Large ships

Abstract

To provide a large ship with a rigid sail capable of securing field of view from a bridge in accordance with the SOLAS treaty.SOLUTION: This invention targets a large ship with 55 m or more in total length where a monitoring position WP of a bridge 19 is installed on a deck 9 in a plan view and where n rigid sails (n is an integer greater than or equal to 3) are installed at intervals along the centerline through a bow 5. The height dimension of all rigid sails is the one less than or equal to the highest dimension (it is a radar mast 21 in this example) of ship hull structures excluding the rigid sails. The height dimension of the rigid sail is determined so that the all tips in the height direction from the n-th rigid sail to the m-th rigid sail can be seen from the virtual view point at the monitoring position for the rigid sails from the n-th rigid sail to the (m+1)-th rigid sail, where m and n are integers, 2≤m<n, when viewed from the monitoring position WP. A width dimension is determined so that both ends in the width direction of the one or more rigid sails installed in the bow direction from the (m-1)-th rigid sail does not exceed a virtual visual line when looking at both ends of the m-th rigid sail from a virtual viewpoint of the monitoring position WP.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to large ships, and in particular, to large ships with a total length of 55 m or more, in which n (n is an integer of 3 or more) rigid sails are installed at intervals along the center line passing through the monitoring position of the bridge and the bow in a plan view on the deck.

Background Art

[0002] Large ships such as bulk carriers (also referred to as bulk carriers) consume a large amount of fossil fuels and thus are sources of CO 2 emissions. In order to suppress the consumption of fossil fuels, attempts have been made to install rigid sails on large ships to assist the propulsion force and reduce CO 2 emissions. A "rigid sail" is a sail made of a steel material or the like without using a soft material such as fabric in order to utilize wind power.

[0003] Since the rigid sail is installed on the deck to receive wind, when a rigid sail extending vertically on the deck is erected, it is necessary to ensure a view from the bridge so as not to affect the navigation of the ship (for example, Patent No. 5763479 (Patent Document 1)).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] To ensure safe navigation, there is an international convention, the "International Convention for the Safety of Life at Sea (SOLAS Convention)", which sets rules for ensuring the safety of ships. The current SOLAS Convention specifies details regarding the visibility from the bridge for ships with an overall length of 55 m or more (see Chapter V, Regulation 22, "Navigation Bridge Visibility" of the SOLAS Convention).

[0006] Note that the safety standards for ships established by each country are defined by laws and regulations based on the SOLAS Convention. For example, in Japan, the rules published by the Nippon Kaiji Kyokai (ClassNK), such as the "Steel Ship Rules", correspond to this.

[0007] An object of the present invention is to provide a large ship having a rigid sail that can ensure visibility from the bridge and complies with the SOLAS Convention.

Means for Solving the Problems

[0008] The ship to be improved by the present invention is a large ship with an overall length of 55 m or more, on which n (n is an integer of 3 or more) rigid sails are installed at intervals along the center line passing through the monitoring position of the bridge and the bow in plan view. In such a large ship, when the rigid sail closest to the bow is defined as the first rigid sail and the rigid sail closest to the monitoring position is defined as the nth rigid sail, the large ship of the present invention satisfies the following three conditions.

[0009] First condition: The height dimension of all rigid sails is equal to or less than the height dimension of the highest one among the hull structures excluding the rigid sails.

[0010] Second condition: When viewed from the monitoring position, from the nth rigid sail to the (m + 1)th rigid sail (where m is an integer satisfying 2 ≤ m < n), from the nth rigid sail to the m +1The height dimension is determined so that the tip in the height direction up to the nth rigid sail does not cross the straight line connecting the monitoring position and the bow.

[0011] Condition 3: The width dimension is determined so that both ends in the width direction of one or more rigid sails installed in the bow direction from the (m - 1)th rigid sail do not cross the virtual line of sight when looking at both ends of the mth rigid sail from the virtual viewpoint of the monitoring position. Here, the "virtual line of sight when looking at both ends of the rigid sail" is a virtual line passing through the virtual viewpoint and the upper and lower ends of the end in the width direction of the rigid sail.

[0012] When the dimensions of the n rigid sails are determined in this way, without the need for special calculations, the n rigid sails do not exist as obstacles blocking the safe line of sight in the line of sight from the bridge to the tip of the bow. That is, the shape dimensions of the rigid sails that can ensure the line of sight from the bridge and comply with the SOLAS Convention can be determined.

[0013] Here, "not cross" includes the state where the end in the width direction of the rigid sail coincides with the virtual line of sight. Also, m is arbitrarily determined by the designer within the range of 2 ≤ m < n.

[0014] If the above conditions are met, other design matters are arbitrary. For example, the width dimensions of the rigid sails from the nth to the (m + 1)th can be arbitrarily determined, but they may also cross the virtual line of sight to enhance the wind-receiving ability.

[0015] The nth to the (m + 1)th rigid sails can be made compliant with the SOLAS Convention if the height dimension Hn satisfies the following formula.

[0016] Height dimension Hn ≤ Zp - (Xn - Xp)tanθ - Zmin However, Xp: Length dimension in the ship length direction from the aft perpendicular of the monitoring position (bridge) Zp: Height dimension from the baseline of the monitoring position (bridge) Xn: Length dimension in the longitudinal direction of the ship from the aft perpendicular of the nth rigid sail from the bow Zmin: Height dimension from the base line at the lower end of the rigid sail θ: The angle formed by the straight line connecting the monitoring position (bridge) and the bow and the load water line (LWL).

[0017] Similarly, if the width dimension Bn of the mth rigid sail to the first rigid sail is determined to satisfy the following formula, it can be considered to comply with the SOLAS Convention.

[0018] Width dimension Bn ≤ ((Xn - Xp) tan 2.5) × 2 However, Xp: Length dimension in the longitudinal direction of the ship from the aft perpendicular of the monitoring position (bridge) Xn: It is the length dimension in the longitudinal direction of the ship from the aft perpendicular of the nth rigid sail from the bow.

Brief Description of the Drawings

[0019]

Figure 1

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Mode for Carrying Out the Invention

[0020] Hereinafter, with reference to the drawings, embodiments of the ship of the present invention will be described in detail.

[0021] FIG. 1 is a perspective view of a bulk carrier, which is an example of a ship in this embodiment. FIG. 2 is a left side view (side view seen from the starboard side) of the bulk carrier in this embodiment. FIG. 3 is a plan view. FIG. 4 is a partially cutaway perspective view of the rear part of the hull provided with the seventh to ninth cargo holds described later.

[0022] <Overall Configuration> The bulk cargo ship 1 of this embodiment is a large ship with a total length of 55 m or more, which is subject to the "International Convention for the Safety of Life at Sea (SOLAS Convention)", an international convention that defines rules for ensuring the safety of ships. The bulk cargo ship 1 has a bow 5 at one end in the advancing direction of the hull 3, a stern 7 at the other end, and a deck (upper deck) 9 on the hull 3. The interior of the hull 3 of the bulk cargo ship 1 is partitioned into a plurality of compartments, and below the deck 9, as partially shown in FIG. 4, cargo holds 11 (first hold 11A to ninth hold 11I) for loading cargo are formed. In FIG. 1, reference numerals 11A to 11I are attached to the positions where the first hold to the ninth hold are located inside. Each of the first hold 11A to the ninth hold 11I includes openings 13A to 13I that open to the deck 9, edge members (hatch coamings) 15A to 15I that surround the peripheries of the openings 13A to 13I, and hatch covers 17A to 17I that slide in the width direction of the hull and close the openings 13A to 13I. On the stern 7, a bridge 19, a radar mast 21, and a chimney 23 are provided.

[0023] The bulk cargo ship 1 of this embodiment is equipped with eight wind propulsion devices 25. In this embodiment, specifically, the eight wind propulsion devices 25 are eight rigid sail devices 25A to 25H. Each of the eight rigid sail devices 25A to 25H includes rigid sails 27A to 27H that are wind propulsion force generating portions. In FIGS. 1 to 3, the rigid sail devices 25A to 25H are in a use state, and the rigid sails 27A to 27H extend vertically on the deck 9. The eight rigid sail devices 25A to 25H are set with storage compartments (29A to 29H) arranged between two holds 11 arranged in the advancing direction FD of the ship (for example, between the first hold 11A and the second hold 11B, between the second hold 11B and the third hold 11C...). In FIG. 1, reference numerals 29A to 29H are attached to the positions where the storage compartments are located. As will be described later, the rigid sails 27A to 27H are configured to be storable in the storage compartments 29A to 29H provided below the deck 9.

[0024] <Design for ensuring visibility from the bridge> In this embodiment, the rigid sails 27A to 27H are arranged at intervals along the center line CL passing through the monitoring position WP of the bridge 19 and the top of the bow 5 on the deck 9 in a plan view. There are eight of them [in the generalized case, n (n is an integer of 3 or more)]. When the rigid sail 27A closest to the bow 5 is defined as the first rigid sail and the rigid sail closest to the monitoring position WP is defined as the nth rigid sail, it is designed to satisfy the following three conditions.

[0025] First condition: The height dimension of all the rigid sails is equal to or less than the height dimension of the highest one among the hull structures excluding the rigid sails. In this embodiment, as shown in FIG. 2, since the radar mast 21 has the highest height dimension (height dimension Zmax shown in FIG. 2), the first to eighth rigid sails (rigid sails 27A to 27H) are all equal to or less than the height dimension of the radar mast 21.

[0026] Second condition: When viewed from the monitoring position WP, the height dimensions are determined such that from the nth rigid sail to the (m + 1)th rigid sail (where m is an integer satisfying 2 ≤ m < n), the tips in the height direction from the nth rigid sail to the mth rigid sail do not cross the straight line connecting the monitoring position and the bow. In this specification, the "virtual viewpoint" is the position of the viewpoints of both eyes when a crew member with an average height stands at the monitoring position. In this embodiment, n = 8, m = 3, the rigid sail 27A is the first rigid sail, the rigid sail 27C is the 3rd (= m) rigid sail, the rigid sail 27D is the 4th (= m + 1) rigid sail, and the rigid sail 27H is the 8th (= n) rigid sail. As shown in FIG. 2, from the eighth rigid sail 27H to the fourth rigid sail 27D, the height dimensions are determined such that the tips in the height direction from the eighth rigid sail 27H to the third rigid sail 27C can all be seen from the virtual viewpoint of the monitoring position WP (the first and second tips cannot be seen). +1

[0027] Condition 3: The width dimensions are defined such that both ends in the width direction of one or more rigid sails installed from the (m - 1)-th rigid sail towards the bow do not cross the virtual line of sight IL when viewing both ends of the m-th rigid sail from the virtual viewpoint of the monitoring position WP. The "virtual line of sight IL" in this specification refers to the one including two planes connecting the virtual viewpoint and the upper and lower ends of both ends in the width direction of the m-th rigid sail. When both ends in the width direction of the m-th rigid sail extend vertically in the up and down direction perpendicular to the deck, it corresponds to the line connecting the virtual viewpoint and any part from the upper end to the lower end of both ends in the width direction of the m-th rigid sail. In this embodiment, n = 8 and m = 3, the rigid sail 27B is the (m - 1 = 2)-th rigid sail, and the rigid sail 27C is the (m = 3)-th rigid sail. As shown in FIG. 3, the width dimensions are defined such that both ends in the width direction of the first and second rigid sails 27A and 27B do not cross the virtual line of sight IL when viewing both ends of the third rigid sail 27C from the virtual viewpoint of the monitoring position WP. Here, "do not cross" includes the state where the end in the width direction of the rigid sail coincides with the virtual line of sight. Also, m can be arbitrarily determined by the designer within the range of 2 ≤ m < n.

[0028] The height dimension Hn of the (m + 1)-th rigid sail from the n-th rigid sail (in this embodiment, the fourth rigid sail 27D from the eighth rigid sail 27H) can be expressed as satisfying the following formula.

[0029] Height dimension Hn ≤ Zp - (Xn - Xp)tanθ - Zmin However, Xp: The longitudinal length dimension from the aft perpendicular of the monitoring position (bridge). Zp: The height dimension from the baseline (bottom reference line) of the monitoring position (bridge). Xn: The longitudinal length dimension from the aft perpendicular of the n-th rigid sail from the bow. Zmin: The height dimension from the baseline (bottom reference line) of the lower end of the rigid sail. θ: The angle formed by the straight line connecting the monitoring position (bridge) and the bow and the loaded waterline (LWL).

[0030] Similarly, the width dimension Bn of the m-th rigid sail from the first rigid sail (in this embodiment, from the third rigid sail 27C to the first rigid sail 27A) can be expressed as satisfying the following formula.

[0031] Width dimension Bn ≦ ((Xn - Xp) tan 2.5) × 2 However, Xp: The longitudinal length dimension from the aft perpendicular of the monitoring position (bridge) Xn: The longitudinal length dimension from the aft perpendicular of the n-th rigid sail from the bow.

[0032] By determining the dimensions of the n rigid sails in this way, without the need for special calculations, when looking from the bridge to the tip of the bow, the n rigid sails do not exist as obstacles blocking the safe view, that is, it is possible to determine the shape dimensions of the rigid sails that can ensure the view from the bridge in compliance with the SOLAS Convention.

[0033] <Elevating mechanism of the rigid sail device> Fig. 4 shows the rear part of the hull 3 where the seventh hold 11G to the ninth hold 11I are provided. As shown in the figure, between the seventh hold 11G and the eighth hold 11H, and between the eighth hold 11H and the ninth hold 11I, partitions (30A to 30H) separating the holds are provided. Note that Fig. 4 shows the partitions 30G and 30H, and the partitions 30A to 30F are not shown in other figures. These partitions 30A to 30H are composed of two partition plates arranged at intervals in the advancing direction of the ship. A storage 29 for storing the rigid sail is provided between the two partition plates.

[0034] Although not all are shown in Fig. 4, there are a total of eight storage compartments 29A to 29H (see Fig. 1) provided in the hull 3, such as a storage compartment 29A between the first cargo hold 11A and the second cargo hold 11B, and a storage compartment 29B between the second cargo hold 11B and the third cargo hold 11C... Each of them is paired with a rigid sail device 25A to 25H. In the example shown in Fig. 4, the rigid sail 27G is in a deployed state taken out from the storage compartment 29G, and the rigid sail 27H is in a stowed state stored in the storage compartment 29H. Since the rigid sails can be stored in the storage compartments as needed, when the wind power hinders navigation, all the rigid sails can be stored in the storage compartments to enable navigation as a normal ship. Also, if the rigid sails are stored in the storage compartments at the port, the rigid sails will not interfere with the cargo crane.

[0035] Fig. 5 is a perspective view showing a state in which the storage compartment 29H and the rigid sail device 25H are cut out from the hull 3. Since the basic structures of the other storage compartments and rigid sail devices are the same, hereinafter, for the sake of convenience of explanation, without distinction, the storage compartment will be referred to as reference numeral 29 and the rigid sail device as reference numeral 25 for explanation, and the description of the other storage compartments and rigid sail devices will be omitted. Fig. 6 is a plan view schematically showing the vicinity of the entrance 31 of the storage compartment 29 and the device body 45 of the rigid sail device 25.

[0036] The storage 29 has a shape extending in the width direction WD, the vertical direction VD, and the traveling direction FD of the hull 3, and a lid member 33 that closes the entrance 31 is arranged on the deck 9 so as to be movable between an open position and a closed position. In the present embodiment, the lid member 33 further includes a lid moving mechanism that moves between an open position for opening the entrance 31 and a closed position for closing the entrance 31. Inside the storage 29, a plurality of vibration suppression rib frames 35 that come into contact when the device main body 45 described later moves up and down are arranged on both sides in the traveling direction FD. The plurality of vibration suppression rib frames 35 are welded to the two partition plates that constitute the partition wall 30 described above. Around the storage 29, a double bottom 37, a pair of lower hopper tanks 39, 39' provided at the lower part on the ship's side, and a pair of upper hopper tanks 41, 41' provided at the upper part on the ship's side are provided. In the vicinity of the entrance 31 of the storage 29, a plurality of (eight in this embodiment as an example) pistons 43 that constitute a fixing device for the device main body 45 described later are arranged (see FIG. 6).

[0037] The rigid sail device 25 includes a rigid sail 27 that is a wind propulsion force generation unit, a device main body 45 to which the rigid sail 27 is fixed, and a lifting device 47 that moves the rigid sail 27 up and down in the vertical direction. The device main body 45 includes a shaft portion 49 that rotatably supports the rigid sail 27, and a drive device 51 including a rotation drive source that rotates the shaft portion 49. Further, on the side surface of the device main body 45, a total of eight cylinders 53 (shown by broken lines in FIG. 6) that receive the extended portions of the pistons 43, four first rollers 55 that contact the wall surface of the storage 29, and four second rollers 57 that contact the vibration suppression rib frame 35 are provided (see FIG. 6). The lifting device 47 includes a pair of lifting mechanisms 59, 59' that lift both ends of the device main body 45 located in the width direction WD in a synchronized manner.

[0038] [Details of the lifting mechanism] As shown in Fig. 5, a pair of elevating mechanisms 59, 59' includes a pair of wire groups 61, 61', a pair of winches 63, 63', a pair of pulley devices 65, 65', a pair of wire leading-out parts 66, 66', and a synchronous drive device 67. The pair of wire groups 61, 61' consists of a plurality of lifting wires (a plurality of chains in this embodiment) respectively connected to both ends of the apparatus main body 45. The pair of winches 63, 63' are arranged on both sides in the width direction WD of the entrance 31 on the deck 9, and wind up or wind down the plurality of wires included in the pair of wire groups 61, 61'. The pair of pulley devices 65, 65' guide the plurality of wires to the corresponding winches 63, 63'. The pair of wire leading-out parts 66, 66' lead out the plurality of wires from the storage into the corresponding pulley devices. The synchronous drive device 67 rotationally drives the pair of winches 63, 63' synchronously in opposite directions.

[0039] Fig. 7 is a schematic diagram for explaining the details of the synchronous drive device 67. In Fig. 7, only the rotating shafts 69, 69' of the pair of winches 63, 63' are shown. The rotating shafts 69, 69' have a pair of ends 69a, 69b and 69'a, 69'b. In this embodiment, the synchronous drive device 67 is composed of a total of four power transmission mechanisms, namely, two prime movers (two electric motors 71 and 73) that are synchronously operated, a first power transmission mechanism 75, a second power transmission mechanism 77, a third power transmission mechanism 79, and a fourth power transmission mechanism 81. The rotation directions of the shafts are as indicated by the arrows.

[0040] Specifically, the first prime mover 71 has a first drive shaft 71a, and the first power transmission mechanism 75 is provided between the first drive shaft 71a of the first prime mover 71 and one end 69a of the rotating shaft 69 of the winch 63, and transmits the rotation of the first drive shaft 71a so that the rotating shaft 69 of the winch 63 rotates in the same direction as the first drive shaft 71a. The second power transmission mechanism 77 is provided between the first drive shaft 71a of the first prime mover 71 and one end 69'a of the rotating shaft 69' of the winch 63', and transmits the rotation of the first drive shaft 71a so that the rotating shaft 69' of the winch 63' rotates in the opposite direction to the first drive shaft 71a.

[0041] More specifically, the first power transmission mechanism 75 includes a first drive sprocket 83 provided on the first drive shaft 71a, a first driven sprocket 85 provided at one end 69a of the rotating shaft 69, and a first chain 87 stretched between the first drive sprocket 83 and the first driven sprocket 85. The second power transmission mechanism 77 includes a second drive sprocket 89 provided on the first drive shaft 71a, a second driven sprocket 93 provided on a first driven shaft 91 disposed near one end 69'a of the rotating shaft 69', and a second chain 95 stretched between the second drive sprocket 89 and the second driven sprocket 93, and a first reverse mechanism 97 provided between the rotating shaft 69' and the first driven shaft, for rotating the rotating shaft 69' in a direction opposite to the rotation direction of the first driven shaft 91 by the rotational force of the first driven shaft 91.

[0042] Further, the second prime mover 73 has a second drive shaft 73a. The third power transmission mechanism 79 is provided between the second drive shaft 73a of the second prime mover 73 and the other end 69'b of the rotating shaft 69' of the winch 63', for transmitting the rotation of the second drive shaft 73a such that the rotating shaft 69' of the winch 63' rotates in the same direction as the second drive shaft 73a. The fourth power transmission mechanism 81 is provided between the second drive shaft 73a of the second prime mover 73 and the other end 69b of the rotating shaft 69 of the winch 63, for transmitting the rotation of the second drive shaft 73a such that the rotating shaft 69 of the winch 63 rotates in a direction opposite to the second drive shaft 73a.

[0043] More specifically, the third power transmission mechanism 79 includes a third drive sprocket 99 provided on the second drive shaft 73a, a third driven sprocket 101 provided on the other end 69'b of the rotary shaft 69', and a third chain 103 stretched between the third drive sprocket 99 and the third driven sprocket 101. The fourth power transmission mechanism 81 includes a fourth drive sprocket 105 provided on the second drive shaft 73a, a fourth driven sprocket 109 provided on a second driven shaft 107 disposed near the other end 69b of the rotary shaft 69, a fourth chain 111 stretched between the fourth drive sprocket 105 and the fourth driven sprocket 109, and a second reverse mechanism 113 provided between the rotary shaft 69 and the second driven shaft 107 for rotating the rotary shaft 69 in a direction opposite to the rotation direction of the second driven shaft 107 by the rotational force of the second driven shaft 107.

[0044] By doing so, the synchronous drive device 67 can be realized using two prime movers 71 and 73, and the load can be dispersed. Also, by using two prime movers, even if one of the two prime movers fails or the like, the synchronous drive device can be driven, and redundancy can also be achieved.

[0045] [Operation of the elevating mechanism] FIG. 8 is a schematic diagram showing a state in which the rigid sail 27 is stored in the storage compartment 29, (A) is a front view, (B) is a plan view, and FIG. 9 is a schematic diagram showing a state in which the rigid sail 27 is taken out of the storage compartment 29 and put into a use state, (A) is a front view, (B) is a plan view. In FIGS. 8(B) and 9(B), the lid member 33 is omitted, and the rigid sail portion is shown as partially transparent for convenience of explanation. In addition, in FIGS. 8 and 9, the same members as those shown in FIGS. 1 to 7 are given the same reference numerals as those given in FIGS. 1 to 7.

[0046] In the state where the rigid sail 27 is stored in the storage 29 (Figs. 8A and 8B), the lid member 33 is in the closed position closing the entrance 31. When using the rigid sail, after moving the lid member 33 to the open position, the first and second electric motors 71, 73 are driven. When the first and second electric motors 71, 73 are driven, the pair of winches 63, 63' wind up the pair of linear body groups 61, 61', and both end portions of the apparatus main body 45 rise in a synchronized state. Then, when the apparatus main body 45 has risen to the vicinity of the entrance 31, the piston 43 is operated, the extended portion of the piston 43 is inserted into the cylinder 53, the apparatus main body 45 is fixed, and the rigid sail is put into the use state (Figs. 9A and 9B).

[0047] [Expansion of Rigid Sail] In the present embodiment, the rigid sails 27D to 27H shown in Fig. 1 also have a structure in which the dimension in the width direction is variable. Specifically, as shown in Figs. 10 and 11, the first expansion part 27a and the second expansion part 27b are stored inside. In the state where the rigid sail 27 is taken out onto the deck 9, by feeding out the first expansion part 27a and the second expansion part 27b, it is possible to expand the area of the rigid sail 27 that receives the wind.

[0048] The above embodiment is described as an example, and the present invention is not limited to this example as long as the gist thereof is not deviated from.

Industrial Applicability

[0049] According to the present invention, it is possible to provide a large ship having a rigid sail that complies with the SOLAS Convention and can secure a view from the bridge.

Explanation of Reference Numerals

[0050] 1 Bulk carrier 3 Hull 5 Bow 7 Stern 9 Deck (upper deck) 11 (11A to 11I) Cargo hold 13 (13A to 13I) Opening 15 (15A to 15I) Molding 17 (17A~17I) Hatch Cover 19 Bridge 21 Radar Mast 23 Chimney 25 (25A~25H) Wind Propulsion Device (Hard Sail Device) 27 (27A~27H) Wind Propulsion Force Generation Part (Hard Sail) 29 (29A~29H) Storage 31 Entrance 33 Cover Member 35 Vibration Damping Rib Frame 37 Double Bottom 39, 39´ A Pair of Lower Hopper Tanks 41, 41´ A Pair of Upper Hopper Tanks 43 Piston 45 Equipment Body 47 Lifting Device 49 Shaft Part 51 Driving Device 53 Cylinder 55 First Roller 57 Second Roller 59, 59´ A Pair of Lifting Mechanisms 61, 61´ A Pair of Linear Body Groups 63, 63´ A Pair of Winches 65, 65´ A Pair of Pulley Devices 67 Synchronous Driving Device 69, 69´ Rotating Shaft 71 First Electric Motor 73 Second Electric Motor 75 First Power Transmission Mechanism 77 Second Power Transmission Mechanism 79 Third Power Transmission Mechanism 81 Fourth Power Transmission Mechanism 83 First Driving Sprocket 85 First Driven Sprocket 87 First Chain 89 Second Driving Sprocket 91 First Driven Shaft 93 Second Driven Sprocket 95 Second Chain 97 First Reversing Mechanism 99 Third driving sprocket 101 Third driven sprocket 103 Third chain 105 Fourth driving sprocket 107 Second driven shaft 109 Fourth driven sprocket 111 Fourth chain 113 Second reverse mechanism

Claims

1. A large ship with a total length of 55 m or more, having n (n is an integer of 3 or more) rigid sails installed at intervals along the center line passing through the monitoring position of the bridge and the bow in plan view on the deck, when the rigid sail closest to the bow is defined as the first rigid sail and the rigid sail closest to the monitoring position is defined as the nth rigid sail, the height dimensions of all the rigid sails are height dimensions equal to or less than the highest height dimension among the hull structures excluding the rigid sails, when viewed from the monitoring position, from the nth rigid sail to the (m + 1)th rigid sail (where 2 ≤ m < n is an integer), the height dimensions are defined such that the tips in the height direction from the nth rigid sail to the (m + 1)th rigid sail do not cross the straight line connecting the monitoring position and the bow, the width dimensions of both ends in the width direction of one or more rigid sails installed in the bow direction from the (m - 1)th rigid sail do not cross the virtual lines of sight when viewing both ends of the mth rigid sail from the virtual viewpoint of the monitoring position, the (m + 1)th rigid sail from the nth rigid sail is defined such that the height dimension Hn satisfies the following formula, height dimension Hn ≤ Zp - (Xn - Xp)tanθ - Zmin the first rigid sail from the mth rigid sail is defined such that the width dimension Bn satisfies the following formula, width dimension Bn ≤ ((Xn - Xp)tan2.5)×2 However, Xp: The length dimension in the ship length direction from the rear vertical line of the monitoring position Zp: The height dimension from the baseline of the monitoring position Xn: The length dimension in the ship length direction from the rear vertical line of the nth rigid sail from the bow Zmin: The height dimension from the baseline at the lower end of the rigid sail θ: The angle formed by the straight line connecting the monitoring position and the bow and the full load waterline is a large ship as described above.

2. The large ship according to Claim 1, wherein the width dimensions of the rigid sails from the nth rigid sail to the (m + 1)th rigid sail cross the virtual lines of sight.

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