IT201700006187A1 - BOAT OF BOAT AND RELATIVE BOAT - Google Patents

Description

BOAT HULL AND RELATED BOAT

FIELD OF THE INVENTION

The present invention relates to a boat hull and a boat comprising such a hull.

The craft of the invention is in particular, although not exclusively, intended for short / medium-range passenger transport for tourist purposes, and for navigation in waters that are at least partly confined and relatively shallow. STATE OF THE TECHNIQUE

Navigation, in particular by motor, in waters that are at least partly confined, such as, for example, city canals, lagoon basins or rivers, poses problems of environmental impact due to the wave formation connected to navigation itself that do not occur, or are in any case negligible, in navigation in the open sea. In the case of navigation in at least partially confined waters, in fact, the waves produced by the motion of the boats interact with the natural or artificial structures bordering the stretch of water in which navigation typically takes place before having been able to dissipate a substantial fraction of their power. The energy of the waves produced by navigation is therefore almost entirely transferred to the structures bordering the body of water, in the form of pressure forces that can damage the structures themselves, or in any case have an impact on them, all the more so when the more the energy and frequency of the waves produced increase. In the case of artifacts present for example in an urban context, such as walls and foundations of buildings that overlook canals, artificial embankments, bridge pillars, etc., this action can in the long run affect the continuity of the water defenses of such artifacts and contribute to their structural weakening. In the case of neighboring natural structures, such as those that can occur for example in lagoon or river basins, the wave formation due to navigation contributes to erosive phenomena on natural banks or embankments and / or to the movement of material on the seabed, especially when these are shallow.

The problems of environmental impact described above are particularly felt, for example, in the city and in the lagoon of Venice, due to antiquity and the exceptional historical, architectural and artistic value of the city in one case, and the fragility of the environment and lagoon ecosystems in the other.

It is known that two main factors responsible for the wave motion generated by a boat are the speed of navigation and the shape and size of the hull. In order to minimize wave formation, low sailing speeds and hulls with displacement hulls are typically preferred.

In the case of the city and the lagoon of Venice, attempts have long been made to mitigate the impact of the wave formation linked to navigation by imposing rather stringent limits on the speed of motor navigation (7 km / h in the Grand Canal, 20 km / h in the external paths in the lagoon). On the other hand, there are no specific directives regarding the shapes and sizes of the hulls, so from this point of view the boats circulating in the city and in the Venice lagoon can naturally have very different characteristics, which do not always take into account the need to minimize the wave formation.

As regards in particular the boats used for transporting passengers circulating in Venice and in the lagoon, it is however possible to trace the most common forms of hull substantially to two main types.

A first type, which includes the hulls of the so-called "vaporetti" used for public transport, for example, is represented by hulls with displacement hulls, with open shapes and no edges. The hulls of this type have good performance in terms of containment of the wave formation, but require more complex and expensive construction techniques, due to a typically round-knee configuration and with surfaces that are almost entirely double-curved. Furthermore, these hulls are generally relatively small in the stern area, a factor which can be disadvantageous, for example in boats intended for navigation for the purpose of tourist visits, where it is desired to be able to arrange the largest possible number of seats for passengers.

A second type consists of hulls with semi-planing hulls, with relatively little stretched shapes and a typically chine configuration. Hulls of this type can be built with simpler and cheaper techniques than hulls belonging to the first type described above. However, these hulls, being designed for navigation at speeds close to planing - which are not always reachable, due to the speed limits imposed - have shapes optimized mainly to have sustenance at high speeds and not to contain the wave formation.

SUMMARY OF THE INVENTION

The purpose of the present invention is to make available a boat hull and a relative boat for passenger transport, in particular for tourist purposes, suitable for short / medium range navigation in waters at least partly confined and relatively shallow, having a configuration that it allows to reduce the wave generation due to navigation, while at the same time maintaining a surface of the main deck as large as possible and a structure as simple as possible from the constructive point of view.

This object is achieved with a boat hull having the characteristics set out in claim 1 and a relative boat having the characteristics set out in claim 13.

In particular, in one aspect, the invention relates to a boat hull with a displacement hull, in which, in a preferred embodiment:

the hull has a double chine configuration;

longitudinal portions of the hull comprised respectively between a keel line and a lower edge line, and between an upper edge line and an upper edge of the hull are formed by single-curved surfaces;

hull widths in a plane of horizontal section placed at a height equal to the construction height of the hull relative to the hull baseline at transverse sections aft with respect to a median cross section of the hull are not less than 80% , and preferably not less than 90% of the maximum width of the hull in the same horizontal section plane. To further characterize the width of the hull, the following dimensionless coefficient C.ue is formulated, defined as the proportionality ratio between the half-width out of the bone to the ordinate considered, in correspondence with the line defined UE, and the maximum half-width of the line EU, in correspondence with section 5.00.

The aforementioned C.ue coefficient assumes, in the case of another preferred construction of the hull according to the present invention, the values shown in the following table a, considered with a tolerance of or - 10%:

Table a

Sect.transv U And C.ue

0 1895 0.902 0.5 1959 0.933 1 2016 0.960 1.5 2061 0.981 2 2090 0.995 2.5 2100 1

Similarly, in another preferred embodiment of the hull according to the present invention, said hull has a prismatic fineness coefficient Cp preferably between the values 0.564 and 0.559 considered with a tolerance of or - 10%. The prismatic fineness coefficient Cp is defined as the ratio between the volume of the submerged part of the hull (bottom) in design conditions and the product of the waterline length, i.e. the hull length measured in the design waterline at the longitudinal plane of symmetry of the hull, and the area of the main section, that is the area of the cross section of the hull that encloses the maximum immersed area.

To further characterize the shapes of the hull bottom according to the present invention, the coefficient Cx, defined as the fineness coefficient, can be used. To evaluate this characteristic in the case of the preferred embodiment of the present invention, the ratio was calculated for each section:

In which

Cx = Coefficient of fineness

Axi = area of the i-th submerged section

Bi, wl = Maximum width of the i-th section, at immersion T

T = corresponding dive

In a further preferred embodiment of the hull according to the present invention, the aforementioned coefficient Cx assumes the values entered in table b below considered with a tolerance of o - 10%:

Table b

Sect.transv B (T = 1.15 m) [m] Ax [m <2>] Cx

0 0.000 0.000

0.5 1.720 0.042 0.021 1 2.498 0.337 0.117 1.5 3.100 0.844 0.237 2 3.488 1.521 0.379 2.5 3.702 2.255 0.530 3 3.842 2.930 0.663 3.5 3.932 3.474 0.768 4 3.988 3.820 0.833 4.5 4.018 3.988 0.863 5 4.024 4.010 0.867 5.5 4.006 3.950 0.857 6 3.962 3.777 0.829 6.5 3.880 3.446 0.772 7 3.736 2.932 0.683 7.5 3.314 2.358 0.619 8 2.798 1.803 0.560 8.5 2.238 1.287 0.500 8.75 1.946 1.029 0.460 9 1.616 0.801 0.431 9.25 1.238 0.562 0.394 9.5 0.824 0.346 0.366 9.75 0.390 0.140 0.313

10 0.000 0.000

A variation of Cx of less than 3% with respect to the reference value in table b above allows optimal values to be maintained. With a variation of Cx

higher than 10% compared to the reference value in table b above, the hull, while maintaining the similarity by affinity, loses a significant part of its performance in terms of reduced wave formation.

The hull according to the present invention is characterized by very open lines. The

so-called starting of the lines can be evaluated based on the trend of the coefficients, and the angular half-widths between the water lines and the diametrical plane. In particular, in a further preferred embodiment of the hull according to the present invention, said angular half-widths between the water lines and the diametrical plane have the values shown in the following table (c) considered with a tolerance of or - 10% :

Table c

WL Half-width forward attachment angle WL end section aft [°] [x / L hull]

0.5 7.1 2.23

0.75 10.1 1.59

1 16.2 0.87

1.25 24.5 0.00

1.5 37.4 0.00

It is possible to consider a tolerance of 3 ° relative to the angle of attack with respect to the reference value in the table c above, and of 7% of the hull length as regards the longitudinal closing position of the water lines, with respect to the reference value. in table c above.

In the context of this description and subsequent claims, the following definitions apply.

"Edge line" means a longitudinal line, generally curved, of the hull, at which two surfaces of the hull join together to form an edge.

A "double chine configuration" means a hull configuration with two chine lines.

The "keel line" means the line of intersection between the out-of-bone surface of the hull and the longitudinal plane of symmetry of the hull itself.

"Baseline" means the horizontal line lying in the longitudinal plane of symmetry of the hull, conducted through the point of intersection between the out-of-bone surface of the hull and a perpendicular to the design waterline and equidistant from the forward perpendicular and from the perpendicular ago.

By "waterline" we mean the horizontal plane that defines, in a design load condition or in another given load condition, the free surface on which the hull floats, separating the immersed part of the hull (hull) from that emerged.

“Forward perpendicular” means the perpendicular to the design waterline plane conducted, in the longitudinal plane of symmetry of the hull, by the point of intersection between the waterline itself and the out-of-bone surface of the hull at the bow.

By "perpendicular back" we mean here the perpendicular to the design waterline plane conducted, in the longitudinal plane of symmetry of the hull, for the transom of the hull, or for a longitudinally intermediate point thereof, if it is not perpendicular to the plane of buoyancy.

The "construction height" of the hull means the height of the hull measured vertically between the baseline of the hull and a straight line joining the points of intersection between the out-of-bone surface of the hull and the out-of-bone surface of the deck, in correspondence of the median cross section of the hull.

The "length" of the hull means the length of the hull outside the frame, measured in the longitudinal plane of symmetry between the forward perpendicular, coinciding with the transom, and the forward point of the hull.

"Length between perpendiculars" means the length of the hull measured in the longitudinal plane of symmetry between the forward perpendicular and the aft perpendicular.

The "immersion" of the hull here means in particular the "immersion in the middle", ie the distance between the design waterline and the keel line, measured perpendicular to the waterline plane in the median cross section of the hull

"Prismatic coefficient of fineness" means the ratio between the volume of the submerged part of the hull (bottom) in design conditions and the product of the waterline length, i.e. the length of the hull measured in the design waterline at the longitudinal plane of symmetry of the hull, and the area of the main section, that is the area of the cross section of the hull that encloses the maximum immersed area.

The particular configuration of the hull of the invention advantageously allows to optimally combine the design requirements of a hydrodynamic and constructive nature mentioned above.

In particular, the choice of a double chine configuration allows to exploit the advantages provided by a displacement type hull in terms of reduction of wave generation at relatively low navigation speeds, and at the same time to create a constructively simple and configurable hull structure in flexible way.

In fact, on the one hand, the hull of the invention has particularly low values of the fineness coefficients, in particular of the prismatic fineness coefficient, and of residual resistance. These values reflect a particularly harmonious and slender hull shape and particularly well-developed hull lines, designed to minimize wave generation. On the other hand, the hull of the invention may be formed for the most part, or possibly even completely, of single-curved surfaces, which make its manufacture simpler than that of hulls with double-curved surfaces, such as example the hulls with round knee. In addition, the hull of the invention is able to maintain very broad shapes even in the aft area, thus helping to maximize the available deck area.

These characteristics make the hull of the invention particularly suitable for a passenger transport boat intended for navigation in at least partly confined waters, such as those of city canals and lagoon or river basins, in particular in the city and in the Venice lagoon. , and to offer a tourist service, for which it is desired to be able to accommodate on board, in particular at the level of a covered deck, as many seated passengers as possible.

Preferably, hull dives in longitudinal section planes aft of a hull median cross section, measured from the waterline under full load, should not be greater than 5% of the full load draft with respect to the values of the hull. generating hull, illustrated in table d below. The transom must always be surfaced.

Table d

Immersion section [mm] <% body immersed>

0 -50 -4.35 0.5 55 4.78 1 189 16.43 1.5 365 31.74 2 561 48.78 2.5 747 64.96

Advantageously, according to this preferred configuration, the hull has particularly slender shapes at the stern in terms of height. This configuration makes it possible to reduce the aft wave train, due to the aft pressure distribution field, which does not involve curves with abrupt changes in height.

Preferably, half-widths of the hull in horizontal section planes, placed at a height of less than 60% of the construction height, forward of a median cross-section of the hull, measured from a longitudinal plane of symmetry of the hull , are preferably not greater than 83%, of a maximum half-width of the hull in a horizontal section plane placed at a height equal to the construction height of the hull with respect to the hull baseline for at least 25% of the length of the hull measured from the bow. Advantageously, according to this preferred configuration, the hull of the invention has particularly slender shapes at the bow in the half-widths. The exhausted bow shapes reduce the formation of the forward shoulder wave, and this is due to a saving in terms of energy dissipated and consequently of fuel.

In a preferred embodiment, a longitudinal portion of the hull between the lower edge line and the upper edge line is formed at least in part by a double-curved surface. The double-curved surface, exclusively in the forward area of the hull, is designed to produce a geometry that reduces the wave formation of the forward shoulder, maintaining the comfort and seaworthiness characteristics typical of boats with a dry bow. Preferably, this double-curved surface extends longitudinally starting from a straight bow of the hull for no more than 25% of a hull length.

To allow navigation in relatively shallow waters, the hull of the invention preferably has a draft amidships, fully loaded, of no more than 1.20 m, preferably equal to about 1.15 m.

Preferably, the upper edge line has heights with respect to a base line such that at a transom it lies above a waterline under any load condition. Preferably, moreover, also the lower edge line has heights with respect to a base line such that in correspondence with a transom it lies above a floating plane in any load condition.

In another aspect, the invention relates to a passenger transport boat comprising a hull having the aforementioned characteristics. All the advantageous aspects described with reference to the hull of the invention, in particular the minimization of the wave motion generated during navigation, the considerable width of the deck surface and the ease of construction translate into similar advantages of the boat comprising this hull.

The boat of the invention is therefore particularly suitable for short / medium range navigation for tourist purposes, and in waters that are at least partly confined and relatively shallow, such as city canals, lagoon basins, rivers, etc.

Preferably, the boat comprises at least one passenger accommodation area on a deck aft of a master area, and the at least one passenger accommodation area is provided with a plurality of seats and occupies the covered deck up to one transom of the boat. The at least one passenger seating area is preferably provided at least in part with a cover.

A passenger accommodation area with the above characteristics is particularly suitable for a boat intended for navigation for tourist purposes.

Preferably, to contain the overall dimensions in height and thus facilitate navigation, for example under bridges of canals or rivers, the boat has a single-deck structure. In particular, the boat has no additional decks above a covered deck.

BRIEF DESCRIPTION OF THE FIGURES

Further characteristics and advantages of the boat hull and of a related passenger transport boat according to the present invention will become more evident from the following description of a preferred embodiment thereof, given below, by way of non-limiting example, with reference to the drawings. attachments, in which:

- Fig. 1 shows a set of longitudinal sections of a preferred embodiment of a boat hull according to the present invention;

- Fig. 2 shows a set of horizontal half-sections of the hull of Fig.1;

- Fig. 3 shows a set of transverse half-sections of the hull of Fig.1;

- Fig. 4 shows a complete cross section aft of the hull of Fig.1; - Fig. 5 shows a complete cross section forward of the hull of Fig.1; - Fig. 6 shows a side schematic view of a boat comprising the hull of Fig.1;

- Fig. 7 shows a schematic top view of the boat of Fig.6;

- Fig. 8 shows a schematic view from above of a deck of the boat of Fig.6; And

- Fig. 9 shows a master cross section of the boat of Fig. 6, devoid of structures above the main deck.

DETAILED DESCRIPTION OF THE INVENTION

Figures 1-5 show a preferred embodiment of a boat hull in accordance with the present invention, indicated as a whole with the reference numeral 1.

Figs. 1-3 constitute the so-called "construction plane" of the hull 1 as a whole, that is the set of sections of the out-of-frame surface of the hull 1 obtained with three sets of section planes respectively parallel to three mutually orthogonal reference planes, i.e. a plane longitudinal symmetry of the hull 1, the trace of which is indicated in the figures with CL, a horizontal plane of buoyancy of the hull 1, whose trace is indicated in the figures with WPL, corresponding to the immersion of an unloaded ship and a median transverse vertical plane of the hull 1, the trace of which is indicated in the figures with 5.00. These sets of section planes, or the corresponding sections of the hull 1, are indicated in Figs.1-3 with the following references: B500, B1000, B1500, B2000 for the longitudinal section planes; wl250, wl500, wl750, wl1000, wl1250, wl1500, wl1750, wl2000 for horizontal section planes, and 0.00, 0.50, 1.00, 1.50, 2.00, 2.50, 3.00, 3.50, 4.00, 4.50, 5.00, 5.50, 6.00, 6.50 , 7.00, 7.50, 8.00, 8.50, 8.75, 9.00, 9.25, 9.50, 9.75, 10 for the cross-sectional planes.

In particular, Fig. 1 shows a set of longitudinal sections of the starboard portion of the out-of-frame surface of the hull 1, obtained with the longitudinal section planes B500, B1000, B1500, B2000 and with the longitudinal symmetry plane of the hull 1 (coinciding with the plane of the figure). Fig. 1 also shows the traces of the vertical cross-section planes, 0.00, 0.50, 1.00, 1.50, ..., 10, and the traces of the horizontal section planes wl500, wl1000, wl1500, wl2000, as well as in hatching a line of base BL of hull 1 and the WPL buoyancy plane trace of hull 1.

Fig. 2 shows a set of horizontal sections (water lines) of the out-of-frame surface of hull 1, obtained with the horizontal section planes wl250, wl500, wl750, wl1000, wl1250, wl1500, wl1750, wl2000. Due to the longitudinal symmetry of the hull 1, only one half of each horizontal section is represented, in particular the one in correspondence with the portion to the left of the hull 1. Fig. 2 also shows the traces of the transversal vertical section planes 0.00, 0.50 , 1.00, 1.50,…, 10 and the traces of the longitudinal section planes B500, B1000, B1500, B2000.

Fig. 3 shows a set of transversal sections of the out-of-bone surface of the hull 1, obtained with the transversal section planes 0.00, 0.50, 1.00, 1.50,…, 0.95. Also in this case, due to the longitudinal symmetry of the hull 1, only one half of each cross section is represented. By convention, to the left of the trace of the longitudinal plane of symmetry CL, transversal half-sections aft with respect to the median transverse plane of the hull 1 are represented, while to the right of the trace of the longitudinal plane of symmetry CL, transverse half-sections forward with respect to the median transverse plane are represented of the hull 1. Fig. 3 also shows the traces of the longitudinal section planes B500, B1000, B1500, B2000 and the traces of the horizontal section planes wl500, wl1000, wl1500, wl2000.

Figures 4 and 5 show, by way of example, two different complete cross sections of the out-of-bone surface of the hull 1. In particular, Figure 4 shows a transverse section astern, in correspondence with the plane of cross-section 2.00, and Fig. .5 shows a cross section forward, in correspondence with the plane of cross section 8.00.

The hull 1 has a double edge configuration, with a lower edge line and an upper edge line extending longitudinally along the hull 1 itself and the traces of which are indicated in the figures respectively by LCL and UCL. The edge lines LCL and UCL divide the surface of the hull 1 into three longitudinal portions 1a, 1b and 1c, indicated in particular in Figs. 3-5.

The longitudinal portion 1a of the hull 1 between a keel line KL and the lower edge line LCL and the longitudinal portion 1c of the hull 1 between the upper edge line UCL and an upper edge UE of the hull 1 are formed by surfaces a single curvature.

In the preferred embodiment of the hull 1 shown here, the longitudinal portion 1b of the hull 1 between the lower edge line LCL and the upper edge line UCL is instead formed at least in part by a double curved surface, which extends longitudinally starting from a bow 2 of the hull 1 preferably for no more than 25% of a length Lpp of the hull 1. This double-curved surface presents, in addition to a curvature in the longitudinal direction, also a curvature in the transverse direction, with concavity facing towards the outside of the hull 1, which decreases longitudinally from the bow 2.

As can be seen in particular from Fig. 2, in the horizontal section plane wl2000, placed at a height equal to a construction height Hc of the hull 1 with respect to the base line BL, the hull 1 has widths which in correspondence with transverse sections a aft with respect to the median cross section 5.00 are not less than 90% of a maximum width Wmax of the hull 1 in the same horizontal section plane wl2000.

The hull 1 comprises a displacement type hull, particularly suitable for relatively low navigation speeds, corresponding to Froude number values below 0.4.

In order to minimize the wave formation during navigation in such conditions, the hull 1 has a particularly slender shape at the stern in the heights and in the bow in the half-widths and hull lines started.

In particular, as can be seen in Fig. 1, the hull 1 has heights in longitudinal section planes aft with respect to the median cross section 5.00, measured starting from the base line BL, not less than 19% of the construction height Hc of hull 1 for at least 25% of the length Lpp of hull 1 measured from the stern, as can also be seen from table d introduced in

precedence.

In proximity to a transom 3 of the hull 1, the upper edge line UCL has such heights with respect to the base line BL as to be above the waterline WPL in any load condition. The lower edge line also has heights, with respect to a base line, such that at

a transom it lies above a waterline under any load condition.

Furthermore, as visible in particular in Fig. 2, the hull 1 has semi-widths in horizontal section planes placed at a height of less than 60% of the height of

construction forward with respect to the median cross-section 5.00, measured from the longitudinal plane of symmetry CL, not exceeding 83% of a maximum half-width Bmax / 2 of hull 1 in the horizontal section plane wl2000, which is located at an equal height at construction height Hc of hull 1 with respect to

baseline BL, for at least 25% of the length Lpp of hull 1 measured from the bow. As mentioned, the hull of the invention has particularly slender shapes at the bow in the half-widths, as can be seen from the aforementioned table c.

Overall, moreover, the hull 1 preferably has a fineness coefficient

prismatic Cp between 0.564 and 0.559. The shapes of the hull bottom according to the present invention can be evaluated through the previously defined fineness coefficient Cx, the values of which are reported in table b introduced previously:

Table b

Sect.transv B (T = 1.15 m) [m] Ax [m <2>] Cx

0 0.000 0.000

0.5 1.720 0.042 0.021 1 2.498 0.337 0.117 1.5 3.100 0.844 0.237 2 3.488 1.521 0.379 2.5 3.702 2.255 0.530 3 3.842 2.930 0.663 3.5 3.932 3.474 0.768 4 3.988 3.820 0.833 4.5 4.018 3.988 0.863 5 4.024 4.010 0.867 5.5 4.006 3.950 0.857 6 3.962 3.777 0.829 6.5 3.880 3.446 0.772 7 3.736 2.932 0.683 7.5 3.314 2.358 0.619 8 2.798 1.803 0.560 8.5 2.238 1.287 0.500 8.75 1.946 1.029 0.460 9 1.616 0.801 0.431 9.25 1.238 0.562 0.394 9.5 0.824 0.346 0.366 9.75 0.390 0.140 0.313

10 0.000 0.000

The hull 1 also has hull lines particularly started due to the geometric characteristics of the hull according to the present invention. Very well established hull lines allow to reach optimal residual resistance values.

The hull 1 has a draft, calculated amidships, when fully loaded, preferably not greater than 1.20 m, and preferably equal to about 1.15 m, which makes said hull 1 particularly suitable for navigation in shallow waters. Figures 6-9 schematically show a preferred embodiment of a

passenger transport boat 100 in accordance with the present invention, comprising the hull 1 described above.

The boat 100 finds a preferred use for the transport of short / medium-range passengers for tourism purposes and is particularly suitable for navigation in at least partly confined waters, such as, for example, city canals, lagoon basins

or rivers, and relatively shallow. Thanks in particular to the use of a hull with the previously described characteristics, the boat 100 is able to minimize the wave formation deriving from navigation and therefore the environmental impact linked to this phenomenon in the aforementioned contexts.

The boat 100 comprises a substantially continuous deck 101 which closes the hull 1 at the top. To limit the overall height and simplify the construction, the boat 100 preferably has a single deck structure, i.e. it does not include further decks beyond above the main deck. As can be seen in particular in Figs. 6, 7 and 8, on the main deck 101 a boarding area 102 is defined in correspondence with a master area located amidships of the boat 100, two passenger accommodation areas 103, 104, respectively aft and forward of the embarkation area 102, and a cockpit 105.

The boarding area 102 consists of a free portion of the main deck 101, accessible from both sides of the boat 100.

The passenger seating areas 103, 104 are instead occupied for a substantial part of their plan surface by a plurality of seats 106, preferably arranged in a plurality of parallel rows.

The aft passenger accommodation area 103 preferably occupies the entire portion of the deck 101 aft of the boarding area 102, up to the transom 3 of the boat 100.

The boat 100 preferably comprises a cover 107 which extends, preferably continuously, over at least a part of the aft passenger accommodation area 103, the forward passenger accommodation area 104, the boarding area 102 and the cockpit 105. A part of the passenger seating area 103 in the stern, in particular the part towards the transom 3, is preferably without cover.

The forward seating area 104 is preferably also closed laterally by transparent surfaces 108. The aft passenger seating area 103 is preferably open laterally.

Fig.9 shows by way of example the median cross section of the hull 1 and of the deck 101 with the relative frames, of conventional type.

The boat 100 comprises propeller propulsion means 110 of a conventional type. Taking into account a maximum payload of about two hundred people envisaged for the boat 100, an engine with a power of 200 HP with maximum torque at 1500 rpm is certainly adequate to guarantee average navigation speeds of 10-15 km / h, such as foreseen for example for use in the city and the lagoon of Venice.

A person skilled in the art will be able to make modifications and variants to the hull and the boat described above to satisfy specific and contingent application needs, modifications and variants falling within the scope of protection of the invention as defined by the attached claims.

Claims (16)

CLAIMS 1. Hull (1) of a vessel with displacement hull, in which: the hull (1) has a double chine configuration; the longitudinal portions (1a, 1c) of the hull (1) comprised respectively between a keel line (KL) and a lower edge line (LCL), and between an upper edge line (UCL) and an upper edge (UE) of the hull (1) are formed by surfaces with a single curvature; the hull widths in a horizontal section plane (wl2000) placed at a height equal to a construction height (Hc) of the hull (1) with respect to a base line (BL) of the hull (1) in correspondence with cross sections abaft with respect to a median cross section (5.00) of the hull (1) are greater than or equal to 80% of the maximum width (Wmax) of the hull (1) in the same horizontal section plane. 2. Hull (1) according to claim 1 characterized by a prismatic fineness coefficient Cp comprised between the values 0.564 and 0.559 considered with a tolerance of 0 - 10%. 3. Hull (1) according to one or more of claims 1 to 2 characterized by a coefficient C.ue, defined as the proportionality ratio between the half-width out of the bone to the ordinate considered, in correspondence with the line defined UE, and the half - maximum width of the EU line, in correspondence with section 5.00, having the values shown in the following table a considered with a tolerance of or - 10% Table a Sect.transv U And C.ue 0 1895 0.902 0.5 1959 0.933 1 2016 0.960 1.5 2061 0.981 2 2090 0.995 2.5 2100 1 4. Hull (1) according to one or more of claims 1 to 3 characterized by a fineness coefficient Cx having the values shown in the following table b considered with a tolerance of or - 10% Table b Sect.transv B (T = 1.15 m) [m] Ax [m <2>] Cx 0 0.000 0.000 0.5 1.720 0.042 0.021 1 2.498 0.337 0.117 1.5 3.100 0.844 0.237 2 3.488 1.521 0.379 2.5 3.702 2.255 0.530 3 3.842 2.930 0.663 3.5 3.932 3.474 0.768 4 3.988 3.820 0.833 4.5 4.018 3.988 0.863 5 4.024 4.010 0.867 5.5 4.006 3.950 0.857 6 3.962 3.777 0.829 6.5 3.880 3.446 0.772 7 3.736 2.932 0.683 7.5 3.314 2.358 0.619 8 2.798 1.803 0.560 8.5 2.238 1.287 0.500 8.75 1.946 1.029 0.460 9 1.616 0.801 0.431 9.25 1.238 0.562 0.394 9.5 0.824 0.346 0.366 9.75 0.390 0.140 0.313 10 0.000 0.000 5. Hull (1) according to one or more of claims 1 to 4 characterized by semi- angular amplitudes between the water lines and the diametrical plane having the values shown in the following table (c) considered with a tolerance of or - 10% Table c WL Half-width forward attachment angle WL end section aft [°] [x / L hull] 0.5 7.1 2.23 0.75 10.1 1.59 1 16.2 0.87 1.25 24.5 0.00 1.5 37.4 0.00 6. Hull (1) according to one or more of claims 1 to 5 characterized by dives in longitudinal section planes (B500, B1000, B1500, B2000) aft of a median cross section (5.00) of the hull (1), measured from the waterline at full load, greater than a smaller or equal percentage at 5% of the draft at full load with respect to the values of the generating hull, illustrated in the following table (d), considered with a tolerance of or - 10% Table d Immersion section [mm] <% body immersed> 0 -50 -4.35 0.5 55 4.78 1 189 16.43 1.5 365 31.74 2 561 48.78 2.5 747 64.96 7. Hull (1) according to one or more of claims 1 to 6 characterized in that the heights of said hull (1) in longitudinal section planes (B500, B1000, B1500, B2000) aft with respect to a median cross section (5.00) of the hull (1), measured from a baseline (BL) of the hull (1), are not less than 19% of the construction height (Hc) of the hull (1) for at least 25% length (Lpp) of the hull (1) measured from the stern. Boat hull (1) according to one or more of claims 1 to 7 characterized in that the half-widths of the hull in horizontal section planes (wl250, wl500, wl750, wl1000, wl1250, wl1500, wl1750, wl2000) placed at a height of less than 60% of the construction height forward of a median cross section (5.00) of the hull (1), measured from a longitudinal plane of symmetry (CL) of the hull (1), are not exceeding 83% of a maximum half-width (Bmax / 2) of the hull (1) in a horizontal section plane (wl2000) placed at a height equal to a construction height (Hc) of the hull (1) with respect to to a baseline (BL) of the hull (1), for at least 25% of the length (Lpp) of the hull (1) measured from the bow. 9. Boat hull (1) according to one or more of claims 1 to 8 characterized in that a longitudinal portion of the hull (1) between the lower edge line (LCL) and the upper edge line (UCL) is formed at least in part by a double-curved surface. 10. Hull (1) of a boat according to one or more of claims 1 to 9 characterized by an immersion amidships at full load less than or equal to 1.20 m. 11. Boat hull (1) according to one or more of claims 1 to 10 characterized in that the upper edge line (UCL) has heights with respect to a base line (BL) such that, in correspondence with a mirror aft (3), said upper edge line (UCL) lies above a waterline (WPL) in any loading condition. Boat hull (1) according to one or more of claims 1 to 11 characterized in that the lower edge line (LCL) has heights with respect to a base line (BL) such that in correspondence with a mirror aft (3) said lower edge line (LCL) lies above a waterline (WPL) in any loading condition. Passenger craft (100) comprising a hull (1) according to one or more of claims 1 to 12. A boat (100) according to claim 13, comprising at least one passenger seating area (103) on a deck (101) abaft a master area, wherein the at least one passenger seating area (103) is provided with a plurality of seats (106) and occupies the main deck (101) up to a transom (3) of the boat (100). Boat (100) according to claim 14, wherein the at least one passenger seating area (103) is provided at least in part with a cover (107). Craft (100) according to one or more of claims 13 to 15, having a single deck structure.