DE202022107298U1 - Ballastless cargo ships - Google Patents

Abstract

die zwischen 0,65 und 0,85 liegt.

Ballastless cargo ship (100), characterized in that the ship (100) comprises:
a fuselage comprising an elongate upper body (101) and an elongate lower body (102), the lower body (102) being disposed beneath the upper body (101), the upper body (101) and the lower body ( 102) having a substantially rectangular cross-section along a length of the fuselage, the lower body (102) having smaller dimensions than the upper body (101); and
at least one cargo hold (110) located at least in correspondence with the upper body (101) for storing at least the cargo and void spaces (109) at least partially in correspondence with the lower body (102);
the lower body (102) having respective side walls (107) connected to a bottom wall (111) of the upper body (101); and
wherein for a predefined parameter, the parameter being selected from a group comprising a maximum draft (T _max ), a minimum draft (T _min ) and a maximum overall beam (B _max ) of the ship, a geometry of the ship is defined by: i) a ratio (%B _max ) between a flat bottom latitude and a maximum water plane area of the ship ranging between 0 and 0.7, ii) a ratio (% T _max ) between a submerged Upper body draft and a maximum vessel draft ranging between 0 and 0.8, and iii) a ship midship section coefficient (C _m ) defined as: $$1-\frac{\left(1-\%T_{max}\right)\ast \left(1-\%B_{max}\right)}{2}$$

which is between 0.65 and 0.85.

Description

TECHNICAL AREA

In general, the present invention relates to ships and preferably to cargo ships without ballast systems, the form of which consists of two separate upper and lower bodies.

STATE OF THE ART

A ship, especially a cargo ship, is designed taking into account the weight of the ship itself and the weight of the cargo to be carried on board. As a result, when unloaded or partially loaded, the ship floats higher relative to the water surface and can become unstable and susceptible to trimming or heeling in cross swell and crosswinds. Also, the ship's propellers are getting closer to the surface of the water, which can cause cavitation damage to them and cause them to operate at a lower than recommended operating range, increasing propeller wear and the need for maintenance. To avoid these problems, ships usually incorporate a ballast system consisting of tanks of seawater that maintain the necessary draft to ensure efficient propeller operation, safe navigation, and to keep the ship balanced. The ballast water is usually loaded and discharged in different ports, which may be in different countries or continents. Due to the improved speed of ships, these ships are able to travel between different countries in a short time, with living aquatic species, especially invasive marine species, contained in the ballast water, so the release of these aquatic living species when this ballast water at a discharged in a place far from where it was loaded can lead to environmental problems that disrupt ecosystems on a global scale.

To prevent certain species from entering the ballast tanks, some ships incorporate filtration systems that block these species. Other ships have ballast water treatment systems that include heating systems, UV light systems, oxygen deprivation systems, etc. to kill or at least reduce the aquatic life species contained in the ballast water. However, all these solutions are inefficient and have high installation and maintenance costs. In addition, these solutions require large amounts of energy to operate and therefore have to burn more fuel, resulting in higher emissions.

Some ships, known as "ballastless ships", feature a group of structural hulls that run the full length of the ship. In ballasting mode, these hulls can be opened to the sea with an inlet port at the bow and an outlet port at the stern, with a flow of water flowing from the inlet port to the outlet port. This allows these hulls to be flooded, reducing hull buoyancy and allowing the ship to sink to the desired ballast draft. An example of such a ship is in U.S. 2003/019 413 A1 (Parsons) described. However, this solution is technically complicated and leads to a large resistance on the ship's hull during passage through the water.

Additionally, multihull vessels without a ballast system are known in the art. These types of ships do not need to carry ballast water. However, the manufacturing and maintenance costs for this type of ship are significantly higher than for single-hull ships. In addition, due to the particular construction of these ships, it is difficult to integrate a sufficiently large cargo hold in one piece, and the beam overall or beam on frames (hereinafter "width") is significantly larger than for single-hull ships. Another disadvantage of these vessels is that the wetted surface area and sea drag increase significantly when the multihull vessels are carrying heavy loads at low speeds.

Ships with a V deadrise designed with a high overall beam are known in the art. In these types of ships, ballast water may not be required to adequately control the ship's center of gravity under various cargo conditions. However, these solutions cannot be used for the transport of goods, e.g. objects, solid materials, etc., which require specific hull geometries, dimensions or shapes.

Therefore, it would be desirable to find an alternative solution to ballast water systems that avoids all the disadvantages mentioned above and ensures safe and efficient navigation of cargo ships.

DESCRIPTION OF THE INVENTION

The subject of the invention is a ballastless ship, in particular a ballastless cargo ship, which has a hull with an elongate upper body which serves as a cargo hold and an elongate lower body which serves as a buoyancy compensation volume, the lower body being arranged below the upper body . The upper and lower bodies have a substantially rectangular cross-section along the length of the torso, with the lower body having smaller dimensions (it is narrower and flatter) than the upper body. The midship area has two bilges per side instead of one. The concept of the ballast effect in conventional (ballasted) construction is replaced by the practical reduction in hull buoyancy volume. In particular, the upper body and the lower body may have a substantially rectangular cross-section along the length of the cargo hold, e.g., the hold of the ship, while the bow and stern of the ship may have a substantially the same or different cross-section. For example, the bow section of the ship may be a bulbous bow, a clipper bow, a curved bow, or some other type of bow. The bow section can be designed to reduce the resistance of the hull when cutting through water. On the other hand, the stern section of the ship may be a square or transom stern, an elliptical stern, a fan stern, a merchant stern, or some other type of stern.

The lower body is connected to the bottom wall of the upper body in the middle part of the ship (below the hold). The underside of both bodies can have a deadrise. This rise can vary along the length of the ship. The connection between the upper body and the lower bodies at bow and stern can become tangentially continuous and occur at the sidewalls. Therefore, the upper and lower volumes at the bow and end of the ship can become one.

The upper body and the lower body may be connected to each other by internal frames, pillars, or the like. The lower body, in cross-section, has distinct concave areas at its edges. The height of the upper body relative to the height of the lower body may depend on the difference between the ship's maximum and minimum displacements. For example, the greater the difference between the ship's maximum and minimum displacements, the greater the height of the lower body relative to the height of the upper body. In some examples, the height of the upper body may be between 45% and 85% relative to the molded depth of the vessel. Thus, in such examples, the height of the lower body may be between 55% and 15% in relation to the molded depth of the vessel. To compensate for this difference between the ship's maximum and minimum displacement, the ship's maximum draft (upper body draft) can be further varied such that the greater this difference, the greater the ship's maximum draft. Alternatively, the beam and draft of the ship can be changed together to compensate for this difference.

The volume distribution of the lower body alters the vertical distribution of hull buoyancy so that in a light (unloaded) condition the ship has a greater draft than other known ships with other ship geometries.

The ballastless cargo ship also comprises at least one cargo hold, in other words at least one volume for the transport of the cargo, such as the hold, arranged at least in correspondence with the upper body, for at least storing the cargo. This cargo hold may entirely occupy the space defined by the upper body, or entirely or partially occupy the space defined by the upper body and also partially occupy the space defined by the lower body of the ship. The cargo hold can also protrude from the upper body so that it partially occupies the ship's deck.

The ballastless cargo ship also includes void spaces in line with the lower body. These voids serve as buoyancy tanks for the ship. A portion of these void spaces may also be used for the storage of fuel tanks, piping systems or a trim leveling system as described below, as well as other systems or elements of the ship. For example, the ratio between the volume of the voids and the maximum volumetric displacement of the ship can be between 0.1 and 0.45, although other ratios can also be achieved depending on the ship design.

The cross section of the lower body may have sloping side walls which may be connected to each other and to the bottom wall or side walls of the upper body. These inclined sei Sidewalls can be substantially planar (the sloping sidewalls can be at a substantially constant angle relative to the water surface) or curved (the sloping sidewalls can be at a variable angle relative to the water surface). In any case, the equivalent average slope of the sloped sidewalls (determined for an equivalent lower body volume with fully flat sloped sidewalls) may range between 0.5° and 85° with respect to the horizontal. In some embodiments, the lower body further includes a flat bottom (also known as a flat bottom wall) located at a central portion of the bottom of the hull and along the length of the hull, and preferably along the length of the holds, such that the sloped side walls both sides of the flat bottom are formed so that the lower body has a substantially truncated V-shaped cross section. This obtuse V-shaped lower body cross-section essentially resembles an inverted trapezoidal cross-section.

The cross-sectional shape defined in this way in the mostly prismatic length of the ship forms four distinct bilges instead of the two in other known ships with different ship geometries. The bilges may be rounded or their forming side and bottom panels may converge at an angle.

• i) ein Verhältnis (%B_max) zwischen dem Breitenmaß des flachen Bodens des Schiffes und der maximalen Breite im Bereich der Wasserfläche des Schiffes, das zwischen 0 und 0,7 liegt,
• ii) ein Verhältnis (% T_max) zwischen dem eingetauchten Tiefgang des oberen Körpers (mit anderen Worten dem vertikalen Abstand, der dem eingetauchten Teil der vertikalen Wände des oberen Körpers entspricht) und dem maximalen Tiefgang des Schiffes, das zwischen 0 und 0,8 liegt, und
• iii) einen Koeffizienten für den mittleren Abschnitt (C_m) des Schiffes, der wie folgt definiert ist:

$$\begin{array}{l}\%T_{max}+\left(1-\%T_{max}\right)\cdot \%B_{max}+\frac{\left(1-\%T_{max}\right)\cdot \left(1-\%B_{max}\right)}{2}=\\ =\frac{1+\%T_{max}+\%B_{max}-\%T_{max}\ast \%B_{max}}{2}=1-\frac{\left(1-\%T_{max}\right)\ast \left(1-\%B_{max}\right)}{2}\end{array}$$

die zwischen 0,65 und 0,85 liegt.The ballastless cargo ship is defined such that for a predefined parameter, the parameter being selected from a group comprising a maximum draft (T _max ), a minimum draft (T _min ) and a maximum beam (also known as beam on frames or beam overall) (B _max ) of the ship, the geometry of the ship is defined by:

• i) a ratio (%B _max ) between the width dimension of the ship's flat bottom and the maximum beam in the area of the water surface of the ship, which is between 0 and 0.7,
• ii) a ratio (% T _max ) between the submerged draft of the upper body (in other words the vertical distance corresponding to the submerged part of the vertical walls of the upper body) and the maximum draft of the ship, lying between 0 and 0.8 lies, and
• (iii) a coefficient for the middle section (C _m ) of the ship, defined as follows:

$$\begin{array}{l}\%T_{max}+\left(1-\%T_{max}\right)\cdot \%B_{max}+\frac{\left(1-\%T_{max}\right)\cdot \left(1-\%B_{max}\right)}{2}=\\ =\frac{1+\%T_{max}+\%B_{max}-\%T_{max}\ast \%B_{max}}{2}=1-\frac{\left(1-\%T_{max}\right)\ast \left(1-\%B_{max}\right)}{2}\end{array}$$

which is between 0.65 and 0.85.

The midship section coefficient of a ship, as used herein, is the ratio between the area of the ship's midships for a given draft and the area of the rectangle containing that area of the ship's midships, the width dimension of the rectangle being the shaped overall breadth of the ship and the height of the rectangle corresponds to the previously determined draft.

The coefficient %B _max , which was defined as the ratio between the width dimension (b) of the ship's flat bottom and the maximum width (B _max ) of the ship in the area of the ship's water surface, is then: $$\%B_{max}=\frac{\text{b}}{B_{max}}$$

Similarly, the coefficient %T _max , which is defined as the ratio between the submerged draft (t) of the upper body and the maximum draft of the vessel (T _max ): $$\%T_{max}=\frac{\text{t}}{T_{max}}$$

The lower hull cross-section provides adequate draft and stability in light conditions, avoiding cavitation damage to the propeller without the need for a ballast system. It also reduces hull drag and improves propulsion efficiency. The presence of two additional bilges increases vortex roll damping. The volume of voids in lower body ensures that the maximum draft of the ship is not exceeded (the voids act like a float when the ship is loaded). The lower body may also have a shape that varies along the length of the body, becoming more pointed towards the bow. This longitudinal distribution of lower body volume changes the position of the hull's center of buoyancy with changes in draft.

Furthermore, by having an upper body with a substantially rectangular cross-section throughout the length of the ship and by eliminating side ballast tanks, the space occupied by the hold in the upper body can be maximized (the hold can have a width dimension substantially equal to the beam of the ship ), compensating for any loss of space in the lower body.

The block coefficient of a ship is defined as the ratio of the ship's underwater volume to the volume of a parallelepiped-shaped block defined by the length between perpendiculars, beam on frames (breadth) and depth (draft) of the ship. In some embodiments, this ship's block coefficient depends on a value of the angle of the sidewalls of the lower body, which may be inclined, relative to the baseline.

For example, given B _max and T _max and t and %T _max constant (only b and % B _max are varied), a larger angle of the sloping sidewalls relative to the flat bottom means a higher block coefficient and vice versa. In other examples, given B _max and T _max and b and % B _max constant (only t and % T _max are varied), a larger angle of the sloping sidewalls to the flat bottom means a lower block coefficient and vice versa. Also, a ship's midship section coefficient and block coefficient are associated with each other. That is, the lower the midship section coefficient, the lower the block coefficient, and vice versa.

und liegt zwischen 0,52 und 0,72, wobei %A_floatmax das Verhältnis zwischen der Fläche des flachen Bodens (A_flatbottom) des unteren Körpers des Schiffs und der Fläche der maximalen Wasserlinie (A_floatmax) des Schiffes ist. Der sich daraus ergebende Blockkoeffizient (C_b) des Schiffes hängt von der Differenz zwischen der maximalen und minimalen Verdrängung des Schiffes ab.In some embodiments, the block coefficient (C _b ) is defined as follows: $$\begin{array}{l}\%T_{max}+\left(1-\%T_{max}\right)\cdot \%A_{flOatmax}+\frac{\left(1-\%T_{max}\right)\cdot \left(1-\%A_{flOatmax}\right)}{2}\\ =\frac{1+\%T_{max}+\%A_{flOatmax}-\%T_{max}\ast \%B_{max}}{2}\\ =1-\frac{\left(1-\%T_{max}\right)\ast \left(1-\%A_{flOatmax}\right)}{2}\end{array}$$

and is between 0.52 and 0.72, where %A _floatmax is the ratio between the flat bottom area (A _flatbottom ) of the vessel's lower body and the area of the maximum waterline (A _floatmax ) of the vessel. The resulting block coefficient (C _b ) of the ship depends on the difference between the ship's maximum and minimum displacement.

Then the coefficient is %A _floatmax , which is defined as the ratio between the flat bottom area (A _flatbottom ) of the lower body of the ship (if the ship does not have a flat bottom, this ratio is zero) and the area of the maximum waterline (A _floatmax ) of the ship is defined: $$\%A_{flOatmax}=\frac{A_{flatbOttOm}}{A_{flOatmax}}$$

In some embodiments, at minimum draft (minimum weight) of the ship, the lower body is at least partially submerged and at maximum draft (maximum weight) of the ship, the lower body is fully submerged and the upper body is partially submerged.

In some embodiments, the at least one cargo hold is a hold, in particular a box-shaped hold. In such cases, due to the lack of lateral ballast tanks in the ship, the cargo hold can have a width dimension which essentially corresponds to the width of the ship over the length of the ship. Therefore, the hold can make maximum use of the space in the ship. Then, a reduction in the shaped depth of the hold caused by the presence of the lower body can be offset by the increase in the width dimension of the hold.

In the case of box-shaped holds, the influence of the transition between the flat bottom of the lower body and the side walls of the upper body on the ship's hydrodynamic parameters is particularly relevant, since it is of interest to achieve the maximum value (shaped width) at the lowest possible draft, because the box-shaped hold should be placed as deep as possible in the ship for reasons of stability and also helps to ensure that the maximum draft is not too great. Therefore, in these special box-shaped holds, the side walls of the lower body can have a smaller angle to the flat floor than in other known holds. For example, in box-shaped cargo holds, the sloping side walls may be at an angle of 0.5° to 85° relative to the flat floor.

In some embodiments, the ship's minimum draft depends on the ship's propulsion system. In other words, the minimum draft may be the draft required for proper immersion of the ship's propulsion system propellers. The ship's minimum draft may also depend on the ship's stability and seakeeping requirements.

In some embodiments, the unballasted cargo ship includes two propellers. In such embodiments, the ballastless cargo ship may further comprise two propulsion engines such that when the ship is sailing at its minimum draft, only one of the two propulsion engines is configured to drive the two propellers, and when the ship is sailing at a draft that is greater than the minimum draft, each propulsion motor drives a corresponding one of the two propellers. Essentially, there are two clearly differentiated extreme loading conditions: empty and full load. When the cargo ships are empty (no cargo), the displacement and draft are small, as is the ship's drag while moving through the water (energy saving). When fully loaded (maximum carrying capacity), the resistance of the ballastless cargo ship is very similar to that of a conventional cargo ship at sea. This can mean that the difference in the power required to propel the ship is large in the two states. As the draft has been reduced to the minimum required for the ship to operate properly, a single prime mover is used to drive the two propellers for unloaded operation. At any other draft greater than the minimum draft, each motor of the two propulsion motors is used to drive one of the two propellers. In some examples, the propulsion engines may be diesel-electric propulsion engines, such as ASD (Azimuth Stern Drive) propulsion engines with mechanical (L-drive, Z-drive) or electric powertrains that allow better control of the to each enable the power delivered by each propeller. These diesel-electric drive motors can be powered by a variety of generators, which can be operated depending on the power requirements of the drive motors.

In some embodiments, the hull also includes a trim compensation system having at least two tanks in fluid communication with one another, wherein a fluid, e.g., fresh water, stored in the at least two tanks is transported between the at least two tanks (weight shift on board), to keep the ship stable. This trim compensation system is able to correct heel and trim. The size of the tanks and the position of the tanks within the ballastless cargo ship can be optimized in such a way that sufficient torque is achieved with as little water as possible. In some examples, there may be at least one tank near each of the side shells (port and starboard) of the hull in fluid communication with each other to correct the ship's heel, and there may be at least one tank near the bow and a other tanks near the stern in fluid communication with each other to correct the ship's trim.

The cargo ship described here manages without ballast water systems and thus avoids the transport of seawater containing invasive marine animals. Therefore, this solution is more effective than current treatment methods in reducing the potential for introduction of the invasive marine species to other alien ecosystems. In addition, significant energy savings are achieved by not treating the ballast water. It also eliminates the need to install tanks, pumps, pipes, ducts and other elements of the water ballast system with the consequent savings in installation and maintenance costs. Another advantage is that the vessel described here is more efficient, since it significantly reduces its drag when moving through the water when empty (lower displacement, lower wetted surface area, and lower power requirements).

character list

A series of drawings are provided to complete the description and to facilitate understanding of the invention. The drawings form part of the description and illustrate an embodiment of the invention which is not to be construed as limiting the scope of the invention but merely as an example of one possible embodiment of the invention.

• Die 1A-C zeigen verschiedene Ansichten eines Ballastlosen Frachtschiffs gemäß einer bestimmten Ausführungsform der Erfindung.
• 2 zeigt einen Querschnitt durch das ballastlose Frachtschiff von 1 entlang der Linie A-A.
• 3A zeigt eine Querschnittsansicht des ballastlosen Frachtschiffs gemäß einer bestimmten Ausführungsform der Erfindung mit den Parametern, die das ballastlose Frachtschiff in zwei Dimensionen definieren.
• 3B zeigt eine Querschnittsansicht des ballastlosen Frachtschiffs aus 3A mit den Parametern, die das ballastlose Frachtschiff in drei Dimensionen definieren.

The drawings include the following figures:

• The 1A-C 12 show different views of a ballastless cargo ship according to a specific embodiment of the invention.
• 2 shows a cross section through the ballastless cargo ship from 1 along line AA.
• 3A Figure 12 shows a cross-sectional view of the unballasted cargo ship according to a particular embodiment of the invention with the parameters defining the unballasted cargo ship in two dimensions.
• 3B Figure 12 shows a cross-sectional view of the unballasted cargo ship 3A with the parameters that define the ballastless cargo ship in three dimensions.

DETAILED DESCRIPTION OF THE INVENTION

The 1A-C 12 show various views of a ballastless cargo ship 100 according to a particular embodiment of the invention.

1A 12 shows a perspective view of the ballastless cargo ship 100 from below. The ballastless cargo ship 100 consists of an upper body 101 and a lower body 102 along the entire length of the ship 100. The 1B and 1C show a bottom and side view, respectively, of the ship 100. The upper body 101 and the lower body 102 of the ship 100 have a substantially rectangular cross-section along their central portion, particularly along the space occupied by the hold (not shown in this figure ). The lower body 102 is narrower and flatter than the upper body 101.

In the bow section 103 of the ship 100, the shape of the lower body 102 tapers to a point, while the lower body 102 in the stern section 104 can widen (the lower body 102 in the stern section 104 is the part of the ship 100 where there is a greater concentration of weights such as machines, etc.). This helps the ship 100 avoid trimming and reduce drag in sea states. The geometry of the arcuate portion 103 of the upper body 101 was chosen to match the geometry of the arcuate portion 103 of the lower body 102, thus avoiding very large "horizontal" areas between the upper body 101 and the lower body 102 that increase drag and reduce efficiency. These geometries, which become more pointed longitudinally, minimize slamming. At a certain point, the lower body 102 forms a transition surface between the bottom of the ship 100 and the upper body 101, so that a space is created for the attachment of the propellers.

While the ballastless cargo ship 100 in the 1A-C Fig. 1 shows a bow section 103 and a stern section 104 with a certain geometry, the bow section and the stern section can have any other geometry depending on the particular ship design.

2 FIG. 14 shows a cross-sectional view of the ballastless cargo ship 100 of FIG 1 along line AA. The upper body 101 of the ship 100 has a generally rectangular cross section defined by the side shells 105 and the bottom wall 111 of the hull and the deck 106 of the ship 100 . The side shells 105 of the upper body 101 are connected at their lower ends to the bottom wall 111 which in turn is connected to the side walls 107 of the lower body 102 by intermediate sloping or curved walls 112 which create concave surfaces on the outer surface of the hull. These sloping or curved walls 112 form the transition area between the bottom wall 111 of the upper body 101 and the lower body 102. In this embodiment, the side walls 107 of the lower body 102 have a certain inclination with respect to the flat bottom 108. The lower body 102 also has rounded lower edges 113 to improve the hydrodynamic conditions of the hull.

The lower body 102 includes voids 109 which serve as buoyancy bodies for the ship 100 . These voids 109 are dimensioned such that the volume of air in the submerged voids 109 corresponds to the volume of air in the fully or partially empty submerged ballast tanks when loaded in a conventional ship. For example, the ratio between the volume of the void spaces 109 and the maximum volumetric displacement of the ship 100 can be between 0.1 and 0.45. The ship 100 further includes a box-shaped cargo hold 110 located within the upper body 101 and protruding slightly above the deck 106 for storage of cargo. This cargo hold 110 has a width which essentially corresponds to the width of the ship 100 and a length which essentially corresponds to the length of the ship 100 . In particular, the length of the cargo hold 110 can essentially correspond to the length of the central section of the ship 100, i.e. excluding the bow section 103 and the stern section 104.

While the ballastless cargo ship is 100 in 2 shows a cargo hold 110 arranged in correspondence with the upper body 101 of the ship 100, the cargo hold 110 may also partially occupy the space contained in the lower body 101 and/or protrude beyond the deck line of the ship 100. While the ballastless cargo ship 100 shows a single hold, in other embodiments it may have more than one hold arranged longitudinally along the length of the ship, more than one hold arranged transversely to the length of the ship, or any combination thereof give.

3A 12 shows a cross-sectional view of an unballasted cargo ship 200 according to a particular embodiment of the invention, including the parameters that define the geometry of the ship 200 in two dimensions (2D). 3B FIG. 14 shows a cross-sectional view of the ballastless cargo ship 200 of FIG 3A , including the parameters that define the ship 200 in three dimensions (3D). The in the 3A-B The cross-sectional view of the unballasted cargo ship 200 shown is similar to the cross-sectional view of the ship 100 of FIG 2 .

The unballasted cargo ships 200 described herein were designed with a hull geometry, shape and buoyancy distribution such that the ship's draft is always between the minimum and maximum hull draft in any load condition. The term "hull or ship draft" as used herein refers to the vertical distance between the waterline and the bottom of the hull, including the thickness of the hull. The minimum draft corresponds to the minimum water depth that a ship can safely navigate in compliance with the applicable maritime regulations. The minimum draft is normally reached when no cargo is carried on board. Similarly, ship's maximum draft refers to the maximum depth of water that a ship can safely navigate and maintain in compliance with applicable maritime regulations and is normally achieved at the ship's maximum deadweight tonnage, i.e. i.e. when fully loaded.

• - Leichtgewicht (LTD),
• - Konstanten (K) = Vorräte und Verbrauchsgüter + Besatzung und Effekten + Öle und Ersatzteile + Effekte auf Lagerräume + Sonstiges), und
• - 10% Verbrauch (Kraftstoffe und Öle in Tanks), so dass,

$${\text{W}}_{\text{min}}=\text{LTD}+\text{K}+10\%\text{Verbr}\text{.}$$

The ship's loading condition, which corresponds to the minimum draft, is that at which the total weight of the ship is the smallest possible weight (W _min ), also known as the minimum displacement. In this case, the total weight is the sum of the following weights:

• - Lightweight (LTD),
• - Constants (K) = Supplies and Consumables + Crew and Effects + Oils and Spare Parts + Effects on Storerooms + Miscellaneous), and
• - 10% consumption (fuels and oils in tanks), so that,

$${\text{W}}_{\text{at least}}=\text{LTD}+\text{K}+10\%\text{consumption}\text{.}$$

Therefore, for the minimum draft, the ship should have a hull underbody volume (V _min ) that _{compensates for this minimum weight (W min )} : $${\text{V}}_{\text{at least}}={\text{W}}_{\text{at least}}/\text{d;}\left(\text{i.e}=\mathrm{1,025}{\text{t/m}}^3;\text{specific gravity of sea water}\right)$$

• - Leichtgewicht (LTD), und
• - Tragfähigkeit (DWT)= Ladung+K+100% Verbrauch, so dass,

$${\text{W}}_{\text{max}}=\text{LTD}+\text{DWT}=\text{D}\left(\text{Vollladungsverdr}\ddot{\text{a}}\text{ngung; Maximalgewicht des Schiffes}\right)$$

On the other hand, the condition of the ship's cargo corresponding to the maximum draft is that in which the total weight of the ship is the maximum possible weight (W _max ). In this condition, the ship's weight, also known as its laden (or maximum) displacement, is the sum of the following weights:

• - Lightweight (LTD), and
• - deadweight tonnage (DWT)= cargo+K+100% consumption, so that,

$${\text{W}}_{\text{Max}}=\text{LTD}+\text{Crossdresser}=\text{D}\left(\text{full charge compression}\ddot{\text{a}}\text{tion; Maximum weight of the ship}\right)$$

Therefore, for the maximum draft, the ship should have a volume (V _max ) of hull underbody that _{balances this weight (W max )} : $${\text{V}}_{\text{Max}}={\text{W}}_{\text{Max}}/\text{d;}\left(\text{i.e}=\mathrm{1,025}{\text{t/m}}^3\right)$$

The transition between V _max and V _min should be such that the rate of volume growth of the lower body is directly related to the change in the hull of the vessel, ie the rate of volume growth of the lower body increases with the growth rate of the beam (B(T)) for that vessel draft. The term "breadth" (also "breadth overall" or "breadth on frames") here refers to the breadth of a ship at the widest point, measured at the ship's nominal waterline. This rate of width growth may be limited by design constraints such as a given maximum draft, minimum draft, and maximum beam of the ship.

$${\displaystyle \int {}_0^{Tmin}}B\left(T\right)dT=AMmin$$

wobei AM_min die Querschnittsfläche ist, die durch den eingetauchten Teil des Mittschiffsabschnitts im Zustand des geringsten Tiefgangs definiert ist.The relationship between the ship's draft (T) and the volume of the hull underbody that balances the corresponding weight (W) can also be expressed as a function of the ship's Afloat(T)) for the draft under consideration. Then the condition for the minimum draft (minimum weight) of the ship as a function of the floating area or as a function of the beam can be expressed as follows: $${\displaystyle \int {}_0^{Tmin}}AflOat\left(T\right)\mathrm{i.e}T=Vmin=Wmin/\mathrm{i.e}$$

$${\displaystyle \int {}_0^{Tmin}}B\left(T\right)\mathrm{i.e}T=AMmin$$

where AM _min is the cross-sectional area defined by the submerged portion of the midship section in the condition of shallowest draft.

$${\displaystyle \int {}_0^{Tmax}}B\left(T\right)dT=A{M}_{max}$$

wobei AM_max die Querschnittsfläche ist, die durch den eingetauchten Abschnitt des Mittschiffsabschnitts im Zustand maximalen Tiefgangs definiert ist.The condition for the maximum draft (maximum weight) of the ship can be expressed as a function of the floating area or as a function of the beam as follows: $${\displaystyle \int {}_0^{Tmax}}AflOat\left(T\right)\mathrm{i.e}T=Vmax=Wmax/\mathrm{i.e}$$

$${\displaystyle \int {}_0^{Tmax}}B\left(T\right)\mathrm{i.e}T=A{M}_{max}$$

where AM _max is the cross-sectional area defined by the submerged portion of the midship section in the maximum draft condition.

Therefore it is necessary to define the functions Afloat(T) and B(T). The functions mentioned can be defined in relation to intervals. In the interval of functions corresponding to the lower body of the hull, the swimming area and draft are constantly increasing.

According to 3A the initial data defining the ballastless cargo ship (assuming that the beam of the ship increases linearly) are the following: maximum draft (T _max ), minimum draft (T _min ), ratio (%B _max ) between the beam dimension (b ) of the flat bottom of the vessel's lower body and the maximum beam (B _max ), ratio (% T _max ) between the submerged draft (t) of the upper body (ie, vertical lateral dimension of the vessel's upper body) as well as the maximum draft ( T _max ) and the maximum width (B _max ). For this particular embodiment, T _max has been considered as a predefined parameter, ie the ship's T _max is used as a constraint for determining the midships section coefficient (C _m ), the % B _max ratio and the % T _max ratio. Alternatively, the midship section coefficient, % B _max ratio and % T _max ratio can be determined using maximum beam (B _max ) or minimum draft (T _min ) as predefined parameters (constraint), since all of these dimensions (maximum draft, minimum draft and maximum width) are related to each other.

alle möglichen Lösungen für die Konstruktion des ballastlosen Frachtschiffs gefunden werden. Jede erhaltene Lösung hat einen minimalen Tiefgang und eine maximale Breite. Je niedriger der % B_max und je höher der % T_max ist, desto niedriger ist der Mittschiffsabschnittskoeffizient und auch der Blockkoeffizient des Schiffes. Darüber hinaus und als Folge davon sind der Mittschiffsabschnittskoeffizient und auch der Blockkoeffizient umso niedriger, je stärker die Seitenwände des unteren Körpers geneigt sind. Der Mittschiffsabschnittskoeffizient und der Blockkoeffizient eines Schiffes stehen in Beziehung zueinander. Das heißt, je niedriger der Mittschiffsabschnittskoeffizient ist, desto niedriger ist der Blockkoeffizient und umgekehrt.Knowing the maximum and minimum displacement of the ship and a given maximum draft (constraint), by varying the values of %B _max and %T _max between 0 and 0.7 and noting that $$1-\frac{\left(1-\%T_{max}\right)\ast \left(1-\%B_{max}\right)}{2}=Cm=\left(\mathrm{0.65,0.85}\right)$$

all possible solutions for the construction of the ballastless cargo ship are found. Each solution obtained has a minimum depth and a maximum width. The lower the % B _max and the higher the % T _max , the lower the midships section coefficient and also the block coefficient of the ship. In addition, and as a consequence, the more inclined the sidewalls of the lower body, the lower the midship section coefficient and also the block coefficient. A ship's midship section coefficient and block coefficient are related. That is, the lower the midship section coefficient, the lower the block coefficient, and vice versa.

According to 3B the initial data defining the unballasted cargo ship (assuming that the ship's lifted area increases linearly and the change in lifted area is due only to a change in breadth) are the following: maximum draft (T _max ), minimum draft (T _min ), ratio (% A _floatmax ) between the area of the flat bottom (A _flatbottom ) of the lower body of the ship and the area defined by a maximum waterline of the ship (A _floatmax ), ratio (% T _max ) between the side vertical dimension (t ) of the upper body of the ship and the maximum draft (T _max ) and maximum beam (B _max ). For this particular embodiment, T _max was considered as a predefined parameter, i.e. the ship's T _max is used as a constraint for determining the block coefficient (C _b ) (and also the midship section coefficient (C _m )), the ratio between the flat bottom area and the maximum water plane area of the ship and the ratio between the submerged draft of the upper body and the maximum draft of the ship. Alternatively, the vessel's ratio (% A _floatmax ) and ratio (% T _max ) can be determined using maximum beam or minimum draft as predefined parameters (constraint), since all of these dimensions (maximum draft, minimum draft and maximum beam ) are related to each other.

alle möglichen Lösungen für die Konstruktion des ballastlosen Frachtschiffs gefunden werden. Jede erhaltene Lösung hat einen minimalen Tiefgang und eine maximale Breite. Je niedriger der % B_max und je höher der % T_max, desto niedriger ist der Blockkoeffizient und auch der Mittschiffsabschnittskoeffizient des Schiffes. Außerdem und als Folge davon sind der Blockkoeffizient und auch der Mittschiffsabschnittskoeffizient umso niedriger, je stärker die Seitenwände des unteren Körpers geneigt sind. Der Blockkoeffizient und der Mittschiffsabschnittskoeffizient eines Schiffes stehen in Beziehung zueinander. Das heißt, je niedriger der Blockkoeffizient, desto niedriger der Mittschiffsabschnittskoeffizient und umgekehrt.Knowing the maximum and minimum displacement of the ship and a certain maximum draft (constraint), by varying the values of %B _max and %A _floatmax between 0 and 0.7 and noting that $$1-\frac{\left(1-\%T_{max}\right)\ast \left(1-\%A_{flOatmax}\right)}{2}=Cb=\left(\mathrm{0.52,0.72}\right)$$

all possible solutions for the construction of the ballastless cargo ship are found. Each solution obtained has a minimum depth and a maximum width. The lower the % B _max and the higher the % T _max , the lower the block coefficient and also the midship section coefficient of the ship. In addition, and as a consequence, the more inclined the sidewalls of the lower body, the lower the block coefficient and also the midship section coefficient. A ship's block coefficient and midship section coefficient are related. That is, the lower the block coefficient, the lower the midship section coefficient, and vice versa.

wobei D die Verdrängung bei voller Ladung (maximales Gewicht des Schiffes), W_load das Gewicht der im Schiff beförderten Ladung, W_cons das Gewicht der Verbrauchsgüter des Schiffes, d=1,025 t/m³ (spezifisches Gewicht des Meerwassers), L die Länge des Schiffes zwischen den Loten und B die geformte Breite ist.By constructing the lower body to the level of the minimum draft (T _min ) of the ship, a volume growth rate of the lower body is achieved which is directly related to the change in the ship's buoyancy area. In other words, the volume growth rate of the lower body increases with the growth rate of the beam for the design under consideration. The block coefficient (C _bm ) for the minimum draft (T _min ), ie the block coefficient of the lower bottom up to the height corresponding to the minimum draft, can be defined as follows: $$C_{bm}=\frac{D-W_{lOa\mathrm{i.e}}-0.9\ast W_{cOns}}{\mathrm{i.e}\ast L\ast B\ast T_{min}}$$

where D is the displacement at full load (maximum weight of the ship), W _load is the weight of the cargo carried in the ship, W _cons is the weight of the ship's consumables, d=1.025 t/m ³ (specific gravity of sea water), L is the length of the ship between the perpendiculars and B is the shaped breadth.

Therefore, the block coefficient of the lower hull for the minimum draft is determined based on the main dimensions of the ship, the required minimum draft and deadweight tonnage (DWT) and the consumption of the ship (autonomy). Then one obtains a value of the block coefficient of the lower body which depends on the minimum draft of the ship and which the ship design cannot exceed, imposing the maximum value of the block coefficient of the ship and therefore the minimum value of its maximum draft.

wobei C'_b der Blockkoeffizient des oberen Körpers im Bereich zwischen dem maximalen Tiefgang (T_max) und dem minimalen Tiefgang (T_min) des Schiffes ist. $$C_b^{\text{'}}=\frac{\left(C_b\ast T_{max}-C_{bm}\ast T_{min}\right)}{\left(T_{max}-T_{min}\right)}$$

The difference between the maximum volume (V _max ) and the minimum volume (V _min ) of the vessel is: $$V_{max}-V_{min}=L\ast B\ast \left(T_{max}-T_{min}\right)\ast C_b^{\text{'}}$$

where C' _b is the block coefficient of the upper body in the range between the maximum draft (T _max ) and the minimum draft (T _min ) of the ship. $$C_b^{\text{'}}=\frac{\left(C_b\ast T_{max}-C_{bm}\ast T_{min}\right)}{\left(T_{max}-T_{min}\right)}$$

und dann $$T_{max}=\frac{\left(D-W_{min}\right)}{d\ast L\ast B\ast C_b^{\text{'}}}+T_{min}$$

$$\begin{array}{l}\left(D-W_{min}\right)=W_{load}+\mathrm{0,9}\ast W_{cons}\\ T_{max}=\frac{\left(W_{load}+\mathrm{0,9}\ast W_{cons}\right)}{d\ast L\ast B\ast C_b^{\text{'}}}+T_{min}\end{array}$$

Since V= W/d, then: $$V_{max}-V_{min}=\frac{\left(D-W_{min}\right)}{\mathrm{i.e}}=L\ast B\ast \left(T_{max}-T_{min}\right)\ast C_b^{\text{'}}$$

and then $$T_{max}=\frac{\left(D-W_{min}\right)}{\mathrm{i.e}\ast L\ast B\ast C_b^{\text{'}}}+T_{min}$$

$$\begin{array}{l}\left(D-W_{min}\right)=W_{lOa\mathrm{i.e}}+0.9\ast W_{cOns}\\ T_{max}=\frac{\left(W_{lOa\mathrm{i.e}}+0.9\ast W_{cOns}\right)}{\mathrm{i.e}\ast L\ast B\ast C_b^{\text{'}}}+T_{min}\end{array}$$

This means that the maximum draft of the ship can be determined based on the main dimensions of the ship, the required minimum draft, the cargo capacity (DWT) and the consumption of the ship (autonomy).

die den Blockkoeffizienten des Schiffes als Funktion des Blockkoeffizienten des unteren Körpers bis zu seinem minimalen Tiefgang und des Blockkoeffizienten des oberen Körpers zwischen seinem minimalen Tiefgang und seinem Höchsttiefgang angibt.The following results from the formulas (1) and (2): $$C_b=\frac{V_{max}\ast C_b^{\text{'}}}{V_{max}+L\ast B\ast T_{min}\ast \left(C_b^{\text{'}}-C_{bm}\right)}$$

giving the ship's block coefficient as a function of the lower body block coefficient up to its minimum draft and the upper body block coefficient between its minimum draft and its maximum draft.

If the midships section coefficient of the ship's upper body (C' _m ) is considered to be 1 (this simplification maximizes the value of the ship's block coefficient and thus provides a minimum T _max , meaning that the maximum beam is at minimum draft or even at a draft lower than the minimum draft is reached), the block coefficient of the upper body is equal to the prismatic coefficient of the upper body (C' _p ), $$C_b^{\text{'}}=C_p^{\text{'}}\ast C_m^{\text{'}}=C_p^{\text{'}}$$

wobei AM die Fläche des Mittschiffsabschnitts des Schiffes im Zustand maximalen Tiefgangs (T_max) und AM_min die Fläche des Mittschiffsabschnitts des Schiffes bis zum minimalen Tiefgang (T_min) ist. Unter Anwendung der Vereinfachung C'_b=C'_p kann der Blockkoeffizient des Schiffs auf der Grundlage des prismatischen Koeffizienten des Schiffs und des prismatischen Koeffizienten des unteren Körpers ermittelt werden: $$C_b=\frac{V_{max}}{\frac{V_{max}}{C_p}-\frac{V_{min}}{C_{pm}}+L\ast B\ast T_{min}}$$

Using the prismatic coefficient of the ship (C _b ) and the prismatic coefficient of the lower body (C _pm ), the prismatic coefficient of the upper body (C' _p ) can be found: $$\begin{array}{l}C{\text{'}}_p\ast \left(AM-A{M}_{min}\right)=C_p\ast AM-C_{pm}\ast A{M}_{min}\\ A{M}_{min}\ast C_{pm}=AM\ast C_p\ast \frac{V_{min}}{V_{max}}\\ \\ {\text{C}}_p^{\text{'}}=\frac{C_p\ast \left(1-\frac{V_{min}}{V_{max}}\right)}{1-\frac{C_p\ast V_{min}}{C_{pm}\ast V_{max}}}\end{array}$$

where AM is the area of the midships section of the ship at the maximum draft condition (T _max ) and _AMmin is the area of the midships section of the ship down to the minimum draft (T _min ). Using the simplification C' _b =C' _p , the ship's block coefficient can be found based on the ship's prismatic coefficient and the lower body prismatic coefficient: $$C_b=\frac{V_{max}}{\frac{V_{max}}{C_p}-\frac{V_{min}}{C_{pm}}+L\ast B\ast T_{min}}$$

The maximum draft can be derived from this: $$T_{max}=\frac{V_{max}}{L\ast B\ast C_b}=\frac{V_{max}}{L\ast B\ast C_p}-\frac{V_{min}}{L\ast B\ast C_{pm}}+T_{min}$$

The remaining parameters of the ship can be derived from this block coefficient and the maximum draft with the predefined constraints.

$$C_{pm}\left(min\right)=\frac{1}{1+\frac{V_{max}}{V_{min}}\ast \left(1/C_p-1\right)}$$

The lower body prismatic coefficient C _pm is finite and cannot be less than 1-AM*(1-C _p )/AM _min since C' _p is less than 1. $$C{\text{'}}_p<1\to {\text{C}}_{\text{pm}}>1-\frac{\text{AT THE}\left(1-C_p\right)}{A{M}_{min}}=\frac{1}{1+\frac{V_{max}}{{\text{V}}_{\text{at least}}}\left(1/C_p-1\right)}$$

$$C_{pm}\left(min\right)=\frac{1}{1+\frac{V_{max}}{V_{min}}\ast \left(1/C_p-1\right)}$$

Since C _pm has a minimum value that cannot be reduced, and since the blocking coefficient C _b decreases as C _pm increases, the value of C _pm should be as close as possible (taking into account the value of C' _p ) to its minimum value (as high a block coefficient as possible is required to achieve as low a maximum draft as possible).

Therefore, the value of the block coefficient has an upper limit that cannot be reached. This maximum value corresponds to a value of the lower body's prismatic coefficient equal to the minimum value it can have, ie C _pm = C _pm (min), so that the value of the upper body's prismatic coefficient is equal to 1, C' _p = 1 $$C_b\left(\text{Max}\right)=\frac{V_{max}}{V_{max}-{\text{V}}_{\text{at least}}+{\text{L B T}}_{\text{at least}}}=\frac{D}{W_{lOa\mathrm{i.e}}+0.9\ast W_{cOns}+\mathrm{i.e}\ast L\ast B\ast T_{min}}$$

So the maximum draft of the ship has a lower limit that cannot be reached and the value of which is: $$T_{max}\left(min\right)=\frac{\left(V_{max}-V_{min}\right)}{L\ast B}+T_{min}=\frac{\left(W_{lOa\mathrm{i.e}}+0.9\ast W_{cOns}\right)}{\mathrm{i.e}\ast L\ast B}+T_{min}$$

The main characteristics of the ship will be within the limits described above.

As an example, a table is presented with various parameters of an unballasted cargo ship according to a specific embodiment of the invention, a conventional slow sea cargo ship and a standard cargo ship (both with ballast systems). Areas of unballasted cargo ships Slow Sea Cargo Ship default ship Ballastless cargo ship Ballastless cargo ship max B/T 1:35-3 2:1-2:3 2.3 1.9 1.4 c _b 0.52-0.72 0.65-0.73 0.74 0.69 0.54 _cm 0.65-0.85 0.97-0.995 0.94 0.79 0.67

The parameters compared in this table are the ratio (B/T) between the beam (B) and the draft (T), the block coefficient (C _b ) and the midship section coefficient (C _m ) of the vessels. The values of the ratio (B/T), the midship section coefficient (C _m ) and the block coefficient (C _b ) were determined based on the formulas described above. When defining the dimensions and ratios given in the table, it was assumed that the length and width of the unballasted cargo ship remain essentially constant. The most important dimensions to be determined are therefore the draft and the formed depth of the ballastless cargo ship.

The column "Ranges of unballasted cargo ships" refers to the values between which the unballasted cargo ship described here moves. The column "Slow sea carrier" refers to the values between which a conventional slow sea carrier with ballast system lies. The Standard Ship column refers to the values of a specific conventional ballasted cargo ship. The values of the columns "Slow Sea Freight Ship" and "Standard Ship" are known from the prior art (Ship design: Methodologies of Preliminary Design, Papanikolaou 2014). The "Ballastless Cargo Ship" column refers to the values of a specific unballasted cargo ship, as described herein, where the shaped depth of the ship has been altered to match the specified parameters. The values in the column "Ballastless cargo ships maximum" were determined for a maximum draft (restriction) of 150% of the maximum draft of a conventional cargo ship. In particular, the “Maximum Ballastless Cargo Ships” column shows values for unballasted cargo ships where only the shaped depth of the ship has been changed and the lower hull has a V-shaped riser (in other words, there is no flat bottom in the lower body and the lower body has a triangular cross-section).

The ratio (B/T) of the unballasted cargo ship described herein is between 1.35 and 3 when the shaped depth of the ship is changed significantly rather than the width, ie the maximum draft of the ship is increased. If the width and not the formed depth is changed significantly (and a similar maximum draft as a conventional ship, ie a ship with a ballast system, is achieved), the ratio (B/T) is between 2-3. The particular value of the ratio (B/T) depends on the difference in ship displacements due to different loading conditions and the specific geometry of the ship. Since only the shaped depth or the draft or both can be changed, there is a wide range [1.35-3] for the ratio (B/T. Then the design of the unballasted cargo ship can be determined to achieve a solution , where the ratio (B/T) substantially corresponds to the values of this ratio for the conventional ship (e.g., the standard cargo ship or the slow sea cargo ship), with the shaped depth and beam of the unballasted cargo ship being higher than the normal values of a conventional ship with similar characteristics The values of C _b and C _m are not affected by the value of the ratio (B/T) since they are affected by the value of the product (BxT)).

If one compares the values determined for the ballastless cargo ship with the values determined for the conventional or standard ships, one can determine how the draft and/or width of the ballastless cargo ship is greater. Therefore, the multiplication of width and draft is higher than in conventional ships (with ballast systems. The block coefficient and therefore also the midship section coefficient is lower than in conventional ships.

In this text, the term "includes" and its derivatives (such as "comprising", etc.) should not be construed in an exclusive sense, ie these terms should not be construed to exclude the possibility that what is being described and defined may contain other elements, steps, etc. The term "another" as used herein is defined as at least one second or more. As used herein, the term "coupled" is defined as connected, whether directly with no intervening elements or indirectly with at least one intervening element, unless otherwise noted. Two elements may be mechanically, electrically, or communicatively linked via a communications channel, path, network, or system.

The invention is of course not limited to the specific embodiments described herein, but also includes all variations that a person skilled in the art (e.g. in terms of choice of materials, dimensions, components, configuration, etc.) contemplated within the general scope of the invention can be as defined in the claims.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• US2003019413A1 [0004]

Claims (15)

An unballasted cargo ship (100), characterized in that the ship (100) comprises: a hull comprising an elongate upper body (101) and an elongate lower body (102), the lower body (102) being below the upper body ( 101) wherein the upper body (101) and the lower body (102) have a substantially rectangular cross-section along a length of the fuselage, the lower body (102) having smaller dimensions than the upper body (101); and at least one cargo hold (110) located at least in correspondence with the upper body (101) for storing at least the cargo and void spaces (109) at least partially in correspondence with the lower body (102); the lower body (102) having respective side walls (107) connected to a bottom wall (111) of the upper body (101); and wherein for a predefined parameter, the parameter being selected from a group comprising a maximum draft (T _max ), a minimum draft (T _min ) and a maximum overall beam (B _max ) of the ship, a geometry of the ship is defined by: i) a ratio (%B _max ) between a flat bottom latitude and a maximum water plane area of the ship ranging between 0 and 0.7, ii) a ratio (% T _max ) between one submerged upper body draft and a maximum ship draft ranging between 0 and 0.8, and iii) a ship midship section coefficient (C _m ) defined as: $$1-\frac{\left(1-\%T_{max}\right)\ast \left(1-\%B_{max}\right)}{2}$$

which is between 0.65 and 0.85. Ship (100) to claim 1 , wherein the lower body (102) comprises a flat bottom wall (108) located at a middle portion of a bottom of the hull and along the length of the hull, and sloping wall portions (112) located at a top of the two side walls (107 ) are designed to connect to the bottom wall (111) of the upper body (101). A ship (100) according to any one of the preceding claims, wherein a block coefficient (C _b ) of the ship is defined as: $$1-\frac{\left(1-\%T_{max}\right)\ast \left(1-\%A_{flOatmax}\right)}{2}$$

and between 0.52 and 0.72, where %A _floatmax is the ratio between an area of the flat bottom wall (108) of the lower body (102) and an area defined by a maximum waterline of the ship. Ship (100) according to any one of the preceding claims, wherein at minimum weight of the ship the lower body (102) is at least partially submerged and at maximum weight of the ship the lower body (102) is fully submerged and the upper body (101) is partially submerged is. Ship (100) according to any one of the preceding claims, wherein the at least one cargo hold (110) is a hold, preferably a box-shaped hold. A ship (100) according to any one of the preceding claims, wherein the at least one cargo hold (110) has a width dimension substantially equal to the overall beam of the ship along the length of the ship. A ship (100) according to any one of the preceding claims, wherein the minimum draft of the ship depends on a propulsion system of the ship. Ship (100) according to any one of the preceding claims, comprising two propellers. Ship (100) to claim 8 , which includes two propulsion engines such that when the ship is sailing at the minimum draft only one of the two propulsion engines is configured to drive the two Pro peller drives, and when the ship is sailing at a draft greater than the minimum draft, each propulsion motor drives a corresponding one of the two propellers. A ship (100) according to any one of the preceding claims, wherein the hull comprises a trim compensation system having at least two tanks fluidly connected to each other, wherein a fluid stored in the at least two tanks is transported between the at least two tanks to keep the ship stabilized . A ship (100) according to any one of the preceding claims, wherein the upper body (101) and the lower body (102) have the substantially rectangular cross-section along a length of the at least one cargo hold (110) of the ship. A ship (100) as claimed in any preceding claim, wherein the lower body (102) has rounded lower edges (113). A ship (100) according to any one of the preceding claims, wherein the width dimension of the lower section (102) varies along the length of the hull, preferably being wider near a stern section (104) of the ship and near a bow section (103) of the ship is narrower. A ship (100) according to any one of the preceding claims, wherein a midships section of the ship has two bilges per side. A ship (100) according to any one of the preceding claims, wherein the side walls (107) of the lower body (102) are inclined relative to the lower flat wall (108) of the lower body (102).

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