FI74245C - Hull for vessels and procedure for navigating vessels in water with ice cover. - Google Patents

Description

Ι · ^ ι £ & ·· 1 „ANNOUNCEMENT n Λ 0 Λ η [BJ (11) UTLÄQQNINQSSKRIFT / ^ 2 4 5 - (45) p '' '•• ntti r · / ;;, tty (51) Kv. p.Vlnt.CI4 Β 63 Β 35/10

SUOMI FINLAND

(FI) (21) Patent application-Patentansökning 791879 (22) Application date-Ansökningsdag 13 · 06.79

Patent and Registry Administration (23) Start date - Giitighetsdag 13.06.79

Patent- och registersty releen (41) Published public - Bhvit offentiig 31.12.79 (44) Date of publication and hearing. - 30 gg q-j

Ansökan utlagd och utl.skriften publicerad · ^ / (86) Kv. application -Int. trap (32) (33) (31) Claim claimed - Begärd priority 30.06.78 USA (US) 920797 Proven-Styrkt (71) Mitsui Engineering 6 Shipbuilding Co., Ltd., 6-4, Tsukiji 5-chome,

Chuo-ku, Tokyo, Japan-Japan (JP) (72) Steven M. Lord, Columbia, Maryland, USA (US),

Hiroshi Tabuchi, Tokyo, Japan-Japan (JP) (74) Ruska £ Co Oy (54) A hull for a vessel and a method for navigating a vessel in ice-covered waters - Skarv föryg och förfarande för navigering av fartyg i vatten med isbetäckning The present invention relates to a hull suitable for navigation in ice-covered waters, the hull comprising a left-hand and a right-hand section with inclined sections for applying a substantially symmetrically distributed bending force to the ice cover on each side of the ship as it travels straight ahead, the hull having starboarding aids on the left and on the side of the body.

The present invention relates to a method and a device for assisting turning for ice-breaking cargo ships, and in particular to a method and device in which an imbalance of forces between the ice and the left and right sides of the hull of a ship assists in turning the ship. The imbalance is caused by the arrangement of the mainly vertical ice-crushing surfaces of the left and right sides, one of which may be selectively brought into contact with the ice cover.

The discovery of oil and 1natural gas fields in the Arctic has led to increased interest in the development of ice-breaking rnh- 74245 ti ships for use in transporting materials from these sources to refineries and consumers in distant markets.

Cargo ships are required to operate efficiently, i.e. they must maintain a satisfactory speed with relatively low fuel consumption. These requirements have dictated the structure of ships with a low value of the ship’s ice resistance per unit of cargo capacity. In the past, ships designed to meet these requirements have been characterized by relatively large length-to-width ratios, tapered bow shapes and long parallel center hull sections. These ships perform very well on ice when transported directly, but they have poor maneuverability due to the crossing of a long parallel hull in a narrow channel cut through the ice. This lack of turning ability on ice has brought serious problems, as the ship’s ability to change course to dodge and direct large areas of icebergs to docking equipment is essential for both safe operation and reduction of transport time and costs.

Other ships are .designed to act primarily as icebreakers for cargo ship convoys, as opposed to operating as ice-breaking cargo ships. These ships should have both well-steered ice and a wide channel for subsequent cargo ships. The required maneuverability and wide channel were obtained by providing a robust, pygmy body with relatively small length-to-width ratios, typically in the range of 0 to 5.5, as disclosed in U.S. Patent No. 857,766. The shape of this type of body at the water surface level allows for some degree of turning within the boundaries of the channel split. However, such a large width-to-width ratio makes such a ship's appearance unsuitable for a cargo ship, i.e., a high-to-width-to-sink ratio results in a relatively high power requirement per unit of capacity. Furthermore, this high 1-width-to-sink ratio also results in increased open water resistance per sink unit.

Another prior attempt to design a steerable cargo ship for ice-covered waters is the wide-width front shape disclosed in Canadian Patent Publication No. 9 ^ 7 ^ 82. The purpose of the wide front substructure is for the bow of the ship to block a sufficiently wide channel through the ice, allowing the relatively narrow hull and stern to be turned outwards during the turn. This principle has also been applied to the modified tanker SS MANHATTAN. Although the large-width front provides a certain degree of improvement in turning ability on ice, it shows to a certain extent the same effects as the above-mentioned convoys with solid and rounded hulls. In other words, the large width requires more propulsion per unit of sink to break through the ice than is required in similar ships with relatively large length-to-width ratios, tapered bow shapes and long parallel center hull sections, and therefore fuel power is sacrificed for better maneuverability.

An earlier aspect of the more controllable icebreaker 1 directly in the structure is to provide a body shape characterized by a recessed portion in the vicinity of the ice-breaking waterline rearward at its greatest width, as disclosed in U.S. Patent 3,727,571. The structure of this body is otherwise similar to the structure of the hull, except that the cargo capacity has been increased by extending the hull outwards to its maximum width below the ice-breaking water line. Although in a smaller amount than in the SS MANHATTAN-type frame structure, this frame structure also loses cargo capacity and fuel power at the expense of better maneuverability.

The object of the present invention is to provide a hull of a ship which is well controllable in ice-covered waters.

Another object is to provide a steering device suitable for changing the shape of the bow of a ship in the plane of the water surface in ice during steering.

Yet another object is to provide a steering device that changes the shape of the bow of the vessel at the level of the water surface in ice during steering, causing an imbalance of forces on the left and right sides of the vessel, thus generating a substantially perpendicular net thrust on the other side of the hull.

It is a further object to provide a method of steering a ship in ice-covered waters by creating an imbalance of forces between the ice cover and the left and right sides of the ship, thereby obtaining a thrust resultant on one side of the ship's hull.

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It is a further object to provide a device having a substantially vertically oriented ice crushing surface positioned on both the left and right sides of the hull in normal forward operation above the ice-covered waterline, and a cooperating setting mechanism adapted to selectively contact the left or right side of the ice crushing device. with ice cream.

The characteristic of the hull of a ship according to the invention is clear from claim 1. The characteristic of the method according to the invention is clear from claim 7.

In particular, the present invention relates to a method and apparatus for assisting in turning in connection with the hull of a ship suitable for navigation in ice-covered waters. The hull includes both a left-hand and a right-hand portion having a sloping shape to apply a substantially symmetrically distributed bending force to the ice cover on each side of the ship as it travels straight ahead. The turning aids are located in both the left and right body parts. The turning aids are spaced out of contact with the ice sheet during straight-ahead travel. Both turning aids include substantially vertically oriented ice-crushing wall portions. The positioning mechanism is arranged to selectively place one turning-assisting, substantially vertically oriented, ice-crushing wall portion in contact with the ice cover, while the other turning-assisting member is disengaged from contact with the ice cover. Improved turning of the vessel is achieved by actuating a setting mechanism to bring the substantially vertically oriented, ice-crushing wall portions of one of the turning assisting members into contact with the ice cover. The substantially vertically oriented ice-crushing wall in contact with the ice cover applies a crushing force to the ice cover, while the other side of the hull continues to apply a bending force to the ice cover, whereby the imbalance of crushing and bending forces helps to turn the ship.

These and other objects and advantages will become more fully apparent from the following description, in which reference is made to the accompanying drawings, in which: Fig. 1A is a sectional view of dome-shaped hull projections according to an embodiment of the invention placed on an ice-breaking cargo ship; illustrates their orientation straight ahead during travel, Fig. 1B is a sectional view similar to Fig. 1A of the position of the hulled hull projections to the right during turning, Fig. 2 is a perspective view of the domed hull projections of Fig. 1A and an ice-breaking cargo ship, Fig. 3 is a horizontal section of water of the dome-shaped hull projections and ice-breaking cargo ship shown in Fig. 1A with the ship tilted to the right for turning left on ice, Fig. 4 shows a vertical plan section of a second embodiment of the invention with a bow shape provided with a normal n on vertical surfaces above the ice-breaking waterline, Fig. 5 is a perspective view of the embodiment illustrated in the figure, showing the shape of the hull of an ice-breaking cargo ship, Fig. 6 is a horizontal projection of the water surface to improve seaworthiness, Fig. 8a is a perspective view of the front of an ice-breaking cargo ship, illustrating a third embodiment of the invention with movable flaps for changing the hull inclination during steering, Fig. 8b shows a detail of one flap of the embodiment of Fig. 8A; a section of the bow arc, showing the position of the flaps when turning to the right, Fig. 10 shows a horizontal section in the plane of the water surface from the s illustrated in Fig. 8a; Fig. 11 is a perspective view of a fourth embodiment of the invention in which the asymmetrical shape of the hull and the vertical crushing force are provided by the projection of the flap from the hull of the icebreaker, Fig. 12 is a sectional view of for turning to the left, and Fig. 13 shows a horizontal section taken in the plane of the water surface from the embodiment illustrated in Fig. 11, showing the flap of the left side pushed out for turning to the right.

Referring now to the drawings, Figures 1A-3 illustrate a ship hull shape 1 of a type generally suitable for navigation in ice-covered waters, with the dome projections 2 of the present invention attached to the bow portion 3 of the ship. As seen in Figure 3, the dome projections 2 are symmetrically arranged. the hull of the ship on both the left side 4 and the right side 5. The wear protrusions 2 include a leading edge 6, a central edge 7 and a trailing edge 8. All edges 6, 7 and 8 comprise substantially vertically extending wall surfaces 9, 10 and 11. The lower edge surfaces 12 of the domed protrusions 2 are angled upwards. , as seen in Figure 1A, to prevent waves from beating when the ship is navigating in open water.

The lines of the arcs ä-20 indicate the general appearance of the hull of the ship, which is mainly inclined. In Figure 1A, line 16a indicates the upper level of the ice cover relative to the hull of the ship as the ship passes directly forward through the ice-covered waters. It should be noted that the dome-shaped protrusions 2 are above the ice cover and therefore do not affect the ice-breaking resistance of the hull when the forward is moved, and therefore the shape of the hull below the waterline can be optimized in any desired way in the ice bog; 7 74245 for driving.

The exact shape and location of the domed projections 2 may vary depending on the shape of each particular hull, the structural strength of the hull, the width constraints of the docking devices, the assumed ice thickness and the ship's heeling and balancing capacity. In general, it is most preferred that the dome-shaped protrusions 2 project outwards over the maximum width of the hull. Extending the domed protrusions 2 beyond the maximum width of the hull allows increased contact with the edge of the broken ice provided by the bow front 22 and also allows for increased clearance between the unbreakable ice cover and the side of the ship on the outside of the turn. This increased clearance allows the stern of the vessel to turn slightly outward, resulting in a slightly tighter turn. Where the docking devices require the smallest possible width, the domed projections can be moved forward in the hull of the ship, whereby the effect of the domed projections 2 on the width of the ship is reduced. It is preferred that the dome-shaped protrusions are not located further rear than the largest point of the width, as such a location would reduce the length of the torque arm through which the crushing forces act when forcing the hull of the ship to turn. An additional benefit of extending the domed protrusions over the greatest width results in an increased ability to cut the sides of the channel formed when the ship passes through the ice during "creative" turns, i.e., when the ship reverses and advances repeatedly for a few ship lengths pages each time until a space wide enough is cleared for a tight turn.

Figure 1B illustrates the position of the ship's hull relative to the ice cover when performing right-hand drive. The dome-shaped protrusion 2 on the left side has landed in contact with the ice cover of the water · Figure 2 is a perspective view of the hull and one dome-shaped protrusion 2. Figure 3 shows a horizontal section in the water surface plane of the first embodiment inclined to the right for left turn.

Figures 4-7 illustrate another embodiment of the invention in which the shape of the hull bow has been modified to include vertical surfaces in the hull above the height of the water ice cover 16a as the 8 74245 ship travels straight ahead. The location of the substantially vertical surfaces 2 ^ is indicated by the lines 25-31 of the arcs. The fold line, i.e. the point where the substantially inclined shape changes to a substantially vertical shape, is shown at 32. The fold line is located slightly above the straight waterline and the vertical surface preferably extends upwards at least slightly above the predicted guide waterline. Above the steering waterline, the hull of the ship may again spread (as shown in Figure 7) if necessary for good seaworthiness.

Figures 8-10 illustrate a third embodiment of the invention in which the movable flaps 36 provide inverting, substantially vertical, ice-crushing surfaces. The movable flaps are placed symmetrically on the left and right sides of the hull of the ship at a height corresponding to the height of the ice cover of the water as the ship moves straight ahead. During straight-ahead travel, the flaps on the left and right sides of the ship are held in their retracted position, i.e., the position where they follow the general appearance of the ship's hull. Preferably, the flaps extend downward from the ice water line a distance greater than the thickness of the ice sheet expected to be encountered during operation. An ejection and retraction mechanism is provided for moving the flaps between a retracted position relative to the hull of the ship and a protruding, substantially vertical position.

This flap ejection and retraction mechanism may be mechanically, hydraulically, pneumatically or electrically operated and this particular mechanism does not form part of the present invention. The flap ejection and retraction mechanism should be able to overcome the ice-crushing forces that the flaps will face during steering. The chambers of the hull, which support the movable flaps, may be sealed to prevent the flow of water or ice inside the hull. The location and shape of the flaps will vary, depending on the shape and structure of the hull of a particular ship, the internal arrangement and the anticipated ice operating conditions. The movable flaps preferably avoid the need to balance or tilt the ship during the turn, and further reduce the clearance required for docking. The flaps 36 are hinged around the longitudinally extending hinge 38 for retraction and ejection.

Figures 11-13 illustrate a fourth embodiment of the invention connecting the protrusion of the dome flavor? and the advantages of moving flaps 36.

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The exterior shape 40 of the movable flap, illustrated in Figure 11-13, allows the use of a single flap on both the left and right sides of the hull, as opposed to the plurality of flaps shown in Figures 8-9. As illustrated in Figures 11 and 13, the movable flap 40 is hinged around both the vertical hinge 41 and the horizontal hinge 42. Two actuators 43 and 44 are provided on each side of the hull to pivot the flaps 40 around the vertical hinge 41 and the horizontal hinge. In order to bring one flap vertically to the ice-crushing position, the actuators 43 and 44 are actuated to pivot the rear edge of one flap outwards around the front vertical hinge 4l and the flap bottom part k. parallel, requiring only one front vertical hinge.

To turn the ship illustrated in Figures 1A-3, it is tilted to one side, as illustrated in Figure IB, by shifting the weight of the ship to the other side, for example, by a tilt tank or some other known method. Thus, in order to guide the ship to turn to the right, the left side of the ship is lowered to bring the dome-shaped protrusion 2 on the left side of the ship's hull into contact with the ice cover. The rudder of the ship is used in the usual way to turn the ship. The substantially vertical walls 9, 10 and 11 of the left side dome-shaped protrusion 2 provide a crushing force to the ice, while the right substantially curved side of the hull continues to apply a bending force to the ice. It is generally known that the flexural strength of ice is much lower than its compressive or crushing strength, and therefore, when the ship is driven forward, the crushing forces produced by the substantially vertical walls of the left side dome protrusion generate a net force tending to push the ship's bow to the starboard, steering to the right.

The substantially vertical wall portions 9, 30 and 11 of the dome-shaped protrusion 2 do not have to be completely vertical, as long as the variation from the vertical during ice contact is below a critical angle, i.e. the angle at which the force acting on the ice changes from crushing to bending. The critical passage 9 is a function of the coefficient of the ship's hull and ice 1. Exact rune in terms of krj i t i non angle 9 = Tang {ji,). Thus, if ^ i / = 0.20, Θ allows a change of 11.3 ° from the vertical.

The second embodiment illustrated in the figures operates essentially in the same manner as described above in connection with the embodiment illustrated in Figures 1A-3, when the turn is made in ice-covered water. Figure 6 illustrates the appearance of the hull of a ship in the plane of the water surface when the ship is tilted left to right for turning.

The third embodiment illustrated in Figures 8-10 and the fourth embodiment illustrated in Figures 11-13 operate in substantially the same manner, assisting the platform in performing hand control. In other words, the flap or flaps on the side opposite to the direction of turn of the ship are pushed out so as to cause a substantially vertical ice-crushing surface to be pressed against the ice cover as the ship moves forward. As explained above, the force of the crushed ice on the side opposite to the desired direction of turn of the ship is greater than the bending force applied to the opposite sides of the ship and therefore generates a net torque which assists the ship in the desired turn control. Figures 9-11 and 13 illustrate flaps that have been pushed out to assist the ship in performing a turn to the right, while Figure 12 illustrates a flap that has been pushed out to assist the ship in performing a turn to the left.

The present invention may comprise other specific embodiments without departing from its nature or characteristic features. Therefore, the described embodiments are to be considered in all respects as illustrative and not restrictive, and the scope of the invention is defined in the appended claims rather than in the foregoing description, and many modifications are possible within the scope of the appended claims.

Claims (7)

A hull (1) for a vessel suitable for navigation in sea-covered waters, the hull comprising a left-hand and a right-hand portion with inclined portions to apply a substantially symmetrically distributed, deflected bending force to the ice cover on each side of the vessel as it travels straight ahead, are turning aids located on the left-hand side i and on the right-hand part of the body, characterized in that the turning aids are located above the ice cover (16a) during the straight-ahead passage and whereby the turning aids! includes wall portions (9, 10, 11; 2 * J; 36; ^ 0) that are accessible to the main! Incest to a vertically oriented position in contact with the ice sheet during turning the vessel; and that the ship is provided with setting devices suitable for selectively contacting one of the turning aids with the ice cover while keeping the inclined part of the opposite side of the ship in contact with the ice cover ;. with; wherein when the vessel is turned, the setting device is actuated to bring said wall portion ((9, 10, 11; 2 * 1; 36; * J0) of one turning aid into contact with the ice cover on the ice cover, while the inclined portion of the opposite side of the vessel continues to apply bending force to the ice cover, whereby the imbalance of crushing and bending forces assists in turning the vessel. 2. A patent according to claim 1 is defined as having the right of symmetrical operation with respect to the right and the right. Ship hull according to claim 1, characterized in that the turning aids are located symmetrically in the left and right parts of the hull. 3. A claim is made to claim 1, which is based on the provisions of the Patent Office. Substructure according to Claim 1, characterized in that the setting device comprises a ballast device. * J. Ship hull according to claim 3, characterized in that the turning aids comprise domed projections (2). 4. A patent according to claim 3, which is intended to be used in conjunction with the invention (2). 5. A patent according to claim 3, which can be used as an embodiment of a non-protective device 14 (24), which can be used as a cross-section. Hull according to Claim 3, characterized in that the means for assisting the turn are essential. 1 i vertically oriented body parts (2¾), which u1 oi protrude from the inclined parts of the body. 12 74245 6. Screw (1) for a fartyg, with a warm fence for the socket and of the waddle fartyget, dä detta gär rakt framät, varvid skrovet har svängning befrämjande medel, belägna pä den vänstra ocen den högra skrovdelen av fartyget, och vardera av vilka har flera klaffar (36; 40) med en väggdel, som kan röras mellan ett indraget, skrovet the first and second part of the connection, the first and the second part of the head (36; 40) is contacted by the person and the device (see 36); istacket, samtidigt som klaffarna pä fartygets motsatta sida hälles i indraget, skrovet följande läge. 6. A hull (1) for a vessel suitable for navigation in ice-covered waters, the hull comprising a left-hand and a right-hand portion having inclined portions for applying a substantially symmetrically distributed bending force to the ice sheet on each side of the vessel as it travels straight forward auxiliary · means located on the port side and the starboard part of the vessel, each having a plurality of flaps (36; 40) with a wall part movable between a retracted position following the hull and an extended substantially vertical position, characterized in that the flaps (36; 40) are in contact with the ice cover and that the vessel has a setting device for selectively pushing the flaps on the other side into contact with the ice cover while holding the flaps on the opposite side of the vessel in the retracted position following the hull. A method of navigating a ship in ice-covered waters, the ship comprising a hull (1) having a left and a right side, each having a sloping portion for applying a substantially symmetrically distributed force to the ice cover on each side of the ship as it travels straight ahead, and substantially vertical wall sections (9). , 10, 11; 24; 36; 40) located above the sloping parts of each side of the ship, characterized in that the ship is positioned so that a substantially vertically oriented wall portion (9, 10, 11; 24; 36; 40) on one side of the ship contacting the ice sheet while keeping the inclined portion on the opposite side of the vessel in contact with the ice; and driving the vessel forward while maintaining a substantially vertically oriented wall portion on one side of the vessel in contact with the ice sheet and continuing to maintain the inclined portion on the opposite side of the vessel in contact with the ice sheet for a time sufficient to assist in turning the vessel toward said opposite side. 74245 13? I * tentkray Skrov (1) för ett fartyg, som warm sig sig för sjöfart i isbelagda vatten, varvld to scratched to the side and to the side of the side of the fence with a small-scale symmetrical design of the headgear in the case of a party to the contract, the colors of the body of the body of the body of the body of the body of the body of the body of the body of the body of the body of the body of the body of the body of the body of the body of the body of the body of the body of the body of the body of the body of the body of the body of the body of the body of the body of the body of the body swinging in the case of a third party (9, 10, 11; 24; 36; 40); and in the case of a fattening device, the fleece may be selected for contact with the fitting, but in addition to fartygets, the fitting shall be connected to the fitting; varvid da fartyget svänges, startas inställningsanordningen för att bringa et svängning befrämjande Medels nämnda vggnel (9, 10, 11; 24; 36; 40) rattles and bovineskraft mot istacket, varvid en obalans i brytnings- och böjningskrafterna befräm-jar fartygets svängning. 7. Förfarande för att navigera ett fartyg i isbelagda vatten, varvid account fartyget hör ett skrov (1) med en vänstra och en högra sida, vardera av vilka har en sluttande del för att rikta en huvudsakligen symmetriskt fördelad kraft mot istäcket head fartor , which may be used for the purpose of reducing the risk of damage (9, 10, 11; 24; 36; 40), the light of which can be found on the side of the shield, 9, 10, 11; 24; 36; 40) the fartygets and the side are in contact with the medicament as long as the fartygets are not in contact with the medicine; 'och föres' fartyget framät veltidigt som den huvudsakligen lodrätt riktade väggdelen pä fartygets andra sida hälles i kontakt med istacket och veltigig som den head fartygets motsatta sida belttgna de del fortsätt-ningsvis hälles i contact medista i nämnda motsatta sidas riktning. I: