Classic yacht Dolfi Brochure En /11

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Classic yacht Dolfi Brochure En 217-8-8 1/11 Classic yacht DOLFI Loa 32' 6'' 9,9 m Lwl 25' 11'' 7,9 m B max 7' 1,5'' 2,4 m Bwl 6' 6,7'' 2, m Draught 5' 1'' 1,55 m Light weight 4718 lbs 214 kg Ballast

Spi Jean-François Masset May 217 481 ft2 44,7 m2 ~ 54 ft2 ~ 5 m2 Introduction du projet : Dolfi s'inscrit dans la tradition des quillards fins et élégants avec petite cabine, inaugurée par les Skerry

Dolfi propose une version renouvelée de ce programme, avec des œuvres vives et un plan de voilure plus modernes, avec le confort d'un cockpit plus large et d'une cabine avec sanitaire, pour des

1 Classic yacht Dolfi Brochure En /11 Classic yacht DOLFI Loa 32' 6'' 9,9 m Lwl 25' 11'' 7,9 m B max 7' 1,5'' 2,4 m Bwl 6' 6,7'' 2, m Draught 5' 1'' 1,55 m Light weight 4718 lbs 214 kg Ballast 283 lbs 945 kg Wetted surface 17 ft2 15,8 m2 Sails surface : Mainsail 212 ft2 19,7 m2 Jib 194 ft2 18 m2 >> Mainsail + Jib 46 ft2 37,7 m2 Light Genoa 269 ft2 25 m2 >> Mainsail + Light Genoa Assymetric Spi Jean-François Masset May ft2 44,7 m2 ~ 54 ft2 ~ 5 m2 Introduction du projet : Dolfi s'inscrit dans la tradition des quillards fins et élégants avec petite cabine, inaugurée par les Skerry cruisers dans les années 192, qui a produit des monotypes très populaires comme le Requin, et dont les qualités nautiques bien spécifiques restent très appréciées des amateurs. Dolfi propose une version renouvelée de ce programme, avec des œuvres vives et un plan de voilure plus modernes, avec le confort d'un cockpit plus large et d'une cabine avec sanitaire, pour des navigations à la journée et le cas échéant une nuit de week-end pour 2 personnes. La carène du Dolfi, avec une longueur 9,9 m pour une largeur de 2,4 m, conserve des lignes et des élancements aux proportions classiques propre à cette tradition. L'élancement avant permet d'avoir un deuxième point d'amure nettement en avant de l'étai du foc, permettant de hisser un gênois léger ou un spi

2 Classic yacht Dolfi Brochure En /11 Project introduction Dolfi wants to be in the tradition of fine elegant keelboats with a small cabin, inaugurated by the Skerry cruisers in the 192s, which has produced very popular monotypes like Hai and Malar, and of which sailing specific qualities remain highly appreciated by amateurs. Dolfi offers a renewed version of this program, with a more modern hull and sail plan, with the comfort of a larger cockpit and of a cabin with sanitary, for day sailings and when occured for weekend for 2 people. Dolfi hull, with a length of 9.9 m for a width of 2.4 m, shows classic lines and slenderness proper to this tradition. The front overhang allows a second tack clearly ahead of the jib one for either a light genoa or an assymetric spi, so avoiding the need of a butt end. The light weight is 4718 lbs (214 kg) with a ballast ratio of 44%. The sail area is 46 ft2 (mainsail + jib), which can be increased in light winds to 481 ft2 with a genoa. The jib can be mounted either on a classical forestay or on a furling system with under-deck drum in order to preserve the aesthetics. The wide cockpit with footrest is designed for a helmsman and two crew members to maneuver and sit comfortably windward. Cabin accommodations include two benches, storage spaces and a toilet in the front space that can be converted into a double V berth. A 1hp sail-drive in-board engine completes the basic equipment. The option of a monolithic glass-resin-plastic construction was adopted to describe the project and establish its mass balance sheet but of course sandwhich composite, molded or strip planking wooden construction is also possible with similar or even lower mass. For a strip-planking construction, the very regular curvatures of the hull do not present specific difficulty a priori. File summary 1. Hull 2. Keel-bulb and Rudder 3. Sail plan 4. Deck plan 5. Accomodations and engine 6. Structure and scantling 7. Electrical, electronics, navigation and security equipment 8. Mass and buoyancy balance sheet Annex 1 : VPP polar plot and design ratios Nota : some design parameters are issued from and compared to recommendations of L.Larsson and R.E. Eliasson in their book 'Principles of yacht design - Second edition', as mentioned in the text. Acknowlegdment

3 Classic yacht Dolfi Brochure En /11 «Dolfi» file 1. Hull Loa: 32' 6'' (9,9 m); Lwl : 25' 11'' (7,9 m) ; Beam : 7' 1,5'' (2,4 m) ; Bwl : 6' 6,7'' (2, m) Draft : 1' 1'' (,33 m) ; Fore freeboard : 2' 6,7'' (,78 m) ; Midship freeboard : 2' 1,2'' (,64 m) ,,, , -, Waterline Displacement LCB (%Lwl) ZCB Cp SW H 1,18'' 57,39 ft3 (1,625 m3) 45,8-3,95'' 119,2 ft2 (11,7 m2) H 68,84 ft3 (1,949 m3) 45,6-4,38'' 56,9% 128,1 ft2 (11,9 m2) H + 1,18'' 81,19 ft3 (2,299 m3) 45,4-4,8'' 139,1 ft2 (12,92 m2)

4 Classic yacht Dolfi Brochure En /11 Sections areas Hull with heel, at iso-displacement : 15 heel angle : , 8,, , -16, Righting moment at 3 : RM3 : ~ 12 kn.m (H light weight condition + crew 5 lbs seated windward)

Classic yacht Dolfi Brochure En 217-8-8 5/11 2.

5 Classic yacht Dolfi Brochure En /11 2. Keel-bulb and Rudder The keel-bulb geometry is sized for a draught of 5'1'' (1,55 m) and a weight of ~ 188 lbs which, with the interface plate with hull of about 23 lbs, leads to a total ballast of 283 lbs (945 kg) put in the mass balance sheet. The keel area is ~ 11,8 ft2 (1,1 m2) so a ratio Keel area / Sail surface(triangles) of 3,39 % («Larrson-Eliasson» criteria : 2,75 to 4,25, average 3,5%). Fastening of the keel-bulb to the hull The interface plate of the keel wing (in green) is fastened with 16 M2 bolts to a central massif made of monolithic GRP. 4 transversal Ω frames and a reinforced keel line forwards and backwards ensure the rigidity of the hull with respect to forces and moments transmitted by the keel. Wetted surface Sw of the keel-bulb : 32,3 ft2 (3, m2)

6 Classic yacht Dolfi Brochure En /11 Rudder : the rudder area is 3,55 ft2 (,33 m2), so ~ 1% of the sail surface (triangles). Its volume is defined by horizontal sections Naca with maximum thickness at,4 chord and a rear cut-off at,95 chord. The axis is positioned slightly forward of the 25% chord line to ensure an optimal compensation of the pressure forces The axis is mounted in the hull with 2 self-aligning bearings type JP3 (type 1 1-xx-4 pour diamètre 4 mm) or equivalent. Rudder wetted area Sm : 7,64 ft2 (,71 m2) Sail plan A 7/8 fractional rig with a single stage of spreaders with a swept angle of 25 allowing to haul in the jib inside the shrouds. A tack ahead of the jib forestay by about 2 ft allows to put up a light genoa or an asymetrical spinnaker. Mast height / waterline : 39' 4'' (11,99 m) Boom height / deck : ~ 3' (,9 m) Sail areas : Mainsail : 212 ft2 (19,7 m2) Jib : 194 ft2 (18, m2) Light Genoa : 269 ft2 (25, m2) Asymmetric spi :~ 54 ft2 (~ 5 m2) >>> Mainsail + Jib : 46 ft2 (37,7 m2) Mainsail + Genoa : 48 ft2 (44,7 m2) Mainsail + Spi : 75 ft2 (~ 7 m2) Ratios : S(Mainsail + Genoa) / Sw : 2,82 S(Mainsail+Jib) / D^(2/3) : 23,

7 Classic yacht Dolfi Brochure En /11 4. Deck plan Roof linesplan :

8 Classic yacht Dolfi Brochure En /11 5. Accomodations and Engine A watertight bulkhead separates the cabin from a front storage space accessible by an opening deck hatch. Accomodations includes, from front to rear: - A front double V berth - A toilet - Two open frames front and behind the mast pillar, - Two benches with storage spaces underneath and on the sides. - A deck hatch above the toilet and two lateral portholes on the sides of the cabin bring natural light. The 1hp sail drive engine is installed under the front of the cockpit, access by a hood opening in the floor of the cockpit and making heightening of 1 cm. The battery is placed under the steps of the descent

9 Classic yacht Dolfi Brochure En /11 6. Structure and scantling The project and its mass balace sheet is established on the basis of a monolithic GRP construction, with as typical scantlings and local reinforcements : Hull, in average :,28'' (7mm) thickness Deck, roof and transom, in average :,2'' (5mm) thickness A central massif in the bottom of the hull for the fastening of the keel interface plate : in monolithic GRP 2,56'' (65 mm) thickness. 4 Ω frames as transverse extension of this central massif, Reinforcements of the keel line, as longitudinal extension of the central massif, 7 transverse frames contributing to the structural rigidity of the hull, A pillar mast, to sustain the compression efforts from the mast to the central massif, Supports for the fastening of the inboard sail drive engine, Local reinforcements to take in the efforts coming from the rig, forestay tacks (jib and genoa), shroud chainplates, backstay tack. Shroud chainplates are positioned at the level of the floor plate-frame N 3, allowing a good take in of the efforts. 7. Electrical, electronics, navigation and security equipment Non exhaustive list : Navigation lights: tricolor lights in mast head, Interior lighting: 2 ceiling lights with switch, 2 12 V sockets Waterproof electrical panel with switches and circuit breakers Marine toilet power supply : wiring for sea water pump and valves Magnetic compass, Depth sounder, Electromagnetic speedometer, Hand-held anemometer,... Multi-function display with 2 display lines + Safety regulatory equipment for navigation within 6 nautical miles of a shelter 8. Mass and buoyancy balance sheet Masses are postioned in order that the longitudinal centre of gravity is optimal in loading conditions with crew. Disp. lbs (kg) Trim ( ) Zrear / H inch (cm) Zfront / H inch (cm) XCG feet (% Lf) ZCG inch (cm) ZCB inch (cm) Light weight 4724 (2143) -,3 -,7'' (-1,79 cm),92'' (2,34 cm) 12' 1,2'' (46,7%) 5,35'' (-13,6 cm) 6,42'' (-16,3 cm) With light crew 33 lbs (15 kg) 555 (2293),7,72'' (1,83 cm),37'' (,94 cm) 11' 8,3 '' (45,1%) 2,91'' (- 7,4 cm) 6,46'' (-16,4 cm) With heavy crew 53 lbs (24 kg) 5254 (2383),16 1,27'' (3,22 cm),41'' (1,5 cm) 11' 6,9 '' (44,7%) 1,57'' (-4 cm) 6,46'' (-16,4 cm)

Classic yacht Dolfi Brochure En 217-8-8 1/11 Annex : VPP polar plot and design ratios Speed estimations from a VPP, for 6, 8, 1, 12, 15, 16 et 2 knots of wind Sum-up of the design ratios, in light

10 Classic yacht Dolfi Brochure En /11 Annex : VPP polar plot and design ratios Speed estimations from a VPP, for 6, 8, 1, 12, 15, 16 et 2 knots of wind Sum-up of the design ratios, in light weight condition except contrary mention Loa/Boa: 4,13 ; LfwlBwl : 3,95 Bwl/Boa :,835 Cp : 56,9 %Lf (Hull body prismatic coefficient) Ballast ratio: 44 % Lwl/D^(1/3) : 6,17 («Larsson-Eliasson» : semi planing capability when > 5,7) St genoa/sw : 2,34 (St genoa : sum of fore triangle (for genoa) + mainsail triangle ; Sw : wetted surface hull, keel and rudder) «Larsson-Eliasson» criteria : 2 to 2,5, average 2,25 S(mainsail + genoa)/sw : 2,82 S(mainsail + jib)/sw : 2,38 St jib /D^(2/3) : 19,97 (St jib : sum of fore triangle (for jib) + mainsail triangle) «Larsson-Eliasson» criteria : 15 to 22, average 19 S(Gmainsail + jib)/d^(2/3) : 23,6 RM3 : ~ 12 kn.m (light weight condition + 5 lbs crew seaten windward) Dellenbaugh angle/ estimation of the stability stiffness : 15,3 (light weight condition + 5 lbs crew) «Larsson-Eliasson» criteria : 15 (stiff) to 21 (tender) S keel-bulb / St triangles : 3,39 % («Larrson- Eliasson» criteria : 2,75 to 4,25, average 3,5) S rudder / St triangles : 1,5 % («Larrson- Eliasson» : 1 to 2, average 1,4) Lead Xv - Xd : Xv-Xd : 4,6 %Lf (with fore traingle jib) Xv-Xd : 7,1 %Lf (with fore triangle genoa) (Xv : centre géometrical center of fore mainsail triangles) ; Xd : CLR following «Larsson-Eliasson» method for fin keel) Criteria for fractional rig: 3 à 7 %Lf

Classic yacht Dolfi Brochure En 217-8-8 11/11 Acknowledgment My warmest thanks

brought me all his experience of navigator and owner to guide this design

11 Classic yacht Dolfi Brochure En /11 Acknowledgment My warmest thanks to Alain Lebeau who encouraged me and supported me in this approach, which brought me all his experience of navigator and owner to guide this design process, which realized all the 3D views and VPP polar plot which illustrate this document.

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