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United States Patent [19]Serter

[11] Patent Number:[45] Date of Patent:

4,875,425Oct. 24, 1989

[54] HULL FORMS[76] Inventor: Erbil H. Serter, 34, Chemin duPommier, CH-1218

Grand-Saconnex, Switzerland[21] Appl. No.: 125,176[22] Filed: N ov. 2 5, 1987[30] Foreign Application Priority DataNov. 26, 1986 [EP] European Pat. Off 86309223.5

[51] Int. CI.4 ..................................... B63H 5/08[52] U.S. Cl :. 114/56[58] Field of Search 114/56, 57, 271, 288,

114/289,290,291[56] References Cited

U.S. PATENT DOCUMENTS1,599,312 9/1926 Chimang 114/573,040,687 6/1962 Huet 114/56

FOREIGN PATENT DOCUMENTS0178294 8/1986 Japan.13506 6/1911 United Kingdom 114/57

Primary Examiner-Joseph F. Peters, Jr.

_--1.-.

Assistant Examiner-Edwin L. SwinehartAttorney, Agent, orFirm-Arnold S. Weintraub; GeraldR. Black[57] ABSTRAcrA hull form for a vessel which hull form is deep-Veebased and is constructed and arranged for use in a dis-placement mode. The hull includes a bow section whichincorporates a plurality of lateral grooves or, alterna-tively, a single lateral formation and which extendsbelow the base or datum line of the hull in a streamlinedteardrop configuration. Preferably, the hull has deep-Vee deadrise angles (1) whose magnitudes in the regionof the transom of the hull are not less than 20. Thesurfaces extending between the keel and the water linelength are non-planar and have developable convex andconcave geometry, all buttock lines of the hull having anegative inclination of between substantially !andsubstantially 4. The invention enables the known ad-vantages of deep-Vee based hull forms to be used indisplacement mode vessels having relatively large dis-placements where, heretofore, "round-bilge" hull formsvery greatly predominated.

9 Claims, 3 Drawing Sheets

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1 4,875,425 2DESCRIPTION OF THE PREFERREDEMBODIMENTSULL FORMS

BACKGROUND OF THE INVENTION Referring to the accompanying drawings, it will im-1. Field of the Invention: 5 mediately be apparent that the hull form of the hardThis invention relates to hull forms and to vessels chine vessel which is illustrated isbasically of deep-Vee. . configuration. The illustrated hull has a beam of 13.4

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3 4In the embodiment shown in the drawing a plurality water line beam ratio between 4 and 12. Both of theseof stations are marked along the base or datum line 5. ratios are variable depending upon the required speed ofThe forward locations 8 at the leading ends of all four of travel and the displacement of any vessel based upon athe grooves 7 are each at station 10. The rearmost end hull form in accordance with the invention.or aft end of the lowermost groove 7 can be anywhere S As shown in FIG. 3 the two chines 3 and 4 mergebetween station 7 and station 8, while the rearmost or with one another towards the bow at a location 15aft end of the uppermost groove 7 can be anywhere which is substantially 0.3 times the magnitude of thebetween statio 51 and station 61. The optimum positions length water level from fore perpendicular aft. Thefor the rear locations 9 and 10 must be calculated for merged chines 3 and 4 continue forwardly to form aeach particular complete vessel design. 'The illustrated 10 bow chine 3. This bow chine and the stem post arerear locations 9 and 10 merely show the foremost and seemed to one another at a distance from the base linerearmost possible positions for the aft ends of the or datum line 5 which is equal to substantially twice thegrooves 7 in one particular vessel. midships draft of the hull. When a hull of high speedIt should further be emphasized that there can be construction is required, its upper chine 3, preferably,more or less than four grooves 7 and that, in particular, 15 incorporates a spray rail. Although not shown in thea single laterally hollowed formation 11 may be substi- drawings, the spray rail has hollow sections extendingtuted for the grooves 7 at each side of the hull form, as inwardly throughout substantially the whole of theshown in FIG. 2. The hollowed formation 11 may ex- length water line. Each bow chine, preferably, has rela-tend, in a vessel having hull dimensions similar to those tively large spray rails and is formed with an interiorof the vessel shown in the drawings, rearwardly from a 20 concave section. Relatively small upwardly openingforward location 8 that is at station 91 to anywhere, slots may be provided with this construction.

depending upon the requirements of the particular ves- A skeg 16 is advantageously fitted at the bottom ofsel, between a rear location 9 at station 6 and an alterna- the transom and, when so fitted, preferably has a depthtive rear location 10at station 5. 'The margins of the two at the transom which is not greater in magnitude thanlaterally hollowed formations 11 at each side of the hull 25 the depth by which the teardrop configuration 6 of theare margins which merge into the corresponding sur- bow section projects beneath the base line or datum linefaces of the hull in a rounded, rather than angular, man- 5. The skeg 16has a length whose magnitude is substan-neroIf desired, a construction employing a combination tially 0.2 times the magnitude of the length water line.of the grooves 7 and the two hollowed formations 11 The skeg is streamlined and progressively reduces to amay be employed. 30 zero projection at its leading end. Shaped skegs in theReferring, now, to FIGS. 3 and 4, each side surface of form of streamlined plates may advantageously also bethe hull is preferably formed, below the upper chine 3, provided at both the port and starboard sides of the hullwith a recessed formation U whose foremost extremity in the form of bilge keels extending forwardly from theis at station 9 and whose rearmost end is at station 5. In transom.FIG. 4 there is diagrammatically illustrated the cross- 35 In a vessel having a displacement mode, deep-Veesectional shape of the recessed formation 12, while based hull form and a length in excess of about 20 me-FIGS. 3 and 4 show locations A,C, DI and 02. By ters, a relatively low added resistance is experienced incomparing FIGS. 3 and 4 it is seen that in the embodi- conditions above sea state 4 (8 foot waves) and thement which is being described, the cross-sectional shape incidence of slamming is very low. Such slammingof the recessed formation 12 is shown at station 8 look- 40 often being entirely absent. In particular, there is usu-ing towards the stem so that the developing shape of ally no slamming whatsoever when the speed-to-lengththe recess 12 can be seen. ratio of the vessel has a value in excess of unity. 'TheLocations BI and Bzare shown in the hull inFIG. 4. lowered resistance to forward progress that is encoun-A line 14 passing through both locations Bz and 02 tered by a vessel having a hull form in accordance withcorresponds to the so-called length water line 1. A line 4S the present invention is particularly significant in sea13 which joins the locations BI and 01corresponds to conditions where the waves have a height of 6 feet orthe so-called length water line 2. more. The directional stability or steerability in seaIt is to be understood that the drawings show the conditions where the wave height is in excess of aboutshape of the recessed formation 12 at only one side of 6 feet is particularly well maintained in a vessel whosethe hull. Of course, the huh form is symmetrical about 50 speed-to-length ratio is in excess ofunity. The resistancea vertical, longitudinally extending, central plane so to forward progress of a vessel having a hull form inthat any specialized shaping of the hull form that is to be accordance with the invention is relatively low at afound at one lateral side thereof, also, occurs symmetri- slow forward speed and, in conditions above sea state 4cally at the opposite laterial side thereof. (8 foot waves), relatively low heave, vertical velocityThe opposite symmetrically inclined surfaces of the S5 and vertical acceleration are experienced together withhull between the keel and the water line length are low roll, pitch and yaw.entirely non-planar and have developable convex and I claim:concave geometry throughout. The maximum depth of 1. A deep-Vee based hull form constructed and ar-any concavity is not greater than substantially 10% of ranged for use ina displacement mode, the hull havingthe hull girth. 60 side walls, a bow, and a bilge, the hull form having aAnother feature of the present invention is that all of datum line disposed proximate to the bilge of the hull,the buttock line of the hull are inclined to a horizontal the bow having a plurality of horizontal cross-sections,plane in a "bow down" configuration. The magnitude the horizontal cross-sectons being generally parallel toof the inclination is variable in, consequently, negative the datum line, the hull form comprising at least onedegrees between substantially one half of a negative 65 lateral groove at each side of the bow section, the hulldegree and substantially 4 negative degrees. The hull having a deadrise angle of at least 20 degrees, said bowadvantageously has a displacement to water line length section being extended below the datum line of the hullratio between 40 and 240 and a water line length to in a streamlined teardrop configuration, each horizontal

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5 4,875,425 6cross-section of the bow disposed downwardly from the side wall, and each groove disposed downwardly alongdatum line being progressively smaller. the hull form being progressively shorter.2. The hull form of claim 1, further comprising a 6.The vessel of claim 4, further comprising a recessedrecessed formation disposed on each side wall of the formation disposed on each side wall of the hull, eachhull, each recessed formation being extended length- S recessed formation being extended lengthwise on eachwise on each side of the hull from a location that is to side of the hull from a location that is to the rear of thethe rear of the bow. bow.3 Th hull f f clai 1 furth . . 7. The vessel of claim 4, further comprising a hollow. e . om;. 0c ann, . er compnsmg a formation disposed on each side wall of the hull, eachhollow formation ~posed on ~ch SIdewall of the hull, 10 hollow formation extending laterally along each sideeach hollow formation extending laterally along each wall from a location that is to the rear of the bow andside wall from a location that is to the rear of the bow, each hollow formation merging into the side wall in aand each hollow formation merging into the side wall in rounded manner.a rounded manner. 8. The vessel of claim 4, and having a displacement in4. A large displacement vessel having a deep-Vee 15 excess of 15 tons.based hull form constructed and arranged for use in a 9. A deep-Vee based hull form constructed and ar-displacement mode, the hull having side walls, a bow, ranged for use in a displacement mode, the hull havingand a bilge, the hull form having a datum line disposed a first side wall and a second side wall, a bow, and aproximate to the bilge of the hull, the bow having a bilge, the hull form having a datum line disposed proxi-plurality of horizontal cross-sections, the horizontal 20 mate to the bilge of the hull, the bow having a pluralitycross-sections being generally parallel to the datum line, o.f ho~ontal cross-sections, the horizon~ cross-sec-the vessel comprising a lateral groove on each side of nons bemg g.~erally par~~l ~othe datum line, the hullthe hull form the hull having a deadrise angle of at least form ~ompnsmg a multiplicity of ~ateral grooves o.n20 degrees, a bow section of the hull form extending each s~deo~the ~ull, the grooves bemg spaced ap~ inbelow the datum line of the hull in a streamlined tear- 25 a vertical direction al~:mgthe first and the ~o~d SIdewall, a forward location of each groove bemg m sub-drop co~gur~tion, each horizontal cross-section of ~he stantial alignment along the first and the second sidebo~ section ~posed downwardly from the datum line wall, each groove disposed downwardly along the hullbemg progressively s~er.. . form being progressively shorter, the bow extending5. The vessel of claim 4, wherem the hull form m- 30 below the datum line of the hull in a streamlined tear-eludes a multiplicity of lateral grooves on each side of drop configuration, each horizontal cross-section of thethe hull, the grooves being spaced apart in a vertical bow disposed downwardly from the datum line beingdirection along each side wall, a forward location of progressively smaller.each groove being in substantial alignment along the .. 0 ... co

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