GB2619409A

GB2619409A - External turret mooring device and ship comprising such an external turret mooring device

Info

Publication number: GB2619409A
Application number: GB2305791.2A
Authority: GB
Inventors: Broucaret Julien; Milani Thomas; Le Gal Jean-Christophe
Original assignee: Perenco
Current assignee: Perenco
Priority date: 2022-04-22
Filing date: 2023-04-20
Publication date: 2023-12-06
Also published as: BR102023007435A2; FR3134793A1; GB202305791D0

Abstract

A turret mooring device (100, Fig 1) comprises an upper mounting 101, a lower mounting 102, a turret 103 and a connecting member 104 fastening said upper mounting to said lower mounting. The upper mounting has a fastening surface 108 configured to fit to a shape of the first part 21a of the bow (21, Fig 1) of the ship (2, Fig 1) and the lower mounting has a fastening surface (115, Fig 2) configured to fit to a shape of the second part 21b of the bow of the ship. The invention also concerns a ship equipped with such a mooring device.

Description

DESCRIPTION

TITLE: External turret mooring device and ship comprising such an external turret mooring device

Technical field of the invention

The invention relates to the field of the mooring of floating offshore apparatus, for example ships.

In particular, the invention concerns what is referred to as an external turret mooring device that is configured to moor ships or other floating apparatus to an anchorage point such as a sea bed. The invention also relates to a ship comprising such a mooring device.

State of the art To moor a ship, mooring devices exist comprising a turret rotatably mounted relative to the ship and connected to a sea bed, generally via chains.

These devices enable the ship to freely pivot around the turret and to keep it in place under the influence of loads acting upon it, for example under the action of waves, wind and current. Furthermore, connections for fluid lines may be established between the ship and a well head, for example, via the turret.

In so-called external turret devices, the turret is positioned externally of the ship hull. Generally in such mooring devices, the turret is installed overhanging from a front part of the ship in order for the chains not to strike against the hull.

For the installation of a so-called external turret, it is known to cut the bow of the ship in order to form a planar surface and to assemble the external turret device, for example by welding, to the planar surface so obtained.

The operations of cutting the bow are however relatively long and costly. Such operations also require the ship to be immobilized in dry dock and potentially, a profit loss during the immobilization period. Furthermore, part of the storage volume may be lost when the bow is cut.

There is a need to facilitate the installation of a mooring device on a ship as well as the use and the maintenance of such a device. Presentation of the invention The invention is thus directed to providing an external turret mooring device that is particularly simple, convenient and economical.

To that end, the invention provides a turret mooring device configured to be fastened on a bow of a ship, comprising an upper mounting configured to be fastened to a first part of the bow, a lower mounting configured to be fastened to a second part of the bow disposed under the first part of the bow, a turret rotatably mounted in said upper mounting and in said lower mounting respectively via an upper bearing accommodated in said upper mounting and a lower bearing accommodated in said lower mounting, said device being characterized in that it comprises a connection member fastening said upper mounting to said lower mounting, and in that said upper mounting has a fastening surface configured to fit to the shape of the first part of the bow of the ship and said lower mounting has a fastening surface configured to fit to the shape of the second part of the bow of the ship.

In the device according to the invention, the upper mounting and the lower mounting are away from each other and are each configured to be fastened, by the fastening surface, to part of the bow of a ship. The upper and lower mountings may be directly fastened to the bow of the ship via the fastening surfaces. without requiring cutting of the bow.

Each connection surface is configured to fit to a shape corresponding to only part of the bow, which avoids having to manufacture en entire service fitting to the shape of the bow in its entirety. Furthermore, the surfaces to fasten have smaller area than the the total surface area of the bow, which facilitates the joining work, for example by welding.

Furthermore, the fact of providing two separate mountings rather than a single-unit assembly makes it possible to reduce the weight of the mooring device. This for example makes it possible to limit, or even avoid employing members for reinforcing the bow to support the mooring device.

By virtue of the connecting member, the upper and lower mountings are held at a predetermined distance from each other in a predetermined spatial position. In other words, the connecting member holds the lower and upper mountings in fixed relationship relative to each other. Thus, the upper mounting, the lower mounting and the connecting member form a fixed assembly able to be mounted directly on the bow of a ship via the fastening surface of each of the upper and lower mountings. It is then possible to align the upper bearing and the lower bearing along a same axis, for example the rotational axis of the turret, before installing the mooring device on a ship.

Thus, the turret mooring device according to the invention may be installed on a ship only by fastening the upper and lower mountings to the bow via the fastening surfaces.

Preferred features of the device according to the invention that are particularly simple, convenient and economical are presented below.

Preferably, the fastening surface of the upper mounting and of the lower mounting is curved. Most ships have a bow of which the surfaces are curved and for which a curved fastening surface is particularly well-adapted. Advantageously, the connecting member comprises at least one 15 metal beam having a first end mechanically connected to the upper mounting and a second end, which is an opposite end to the first end, which is mechanically connected to the lower mounting. On account of its elongate structure, the at least one beam makes it possible to ensure the holding in position of the upper and lower mountings relative to each other, while limiting the weight of the mooring device.

Advantageously, the first end of the beam is mechanically connected at a location towards a distal end of the upper mounting and said second end of the beam is mechanically connected at a location towards a proximal end of the lower mounting. The proximal end of the upper and lower mountings is located towards their fastening surface while the distal end is axially away from the proximal end. In other words, when the mooring device is installed on the ship, the proximal end is the closest part to the bow of the ship while the distal end is the part furthest away from the bow. Thus, part of the load to which the upper mounting is subjected is transferred to the proximal end of the lower mounting by at least one metal beam. When the mooring device is installed on a ship, these forces are transmitted to the bow of the ship on account of the direct proximity with the proximal end where the second end of the at least one beam is fastened. This arrangement of the at least one beam thereby makes it possible to reinforce the lower mounting at the location of its distal end without appreciably affecting the lower mounting. Furthermore, this arrangement makes it possible to free space around the turret at the location of the lower bearing, and in particular makes it possible to easily access the lower bearing.

Preferably, the connecting member comprises two metal beams substantially parallel to each other, the first ends of the two metal beams being mechanically connected to a lower surface of the upper mounting on opposite sides of the upper mounting. Some of the force to which the upper mounting is subjected is thus distributed between the two metal beams. The term "on opposite sides" means that the first ends of the two metal beams are diametrically opposite relative to the upper bearing. This makes it possible to spread the axial loads to which the upper mounting is subjected, for example the weight of the turret which acts substantially uniformly on the periphery of the upper bearing.

Advantageously, a lower surface of the upper mounting is inclined relative to an upper surface of the upper mounting such that the distance between the upper surface and the lower surface reduces on going from a proximal end towards a distal end of the upper mounting. The mass of the upper mounting is thus reduced, in particular towards the distal end were the upper bearing is located.

Alternatively or in addition, a lower surface of the lower mounting may also be inclined relative to an upper surface of the lower mounting such that the distance between the upper surface and the lower surface reduces on going from a proximal end towards a distal end of the lower mounting.

Advantageously, the lower bearing comprises several slide pads in circular arrangement around the turret. The slide pads make it possible to rotationally guide the turret at the location of the lower mounting. In comparison with conventional rolling bearings such as ball bearings, the slide pads have 30 lower cost and may be easily replaced.

Preferably, the slide pads are demountably mounted in mountings disposed in circular arrangement in the lower mounting. The slide pads may thus be replaced individually which facilitates the maintenance of the mooring device. Furthermore, the construction of the mooring device according to the invention facilitates the accessibility to the lower bearing and for example makes it possible to access the bearing to replace the slide pads.

Advantageously, the slide pads cooperate with the mountings with a slide connection of axis parallel to the rotational axis of the turret and the mountings comprise a first translational stop means configured to stop the movement of the slide pads in a first direction. Preferably, the first direction corresponds to a direction going from the upper surface of the lower mounting Zo to the lower surface of the lower mounting. In other words, the first direction is preferably downward, when the turret is in operating position. Thus, the slide pads are held in position in the mountings by gravity. This makes it possible to avoid fastening by screwing in which the slide pads are holed and in which the surface area in contact with the turret is reduced. Moreover, since the slide pads may be inserted into or removed from the mountings in a vertical movement, it is possible to replace the slide pads without having to remove the turret.

Advantageously, the mountings comprise a second translational stop means movable between a first position in which the second translational stop means prevents the translational movement of the slide pads in a second direction opposite to the first direction, and a second position in which the second translational stop means allows the translational movement of the slide pads in the second direction. This makes it possible to provide additional safety when the slide pads are received in the mountings. In particular, the slide pads installed in the mountings cannot move in any direction when when the second translational stop means is in its first position.

Preferably, the slide pads form a dovetailed assembly with the mountings.

Advantageously, the slide pads comprise a lifting member fastened on an upper face of the slide pads. When the lifting member facilitates the gripping of the slide pads by a lifting apparatus, for example a crane. The lifting member thus enables the slide pads to be able to be moved easily via the lifting member.

Advantageously, the mooring device comprises a means for deviating a chain in a horizontal plane and a means for deviating a chain in a vertical plane, the means for deviating a chain in a horizontal plane and the means for deviating a chain in a vertical plane being positioned on an upper face of the turret, the means for deviating a chain in a vertical plane being positioned between the means for deviating a chain in a horizontal plane and at least one through-aperture provided in an upper face of the turret. The means for deviating a chain in a vertical plane makes it possible to guide the chain between the through-aperture and the means for diverting a chain in a horizontal plane. Thus, the means for deviating a chain in a vertical plane makes it possible to transform the vertical movement of the chain at the through-aperture into a horizontal movement at the means for deviating a chain in a horizontal plane. In this way, the chain can be linked to a tensioning means, for example a winch, not located above the turret, but substantially at the same level as the upper face of the turret. The device for tensioning the chains, generally mounted on the upper face of the turret to pull the chains vertically, may be located out of the turret, for example on the ship. This makes it possible not to increase the weight of the turret. The means for deviating a chain in a horizontal plane may enable the chain to be guided between the means for deviating a chain in a vertical plane and the means for tensioning the chains. When the ship pivots around the turret, the chain winds around the means for deviating a chain in a horizontal plane or unwinds. However, by virtue of the means for deviating a chain in a horizontal plane, the chain can maintain a same angle of deviation between the tensioning device and the means for deviating a chain in a vertical plane.

Advantageously, the means for deviating a chain in a vertical plane is fastened demountably on the upper face of the turret. Thus, it is possible to use only a single means for deviating a chain in a vertical plane for several chains passing through different through-holes.

According to a second aspect, the invention also relates to a ship having a bow comprising a turret mooring device as described above, the upper mounting being fastened by the fastening surface to an upper part of the bow and the lower mounting being fastened by the fastening surface to a lower part of the bow located under the upper part of the bow.

Brief description of the drawings

The disclosure of the invention will now be continued with the description of an embodiment, given below by way of illustrative and non-limiting example, with reference to the accompanying drawings.

-Figure 1 diagrammatically and partially represents a ship provided with a turret mooring device in accordance with the invention; - Figure 2 is a partial view in in perspective of the turret mooring device of Figure 1, fastened to the bow of a ship; -Figure 3 is a similar view to that of Figure 2, from another viewing angle; -Figure 4 is a side view of the turret mooring device of Figures 1 to 3 shown semi-transparent; - Figure 5 is a cross-section view of the mooring device identified with the the reference VI-VI in Figure 4; -Figure 6 is a cross-section view of the mooring device identified with the the reference VII-VII in Figure 4; -Figure 7 is a partial view in perspective of a lower bearing of the lower mounting of the turret mooring device in which the turret is not shown; -Figure 8 is a view from above of the turret mooring device, showing an upper face of the turret; and -Figure 9 is a partial view in perspective of the turret mooring device, showing the upper face of the turret.

Detailed description

Figure 1 is a diagrammatic representation of a ship 2, for example of Floating Production Storage and Offloading type (also known by the initialism FPSO). Such a ship 2 is configured to receive petroleum or gas from an oil rig or from a subsea production well system, also known as a production well or a wellbore. The ship 2 may also be configured to separate effluents and/or store petroleum or gas production until tankers come to retrieve it and transport it to port. Of course, the invention is not limited to the type of ship illustrated in Figure 1 and may be implemented for any type of ship.

The ship 2 has a hull able to float on the sea 8 such that the ship can s move over a production well 6. The ship 2 has a bow 21, also called prow, forming the front of the ship 2, a stern 22 located at an opposite end and forming the back of the ship 2 as well as a main deck 23. The ship 2 may also comprise reservoirs (not shown) configured to store petroleum, gas or any other fluid.

In the example illustrated in Figure 1, the ship 2 is anchored to a sea bed 4 via a turret mooring device 100 fastened to the hull of the ship 2, adjacent the bow 21. The mooring device 100 may thus be qualified as external in that it is fastened to the exterior of the hull of the ship 2. The ship 2 is able to freely orientate itself around the mooring device 100 located on the bow 21, which constitutes a geostationary point when it is connected to the sea bed 4.

In particular, the mooring device 100 comprises chains 125 which connect the mooring device 100 to the sea bed 4 and a fluid line 126 which connects the mooring device 100 to the production well 6. The mooring device 100 thus serves here to immobilize the ship 2 relative to the sea bed 4 and to transfer fluid, for example petroleum or gas, from one or more production wells 6 to the ship 2 that stores them.

The mooring device 100 is more visible in Figures 2 to 4.

The mooring device 100 comprises an upper mounting 101, a lower mounting 102 and a connecting member 104 mechanically connecting the upper mounting 101 to the lower mounting 102. The mooring device also comprises a turret 103 mounted rotatably in the upper mounting 101 and in the lower mounting 102, respectively via an upper bearing 105 and a lower bearing 112.

The lower mounting 102 and the upper mounting 101 are at a distance from each other. The lower mounting 102 and the upper mounting 101 each have an opening provided respectively to receive the upper bearing 105 and the lower bearing 112. The opening of the upper mounting 101 and the opening of the lower mounting 102 are aligned and the turret 103 is rotatably mounted in the upper bearing 105 and the lower bearing 112.

The upper mounting 101 and the lower mounting 102 each have a proximal end 106, 113 and a distal end 107, 114 that is an axially opposite end to the proximal end 106, 113. The openings of the upper 101 and lower 102 mountings here are located towards their distal end 107 and 114.

The upper bearing 105 serves to support and rotatably guide an upper part of the turret 103. The upper bearing 105 is configured to bear radial and axial loads. In particular, the upper bearing 105 is configured to bear both to the loads of the turrets 103 and other loads, axial or radial, acting on the turret 103.

The lower bearing 112 serves to support and rotatably guide a lower part of the turret 103. The lower bearing 112 is configured to bear radial loads. In particular, the lower bearing 112 is configured to bear part of the radial loads is acting on the turret 103.

The upper mounting 101 has a fastening surface, an upper surface 109, a lower surface 110 and a lateral surface 111 connecting the upper surface 109 to the lower surface 110. The upper and lower surfaces 109 and 110 are planar, the lower surface 110 being inclined relative to the upper surface 109 such that the thickness of the upper mounting 101, that is to say the distance between the upper surface 109 and the lower surface 110, reduces in a direction going from the proximal end 106 to the distal end 107. This in particular makes it possible to reduce the mass cantilevered from the upper mounting 101, at the location of the distal end 107.

The fastening surface 108 is configured to fit to the shape of an upper part 21a of the bow 21 of the ship 2. The fastening surface 108 is thus provided to be mechanically connected to the hull of the ship 2 at the upper part 21a of the bow 21. On account of the curved shape of the bow 21, and in particular its upper part 21a, the fastening surface 108 is curved. This makes it possible to fasten the upper mounting 101 directly to the hull of the ship 2 without requiring the bow 21 to be fully cut.

The lower mounting 102 has a fastening surface 115, an upper surface 116, a lower surface 117 and a lateral surface 118 connecting the upper surface 116 to the lower surface 117. The upper surface 116 and the lower surface 117 are planar and extend substantially parallel with each other such that the thickness of the lower mounting 102, that is to say the distance between the upper surface 116 and the lower surface 117, is substantially constant.

The fastening surface 115 is configured to fit to the shape of a lower part 21b of the bow 21 of the ship 2. The fastening surface 115 is thus provided to be mechanically connected to the hull of the ship 2 at the lower part 21b of the bow 21. On account of the curved shape of the bow 21, and in particular its lower part 21b, the fastening surface 115 is curved. This makes it possible to fasten the lower mounting 102 directly to the hull of the ship 2 without requiring the bow 21 to be fully cut.

In the example shown, the upper mounting 101 is fastened to an upper part 21a of the bow 21 by the fastening surface 108 and the lower mounting 102 is fastened to a lower part 21b, located below the upper part 21a, by the fastening surface 115. By the term "below", the present description aims here to describe part of the bow 21 located at a lower height when the ship 2 is afloat. In particular, the hull here has a protrusion, also called bulb, at the lower part 21b and the lower mounting 102 is fastened to the bulb. This in particular makes it possible to reduce the dimensions of the lower mounting 102, and more particularly the distance between the proximal end 113 and the distal end 114, to align the lower deck 112 with the upper deck 105.

The turret 103 is provided to be fastened to the sea bed 4 and serves as a geostationary point around which the ship 2 is able to pivot. When the mooring device 100 is installed on the ship 2, the turret 103 extends vertically. In the example shown, the turret 103 comprises a body 119, chain guides 120, an upper face 121, a lower face 122, an upper neck 123 and a lower neck 124.

The body 119 has a cylindrical general shape, delimited axially by the upper face 121 and by the lower face 122 which is an axially opposite face to the upper face 121. The upper face 121 is located above the upper mounting 101 and the lower face 122 is located below the lower mounting 102. In other words, the upper face 121 of the turret 103 projects from the upper surface 109 of the upper mounting 101 and the lower face 122 of the turret 103 projects from the lower surface 117 of the lower mounting 102.

The chain guides 120 are distributed over the periphery of the body 119 of the turret 103. The chain guides 120 comprise fixed guides 120a and pivoting guides 120b.

The fixed guides 120a are disposed on part of the turret 103 located between the upper mounting 101 and the lower mounting 102 and mainly serve to guide the chains 125 along the turret 103. For this, the fixed guides 120a extend axially over several levels in order to guide the chains 125 over the whole length of the turret 103, that is to say from the upper face 121 to the lower face 122. The upper face 121 of the turret 103 is provided with through-apertures 127 through which pass the chains 125. These through-apertures 127 are aligned with the fixed guides 120a in order not to deviate the chains 125 along the body 119 of the turret 103.

The pivoting guides 120b, visible in Figures 3 and 4, are disposed over part of the turret 103 located under the lower mounting 102, in the vicinity of the lower face 122 of the turret 103. The pivoting guides 120b are used to guide the chains 125 in the manner of a rotary joint, that is to say enabling rotation around the longitudinal axis of the turret 103 and around an axis transverse to the longitudinal axis of the turret 103, in order to avoid wear of the chains 125 and of the pivoting guides 120b The pivoting guides 120b may also have a function of translationally retaining the chains 125.

As illustrated in Figure 4, the upper collar 123 is located adjacent the upper face 121 of the turret 103. The upper collar 123 cooperates with the upper bearing 105 in order to bear and rotationally guide the turret 103 at the upper mounting 101. The upper collar 123 is disposed in the opening of the upper mounting 101. The upper collar 123 comprises fixed guides 120a enabling the chains 125 to pass through without being deviated.

The lower collar 124 is located adjacent the lower face 122 of the turret 103. The lower collar 124 cooperates with the lower bearing 112 in order to bear and rotationally guide the turret 103 at the lower mounting 102. The lower collar 124 is disposed in the opening of the lower mounting 102. The lower collar 124 comprises fixed guides 120a enabling the chains 125 to pass through without being deviated. In the example shown, the lower collar 124 is situated at a distance from the upper collar 123.

The connecting member 104 serves to fixedly and definitively position the upper mounting 101 relative to the lower mounting 102. In the illustrated example, the connecting member 104 comprises two metal beams. The use of two beams makes it possible to reduce the loads applied on each metal beam while limiting the weight of the mooring device 100. As a variant, the connecting member may comprise a single beam, or more than two beams. The metal beams here have a narrow and elongate structure and, by way of comparison, have a much smaller diameter than that of the turret 103. The metal beams have a diameter less than 1 meter and preferably comprised between 40 cm and 80 cm, or even between 50 cm and 70 cm.

Each metal beam has a first end 130 mechanically connected to the upper mounting 101 and a second end 131, which is an opposite end to said first end 130, mechanically connected to the upper surface 109 of the lower mounting 102.

The first end 130 of each of the metal beams is mechanically connected towards the distal end 107 of the upper mounting 101. In particular, the first ends 130 are located around the opening of the upper mounting 101 so as to be diametrically opposite relative to that opening.

The second end 131 of each of the metal beams is mechanically connected adjacent the proximal end 113 of the lower mounting 102, that is to say in the vicinity of the fastening surface 115. In this way, the opening of the lower mounting 102 is clear since that opening is located adjacent the distal end 114. This arrangement of the metal beams thus facilitates the access to the upper bearing 105 from the upper surface 116.

The metal beams are inclined relative to the longitudinal axis of the turret 103. In practice, the metal beams form an angle with the horizontal comprised between 45 and 90°, preferably between 60° and 70° when the mooring device 100 is installed on the ship 2. The loads acting on the upper mounting 101 are transmitted to the lower mounting 102 by the connecting member 104, then to the part of the hull of the ship 2 located in direct proximity with the second end 131 of the metal beams.

s Figure 5 shows the upper bearing 105 of the upper mounting 101 in a cross-section view. The upper bearing 105 is configured to bear both radial and axial loads applied by the turret 103. As a matter of fact, the upper bearing 105 is provided to bear the weight of the turret 103 as well as the loads transmitted to the turret 103, for example via chains, of swell and wind. In the illustrated example, the upper bearing 105 is formed by a thrust bearing which may have balls or rollers. Of course, the invention is not limited to this type of bearing and any other rotational bearing provided to bear a mainly axial load may be envisioned, for example such as slewing bearings. Thus, the upper bearing 105 comprises a first part joined to the upper mounting 101 and a said part joined to the upper collar 123, the first part cooperating with the second part in a rotational movement.

As can be seen in Figures 6 and 7, the lower bearing 112 comprises mountings 132 and slide pads 134 accommodated in the mountings 132.

The mountings 132 are disposed on the peripheral surface delimiting 20 the opening of the lower mounting 102. The mountings 132 are disposed in a circular arrangement in the opening of the lower mounting 102 and uniformly distributed along the peripheral surface. Each mounting 132 defines a groove 133 extending along an axis parallel to the longitudinal axis of the turret 103. In other words, the groove 133 extends along a vertical axis when the mooring device 100 is installed on the ship 2. The groove 133 here has a cross-section of a trapezium in order to form a dovetail assembly with a part of complementary cross-section. Of course, the invention is not limited to such a cross-section of the groove and other variants may be envisioned in order to provide a slide connection through cooperation between the groove and a part of complementary cross-section. For example, the groove may have a T-shaped cross-section.

The mountings 132 comprise a first translational stop means (not shown) preventing the movement of the slide pads 134 in a first direction, and a second translational stop means 135 preventing the movement of the slide pads 134 in a second direction that is an opposite direction to the first direction.

The first translational stop means is located at a first end of the groove 133. In the illustrated example, the first stop means is located adjacent the lower surface 117 of the lower mounting 102 in order to prevent the movement of a slide pad 134 downward, that is to say in a direction towards the lower surface 117, when the aforementioned is received in the bearing 132. The first translational stop means may be a member assembled to the mounting 132 or form an integral part of the mounting 132. The first translational stop means may be formed by an end of the groove 133, if the latter is blind for example.

The second translational stop means 135 is located a second end of the groove 133 which is an axially opposite end to the first end in order to prevent the movement of a slide pad 134 upward, that is to say towards the upper surface 116 of the lower mounting 102, when the aforementioned is received in the mounting 132.

The second stop means 135 is configured such that, in a first position, the second translational stop means 135 prevents the upward movement of a slide pad 134 received in the mounting 132, and such that, in a second position, the second stop means 135 allows the upward movement of that slide pad 134.

As can be seen in Figure 7, the second translational stop means 135 is formed by a pin which, in the first position, projects from the peripheral surface of the opening of the lower mounting 102 to be in register with the groove 133. In the second position not shown, the pin is not in register with the groove 133.

To move between the first position and the second position, the pin may be demountable from the peripheral surface of the opening, in which case, in the second position, the pin is no longer on the peripheral surface. The pin may also be retractable relative to the peripheral surface, that is to say that in the first position, the pin is retracted and is not in register with the groove 133 and in a second position, the pin is extended and is located in register with the groove 133 such that a slide pad 134 accommodated in the mounting 132 encounters the pin when it is translationally moved upward. To retract or extend, the pin may be threaded and/or associated with a motor means to translationally move the pin. Of course, the invention is not limited to the example described above and other translational stop means may be envisioned. For example, the translational stop means may comprise a movable cover at least partly covering the upper end of the groove.

The slide pads 134 are used to rationally guide the turret 103 in the lower mounting 102 by cooperating with the lower collar 124. For this, the slide pads 134 are disposed in circular arrangement in the opening of the lower mounting 102 and are uniformly distributed along the peripheral surface forming the opening. In the illustrated example, the lower bearing 112 comprises 24 slide pads 134. Of course, the lower bearing 112 may comprise more or fewer slide pads 134 and the same applies for the mountings 132.

Each slide pad 134 comprises a slide face 134a, an upper face 134b, a lower face 134c separated from the upper face 134b by the slide face 134a, and lateral faces 134d separated from each other by the slide face 134a.

The slide face 134a is configured to cooperate with the lower collar 124 of the turret 103 and may be slightly curved as can be seen in Figure 7. As a variant, the slide face may be substantially planar. In order to limit friction, the slide face 134a is manufactured from a material having, in contact with the lower collar 124, a low coefficient of friction. In particular, the slide face 134a may in particular be formed from a polyester composite while the collar may for example be manufactured from Inconel® alloys.

The lateral faces 134d are substantially planar and are beveled such that the slide pads 134 have a substantially trapezium-shaped cross-section to cooperate with the groove 133 of the mountings 132.

The upper face 134b of the slide pads 134 is provided with lifting members 136 enabling them to be manipulated. The lifting member 136 forms a ring configured to receive a hook or other member for lifting the slide pad 134.

The lifting member 136 is preferably centered on the upper face 134b of the slide pads 134 in order not to create imbalance on lifting. The lifting member 136 may be fastened to the upper face 134b by any appropriate means, for example by screwing or welding.

Putting the slide pads 134 in place in the mountings 132 is preferably carried out when the device is in a position similar to its installed position on the ship 2, that is to say when the turret 103 is positioned vertically with the upper mounting 101 above the lower mounting 102.

Thus to be put in place in the mounting 132, the slide pad 134 is lowered, for example from the upper surface 109 of the lower mounting 102, through the opening of the lower mounting and cooperates with the groove 133 in a sliding connection until the lower face 134c comes into stopped engagement against the first translational stop means. When the lower face 134c of the slide pad 134 is in stopped engagement against the first translational stop means, the slide pad 134 can only move translationally upward on account of the dovetail assemblage. In order to immobilize the slide pad 134, and in particular avoid the latter moving translationally upward, the second translational stop means 135 is moved into the first position.

To remove a slide pad 134, for example to replace a worn slide pad with a new slide pad, the second translational stop means 135 is moved into the second position in order for the slide pad 134 to be lifted to the upper surface 116 of the lower mounting 102 for example.

The steps of lowering and lifting the slide pad 134 may be carried out with a lifting apparatus (not shown) such as a crane or a winch with a member such as a hook configured to cooperate with the lifing member 136.

The lifting apparatus may for example be positioned on the upper surface 116 of the lower mounting 102. The positioning of a lifting apparatus on the upper surface 116 is moreover facilitated by the arrangement of the connecting member 104 described above.

As can be seen in Figures 8 and 9, the turret 103 comprises a means for deviating a chain in a horizontal plane 128 and a means for deviating a chain in a vertical plane 138. The means for deviating a chain in a horizontal plane 128 and vertical plane 138 are disposed on the upper face 121 of the turret 103.

By horizontal and vertical, the present description seeks to describe an orientation of planes in which the chain 125 is deviated, when when the mooring device 100 is installed on the ship 2 or in a similar position.

As Figure 9 shows, the ship 2 comprises a winch 24 provided to wind in or wind out the chains 125 or the fluid line 126. The winch 24 is positioned here on the main deck 23 of the ship 2.

In the example shown, the means for deviating a chain in a horizontal plane 128 serves to guide a chain 125 between the main deck 23 of the ship 2, where the chain is connected to a winch 24, and the means for deviating a chain in a vertical plane 138.

The means for deviating a chain in a horizontal plane 128 is formed here by a tubular portion projecting from the upper face 121 of the turret 103. The tubular portion is centered on the upper face 121 of the turret 103 which makes it possible to preserve the alignment of the chain 125 with the winch 24 when the ship 2 pivots around the turret 103. The tubular portion here is rotationally coupled to the turret 103.

As a variant, the means for deviating a chain in a horizontal plane may be formed by a pulley or any other circular member around which a chain is capable of winding.

When the mooring device 100 is installed on the ship 2, the chain extends substantially horizontally between the winch 24 and the means for deviating a chain in a horizontal plane 128. The means for deviating a chain in a horizontal plane 128 is provided with a groove 129 in order to improve the guiding of the chain 125 in the horizontal plane and is thus positioned so as to be substantially at the same level as the winch 24.

The means for deviating a chain in a vertical plane 138 serves to guide a chain 125 between the means for deviating a chain in a horizontal plane 128 and a through-aperture 127 of the upper face 121 of the turret 103. The means for deviating a chain in a vertical plane 138 is formed here by a pulley and is demountably fastened to the upper face 121 of the turret 103. This makes it possible to use only one pulley to tension the chains 125 passing through different through-apertures 127.

As a variant, the means for deviating a chain in a vertical plane may be formed by a tubular portion or any other circular member around which a chain is capable of winding.

To tension a chain 125 passing through a through-aperture 127, the s means for deviating a chain in a vertical plane 138 is positioned on the upper face 121 of the turret 103 to guide the chain 125 along an axis passing via the center of the through-aperture 127 and tangential to the means for deviating a chain in a horizontal plane 128, as can be seen in Figure 9.

The chain 125 is next wound around the means for deviating a chain in a vertical plane 138 then around the means for deviating a chain in a horizontal plane 128 before being connected to the winch 24.

The winch 24 can then wind the chain 125 in or out to adjust the tension. When a desired tension has been reached, the chain 125 may be retained by the pivoting guides 120b and thus be removed from the winch 24, from the means for guiding in a horizontal plane 128 and vertical plane 138.

To wind in another chain 125 passing through another through-aperture 127, the means for deviating a chain in a vertical plane 138 is moved on the upper face 121 of the turret 103 in order to be correctly orientated, such that the steps described above can again be implemented until the chains 125 each have a desired tension.

In the example illustrated in Figure 9, the winch 24 is offset relative to the center of the upper face 121 of the turret 103 in order for the path of the chain 125 (represented in dashed line) between the winch 24 and the means for deviating a chain in a horizontal plane 128 to be substantially at a right angle to the winding axis of the winch 24. In this configuration, only the chains 125 passing through the through-apertures 127 located in the lower part, that is to say the half-circle at the bottom of the figure, can wind around the means for deviating a chain in a horizontal plane 128. These chains 125 thus wind around the means for deviating a chain in a horizontal plane 128 in an anti-clockwise direction when they are tensioned, that is to say when the winch 24 winds in the chains 125.

To wind in or out the chains 125 passing through the through-apertures 127 located in the upper part, that is to say the half-circle at the top of the Figure 9, of the upper face 121 of the turret 103, the winch is offset in order for the path of the chain 24 between the winch 125 and the means for deviating a chain in a horizontal plane 128 to be substantially at a right angle to the winding axis of the winch 24 and for that path to be tangential to the means for deviating a chain in a horizontal plane 128 at a point diametrically opposite that shown in Figure 9. When the winch 24 winds in the chains 125, these latter wind around the means for deviating a chain in a horizontal plane 128 in a clockwise direction.

As a variant, the winch may be positioned between the two positions already described, that is to say aligned with the center of the upper face of the turret. In this way, the winch can stay at the same location whatever the position of the apertures on the upper face of the turret.

Of course, the invention is not limited to the embodiment described above. In particular, an upper mounting comprising a lower bearing itself comprising several slide pads disposed in a circular arrangement around the turret as described above may be used on other mooring devices independently of a mooring device comprising an upper mounting configured to be fastened to a first part of the bow, a lower mounting configured to be fastened to a second part of the bow disposed under the first part of the bow and a connection member fastening the upper mounting to the lower mounting.

Similarly, a turret comprising a means for deviating a chain in a horizontal plane and a means for deviating a chain in a vertical plane, the means for deviating a chain in a horizontal plane and the means for deviating a chain in a vertical plane being positioned on an upper surface of the turret, the means for deviating a chain in a vertical plane being positioned between the means for deviating a chain in a horizontal plane and at least one through-aperture provided in an upper surface of the turret as described above may be used on other mooring devices independently of a device comprising an upper mounting configured to be fastened to a first part of the bow, a lower mounting configured to be fastened to a second part of the bow disposed under the first part of the bow and a connecting member fastening the upper mounting to the lower mounting. s

Claims

CLAIMS1. A turret mooring device (103) configured to be fastened on a bow (21) of a ship (2), comprising an upper mounting (101) configured to be fastened s to a first part (21a) of the bow (21), a lower mounting (102) configured to be fastened to a second part (21b) of the bow (21) disposed under the first part (21a) of the bow (21), a turret (103) rotatably mounted in said upper mounting (101) and in said lower mounting (102) respectively via an upper bearing (105) accommodated in said upper mounting (101) and a lower bearing (112) accommodated in said lower mounting (102), said device being characterized in that it comprises a connection member (104) fastening said upper mounting (101) to said lower mounting (102), and in that said upper mounting (101) has a fastening surface (108) configured to fit to the shape of the first part (21a) of the bow (21) of the ship (2) and said lower mounting (102) has a fastening surface (115) configured to fit to the shape of the second part (21b) of the bow (21) of the ship (2).
2. The turret mooring device (103) according to claim 1, characterized in that said fastening surface (108, 115) of the upper mounting (101) and of the lower mounting (102) is curved.
3. The turret mooring device (103) according to one of claims 1 or 2, characterized in that said connecting member (104) comprises at least one metal beam having a first end (130) mechanically connected to said upper mounting (101) and a second end (131), which is an opposite end to the first end (130), which is mechanically connected to said lower mounting (102).
4. The turret mooring device (103) according to claim 3, characterized in that the first end (130) of the metal beam is mechanically connected at a location towards a distal end (107) of said upper mounting (101) and said second end (131) of said metal beam is mechanically connected at a location towards a proximal end (106) of said lower mounting (102).
5. The turret mooring device (103) according to any one of claims 3 or 4, characterized in that said connecting member (104) comprises two metal beams substantially parallel to each other, the first ends (130) of the two beams s being mechanically connected to a lower surface (110) of said upper mounting (101) on opposite sides of said upper mounting (105).
6. The turret mooring device (103) according to any one of claims 1 to 5, characterized in that a lower surface (110) of the upper mounting (101) is inclined relative to an upper surface (109) of the upper mounting (101) such that the distance between the upper surface (109) and the lower surface (110) reduces on going from a proximal end (106) towards a distal end 007) of the upper mounting 001).
7. The turret mooring device (103) according to any one of claims 1 to 6, characterized in that the lower bearing (112) comprises several slide pads (134) in circular arrangement around the turret 003).
8. The turret mooring device (103) according to claim 7, characterized in that the slide pads (134) are demountably mounted in mountings (132) disposed in circular arrangement in the lower mounting 002).
9. The turret mooring device (103) according to claim 8, characterized in that the slide pads 034) cooperate with the mountings 032) with a slide connection of axis parallel to the rotational axis of the turret (103) and in that the mountings 032) comprise a first translational stop means preventing the movement of the slide pads (134) in a first direction.
10. The turret mooring device (103) according to claim 9, characterized in that the mountings (132) comprise a second translational stop means (135) movable between a first position in which the second translational stop means prevents the translational movement of the slide pads (134) in a second direction opposite to the first direction, and a second position in which the second translational stop means (135) allows the translational movement of the slide pads (134) in the second direction.
11. The turret mooring device (103) according to any one of claims 8 to 10, characterized in that the slide pads (134) form a dovetailed assembly with the mountings (132).
12. The turret mooring device (103) according to any one of claims 8 to to 11, characterized in that the slide pads (134) comprise a raising member (136) fastened on an upper face (134b) of the slide pads (134).
13. The turret mooring device (103) according to any one of claims 1 to 12, characterized in that it comprises a means for deviating a chain in a is horizontal plane (128) and a means for deviating a chain in a vertical plane (138), the means for deviating a chain in a horizontal plane (128) and the means for deviating a chain in a vertical plane (138) being positioned on an upper face (121) of the turret (103), the means for deviating a chain in a vertical plane (138) being positioned between the means for deviating a chain in a horizontal plane (128) and at least one through-aperture (127) provided on the upper face (121) of the turret (103).
14. The turret mooring device (103) according to claim 13, characterized in that the means for deviating a chain in a vertical plane (138) is fastened demountably on the upper face (121) of the turret (103).
15. A ship having a bow (21), characterized in that it comprises a turret mooring device (103) according to any one of claims 1 to 14, said upper mounting (101) being fastened by the fastening surface (108) to an upper part (21a) of the bow (21) and the lower mounting (102) being fastened by the fastening surface (115) to a lower part (21b) of the bow (21) located under the upper part (21a) of the bow (21).