the case of long regattas with a reduced crew, allows for a very comfortable stand-by phase.
The concealed lifting system for the outboard motor has also undergone detailed engineering so as to render this operation simple and efficacious enabling the motor to be completely hidden and the hole necessary for passing the engine strut drive closed with a sliding hatch, perfectly flush with the hull.
A high modulus Hall carbon mast with PBO Smart rigging, the very latest generation of deck equipment and numerous small but high quality details such as carbon pulpits and stanchions complete the efficacy of this thorough-bred racer that launches with an over-all weight of 4,189 lbs of which over 2,000 lbs are dedicated to the keel and torpedo.
The sail area upwind, in the racing version with square top mainsail, is around 775 sq ft, while downwind it is around 2,260 sq ft thanks to a mast head gennaker at the end of a retractable bowsprit in excess of 6.5 ft in length.
The Open version will make use of a furling Code Zero or similar.