Technical field

The present invention relates to an arrangement for a marine structure, which ar- rangement is attached to the marine structure at a side of the marine structure facing the sea according to the pre-characterizing portion of claim 1 . The present invention also relates a marine structure according to claims 15 and 16.

Background art

On a general level, there are situations where equipment or personnel have to be lowered into the sea from a marine vessel or other marine structure. A crane or other lifting device is normally used for this purpose. This can be the case with equipment such as measuring instruments, tools, drills, remotely or autonomously operated vehicles, as well as divers for operating such equipment. As an example of a typical marine measuring instrument is a CTD device, a so-called CTD Rosette, for meas- uring e.g. salinity, temperature, depth and concentration of particles in a water column. Such equipment and personnel are often sensitive to the lowering conditions and necessitate calm waters. However, in high seas and ice conditions, protection is needed.

It is known to provide protection, particularly in ice conditions, by flushing surround- ing broken ice using thrusters on the marine vessel. The marine vessel is driven towards the edge of the ice field in such a direction that broken ice is not carried to the other side of the marine vessel, whereby the thrusters can additionally secure that any broken ice does not collect on said side of the marine vessel. In this manner, an ice-free region can be created alongside the ship for lowering and raising equip- ment from and into the sea. This approach has the advantage that no specific structures need to be deployed on the ship, but on the other hand, the drawback is that flushing is very heavily dependent on e.g. ice, wind and wave conditions. In addition, flushing requires a significant additional amount of power and fuel.

On more stable marine structures, such as off-shore platforms, large diameter pipes have also been used for protecting equipment that is lowered into the sea. These are usually very heavy and cumbersome to move, and further, during any movement of the platform, even during positioning, such pipes significantly add resistance and may be broken off in ice conditions. For these reasons such pipes are rendered useless for marine vessels, such as ships.

A further protective measure for marine vessels or marine structures, intended and equipped for various operations at sea, additionally to pure transit, is to provide the vessels with downwards open internal compartments e.g. in the form of so-called moon pools or so-called keel cavities. Typical marine vessels in this case would include e.g. installation vessels, support vessels, construction vessels, survey vessels, research vessels, seismic vessels, diving support vessels, drill ships, oil tankers, off-shore platforms and corresponding structures, as well as other water craft. The internal compartments are intended for carrying out off-shore operations such as installation, excavation, drilling, laying and surveying pipe lines and cables, salvage, loading, and mooring, etc. on the sea bed or in submerged conditions, which operations represent so-called moon pool operations or submerged loading operations. A moon pool, usually in the form of an internal vertical shaft, provides access to sites below the water level of a surrounding body of water from the inside or from an open deck of the marine vessel. Such structures may be found in KR 20100007184 U, KR 20120027853 A, WO 2012/032163 A1 , WO 2013/167805 A1 and KR 20160001006 A. A keel cavity normally provides a submerged connection e.g. for submerged turret loading. An example may be found in US 6,517,290 B1 . Normally the above mentioned operations are carried out in open seas.

Although a moon pool is a very convenient feature of a marine structure or marine vessel, it has serious drawbacks. Firstly, a moon pool requires considerable space inside a marine vessel or marine structure, particularly in a very central location. This usually has a considerable impact on the arrangement of a vessel. Typically when a vessel is designed, the structures of the vessel are designed around the moon pool. The moon pool places requirements on the strength of a vessel. It weakens the structure of a vessel unless structural details are enhanced to counter that effect. Also, a moon pool takes up valuable space, valuable storage space on a vessel. A moon pool decreases the displacement of a vessel, which means that it has less deadweight capability, i.e. less payload.

Summary of the invention

An object of the present invention is to avoid the above mentioned drawbacks and to provide an arrangement that can be flexibly installed on a marine structure. This object is attained by an arrangement according to claim 1 . The basic idea of the invention is to provide an arrangement for a marine structure that is readily deployable when needed and that is retractable from deployment in such a manner that it minimizes any obstruction to the marine structure. This is realized by an arrangement comprising at least one side wall arranged to extend in a vertical direction from above sea level to below sea level, whereby the arrangement in a first retracted position is aligned against the side of the marine structure and in a second extended position is extended from the side of the marine structure in order to provide an enclosure between the side of the marine structure and the at least one side wall. The enclosure is open ended in the vertical direction and sur- rounded by the at least one side wall in order to provide access from the side of the marine structure into the enclosure and to the sea. The arrangement is provided with an activating means for moving the at least one side wall of the arrangement in order to position the arrangement in the first retracted position or the second extended position. The advantage of such an arrangement is that it can be easily in- stalled on a marine structure, also as a retrofit on existing marine structures. Furthermore, it can be designed taking into account the prevailing conditions, e.g. by considering the material of said at least one side wall and the nature of the activating means. Access from the marine structure to the sea and respectively from the sea to the marine structure is ensured by the open ended structure. The definition that the at least one side wall is arranged to "extend in a vertical direction from above sea level to below sea level" is to be understood in view of the purpose of the arrangement. The vertical extension, i.e. height of the arrangement, i.e. the height in a vertical direction along the side of the marine structure with regard to a horizontal sea level or sea surface, has to be such that it allows protected ac- cess from the side of the marine structure into the arrangement, later also called a side pool, and consequently also to the sea On the other hand, the arrangement has to extend below sea level to a sufficient degree, in order to protect the inside of the arrangement, in other words e.g. any equipment or persons within the arrangement from wave action or ice or other debris in the sea. Clearly, the term "vertically" has to be understood so that it necessarily does not literally mean absolutely vertical. The relevant side of the marine structure to which the arrangement is attached may be inclined or slanted, whereby the arrangement would be aligned with the said side. This falls within the competence and understanding of a person skilled in the art. For instance, on a marine vessel, the vertical extension of the arrangement could preferably be from above the uppermost water line to below the lowermost water line.

A person skilled in the art can design the arrangement according to the present invention with an appropriate extension, i.e. height of the arrangement, in view of its purpose, intended use or prevailing deployment conditions.

Advantageously, the at least one side wall of the arrangement is arranged in a recess at the side of the marine structure. In this manner, it does not form any unde- sired obstruction when not in use. Furthermore, it allows for a streamlined design of the marine structure.

The at least one side wall of the arrangement can be arranged between at least two opposite projections fixed to the side of the marine structure. This is advantageous e.g. for retrofit installations. Furthermore, e.g. on a moving marine vessel, the projections can direct any ice or debris away from the arrangement in order not to dam- age any components of the arrangement.

In an advantageous embodiment, the arrangement is provided with two or more side walls, which are connected to each other by means of a first hinge connection or first joint connection and which are connected to the side of the marine structure by means of a second hinge connection or second joint connection. In this manner the arrangement can be constructed so that the configuration of the arrangement can be adapted to the prevailing conditions and intended use of the arrangement.

The activating means can advantageously comprise at last one hydraulic cylinder or pneumatic cylinder, at least one leadscrew device, a cable or chain device, or a gear device, at least one electronic actuator, or at least one compressor device for moving at least one side wall of the arrangement. This provides the possibility of using a variety of different activating means and side wall elements for the arrangement in order to adapt to the prevailing conditions and intended use of the arrangement.

The material of the at least one side wall can also be varied according to the pre- vailing conditions and the intended use of the arrangement. The material can comprise e.g. a rigid plate material or a layer of flexible material. In a corresponding manner, the structure of the at least one side wall can comprise e.g. a rigid structure, a foldable structure, a flexible structure or a flexible bellows- type structure.

Advantageous embodiments of the present invention are defined in claims 2-14. The marine structure is defined in claims 15 and 16.

The term "marine structure" is to be understood as defining a marine vessel comprising e.g. installation vessels, support vessels, construction vessels, survey vessels, research vessels, seismic vessels, diving support vessels, drill ships, oil tankers, off-shore platforms and corresponding structures, as well as other water craft, and generally ships. Further, the term "marine structure" is considered to include harbor infrastructure, such as a quay or a pier, which also can be provided with an arrangement according to the present invention.

Brief description of drawings

In the following the invention will be described by way of example only with reference to the accompanying schematic drawings, in which

Figures 1 to 3 illustrate a first embodiment of an arrangement according to the present invention,

Figures 4 to 6 illustrate the first embodiment deploying alternative mechanisms,

Figure 7 illustrates a second embodiment as an alternative in view of the first em- bodiment,

Figures 8 to 10 illustrate a third embodiment with another alternative mechanism, Figure 1 1 illustrates a fourth embodiment with another alternative mechanism, Figures 12 and 13 illustrate a fifth embodiment, Figures 14 and 15 illustrate a sixth embodiment, Figure 16 and 17 illustrate a seventh embodiment, Figure 18 illustrates an eighth embodiment, Figure 19 illustrates an example of an arrangement attached to the side of a marine structure,

Figure 20 illustrates an example of a cover structure for the arrangement according to the invention, Figures 21 to 23 illustrate alternative deployments for the arrangement according to the present invention, and

Figure 24 illustrates a perspective view of the deployment of the arrangement according to the present invention.

Description of the invention In the following, a marine structure is indicated by reference numeral 1 , whereby a side of the marine structure is indicated by reference numeral 2. Said side 2 of the marine structure is facing the sea as indicated by reference sign S. In the following the marine structure will be called a vessel.

Figures 1 to 6 illustrate a first embodiment of the present invention. The arrange- ment 3 comprises at least one side wall arranged to extend in a vertical direction from above sea level to below sea level, in the present embodiment three side walls 31 . The side walls 31 are connected to each other by means of a first hinge connection or first joint connection indicated by reference numeral 32. The distal or outer ends of the two outer side walls 31 are connected to the side 2 of the vessel by means of a second hinge connection or second joint connections indicated by reference numeral 33, which are slidably engaged with the side 2 of the vessel. In the following, said first and second connections will be called first or second hinges.

In Figure 1 the arrangement 3 is shown in a first retracted position A, when the arrangement is not deployed for use, in which it is aligned against the side 2 of the vessel. In the present embodiment, the arrangement is arranged in a first recess 21 at the side 2 of the vessel. The depth of the first recess 21 corresponds to the thickness of the side walls 31 including the first and second hinges. In this embodiment the second hinges are slidably engaged with the recess 21 . In this manner, the arrangement 3 is flush with the side 2 of the vessel. Consequently, the arrangement does not result in any obstructions or resistance during operation, e.g. travel of the vessel. Figures 2, 4, 5 and 6 illustrate how the arrangement 3 is moved from the first retracted position A into a second extended position B, in which it provides an enclosure SP, which in a vertical direction is open ended, between the side 2 of the vessel and the three side walls 31 . Figure 3 illustrates the arrangement 3 in a second ex- tended position B.

Clearly, the positions shown in Figures 2, 4, 5 and 6 can also constitute a second extended position B providing an enclosure SP taking into account the prevailing conditions and the intended use of the arrangement.

In order to move the side walls in order to position the arrangement in said positions, the arrangement is provided with activating means.

Figure 4 illustrates the activating means as two hydraulic cylinders or pneumatic cylinders 4 arranged in the vessel, which are connected to the first hinges for extending or retracting the arrangement 3. The cylinders are arranged in a right angle with respect to the side of the vessel. Figure 5 illustrates an alternative positioning for the cylinders. The two cylinders are arranged at the opposite ends of the recess 21 , in parallel with the side of the vessel. Thus, the cylinders are connected to the second hinges at the distal ends of the outer side walls. The number of cylinders can vary, e.g. depending on the vertical height of the arrangement, i.e. the extent of the arrangement, which extends along the side of the vessel from above sea level to below sea level.

Figure 6 illustrates another example corresponding to Figure 4. In this case, however the activating means are shown as two leadscrew devices 5. Alternatively, the activating means could be e.g. electronic actuators (Fig. 13).

Figure 7 illustrates a second embodiment as an alternative in view of the first em- bodiment. The reference numerals in this embodiment correspond to those of Figures 1 to 6, and are thus not discussed in more detail in this connection. In this embodiment, the arrangement is arranged between projections 22 fixed to the side of the vessel. The projections 22 preferably extend from above sea level to below sea level, more exactly along the vertical extension, i.e. the height of the arrange- ment, i.e. the height in a vertical direction along the side of the vessel with regard to the horizontal sea level or sea surface. The projections may also be arranged along the length of the arrangement, i.e. in a longitudinal direction along the side 2 of the marine structure, generally in parallel with the horizontal sea level. The projections 22 are preferably, as indicated in Figure 7, in the form of wedges that can conduct e.g. ice or other debris in the water past the arrangement 3 when it is in its first retracted position. In this manner, the arrangement 3 lies flat against the side 2 of the vessel. Consequently, the arrangement does not in any significant manner result in any obstructions or resistance during operation, e.g. travel of the vessel. The activating means discussed above in connection with the first embodiment of Figures 4 to 6 can be used in connection with this embodiment as well.

According to this embodiment of the present invention, the arrangement 3 can easily be carried out as a retrofit application on a vessel.

The side walls of the embodiment according to the first and second embodiments of the invention are preferably of rigid plate material or of a layer of flexible material. The material can be chosen based on the prevailing conditions, i.e. high seas, strong currents, or ice conditions.

Figures 8 to 10 illustrate a third embodiment of the present invention. The reference numerals in this embodiment correspond to those of Figures 1 to 6, and are thus not discussed in more detail in this connection. The arrangement 3 comprises at least one side wall arranged to extend in a vertical direction from above sea level to below sea level, in this embodiment three side walls 31 rigidly fixed to each other in order to form a rigid U-shaped enclosure SP, which is open ended in the vertical direction. The side 2 of the vessel is provided with a first recess 21 to receive the side wall 31 , which constitutes the base of the rigid U-shaped enclosure and which is aligned with the side 2 of the vessel, and thus faces the sea S. Further, the vessel is provided with two second recesses 23 for receiving the side walls 31 that constitute the two legs of the rigid U-shaped enclosure. These two second recesses 23 are arranged perpendicularly with respect to the direction of the side 2 of the vessel and extend into the vessel.

The definition rigid U-shaped enclosure does not necessarily indicate that the material of the side walls is rigid, only the configuration of the arrangement is rigid. Thus, the side walls of the embodiment according to the third embodiment of the invention are preferably of rigid plate material or of a layer of flexible material. In Figure 8 the arrangement 3 is shown in the first retracted position A and in Figure 9 in a second extended position B, in which it forms the enclosure SP, which is open ended in the vertical direction. Figure 10 illustrates an alternative activating means, in this case a cable or chain activated device 6. The activating means discussed above in connection with the first embodiment of Figures 4 to 6 can be used in connection with this embodiment as well. An extended position B as indicated in Figure 10 can also be relevant in view of the discussion above in connection with Figures 1 -6. Figure 1 1 illustrates a fourth embodiment of the present invention. The reference numerals in this embodiment correspond to those of Figures 1 to 6, and are thus not discussed in more detail in this connection. The arrangement 3 includes at least one side wall arranged to extend in a vertical direction from above sea level to below sea level, in this embodiment two side walls 31 , of which one side wall 31 , having a rigid configuration, at its first end is turnably fixed in a first recess 21 at the side 2 of the vessel, which is arranged to receive said side wall 31 , when the arrangement is in the first retracted position A (not shown), i.e. when the side wall is turned against the side 2 of the vessel. The second end, opposite to the first end, is connected to a foldable side wall 31 , which in turn is fixedly arranged in a third recess 24 in the vessel. The third recess 24 is arranged perpendicularly with respect to the direction of the side 2 of the vessel.

The activating means in this embodiment is a gear device 7, which can move the side wall 31 away from and against the side 2 of the vessel, thus positioning the arrangement between the first retracted position A (not shown), in which the foldable side wall is received in the third recess 24, or the second extended position B (not shown), in which the foldable side wall is drawn out from the third recess 24, in order to form an enclosure SP, which is open ended in the vertical direction, within the side wall 31 , having a rigid configuration, and the foldable side wall 34.

The activating means discussed above in connection with the first embodiment of Figures 4 to 6 can be used in connection with this embodiment as well.

The side wall, having a rigid configuration, according to the fourth embodiment of the invention, is preferably of rigid plate material or of a layer of flexible material. The foldable sidewall can be formed of hinged sections of corresponding material. Alternatively, the foldable wall can be formed of a layer of flexible material without hinged sections.

Figures 12 and 13 illustrate a fifth embodiment of the present invention. The reference numerals in this embodiment correspond to those of Figures 1 to 6, and are thus not discussed in more detail in this connection. The arrangement comprises at least one side wall arranged to extend in a vertical direction from above sea level to below sea level, in this embodiment two side walls 31 , whereby, when the arrangement is in the second extended position B, the two side walls 31 form a triangular space, which constitutes the enclosure SP, which is open ended in the vertical direction. Figure 13 illustrates an electronic actuator 8. In other respects the descrip- tion above, including the activating means, in relation to Figures 1 to 6 applies to this embodiment as well. The difference is mainly in the number of side walls.

This embodiment could also be carried out in the same manner as described in connection with Figure 7, i.e. by providing projections on the side 2 of the marine vessel. Figures 14 and 15 illustrate a sixth embodiment of the present invention. The reference numerals in this embodiment correspond to those of Figures 1 to 6, and are thus not discussed in more detail in this connection. The arrangement 3 comprises at least one side wall arranged to extend in a vertical direction from above sea level to below sea level, in this embodiment two side walls 31 , which are arranged in two fourth recesses 25 respectively in the vessel, which are positioned in a right angle with respect to each other and in a 45° angle with respect to the side 2 of the vessel. The two side walls 31 can be extended from or retracted into the two fourth recesses 25 respectively. When the side walls 31 are extended from the two fourth recesses 25, the outer ends of the side walls 31 , extending into the sea S, are joined in order to form a triangular space, which constitutes the enclosure SP, which is open ended in the vertical direction.

The mechanisms discussed above in connection with the first embodiment of Figures 4 to 6 can be used in connection with this embodiment as well. The side walls of the embodiment according to the third embodiment of the invention are preferably of rigid plate material or of a layer of flexible material.

Figure 16 and 17 illustrate a seventh embodiment of the present invention. The reference numerals in this embodiment correspond to those of Figures 1 to 6, and are thus not discussed in more detail in this connection. The arrangement comprises at least one side wall arranged to extend in a vertical direction from above sea level to below sea level, in this embodiment one side wall 31 of flexible material, which at its both ends is fixedly arranged at opposite ends of the recess 21 in the side 2 of the vessel. The flexible side wall 31 preferably has an inflatable structure, whereby the activating means can be e.g. a compressor 9 for supplying air to inflate the flexible side wall 31 in order to set the arrangement 3 in its second extended position B in order to form the enclosure SP, which is open ended in the vertical direction, within the flexible side wall 31 and the side 2 of the vessel.

This embodiment could also be carried out in the same manner as described in connection with Figure 7, i.e. by providing projections on the side 2 of the vessel. Figure 18 illustrates an eighth embodiment of the present invention. The reference numerals in this embodiment correspond to those of Figures 1 to 6 and are thus not discussed in more detail in this connection. The arrangement comprises at least one side wall arranged to extend in a vertical direction from above sea level to below sea level, in this embodiment three side walls 31 fixed to each other in order to form a U-shaped enclosure, which is open ended in the vertical direction. The side 2 of the vessel is provided with a first recess 21 to receive the side wall 31 , which constitutes the base of the U-shaped enclosure and which is aligned with the side 2 of the vessel, and thus faces the sea S. Further, the vessel is provided with two fifth recesses 26 for receiving the side walls 31 that constitute the two legs of the U- shaped enclosure. These two fifth recesses 26 are arranged perpendicularly with respect to the direction of the side 2 of the vessel.

The side walls 31 that constitute the two legs of the U-shaped enclosure can be e.g. in the form of flexible side walls, which preferably would have an inflatable structure, as described above in connection with the seventh embodiment of Figure 16 and 17. The activating means could thus be a compressor. Alternatively, the side walls 31 that constitute the two legs of the U-shaped enclosure can be e.g. in the form flexible side walls with a bellows-type structure, whereby the activating means of the first embodiment of Figures 4 to 6 could also be deployed within the bellows-type side wall. Figure 19 illustrates an arrangement 3 according to the present invention at the side of a vessel. The side of the vessel is provided with an opening 26, which allows access into the arrangement 3. The reference numerals correspond to those of Figures 1 to 6 and are thus not discussed in more detail in this connection. Clearly, access can be also e.g. from a deck of a vessel. Figure 20 illustrates an example of a cover structure 10 for the arrangement according to the invention. The reference numerals correspond to those of Figures 1 to 6 and are thus not discussed in more detail in this connection. The cover structure 7, which is in the form of an awning or blind. The shape of this cover structure is advantageous for the first, second, third and eighth embodiments as described above. The cover structure can be fastened in an appropriate manner to the side 2 of the vessel, whereby the side of the vessel advantageously would be provided with an opening 26 as described in connection with Figure 19. Clearly, cover structures can be arranged also for the fourth, fifth, sixth and seventh embodiments of the present invention.

A cover structure provides protection from the elements for the volume enclosed by the arrangement, i.e. the enclosure SP, which itself is open ended in the vertical direction, with the cover structure. Further, if there is a opening, e.g. a door, in the side 2 of the vessel so that the cover structure covers the door as well, the cover structure can provide protected access to the enclosure from inside of the vessel. Such an arrangement allows provision of a warm, or at least non-freezing, working environment for crew and equipment even in subzero temperatures. Such an environment is advantageous also for providing protected access to the sea for e.g. divers and swimmers. An enclosure with a cover structure basically provides the convenience of a traditional fixed moon pools.

Figures 21 to 23 illustrate alternative deployments for the arrangement according to the present invention. The arrangement 3 according to the invention can be located at any side 2 (Figure 21 ) of the vessel, also including the aft or stern of the vessel (Figure 22). For practical reasons, while such an arrangement could be deployed in the front or bow of a vessel, this might not be a very advisable location due to structural reasons. Further, in catamaran vessels, which have two hulls 1 1 , or trimaran vessel which have three hulls, the arrangement according to the invention can be located also on an inner side of any of the hulls of the vessel, whereby the location would be somewhat more protected (Figure 23). Figure 24 illustrates a perspective view of the deployment of the arrangement according to the present invention. The reference numerals correspond to those used in connection with the above described embodiments and are therefore not discussed in any more detail in this connection. The marine structure 1 , in this embodiment shown as a marine vessel, or more commonly called a ship, is provided with an arrangement 3, with three side walls, each indicated by reference numeral 31 . The arrangement is shown in a second extended position B. The side walls of the arrangement extend in a vertical direction from above sea level to below sea level. In this case the sea level corresponds to the water line WL of the marine vessel.

The definition that the at least one side wall is arranged to "extend in a vertical di- rection from above sea level to below sea level", as discussed above, is to be understood in view of the purpose of the arrangement. The vertical extension, i.e. height of the arrangement, i.e. the height in a vertical direction along the side of the marine structure with regard to a horizontal sea level or sea surface, has to be such that it allows protected access from the side of the marine structure into the arrange- ment, later also called a side pool. On the other hand, the arrangement has to extend below sea level to a sufficient degree, in order to protect the inside of the arrangement, in other words e.g. any equipment or persons within the arrangement from wave action or ice or other debris in the sea.

Clearly, the term "vertically" has to be understood so that it necessarily does not literally mean absolutely vertical. The relevant side of the marine structure to which the arrangement is attached may be inclined or slanted, whereby the arrangement would be aligned with the said side. This falls within the competence and understanding of a person skilled in the art.

Further, on a marine vessel, the "vertical" extension of the arrangement could pref- erably be from above the uppermost water line to below the lowermost water line. For an ice-reinforced marine vessel the extension could be e.g. from an upper ice water line to a lower ice water line.

In the exemplary embodiment of Figure 24, the arrangement 3 extends from a deck 1 1 of the marine vessel 1 to below the water line WL, whereby the height of the arrangement is indicated by reference marking H.

A person skilled in the art can design the arrangement according to the present invention with an appropriate extension, i.e. height of the arrangement, in view of its purpose, intended use or prevailing deployment conditions.

Further, as indicated by reference numeral 26 (discussed in connection with Figure 19) the side 2 of the marine vessel 1 is shown to be provided with an opening 26 for access into and from the arrangement 3.

In the above, the invention has been defined as an "arrangement". The arrangement could also be called a "side pool", a "flexible side pool" or a "foldable side pool" in view of the more established definition "moon pool." In the following various advantages and deployments of the arrangement of the present invention will be discussed. In this connection the term "side pool" will be used for the term "arrangement". A side pool according to the present invention has several advantages. Firstly, the side pool requires only little space on the vessel, when it is not being used. Further, the space taken up is in a more convenient location than in case of a traditional moon pool within the interior of a vessel. The side pool can be added to an existing vessel as a retrofit construction, which is a significant advantage as a traditional moon pool typically cannot be implemented into an existing vessel due e.g. to the structural weakening caused by the traditional moon pool. The side pool does not decrease the displacement of the ship, which is one of the problems of traditional, fixed moon pools. A side pool is very practical when the side pool is needed only from time to time for temporary needs, such as only when the vessel operates in ice conditions. The side pool is advantageous in broken or crushed ice, or in situations where there is other debris in the sea. While the side pool helps protect any instruments or equipment lowered into or raised from the sea within the side pool from any damage caused by broken pieces of ice, the side pool will also protect any such equipment from actions of waves and other debris in the sea.

Further, a side pool when folded flat against the side surface of the vessel does not disturb the normal operations of the vessel. Also, the side moon pool can be implemented with low costs. A side pool can be retrofitted on existing vessels, which with regard to a traditional moon pool arrangement is nearly impossible, or at least not financially reasonable.

A side pool provides an enclosed and controlled environment where different anti- ice auxiliary systems - for example, air bubblers or hot water sprays - are more efficient than when applied just along the side of the vessel without such an enclo- sure. These systems allow keeping the side pool deployed and ice-free in very cold ambient temperatures.

A side pool structure allows combining the functions of a research vessel and a logistics vessel. A traditional moon pool is required for the functionality e.g. for a research vessel in ice conditions, but a traditional moon pool is a large disadvantage for a general logistics vessel. Consequently, a side pool can e.g. be deployed in a generic logistics vessel in order to support research functions. When the side pool is folded against the side of a vessel, it does not considerably affect the strength of the side of the vessel against ice pressure. A side pool can also be used to provide a safe route for a diver or a swimmer to go into the sea or out of the sea in a protected manner both e.g. in high seas and ice conditions. Thus, the side pool can e.g. be deployed for providing a temporary swimming pool for recreational purposes on a vessel. The side pool can be easily imple- mented in differing sizes depending on prevailing needs and e.g. the size of equipment, which needs to be lowered in a protected manner into the sea.

A side pool can also be used as an environmental protection device to inhibit or slow down the spreading of any oil or other substances accidentally leaked from equipment lowered into the sea through the side pool. This is advantageous in sensitive environments, e.g. in polar environments, where avoiding pollution is extremely important and highly regulated.

A side pool can be deployed on a variety of marine structures as discussed above, also fixed harbor structures, such as a quay or pier.

A side pool, and more particularly the side wall or the side walls, can be manufac- tured of various materials, such as steel, aluminum, or other metal material. Further, the material can be a composite material, e.g. based on glass or carbon fiber. Depending on the deployment of the side pool, general so-called shipbuilding material can also be used.

The description and the accompanying schematic drawings are only intended to clarify the basic idea of the invention, whereby the invention may vary in detail, e.g. regarding the type of the marine structure, the side walls, the material and structure of the side walls, the activating means, the cover structure, etc., within the scope of the ensuing claims.