Mobile dry setting element and installation, process for using same and use thereof

Abstract

 A truncated elongated oval-shaped dry setting element having two truncated elongated oval-shaped ends one of which is open and the other submergible end is closed by a floor accommodating a U-shaped receiving collar, the opening between the ends of said truncated elongated oval-shaped dry setting element and the width of the U-shaped receiving collar being sufficient to accommodate a partially submerged isolated structure such that said U-shaped receiving collar is sealable under water against said isolated structure with a collar sealing element closing the U of said collar in the plane of the collar with said isolated structure in place, and the opening between the ends of the first truncated elongated oval-shaped dry setting element being closable with a closure, wherein said dry setting element comprises a U-shaped structure replicating the opening formed by said U-shaped receiving collar at a sufficient distance from said U-shaped receiving collar so as to receive said isolated structure without substantially reducing said dry working space and such that when secured in said U-shaped structure there is substantially no movement of the dry setting installation relative to said isolated structure once said isolated structure is in place; a dry setting installation (1) for generating a substantially dry working space for carrying out work on a partially submerged isolated structure, the dry setting installation (1) comprising a first truncated elongated oval-shaped dry setting element according to as disclosed above, which with said collar sealing element and said closure in place is capable of forming a cofferdam round said isolated structure; a process for treatment of a partially submerged isolated structure, said process comprising the steps of: the receiving of said isolated structure by a dry setting element according to claim 1, said isolated structure being arrested by the bottom of the U of said U-shaped receiving collar and the bottom of the U of the U-shaped structure replicating the opening formed by said U-shaped receiving collar of said dry setting element; securing said isolated structure in said U-shaped receiving collar by closing the U of said collar in the plane of said collar with a collar sealing element and securing said isolated element where said U-shaped structure engages with said isolated element; closing the opening between the ends of said truncated elongated oval-shaped dry setting element with a sealing closure thereby providing a dry setting installation; pumping the water out of said dry setting installation thereby providing a cofferdam round said isolated structure; cleaning said surface of said isolated structure; applying a curable adhesive coating to said isolated structure; curing said curable adhesive coating; filling said dry setting installation with water, removing said sealing closure and said collar sealing element and removing said isolated element from said dry setting element; and the use of the above-disclosed mobile dry setting installation for carrying out maintenance on partially submerged isolated structures.

Description

Technical field of the invention

[0001] The present invention relates to the field of partially submerged isolated structures. More particularly, the present invention relates to a dry setting element, a dry setting installation, a process for treatment of a partially submerged isolated structure and the use of the mobile dry setting installation.

Background of the invention

[0002] Marine structures not only consist of sheet pile walls, but also isolated partially submerged hollow or solid structures such as piers, columns, pipes, piles, pilasters, stanchions, pylons and uprights. Such isolated partially submerged structures require treatment to prevent and/or combat corrosion by salt water and/or water-borne pollution in seawater, brackish water or freshwater as well as infestation by marine organisms such as barnacles in salt water and zebra mussels in freshwater.

[0003] In order to perform maintenance or control operations on these isolated partially submerged hollow or solid structures for example to check the level of corrosion, perform treatment against corrosion or replace or repair corroded parts of the structures, it is useful to make these structures easily accessible in a dry environment. Dry setting installations, also referred to as cofferdams or caissons, enable free access to the site in a dry environment.

[0004] US 5,292,206 discloses a device for sealing a caisson comprising a bottom, two upright side walls and a back wall in a watertight way against a sheet pile wall having a longitudinal profile composed of a succession of grooves and ridges, said device comprising the combination of: a) an inflatable continuous air chamber extending along the bottom of the caisson over the total width of the caisson and along the upright side walls thereof to sealingly engage the ridges of the sheet pile wall while conforming to irregularities therein; b) a series of deformable sealing elements disposed along the bottom of the caisson to sealingly engage the grooves of the sheet pile wall, each having a profile approaching the profile of a groove, which elements are each mounted between two horizontal guiding plates disposed one above the other in a manner such as to allow a displacement of the elements in the direction of the sheet pile wall in front of the grooves therein, while said inflatable air chamber is provided for pressing these elements against the wall to enable the deformable sealing elements to adapt to deformed and irregular grooves; c) a core provided between each of said sealing elements and the air chamber, which core is adapted to be displaced between said guiding plates and is fixed to the adjoining sealing element; and d) means for allowing a lateral displacement of said sealing elements together with the guiding plates above and underneath these sealing elements with respect to the caisson.

[0005] EP 2163692A discloses a dry setting installation (1) for generating a substantially dry working space for carrying out work at an underwater structure, the dry setting installation (1) comprising two side-walls (2), a back wall (3), a bottom (4) and, for each side-wall, a side edge sealing means (20) provided on the side-wall edge for providing a substantially sealing contact between the side-walls (2) and the underwater structure, characterised in that the dry setting installation comprises a distance variation means (30) for varying the distance between the side edge sealing means (20) of the two side-walls (2).

[0006] GB 2114636A discloses a working chamber for use in underwater work on an underwater member, the chamber consisting of two or more chamber sections which can be locked together in contact with each other; an opening being provided at the bottom and the top of the chamber and adapted for the introduction of the member in connection with which the chamber is to be used; a sealable manhole being provided in the upper part of the chamber.

[0007] GB 2226843A discloses an apparatus for allowing work to be carried out on a foundation pile, at least part of which is submerged, comprising means for locating a work platform around the pile, the work platform being surrounded by an upwardly extending wall, means for providing a seal between the work platform and the pile, means for locating the work platform in a desired location relative to the pile whilst the seal between the work platform and the pile is being effected and means for removing any water between the surrounding wall and the pile from above the seal. In a preferred embodiment he work platform is formed in two portions, each portion of the work platform having a part-circular cut-out and a section of wall secured thereto.

[0008] GB 2046818A discloses equipment for carrying out underwater operations on the exposed head sections of foundation piles and the like, the equipment having a submergible water-free working chamber adapted to be disposed over the exposed head section, a floor near the bottom edge of the chamber, the floor having an aperture with sealing means for sealing between the head section of a foundation pile requiring attention and the floor, and the working chamber being connected to at least one shaft extending upwardly for projection beyond the water surface.

[0009] A major problem with maintenance of any kind is the hinder that it engenders. This is particular serious in the case of hinder to waterways and marine installations e.g. harbours, ports, bridges and oil platforms. It is important that such hinder should be reduced to a minimum. There is a therefore a need for rapidly mountable and demountable installations allowing such work to be carried out expeditiously. A further requirement is that the installation be as compact as possible both as regards limiting physical hinder during the maintenance activities and providing accessibility to isolated partially submerged structures very close to one another.

Summary of the invention

[0010] It is an object of the present invention to provide a reusable dry setting element enabling the rapid treatment of partially submerged isolated structures in a sort of mobile dry dock for such isolated structures with a rapid, for example 8 hours or less, turn-around-time i.e. the time taken for the whole process of treatment from the accommodation of the isolated structure in the reusable dry setting element to the removal of the treated isolated structure from the reusable dry setting element.

[0011] An advantage of the present invention is that maintenance is possible of tubing and piles which are close together. For example a working zone 2000 mm in diameter is required for treating a tube or pile 42 mm in diameter. Tubes or piles up to 1000 mm can be treated with a single dry setting element according to the present invention and tubes or piles up to 2500 mm can be treated using two dry setting elements according to the present invention.

[0012] A further advantage of the present invention is that marine installations remain fully operational.

[0013] A still further advantage of the present invention is that due to the rapid turn-around-time treatment can be contemplated under circumstances which would not be contemplatable were a much longer turn-around-time be necessary for reasons of stability of the environment of the isolated element itself.

[0014] The above objective is accomplished by a dry setting element, a dry setting installation, a process for treatment of a partially submerged isolated structure and the use of the mobile dry setting installation of the present invention.

[0015] According to a first aspect of the present invention a truncated elongated oval-shaped dry setting element is provided having two truncated elongated oval-shaped ends one of which is open and the other submergible end is closed by a floor accommodating a U-shaped receiving collar, the opening between the ends of said truncated elongated oval-shaped dry setting element and the width of the U-shaped receiving collar being sufficient to accommodate a partially submerged isolated structure such that said U-shaped receiving collar is sealable under water against said isolated structure with a collar sealing element closing the U of said collar in the plane of the collar with said isolated structure in place, and the opening between the ends of the first truncated elongated oval-shaped dry setting element being closable with a closure, wherein said dry setting element comprises a U-shaped structure replicating the opening formed by said U-shaped receiving collar at a sufficient distance from said U-shaped receiving collar so as to receive said isolated structure without substantially reducing said dry working space and such that when secured in said U-shaped structure there is substantially no movement of the dry setting installation relative to said isolated structure once said isolated structure is in place.

[0016] According to a second aspect of the present invention a dry setting installation (1) is provided for generating a substantially dry working space for carrying out work on a partially submerged isolated structure, the dry setting installation (1) comprising a first truncated elongated oval-shaped dry setting element as disclosed above, which with said collar sealing element and said closure in place is capable of forming a cofferdam round said isolated structure.

[0017] According to a third aspect of the present invention provides a process for treatment of a partially submerged isolated structure is provided, said process comprising the steps of: the receiving of said isolated structure by a dry setting element according to claim 1, said isolated structure being arrested by the bottom of the U of said U-shaped receiving collar and the bottom of the U of the U-shaped structure replicating the opening formed by said U-shaped receiving collar of said dry setting element; securing said isolated structure in said U-shaped receiving collar by closing the U of said collar in the plane of said collar with a collar sealing element and securing said isolated element where said U-shaped structure engages with said isolated element; closing the opening between the ends of said truncated elongated oval-shaped dry setting element with a sealing closure thereby providing a dry setting installation; pumping the water out of said dry setting installation thereby providing a cofferdam round said isolated structure; cleaning said surface of said isolated structure; applying a curable adhesive coating to said isolated structure; curing said curable adhesive coating, filling said dry setting installation with water, removing said sealing closure and said collar sealing element and removing said isolated element from said dry setting element.

[0018] According to a fourth aspect of the present invention provides the use of the mobile dry setting installation as disclosed above for carrying out maintenance on partially submerged isolated structures.

[0019] Particular and preferred aspects of the invention are set out in the accompanying independent and dependent claims. Features from the dependent claims may be combined with features of the independent claims and with features of other dependent claims as appropriate and not merely as explicitly set out in the claims.

[0020] Although there has been constant improvement, change and evolution of devices in this field, the present concepts are believed to represent substantial new and novel improvements, including departures from prior practices, resulting in the provision of more efficient, stable and reliable devices of this nature.

[0021] The above and other characteristics, features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. This description is given for the sake of example only, without limiting the scope of the invention. The reference figures quoted below refer to the attached drawings.

Brief description of the drawings

[0022] 

Fig.1 is a schematic of the cross-section of the truncated elongated oval-shaped dry setting element A of the present invention, where D is the bottom plate, E is the profile of the bottom, F is a reinforcement parallel and contiguous with the oval-shaped outside wall, G is a reinforcement perpendicular to the oval-shaped outside wall forming part of the U-shaped receiving collar, H is the oval-shaped outside wall, I represents reinforcement ribs, J is sealing, and K is a ladder providing access from the top of the dry setting element;

Fig.2 is a series of three schematics showing the process by which a pylon P is enclosed in the truncated elongated oval-shaped dry setting element, A, of the present invention and a dry setting installation realised by closing the dry setting element with a collar sealing element (see middle schematic), B and a closure CL (see bottom schematic).

Fig.3 is a schematic of a dry setting installation round a non-vertical pylon, where D is the bottom plate, E is a round bottom profile, F is a reinforcement parallel and contiguous with the oval-shaped outside wall, G is reinforcement perpendicular to the oval-shaped outside wall H, J is sealing, K is a ladder, L is a distance block, M is a support perpendicular to the oval-shaped outer wall, and N is an adjustable platform.

Description of illustrative embodiments

[0023] The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention.

[0024] Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

[0025] Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other orientations than described or illustrated herein.

[0026] It is to be noticed that the term "comprising", used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression "a device comprising means A and B" should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.

[0027] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

[0028] Similarly it should be appreciated that in the description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

[0029] Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0030] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

[0031] The following terms are provided solely to aid in the understanding of the invention.

Definitions

[0032] The term "isolated underwater structure", as used in disclosing the present invention, means a solid or hollow structure surrounded by water for example a column, a pile, a pilaster, a stanchion, a pylon, an upright and a single pier.

[0033] The term "marine structure", as used in disclosing the present invention, means any structure which is partially submerged and includes the supports of bridges, oil platforms, piping,

[0034] The term "U-shaped", as used in disclosing the present invention, means a shape with substantially parallel elements linked at ends approximately opposite to one another.

[0035] The term "oval-shaped" or "ovoid-shaped", as used in disclosing the present invention, means a rounded shape and includes circular and ellipsoidal shapes.

[0036] The term "elongated oval-shaped" or "elongated ovoid-shaped, as used in disclosing the present invention, means a object with an oval or ovoid profile extended in a direction substantially perpendicular to the plane of the oval or ovoid e.g. at an angle between 70° and 110°, with angle between 80° and 100° being preferred.

[0037] The term "surface", as used in disclosing the present invention, means the surface of a support for the adhesive coating, the support being any material to which the adhesive coating can adhere e.g. a non-conductive support such as concrete or ceramic or a conductive support such as steel.

[0038] The expression "without substantially reducing said dry working space ", as used in disclosing the present invention, means that the dry working space there less than 10% reduction in working space and preferably less than 5% reduction in working space.

[0039] The term "working space", as used in disclosing the present invention, means the space available for activities involved in the treating the surface of the isolated element.

[0040] The expression "substantially no movement", as used in disclosing the present invention, means insufficient movement to result in water leakage.

[0041] The term "substantially planar", as used in disclosing the present invention, means at least 90% in the same plane.

[0042] The term "substantially parallel elements", as used in disclosing the present invention, means deviating from parallel by a maximum of 20°, preferably a maximum of 10°.

[0043] The invention will now be described by a detailed description of several embodiments of the invention. It is clear that other embodiments of the invention can be configured according to the knowledge of persons skilled in the art without departing from the true spirit or technical teaching of the invention, the invention being limited only by the terms of the appended claims.

[0044] Truncated elongated oval-shaped dry setting element

[0045] According to a first aspect of the present invention a truncated elongated oval-shaped dry setting element is provided having two truncated oval-shaped ends one of which is open and the other submergible end is closed by a floor accommodating a U-shaped receiving collar, the opening between the ends of said truncated oval-shaped dry setting element and the width of the U-shaped receiving collar being sufficient to accommodate a partially submerged isolated structure such that said U-shaped receiving collar is sealable under water against said isolated structure with a collar sealing element closing the U of said collar in the plane of the collar with said isolated structure in place, and the opening between the ends of the first truncated elongated oval-shaped dry setting element being closable with a closure, wherein said dry setting element comprises a U-shaped structure replicating the opening formed by said U-shaped receiving collar at a sufficient distance from said U-shaped receiving collar so as to receive said isolated structure without substantially reducing said dry working space and such that when secured in said U-shaped structure there is substantially no movement of the dry setting installation relative to said isolated structure once said isolated structure is in place.

[0046] Fig.1 is a schematic of the cross-section of the truncated elongated oval-shaped dry setting element A of the present invention, where D is the bottom plate, E is the profile of the bottom, F is a reinforcement parallel and contiguous with the oval-shaped outside wall, G is a reinforcement perpendicular to the oval-shaped outside wall forming part of the U-shaped receiving collar, I represents reinforcement ribs, H is the oval-shaped outside wall, J is sealing, and K is a ladder providing access from the top of the dry setting element.

Dry setting installation

[0047] According to a second aspect of the present invention a dry setting installation (1) is provided for generating a substantially dry working space for carrying out work on a partially submerged isolated structure, the dry setting installation (1) comprising a first truncated elongated oval-shaped dry setting element according to the present invention, which with said collar sealing element and said closure in place is capable of forming a cofferdam round said isolated structure.

[0048] According to a preferred embodiment of the second aspect of the present invention, said opening between the ends of the first truncated elongated oval-shaped dry setting element is closable with a substantially planar sealing element.

[0049] According to a preferred embodiment of the second aspect of the present invention, said opening between the ends of the first truncated elongated oval-shaped dry setting element is closable with a second dry setting element having an identical opening between the ends of the second truncated oval-shaped dry setting element as that of the first dry setting element, with the second dry setting element being preferably identical to that of the first dry setting element..

[0050] A collar seal for the first dry setting element, which is sealable under water against the isolated structure, can be constructed to seal against any shape of isolated structure e.g. a polygonal hollow pile or a cylindrical hollow pile. This seal is preferably a pneumatic seal using inflatable air-bags.

[0051] Once the isolated structure is in place, the opening in the plane of the collar is sealed with a collar seal that preferably does not protrude beyond the external surface of the collar and is preferably substantially planar. The collar seal can, for example, be attached by bolts or by attached by welding, the external water pressure being sufficient to provide a water-tight seal upon pumping the water out of the dry setting installation.

[0052] According to a preferred embodiment of the first aspect of the present invention, said opening along the length of said dry setting installation is closed by a sealable door.

[0053] The (longitudinal) opening in the first U-formed dry setting element of the present invention which accommodates the isolated structure can either be sealed with a substantially planar closure element, in the case of smaller isolated structures e.g. those with small diameters e.g. with a diameter of 300 mm to 1000 mm, or with a second U-formed dry setting element, in the case of larger isolated structures e.g. with a diameter of up to 2500 mm, for examples 1220 mm. The sealing can be achieved by either bolting or welding the substantially planar closure element to the U-formed dry setting element or by bolting or welding a second U-formed dry setting element to the first U-formed dry setting installation.

Process

[0054] According to a third aspect of the present invention a process for treatment of a partially submerged isolated structure is provided, said process comprising the steps of: the receiving of said isolated structure by a dry setting element according to claim 1, said isolated structure being arrested by the bottom of the U of said U-shaped receiving collar and the bottom of the U of the U-shaped structure replicating the opening formed by said U-shaped receiving collar of said dry setting element; securing said isolated structure in said U-shaped receiving collar by closing the U of said collar in the plane of said collar with a collar sealing element and securing said isolated element where said U-shaped structure engages with said isolated element; closing the opening between the ends of said truncated elongated oval-shaped dry setting element with a sealing closure thereby providing a dry setting installation; pumping the water out of said dry setting installation thereby providing a cofferdam round said isolated structure; cleaning said surface of said isolated structure; applying a curable adhesive coating to said isolated structure; curing said curable adhesive coating, filling said dry setting installation with water, removing said sealing closure and said collar sealing element and removing said isolated element from said dry setting element.

[0055] The dry setting element can, for example, be operated from a motorised pontoon measuring 8 m by 25 m with during the treatment operation an overhanging superstructure requiring a total width of water of 12 m. In such an example, the dry setting elements and seals and closures therefor (i.e. the mobile cofferdam) and auxiliary equipment necessary for the total maintenance operation are all present on the pontoon.

[0056] The longitudinal opening in the first U-formed dry setting element of the present invention which accommodates the isolated structure can, for example, be sealed with a substantially planar closure element, in the case of smaller isolated structures e.g. those with small diameters, or with a second U-formed dry setting element, in the case of larger isolated structures. The sealing can, for example, be realised by, for example, bolting the substantially planar closure element to the U-formed dry setting element or by bolting a second U-formed dry setting element to the first U-formed dry setting installation. Sealing is easier with the dry setting element being tilted as there is more space for the sealing process to be performed.

[0057] According to a preferred embodiment of the third aspect of the present invention, said sealing closure and said collar sealing element are mountable and removable by one or more divers, preferably a single diver.

[0058] According to a preferred embodiment of the third aspect of the present invention, said opening between the ends of the first truncated oval-shaped dry setting element is closable with a substantially planar sealing element.

[0059] According to another preferred embodiment of the third aspect of the present invention, said opening between the ends of the first truncated oval-shaped dry setting element is closable with a second dry setting element having an identical opening between the ends of the second truncated elongated oval-shaped dry setting element as that of the first dry setting element, with the second dry setting element being preferably identical to that of the first dry setting element. The sealing closure and collar sealing element are rendered water-tight by the water pressure external to the dry setting installation.

[0060] According to a preferred embodiment of the third aspect of the present invention, said collar sealing element is secured with bolts.

[0061] According to a preferred embodiment of the third aspect of the present invention, the part of the U-shaped collar engaging with said isolated structure is a pneumatic seal.

[0062] According to a preferred embodiment of the third aspect of the present invention, said isolated element is tubular, polygonal e.g. six, eight, ten or twelve-sided in cross-section.

[0063] According to a preferred embodiment of the third aspect of the present invention, said isolated element is conductive e.g. metallic or non-conductive e.g. ceramic, particularly concrete.

[0064] According to a preferred embodiment of the third aspect of the present invention, said isolated element is hollow or solid.

[0065] According to a preferred embodiment of the third aspect of the present invention, said cleaning of the surface is performed with a high pressure jet of water e.g. working at a pressure of 130 to 2500 bar, preferably until a chloride concentration below 50 ppm is realised. This cleaning removes any incrustation and reduces the concentration of chlorides on the surface of the isolated structure to an acceptable level e.g. below 50 ppm. Mains water or freshwater is preferably used during the cleaning process.

[0066] According to a preferred embodiment of the third aspect of the present invention, the surface of the isolated element is blasted with fine particles, e.g. sand or other mineral, to a finish corresponding to Swedish Standard for sandblasting cast iron of Sa2.5 i.e. very thorough blast cleaning, near white metal 85% clean, the surface shall be free from visible oil, dirt and grease, from poorly adhering mill scale, rust, paint coatings and foreign matter, the metal has a greyish colour; and any traces of contamination shall be visible only as slight stains in the form of spots or stripes.

[0067] According to a preferred embodiment of the third aspect of the present invention, said dry setting installation is filled with water before said curable adhesive coating is cured.

[0068] The curable adhesive coating is preferably applied after removing fine particles from the surface and a nominal coating thickness of 400 µm applied with an airless spraying apparatus. Any major surface irregularities or joints are preferably filled with a paste e.g. Humidur® epoxy paste to seal them. After visual checking of the spray work and the unhardened layer thickness, the dry setting installation is filled with water.

[0069] According to a preferred embodiment of the third aspect of the present invention, said curable adhesive coating is exclusive of solvents.

[0070] Fig.2 is a series of three schematics showing the process by which a pylon P is enclosed in the truncated elongated oval-shaped dry setting element, A, of the present invention and a dry setting installation realised by closing the dry setting element with a collar sealing element (see middle schematic), B and a closure CL (see bottom schematic). Schematic I) is the initial situation with a dry setting element and a pylon. The dry setting element is then moved in the direction of the arrow until, as shown in schematic II), the pylon has been received by the U-shaped receiving collar, which is lined in at least the part thereof engaging the pylon with a sealing means, and the dry setting element is sealed with a collar sealing element, B, and a closure, CL, to realise a dry setting installation enclosing the part of the pylon for which maintenance work is required, as shown in schematic III).

[0071] Fig.3 is a schematic of a dry setting installation round a non-vertical pylon, where D is the bottom plate, E is a a round bottom profile, F is a reinforcement parallel and contiguous with the oval-shaped outside wall, G is reinforcement perpendicular to the oval-shaped outside wall H, J is sealing, K is a ladder, L is a distance block, M is a support perpendicular to the oval-shaped outer wall, and N is an adjustable platform. Fig. 3 shows how the dry-setting installation accommodates a non-vertical pylon.

[0072] Anti-corrosion treatment with Humidur® may involve, for example:

1) cleaning and removal of vegetation from the surface to be treated with a high pressure cleaner (e.g. 300 bar);

2) needle hammering and chip off scaling corrosion;

3) grit-blasting of the surface to the Swedish Standard of SA 2.5;

4) rinse with freshwater to remove the chlorides from the surface;

5) dry blasting of the surface;

6) prebrushing and/or filling of joints and seams with Humidur® P (putty) or with rapidly hardening putty (compatible with the paint system) in the event of leaking;

7) airless spraying of the surface with Humidur® ML (400 µm nominal layer thickness followed by visual inspection.

Curable adhesive coatings

[0073] Curable adhesive coatings are preferred which are based on hardening systems selected from the group consisting of polyhydroxy-resins/polyisocyanate systems, epoxy/amine systems, phenoxyresin/polyisocyanate systems, epoxy/polyaminoamide resin systems, dialkanolamine-modified epoxy-resins/polyisocyanate systems, epoxy/polyisocyanate systems and silicone systems being preferred and epoxy/amine systems being particularly preferred.

[0074] The adhesive coating used in the process, according to the present invention, may further comprise additives e.g. fire retardants, stabilizers etc. Preferred additives include zinc phosphate and zinc oxide.

[0075] The adhesive coating is preferably applied to the support in situ according to the manufacturer's recommendations on fresh or newly cleaned e.g. by sandblasting surfaces. Curing is preferably performed at ambient temperature.

[0076] INTERGARD® 403 is a tar-free, light-coloured epoxy coating for marine applications.

Polyhydroxy-resins:

[0077] The synthesis of resin (1) proceeds by using bisphenol and epichlorhydrin as starting materials as described e.g. in "The Chemistry of Organic Film Formers" by D. H. Solomon, John Wiley & Sons, Inc. New York (1967), the chapter "Epoxy Resins", p. 179 - 189).

[0078] Preferred bisphenol-epichlorhydrin resins are derived from bisphenol A (4,4'-isopropylidenediphenol) and epichlorhydrin.

[0079] Suitable commercially available resins according to general formula (I) are phenoxy resins from InChem Corp. sold under the tradename PHENOXY, e.g. PHENOXY® PKHC, PHENOXY® PKHH, PHENOXY® PKHJ and PHENOXY® PKHM-301 and high molecular weight epichlorhydrin epoxy resins such as EPONOL® Resin 53-BH-35 and EPONOL® Resin 55-BH-30 (tradenames of Hexion Specialty Chemicals Inc.), DER 684-EK40 (tradename from Dow chemical); EPIKURE® P201 and EPIKURE® P202 from Hexion Specialty Chemicals Inc.

Dialkanolamine-modified epoxy resins:

[0080] Dialkanolamine-modified epoxy resins can be prepared from commercially available epoxy resins by reaction with dialkanolamines in the melt or in a solvent mixture under reflux (see above-mentioned book of D.H. Solomon, p. 189-191).

(A) In the melt reaction the epoxy resin is heated to its melting point in a vessel equipped with a stirrer and a thermometer and the equivalent amount of dialkanolamine quickly added with stirring. The mixture is further heated at temperatures between 100°C and 200°C depending on the chain length of the epoxy resin for two hours with inert gas being bubbled through the reaction mixture. After 2 hours the product is poured out of the vessel, allowed to cool and then broken up into small particles. The reaction is exothermic and cooling is necessary for larger quantities to avoid local overheating.

(B) In the reaction in a solvent mixture a 50 wt % solution of epoxy resin in a mixture of ethylglycol acetate, methylisobutylketone and xylene (2:1:1) is added to a vessel equipped with a reflux condenser, a thermometer and a stirrer. The equivalent amount of dialkanolamine is then added with stirring and the reaction mixture heated to its boiling point. After 2 hours under reflux, the reaction mixture is cooled and a 50 wt % solution of the dialkanolamine-modified epoxy resin obtained.

Polyisocyanates and polyisocyanate precursors:

[0081] Particularly suitable polyisocyanates and blocked polyisocyanates are derived from polyisocyanates or mixtures thereof e.g. 1,6-hexane diisocyanate (HDI); toluylene diisocyanate (TDI); diphenylmethane-4,4'-diisocyanate (MDI); 1,4-cyclohexane diisocyanate and 4,4'-diisocyanate-dicyclohexylmethane; isophorondiisocyanate (IPDI); triphenylmethane-4,4',4"-tri-isocyanate, thiophosphoric acid tris(p-isocyanatophenyl ester).

[0082] The polyisocyanate may be set free in situ, e.g. by heat, from a blocked polyisocyanate also called a polyisocyanate precursor. Huntsman produces a large variety of MDI polyisocyanates and blocked MDI polyisocyanates under the tradename SUPRASEC e.g. SUPRASEC® 1000, pure MDI; SUPRASEC® 1004, modified MDI; SUPRASEC® 1007, MDI-based; SUPRASEC® 1100, pure MDI; SUPRASEC® 1306, pure MDI; SUPRASEC® 1400, pure MDI; SUPRASEC® 1412, MDI-based; SUPRASEC® 1612, MDI-based; SUPRASEC® 2004, modified MDI; SUPRASEC® 2008, MDI-based; SUPRASEC® 2010, MDI-based; SUPRASEC® 2018, MDI-based; SUPRASEC® 2020, modified MDI; SUPRASEC® 2021, MDI-based; SUPRASEC® 2023, MDI-based; SUPRASEC® 2029, modified MDI; SUPRASEC® 2030, MDI-based; SUPRASEC® 2034, MDI-based; SUPRASEC® 2049, MDI-based; SUPRASEC® 2050, MDI-based; SUPRASEC® 2054, MDI-based; SUPRASEC® 5005, polymeric MDI; SUPRASEC® 5025, polymeric MDI; and SUPRASEC® 5030, polymeric MDI.

[0083] Bayer Materials Science AG, Germany produces a large variety of polyisocyanates and blocked polyisocyanates under the tradename DESMODUR e.g. DESMODUR® N75, a 75% solution of a biuret HDI, DESMODUR® N100, a biuret HDT; DESMODUR® N3200, a biuret HDI (lower viscosity than DESMODUR® N100); DESMODUR® N3300, an HDI isocyanurate; DESMODUR® N3390, a 90% solution of an HDI isocyanurate; DESMODUR® L75, a 75% solution of a TDI-adduct, DESMODUR® IL, a TDI-isocyanurate; DESMODUR® IL 1351, a TDI-polyisocyanate; DESMODUR® HL, a TDI/HDI-polyisocyanate; DESMODUR® VL, a MDI-polyisocyanate; DESMODUR® Z4370, an IPDI-isocyanurate; and blocked polyisocyanates, such as: DESMODUR® BL3175, a blocked HDI-type crosslinking stoving urethane resin; and DESMODUR® BL100, a blocked TDI-type crosslinking stoving urethane resin.

[0084] A suitable polyisocyanate precursor, also called a blocked polyisocyanate compound, for use according to the present invention has the following structural formula P:

[0085] Said polyisocyanate precursor has a good stability at room temperature (20°C) and generates free polyisocyanate in the temperature range of 100° to 150°C.

[0086] The synthesis of resins (1) proceeds by using a bisphenol and epichlorhydrin as starting materials as described e.g. in "The Chemistry of Organic Film Formers" by D. H. Solomon, John Wiley & Sons, Inc. New York (1967), the chapter "Epoxy Resins", p. 179-189).

Epoxy resins:

[0087] Examples of epoxy resins for use according to the present invention are within the scope of at least one of the following formulae (I), (II), (III), (IV) and (V):

wherein R" is an alkyl group and a ≥ 0

in which: X represents S, SO₂,

each of R¹, R², R³, R⁴, R⁷, R⁸, R⁹ and R¹⁰ (same or different) represents hydrogen, halogen, an alkyl group or an aryl group; or R⁷ together with R⁸ and R⁹ together with R¹⁰ represent the atoms necessary to close a cycloaliphatic ring, and x is zero or an integer;

wherein R¹² is an alkyl group;

wherein X has the same meaning as above;

wherein each of R¹³ and R¹⁴ (same or different) represents hydrogen or an alkyl group and b ≥ 0.

[0088] Commercially available bisphenol A-epichlorhydrin epoxy resins according to formula II are mentioned hereinafter by their tradenames: EPON® 828, EPON® 1001, EPON® 1002, EPON® 1004, EPON® 1007, EPON® 1009, EPONOL® Resin 53-BH-35 and EPONOL® Resin 55-BH-30 from Hexion Specialty Chemicals Inc.; BECKOPOX® 828, BECKOPOX® EP309 and BECKOPOX® EP307 from CYTEC; DER® 331, DER® 667, DER® 668, DER® 669, DER® 681 and DER® 684- EK40 from Dow Chemical, U.S.A.; and ARALDITE® GT 6071, ARALDITE® GT6609, ARALDITE® GT6097, ARALDITE® GT6099, and ARALDITE® GT7077 from Huntsman.

[0089] A commercially available bisphenol F-epichlorhydrin epoxy resin according to formula II is: DER® 352 from Dow Chemical, USA; EPIKOTE® 862 from Hexion Specialty Chemicals Inc.; and ARALDITE® GY 28 and ARALDITE® GY 282 from Huntsman.

[0090] A commercially available bisphenol A/bisphenol F-epichlorhydrin epoxy resin according to said formula II is: EPON® 235 from Shell Chemical Co.

[0091] A commercially available epoxy resin according to said formula IV is: ARALDITE® MY 721 from Huntsman.

[0092] Commercially available phenol novolak epoxy resins according to said formula V are: DEN 431, DEN 438 and DEN 439 from Dow Chemical; EPIKURE® 155 and EPIKURE® 152 from Hexion Specialty Chemicals Inc.; and ARALDITE® PY 307-1, ARALDITE® EPN 1180, ARALDITE® EPN 1179, ARALDITE® GY 1180 and ARALDITE® EPN 1138 from Huntsman.

[0093] The preparation of epoxy resins proceeds, for example, by etherification of a polyphenol with epichlorhydrin or dichlorhydrin in the presence of an alkali as described e.g. in US 5,051,209. Many examples of epoxy resins are described in the Handbook of Epoxy Resins, Henry Lee and Kris Neville, 1967, McGraw Hill Book Company.

[0094] The synthesis of resins (1) proceeds by using a bisphenol and epichlorhydrin as starting materials as described e.g. in "The Chemistry of Organic Film Formers" by D. H. Solomon, John Wiley & Sons, Inc. New York (1967), the chapter "Epoxy Resins", p. 179-189).

[0095] Preferred bisphenol-epichlorhydrin resin derivatives are prepared from bisphenol A (4,4'-isopropylidenediphenol) and epichlorhydrin.

Amines:

[0096] Amines for curing epoxy resins include polyetheramines, ethyleneamines and their adducts, polyamides and amidoamines, arylyl diamines, cycloaliphatic amines, aromatic amines, Mannich bases and phenalkamines and Lewis bases/catalytic curing agents. Depending upon the choice of amine curing temperatures from room temperature are available.

[0097] Examples of poly NH-group amines for use according to this invention, which are able to render epoxy resins insoluble in methylene chloride are:

i) polyetheramines (PEAs) and their adducts e.g. polyoxypropylene amines commercially available under the tradename JEFFAMINE® from Huntsman e.g. JEFFAMINE® T-403 with the general formula:

in which c+d+e is about 5.3 JEFFAMINE® D-230 with the general formula:

in which f is about 2.6 JEFFAMINE® M-300 with the general formula:

in which g is about 2; JEFFAMINE® D-400; JEFFAMINE® D-2000; JEFFAMINE® HK-511; JEFFAMINE® M-2070; JEFFAMINE® T-5000; EPIKURE® 3230 and EPIKURE® 3233 from Hexion Specialty Chemicals Inc.

ii) polyamides and amidoamines. Examples of polyaminoamide resins for use according to this invention are the reaction products of polymeric fatty acids and polyalkylene polyamines. Illustrative of such polyalkylene polyamines are ethylene diamine, diethylene triamine and triethylene tetramine. These polyaminoamides have a high amine number, preferably in the range of 50 to 400. The polymeric fatty acids can be prepared by thermal polymerization of unsaturated fatty acids, for example, linoleic acid, linolenic, oleic acid, stearic acid and the like as described e.g. in US 5,051,209. VERSAMID® (tradename) resins sold by Cognis are, for example, condensation products of dimer acids and a mixture of alkylene polyamines. Commercially available polyaminoamides for use according to this invention are mentioned hereinafter by their tradenames: VERSAMID® 140, VERSAMID® 125 and VERSAMID ®115 from Cognis; UNIREZ® 1002, UNIREZ® 1307 and UNIREZ® 5211 from Union Camp Chemicals (UK) Ltd.; EPIKURE® 3060, EPIKURE® 3100, EPIKURE® 3115, EPIKURE® 3125, EPIKURE® 3140, EPIKURE® 3055, EPIKURE® 3180, EPIKURE® 3060, EPIKURE® 3090, EPIKURE® 3123, EPIKURE® 3940 and EPIKURE® 8540-MU-60 from Hexion Specialty Chemicals Inc., ARADUR® 140, ARADUR® 115, ARADUR® 125 from Huntsman; BECKOPOX® EH 654, BECKOPOX® EH 651 and BECKOPOX EH 652 from CYTEC; and EPILINK® 173, EPILINK® 350, EPILINK® 353 and EPILINK® 354 from Akzo-Nobel, The Netherlands.

iii) ethylene diamines such as DETA (diethylenetriamine), TETA (triethyleneteramine), TETA (tetraethylenepentamine) and AEP (N-aminoethylpiperazine) available from Huntsman;

iv) aliphatic polyamines such as EPIKURE® 3213, EPIKURE® 3214, EPIKURE® 3223, EPIKURE® 3234, EPIKURE® 3245, EPIKURE® 3266, EPIKURE® 3270, EPIKURE® 3271, EPIKURE® 3273, EPIKURE® 3274, EPIKURE® 3282, EPIKURE® 3295, EPIKURE® 3164, EPIKURE® 8537-WY-60, EPIKURE® 3200, EPIKURE® 3213 and EPIKURE® 3283 from Hexion Specialty Chemicals Inc.; and ARADUR® 45 and ARADUR® 76 from Huntsman.

v) heterocyclic poly NH-group amines e.g. 4-aminomethylpiperidine and 4-amino-2,2,6,6-tetramethylpiperidine

v) cycloaliphatic poly NH-group amines e.g. PACM [bis-(p-aminocyclohexyl)-methane], DACH (diaminocyclohexane) and DMCH [bis-(dimethyldiamino-cyclohexyl)methane and isophorondiamine derivatives commercially available as EPILINK 420 from Akzo-Nobel, The Netherlands, EPI-CURE® 3300, EPIKURE® 3381, EPIKURE® F205, EPIKURE® F206 from Hexion Specialty Chemicals Inc ; and ARADUR® 2963 from Huntsman;

vi) aromatic poly NH-group amines or derivatives thereof e.g. MDA (methylene dianiline), m-PDA (m-phenylene diamine), DDS (diaminophenyl sulfone); 4.4'-diaminodiphenylmethane (DDM)-derivatives commercially available as EPI-CURE® 153 from Hexion Specialty Chemicals Inc., ARADUR® 850 from Huntsman, 4,4'-diaminodiphenylsulphone; 1,3,5-tris(4'-aminophenyl)benzene, and 3,5-diphenylaniline, 3,5-di(2-thiophenyl)-aniline, 5-(4-aminophenyl)-2,4-bis(4-methoxyphenyl)-oxazole, N-(4-amonophenyl)carbazole and meta-phenylenediamine;

vii) aromatic poly NH-group amines wherein aliphatic amino groups are attached to an aromatic backbone e.g.: meta-xylylene diamine commercially available as EPILINK® MX from Akzo, The Netherlands; 3-phenyl-2-propylamine, phenalkamines on the basis of cashew nut shell liquid commercially available as CARDOLITE® NC541 and CARDOLITE® NC541 LV from Cardolite Corporation;

viii) Manich base-type amine such as EPIKURE® 3251 from Hexion Specialty Chemicals Inc.; ARADUR® 14 from Huntsman; and BECKOPOX® EH 628 from CYTEC.

ix) Dicyandiamide such as EPIKURE® P104, EPIKURE® P108 and EPIKURE® P143 from Hexion Specialty Chemicals Inc.

[0098] Lewis bases/catalytic curing agents for use according to the present invention, which are able to render epoxy resins insoluble in methylene chloride by catalyzing the self-crosslinking of epoxy resins are cyclic aliphatic amines and tertiary amines, e.g. piperidine, 2,5-dimethyl-piperazine, triethylamine, benzyldimethylamine (BDA), 2-dimethyl-amino-methylphenol (DMAMP), 2,4,6-tris(dimethylaminomethyl)phenol (TDMAMP)

polyhydroxy resin/polyisocyanate systems:

[0099] The binder is composed essentially of resins (1) and/or (2) crosslinked with at least one polyisocyanate, said resin (1) before its crosslinking corresponding with the following general formula (I):

in which: X represent S, SO₂,

each of R¹, R², R³, R⁴, R⁹ and R¹⁰ (same or different) represents hydrogen, halogen, an alkyl group or an aryl group; where R⁵ = OH,

each of R⁷ and R⁸ (same or different) represents hydrogen, an alkyl group, an aryl group or together represent the necessary atoms to close a cycloaliphatic ring; and x ≥ 4; and said resin (2) before its crosslinking being an epoxy resin that has undergone a reaction with a dialkanolamine. Preferably having a total amount of free HO-groups in an equivalent ratio range from 1.8:1 to 1:1.8 with respect to the free isocyanate groups of said polyisocyanate(s).

[0100] The hardening reaction taking place preferably at elevated temperature is mainly based on the reaction between the isocyanate groups or the thermo-generated isocyanate groups and the free hydroxyl groups of the resins (1) and/or (2), but is also based on the formation of allophanate groups in a reaction of already formed urethane groups in said resin with isocyanate groups of the polyisocyanate [D. H. Solomon "The Chemistry of Organic Film Formers", John Wiley & Sons, Inc. New York, (1967) p. 203].

epoxy/polyisocyanate systems:

[0101] The binder has been made insoluble in methylene chloride by crosslinking and consists essentially of at least one resin (1) crosslinked with at least one polyisocyanate, said resin (1) before its crosslinking corresponding to the following general formula (I):

in which: X represent S, SO₂,

each of R¹, R², R³, R⁴, R⁹ and R¹⁰ (same or different) represents hydrogen, halogen, an alkyl group or an aryl group; R⁵ is -OH,



each of R⁷ and R⁸ (same or different) represents hydrogen, an alkyl group, an aryl group or represents the necessary atoms to complete, together with the carbon atom to which they are attached, a cycloaliphatic ring, and n is zero or an integer; wherein the ratio of total free hydroxy-groups in said resin(s) according to formula (I), expressed as hydroxy-equivalents, to the total isocyanate equivalents in said polyisocyanates is in the range 3.0:1 to 1:2.0.

[0102] The hardening reaction taking place preferably at elevated temperature is mainly based on the reaction between the isocyanate groups or the thermo-generated isocyanate groups and the free hydroxyl groups of the resins (1) and/or (2), but is also based on the formation of allophanate groups in a reaction of already formed urethane groups in said resin with isocyanate groups of the polyisocyanate [D. H. Solomon "The Chemistry of Organic Film Formers", John Wiley & Sons, Inc. New York, (1967) p. 203].

Epoxy/amine system:

[0103] The binder is composed of one or more polyepoxy compounds self-crosslinked under the influence of at least one amine catalyst and/or crosslinked by reaction with at least one primary and/or at least one secondary poly NH-group amine and/or at least one polyamide resin having amino groups and being called herein polyaminoamide resins. Epoxy/amine systems for marine applications include SIGMAGUARD® 603, which is a two component solvent-free amine-cured epoxy-coating; and JOTUN® 87, which is a polyamine-cured epoxy mastic coating.

[0104] Particularly preferred are the HUMIDUR® range of two-pack, solvent-free polyamine cured epoxy systems from ACOTEC N.V: with outstanding rust resisting capacities. These contain binding agents with modifying components, which ensure excellent adhesion of the coating to the metallic or non-mrtallic substrate . The pigmentation consists of specially developped abrasion resistant extenders and colouring pigments. High molecular weight elastifiers are added to provide for sufficient flexibility. The resulting composition combines excellent adhesion, abrasion and impact resistance, and is at the same time hydrophobic, thus enabling the product to cure at low temperatures, even while immersed. The A component in each case contains non-crystallizable epoxy resins, high-tech modifying agents, elastifiers, lamelar abrasion and impact resistant fillers, and colouring pigments and the B-component contains the polyamine hardener complex.

Epoxy/polyamide system:

[0105] The binder is composed of one or more polyepoxy compounds crosslinked with polyamides. Epoxy/polyamide systems for marine applications include HEMPADUR MASTIC 45880/HEMPADUR MASTIC 45881 from HEMPEL.

[0106] It is to be understood that although preferred embodiments, specific constructions and configurations, as well as materials, have been discussed herein for devices according to the present invention, various changes or modifications in form and detail may be made without departing from the scope and spirit of this invention. Steps may be added or deleted to methods described within the scope of the present invention.

Claims

1. A truncated elongated oval-shaped dry setting element having two truncated elongated oval-shaped ends one of which is open and the other submergible end is closed by a floor accommodating a U-shaped receiving collar, the opening between the ends of said truncated elongated oval-shaped dry setting element and the width of the U-shaped receiving collar being sufficient to accommodate a partially submerged isolated structure such that said U-shaped receiving collar is sealable under water against said isolated structure with a collar sealing element closing the U of said collar in the plane of the collar with said isolated structure in place, and the opening between the ends of the first truncated elongated oval-shaped dry setting element being closable with a closure, wherein said dry setting element comprises a U-shaped structure replicating the opening formed by said U-shaped receiving collar at a sufficient distance from said U-shaped receiving collar so as to receive said isolated structure without substantially reducing said dry working space and such that when secured in said U-shaped structure there is substantially no movement of the dry setting installation relative to said isolated structure once said isolated structure is in place.

2. A dry setting installation (1) for generating a substantially dry working space for carrying out work on a partially submerged isolated structure, the dry setting installation (1) comprising a first truncated elongated oval-shaped dry setting element according to claim 1, which with said collar sealing element and said closure in place is capable of forming a cofferdam round said isolated structure.

3. The dry setting installation (1) according to claim 2, wherein said opening between the ends of the first truncated elongated oval-shaped dry setting element is closed with a substantially planar sealing element.

4. The dry setting installation (1) according to claim 2, wherein said opening between the ends of the first truncated elongated oval-shaped dry setting element is closed with a second dry setting element according to claim 1 having an identical opening between the ends of the second truncated elongated oval-shaped dry setting element as that of the first dry setting element.

5. A process for treatment of a partially submerged isolated structure, said process comprising the steps of:

- the receiving of said isolated structure by a dry setting element according to claim 1, said isolated structure being arrested by the bottom of the U of said U-shaped receiving collar and the bottom of the U of the U-shaped structure replicating the opening formed by said U-shaped receiving collar of said dry setting element;

- securing said isolated structure in said U-shaped receiving collar by closing the U of said collar in the plane of said collar with a collar sealing element and securing said isolated element where said U-shaped structure engages with said isolated element; closing the opening between the ends of said truncated elongated oval-shaped dry setting element with a sealing closure thereby providing a dry setting installation;

- pumping the water out of said dry setting installation thereby providing a cofferdam round said isolated structure;

- cleaning said surface of said isolated structure; applying a curable adhesive coating to said isolated structure;

- curing said curable adhesive coating,

- filling said dry setting installation with water,

- removing said sealing closure and said collar sealing element and

- removing said isolated element from said dry setting element.

6. Use of the mobile dry setting installation according to claim 2 for carrying out maintenance on partially submerged isolated structures.

7. Use according to claim 6, exclusive of exposed head sections of foundation piles.

Drawing