Apparatus for submersible cable intervention

Abstract

A modular apparatus (100) for high and low voltage submerged cable intervention comprising at least two units (2), each unit comprising a base shell (4), a top shell (6) and at least two side panels (18) which combine to form a sealed interior space (8). The side panels at the distal end (14) of the unit (2) allow a cable to pass through the exterior of the unit into the interior space (8). The side panels on the proximal end (16) of the unit (2) are moveable curved doors (28) which are in line with the longitudinal axis of the base shell (4) when the curved doors (28) are in the open position. The two units (2) can be brought together with the proximal ends (16) sealed to enable both curved doors (28) to be opened to form a combined interior space (8).

Description

Technical Field

[0001] This invention relates to a submarine cable intervention habitat and method that allows users to perform in-situ submarine cable intervention activities in power and fiber optic applications, such as cable splicing for cable repair and submarine connections of dry mating cable connectors. Background Technology

[0002] This invention relates to submarine cable intervention. Specifically, it relates to submarine cable splicing and connection using dry-fit connectors within the voltage range of 400V to 220kV submarine cables, and to apparatus for achieving such activities. Submarine cables are commonly used to transmit power and / or data between remote locations. Cables are typically laid along the seabed to avoid the need for complex support structures or cable routing. They may be buried in the seabed and / or covered. For example, they may be covered by rocks or concrete slabs. Over time, cables may fail or become damaged. As is known to those skilled in the art, damage to submarine cables typically occurs at specific locations along the cable, rather than throughout its entire length.

[0003] Repairing or splicing damaged or faulty cables in water (submarine) is challenging. Limitations such as cable access, visibility, humid environments, and high-voltage conditions increase the complexity of the process. Therefore, cable intervention or repair of faulty submerged cables is typically carried out on specialized repair vessels and generally includes the following steps:

[0004] 1. Accurately locate the fault location, preferably pinpointing it to the exact location;

[0005] 2. Remove any buried or protective objects (such as concrete panels) placed on the cable on both sides of the fault to allow for repair;

[0006] 3. Remove a section of cable by cutting both sides of the fault location using a properly equipped remotely operated vehicle (ROV); 4. Collect each end of the cable back into the container in turn;

[0007] 5. Add a new section of cable between the cut ends; and

[0008] 6. Return the repaired portion to the seabed.

[0009] Because both ends of the cable on either side of the fault were retrieved to the ship located on the sea surface, while the rest of the cable length lay on the seabed, a large section of cable had to be lifted from the seabed for repair. The length of the cable section lifted from the seabed was greater than the water column depth of the cable at that location. The length of the new cable section added between the two cable ends as part of the repair was determined by the water column depth at the fault location (i.e., the distance from the seabed to the sea surface). Typically, the required length of the new cable section was approximately three times the water depth at the repair location, but it could often be as long as 1000m, thus requiring a large section of new cable to be repositioned back to the seabed once the repair was complete.

[0010] To ensure the faulty section of the cable has been removed, the repair method may also include a step of inspecting and testing the first recovered cut end of the cable on board before returning it to sea. The repaired first end can be marked with a buoy and returned to sea, while the second cut end is retrieved. This requires an additional step: applying a temporary protective coating to the first cut end of the cable to protect it once it is back in the water, and then removing the protective coating when the repair is complete.

[0011] Furthermore, if the first end returns to the seabed, it needs to be retrieved twice. Each recovery operation can take up to 24 hours to complete, slowing down the repair operation and increasing the overall cost. Recovery operations are typically performed using grappling hooks, which can strain the cable or cause other types of damage. Additionally, the retrieval operation can directly damage the cable, so there is a risk that the cable end may acquire further damage during retrieval from the seabed.

[0012] It should be understood that cable repair typically involves inserting a new section of cable. This can be problematic if the initial cut is not placed correctly, as it may mean that additional cable may need to be cut from the end of the cable to eliminate the fault after testing or inspection. Therefore, a relatively large extra length of spare cable must be considered in the backup philosophy used for repairs.

[0013] Improved fault location accuracy reduces the number of existing cables, which typically must be cut and discarded once a fault is identified. However, existing repair systems, especially for cables in deep water, still require a significant number of additional cables for repair, particularly in deep-water areas.

[0014] The additional cable must be stored and transported on board to the location of the fault. Accidental lengths of cable are also often carried to ensure sufficient cable for any type of repair, even if the fault has been incorrectly identified. Excess cable loops occupy valuable space on board, and in most cases, these loops are not used during repairs, so the additional cable must be returned to shore after repairs are completed. This additional cable is typically shorter than the full roll of cable the project might require, thus limiting its potential use in different applications or subsequently within the project, and the cable may frequently be scrapped. The need for longer lengths of additional cable also increases repair costs, and problems with cable supply can lead to repair delays. For cables used in repair procedures, the extra length of cable installed is often laid in repair loops on the seabed, and because these loops are often perpendicular to the cable line, they may fall outside the cable's consent corridor (or consent coverage area), and even if they are consented to, this can introduce complexity and time issues in obtaining the necessary consents from all relevant parties.

[0015] WO 2017 / 036503 discloses a diving habitat chamber for repairing submarine cables, suitable for low-voltage cables. The chamber comprises two semi-shells assembled to form a single container environment. An access port through at least one semi-shell allows a user to enter the contained environment from the outside of the chamber, and windows in the side walls of the chamber allow the user to see inside. However, this diving habitat chamber is limited to low-voltage applications, and the chamber size cannot be expanded, scaled up, or modularized for longer or more complex repairs.

[0016] Existing systems are designed for repairing low- and medium-voltage submarine cables and are unsuitable for repairing or splicing high-voltage submarine cables. Due to the geometry, size, weight, and electrical stress associated with high-voltage cables, existing single-chamber designs cannot provide sufficient space within the chamber for high-voltage cable repair or splicing. Single cable paths on the sides of the chamber are also unsuitable for high-voltage cables, as they must be split into their constituent cores for repair. Furthermore, while some aspects of cable repair preparation for low- or medium-voltage cables can be performed in a humid environment prior to splicing, the entire process of splicing high-voltage cables must be carried out in a dry environment, again requiring more space within the chamber. The total length of cable sections to be prepared for high-voltage cable repair in a dry environment, coupled with the need to introduce new cable components and sections into the chamber while maintaining a dry environment, makes the single-chamber option impractical, and there is no guidance on extending the available windows of existing single-chamber systems. Therefore, it is necessary to invent a more universal chamber system whose functionality overcomes the problems of existing technologies and thus enables the repair of high-voltage cables.

[0017] As used herein, it will be understood that the term "sea" is understood to encompass a wide range of wet environments. The term "sea" should not be construed as limiting in terms of geography or typical conditions. It will be appreciated that the advances of the present invention presented herein are primarily applicable to subsea cable interventions such as splicing or connecting, however, they may equally be usefully applied to freshwater cable interventions such as splicing or connecting. Likewise, the term "cable" should not be given a purely literal meaning, but should be construed broadly to encompass conduits through which different resources may be transmitted, including power and data.

[0018] Similarly, the prior art is entirely unsuitable for performing a dry-mateable cable connection due to the limited functionality of its single chamber, which cannot be connected to another chamber or opened on the seabed without compromising the integrity of the dry environment inside the chamber.

[0019] As described in the background section, conventionally, to repair a fault in a cable, the cable is retrieved from the seabed and brought above the water surface so that the cable repair can be performed in a dry environment. The invention of subsea habitats for subsea cable repair represents a significant change in the methodology of subsea cable interventions, as it means that cable repairs can be performed underwater without the need to bring the cable above the water level, however, the limitations of the concept including its limited applicability, which restricts its use to low voltage applications, and the lack of flexible geometries mean that further developments are needed in the field to provide improved, more efficient apparatus with a broader range of capabilities and functions.

[0020] The prior art is designed for low or medium voltage subsea cable repair and does not provide the functionality required for high voltage subsea cable repair / splicing. In the context of voltage throughout this document, the following terms extra-high voltage, high voltage, medium voltage and low voltage shall be understood to include voltages within the ranges specified below.

[0021] - Extra-high voltage - voltage range of ≥220 kV (Um=245 kV).

[0022] - High voltage - voltage range of 30 kV (Um=36 kV) < HV < 220 kV (Um=245 kV)

[0023] Medium voltage - voltage range of 6kV ≤ MV ≤ 30 kV (Um=36 kV).

[0024] Low voltage - voltage range of LV ≤ 6 kV.

[0025] Due to the geometry, dimensions, weight, and electrical stress associated with high-voltage cables, existing single-chamber designs are unsuitable for high-voltage cable interventions, such as splicing or dry-mate connections. Furthermore, while some aspects of cable intervention preparation for low- or medium-voltage cables can be performed in a humid environment prior to splicing or connecting, the entire process of splicing high-voltage cables and connecting dry-mate connectors must be carried out in a dry environment. For cable replacement—the total length of cable segments needed for high-voltage cable repair must be prepared in a dry environment, coupled with the need to introduce new cable components and segments into the chamber while maintaining a dry environment—the single-chamber option is not feasible. Therefore, for high-voltage cable repair or splicing, or both, and for dry-mate cable connections, the connectable modular chamber device according to the invention has been developed to address the problems of the prior art.

[0026] Existing technologies also have limitations in terms of glove design and visibility within the habitat. Due to the more complex nature of high-voltage cables (especially with multiple cores of larger diameter, and therefore larger bending radii), increased flexibility is necessary to perform fiber splicing of high-voltage cables. Glove-wearing divers cannot achieve the required level of dexterity because the gloves need to be kept under pressure throughout the operation by allowing partial filling inside, which makes the gloves bulky and reduces their functionality.

[0027] This invention is modular in form and designed to connect and disconnect underwater while maintaining at least one dry environment, thereby enabling cable work from three different angles. Based on the innovative and complex geometry of the bend gate, this disconnect and reattachment capability is a significant and creative improvement over existing technologies, allowing divers to perform high-voltage or low-voltage cable repairs efficiently and comfortably within a modular repair chamber. Summary of the Invention

[0028] According to a first aspect of the invention, a modular device for high-voltage and low-voltage immersion cable intervention is provided, comprising at least two units, each unit comprising:

[0029] A bottom shell, a top shell, and at least two side plates, wherein the bottom shell, the top shell, and the at least two side plates are combined to form a sealed internal space;

[0030] The side panel located at the distal end of the unit allows cables to pass through the exterior of the unit into the interior space; and the side panel at the proximal end of the unit is a movable curved door, which, when in the open position, is aligned with the longitudinal axis of the base shell, and when in the closed position, is movable to a lateral orientation to seal the proximal end.

[0031] This allows the initial cable intervention to be carried out in the sealed internal space of each unit, and then the two units can be placed together with the proximal end sealed to the proximal end so that the two curved doors can be opened, thereby forming an internal space with a minimum distance between the outer edges of the two curved doors.

[0032] Preferably, the device includes a partial base plate within the internal space, wherein when the curved doors are in the open position, each curved door is located in line with the longitudinal axis of the base shell and below the partial base plate, and when the curved doors are in the closed position, each curved door can be moved to a lateral position from below the partial base plate.

[0033] Preferably, the device includes a bracket on which the bottom and top shells of the at least two units are positioned, such that the bottom and top shells are movable within the bracket to facilitate engagement or disengagement of the units.

[0034] Preferably, the internal space includes a pressure difference relative to the outside of the device.

[0035] Preferably, the device includes a gas supply source or gas tank for differential pressure control components.

[0036] Preferably, for cable intervention activities, the pressure difference is in the range of 0 mbar to 100 mbar.

[0037] Preferably, for purging activities, the pressure differential is in the range of 5 mbar to 1 bar.

[0038] Preferably, the device includes at least one observation port.

[0039] Preferably, the device includes at least one access port.

[0040] Preferably, the device includes a glove and sheath seal for use in conjunction with the at least one access port.

[0041] Preferably, each curved gate can be moved by means of a rack and pinion device, wherein the rack is arranged along the edge of the curved gate, and the pinion can be operated by a manual handle or an electric motor.

[0042] Preferably, an access board is provided to selectively cover the access ports.

[0043] Preferably, the side plate includes a cable seal.

[0044] Preferably, the side plate includes a pre-assembled gasket to accommodate a cable seal.

[0045] A method for performing cable intervention in a seabed environment is also provided, comprising the following steps:

[0046] Provided on the seabed at least a first modular device for high-voltage and low-voltage submerged cable intervention according to any of the preceding claims;

[0047] Insert the cable end into the modular device and evacuate the internal space;

[0048] Prepare cable ends for cable intervention, such as joints, additional connectors, etc.

[0049] The second sealed modular equipment on board provides items for cable intervention, such as new cable ends, new cable segments, induction groups, etc.

[0050] The second sealing modular device is deployed on the seabed and positioned adjacent to the first modular device, such that the first and second modular devices are connected to each other.

[0051] Opening the curved doors of the first and second modular devices creates an extended interior space where cable intervention can be performed in a dry environment; and

[0052] The cable intervention was performed in an environment where there was virtually no moisture. Attached Figure Description

[0053] Embodiments of the present invention will now be described with reference to the accompanying drawings, in which:

[0054] Figure 1 A perspective view of the device according to the present invention is shown;

[0055] Figure 2 It shows Figure 1 An exploded perspective view of the equipment;

[0056] Figure 3 It shows Figure 1 and Figure 2 A floor plan of the equipment;

[0057] Figure 4 It shows Figure 1-3 A side view of the device;

[0058] Figure 5 It shows Figure 1-4 A side view of the device, showing the side panel;

[0059] Figure 6 A perspective view of the base and top shell of the device is shown;

[0060] Figure 7 A perspective view of a unit of the device according to the invention is shown, illustrating features such as a handle, a closed curved door, and an observation port;

[0061] Figure 8 It shows Figure 7 A perspective view of the unit, with the curved door in a partially open position;

[0062] Figure 9 An exploded perspective view of the components of a device with a four-unit configuration is shown;

[0063] Figure 10 A gantry frame cradle according to the present invention is shown;

[0064] Figure 11a The invention illustrates two brackets and a continuous length of cable already positioned within the brackets;

[0065] Figure 11b It shows Figure 11a The bracket in which the cable was cut at approximately the location of the cable fault;

[0066] Figure 12 A high-voltage cable is shown, with its constituent cores A, B, and C separated from each other, ready to be inserted into a side plate;

[0067] Figure 13a It shows Figure 11a The bracket, in which the cantilever track extends fully to prepare for receiving the base shell and the top shell;

[0068] Figure 13b It shows Figure 11a The bracket has a base shell and a top shell positioned on a cantilever track;

[0069] Figure 14a It shows Figure 11a The bracket, in which the bottom shell has slid down to the position below the cable via the guide rail, and the top shell has moved to the position above the cable;

[0070] Figure 14b It shows Figure 14b The bracket in which the base shell and the top shell move upward along the cable to their final positions for cable interaction activities;

[0071] Figure 15 The cut sections of cables A and B located inside the device are shown;

[0072] Figure 16 Two device units in contact with each other are shown;

[0073] Figure 17 The image shows the cable section after it has been removed. Figure 11a The brackets, in which the units are separated from each other, and one unit on each bracket is recycled back to the ship;

[0074] Figure 18 As shown Figure 17 The faulty cable between the two units shown was restored to the ship's section;

[0075] Figure 19 An optional side panel, referred to as a blank panel, is shown, which is fitted to the proximal end of the unit;

[0076] Figure 20 A unit in which the curved door is in the closed position is shown;

[0077] Figure 21 Cables A and B are shown, ready for cable intervention, with the cable sheath and insulation stripped to expose the cable core.

[0078] Figure 22 The diagram shows a new cable segment arranged between two units to replace a faulty cable segment removed from the continuous line of the cable, wherein the brackets are again used to position each unit on its respective bracket so that they can be aligned to contact the unit already on the bracket.

[0079] Figure 23 It has been shown that it has been followed Figure 22 The final location of the newly deployed cable segment;

[0080] Figure 24 The glove system and wrist sealing system of the dry suit used with the equipment are shown;

[0081] Figure 25 The image shows a glove connected to a wrist sealing system and an outlet hose connected to a bilge pump, which is connected to an outlet flow valve.

[0082] Figure 26 An end flange for cable insertion is shown, which includes a cable gland for inserting a power cable core;

[0083] Figure 27 An end flange for cable insertion is shown, featuring a seal and a manufactured gasket;

[0084] Figure 28 A perspective view of the device seated on the bracket is shown;

[0085] Figure 29 It shows Figure 28 A side view of the device;

[0086] Figure 30 A front view showing the position of the curved door and gears inside the device according to the invention in the open position;

[0087] Figure 31A front view showing the position of the curved door and gears inside the device in the closed position;

[0088] Figure 32 A front view shows the location of the curved door in the open position inside the device;

[0089] Figure 33 A perspective cross-sectional view of a curved door in the closed position below the grid floor of the equipment is shown;

[0090] Figure 34 A perspective view shows a curved door in the closed position beneath the grid floor of the equipment; and

[0091] Figure 35 The illustration shows a perspective view of the components of a device in a two-unit configuration.

[0092] The following is a list of the components used in the description below.

[0093] number part

[0094] 100 devices

[0095] Unit 2

[0096] 4. Base Shell

[0097] 6. Top shell

[0098] 8. Interior Space

[0099] 10 Simple brackets

[0100] 12 orbits

[0101] 14. Remote

[0102] 16 Proximal

[0103] 17 Motors

[0104] 18 side panels

[0105] 19 Access Board

[0106] 22. Basal portion

[0107] 24 Top side section

[0108] 26 Cable Port

[0109] 27 Cable seals

[0110] 28 Curved door

[0111] 29 Flange

[0112] 30 handles

[0113] 31 Valve

[0114] 32 Tool Box

[0115] 34 cameras

[0116] 36 Grid Flooring

[0117] 38 lights

[0118] 42 Purging device

[0119] 44. Hanging lugs

[0120] 50 rack

[0121] 52 small gears

[0122] letter

[0123] Cables A, B, and C Detailed Implementation

[0124] Now refer to the attached diagram. Figures 1 to 35 The first embodiment of the device, generally indicated as 100, is shown, which provides a habitat for low, medium, or high voltage submarine cable interventions, such as joining or connecting activities.

[0125] like Figure 1 As shown, the device 100 includes at least two units 2. Each unit includes a base shell 4 and a top shell 6 fixed together to form an internal space 8 therebetween. The base shell 4 and the top shell 6 may be fixed together by pins, by welding, or as shown in the diagram. Figure 6 , Figure 7 , Figure 8 and Figure 9 The nuts and bolts shown are fastened together. A seal is provided between the bottom shell 4 and the top shell 6. Preferably, the seal is a neoprene rubber or cork sealing strip.

[0126] like Figure 2As shown, the base shell of each unit 2 is configured to sit on a track or a set of tracks. Each set of tracks includes at least two parallel tracks. The track or track set is part of a large frame structure referred to as bracket 10. In some cases, a simple bracket 10 is sufficient for positioning and / or holding unit 2 or assembled multi-part unit 2. A simple bracket may include cantilevered tracks on which the structure can slide, but it does not include a lifting device. In other cases, a benchtop function is required on the bracket 10 to enable the lifting, lowering, moving, sliding, and replacement of a part of the unit, for example, holding the top shell 6 while the base shell 4 is properly positioned, and then lifting and lowering the top shell 6 so that it is on top of the base shell 4. Each base shell or unit 2 may be positioned on a track or track set and then slid along the track set to reach a desired position. The cantilevered tracks allow for additional movement of the base shell 4 and unit 2. The benchtop function of the bracket allows items to be lifted and lowered within the bracket. Figure 3 and Figure 4 As shown, the track or track assembly 12 can be used to align the units 2, such that at least two units 2 achieve a sealable fit when positioned on the track 12 and in contact with each other. The at least two units 2 can then be connected to each other to allow for the use of, as shown in... Figure 20 and 28 The extended intervention chamber is formed by a quick-connect latch, multiple nuts and bolts, various welding techniques, or any combination of the aforementioned connection methods. A seal is provided between each unit 2. Preferably, the seal is a neoprene or cork sealing strip. Preferably, each unit 2 has a length of 5 meters, 4.5 meters, 3.5 meters, 3 meters, 2.5 meters, or 2 meters.

[0127] When the bracket 10 is used in conjunction with the rack function, the base shell 4 can be positioned on the guide rail 12, and the top shell 6 can be initially positioned on the upper rack element. This allows the base shell 4 to be positioned on the guide rail 12 of the bracket 10, and then the cable can be moved into place by placing it on top of the open base shell. The top shell 6 is then positioned on the upper rack element of the bracket 10 and then slid or lifted into place on top of the base shell 4, meaning the cable is now located within the internal space 8 defined by the base shell 4 and the top shell 6. This installation system allows the unit 2 to be assembled essentially around the cable in the seabed environment while the cable remains intact. Under certain conditions, when the gantry crane can be positioned very close to the cable to be repaired, this means very little cable movement and minimal disturbance in placing it within the unit, representing a significant saving of time and resources compared to the traditional methods of restoring the cable to the surface water level or actually even cutting the cable and independently traversing both ends of the cable through the habitat system.

[0128] The intervention room may include multiple units 2, such as two combined units, three combined units, or four combined units. Each unit 2 includes a distal end 14 and a proximal end 16. The placement of the proximal end 16 of the unit 2 depends on the activity under discussion.

[0129] In the case where unit 2 simply extends into the extended intervention chamber, the proximal end 16 of one unit 2 will contact the distal end 14 of the next unit 2, thereby leaving the distal end of one of the units at the end of both unit assemblies.

[0130] When the first unit 2 and the second unit 2 need to be used independently, as two separate components—for example, for connecting the two ends of a cable—before being connected together to form a larger assembly, the first unit 2 must be arranged such that the proximal end 16 of the first unit 2 faces outward in the direction of the second unit 2. Similarly, the second unit 2 must be arranged such that the proximal end 16 of the second unit 2 faces outward in the direction of the first unit 2. In this arrangement, when the first unit 2 and the second unit 2 are placed together, they will be connected to each other at the proximal ends 16 of the two units 2. These components can also be extended into the extended intervention chamber by adding additional units 2 to one or both of the first unit 2 and the second unit 2.

[0131] To seal the internal space 8, it is necessary to provide at least one side plate 18 at each end of unit 2. The side plates 18 can be attached to one or both of the base shell 4 or the top shell 6. The design of the side plates 18 can vary depending on the anticipated repair procedures and required features. For example, for low-voltage cable types, some repair procedures may require a side plate 18 with one cable access point or port, while for high-voltage phase-separated cables, other repair procedures may require a side plate 18 with multiple cable access points or ports, such as three cable access points or ports. Additionally, a side plate 18 can be configured as a separate component applicable to unit 2, such as... Figure 5 As shown, another side plate 18 can be formed from two separate parts, having a bottom side portion 22 that can be attached to the bottom shell 4 and a top side portion 24 that can be attached to the top shell 6. Figure 1 , 2As shown in Figure 5, in a preferred embodiment, the first side plate adapted to be applied to the distal end of the side plate 18 comprises two separate portions 22 and 24, which together form a complete side plate 18, although it will be understood that the side plate 18 may alternatively consist of only a portion extending from the base shell 4 to the top shell 6. In a preferred embodiment, the base side portion 22 is a generally rectangular plate-like structure. In a preferred embodiment, the top side portion 24 is a generally semi-circular plate-like structure. Both the bottom side portion 22 and the top side portion 18 can be directly bolted to flanges 29 disposed at the distal end 14 and proximal end 16 of each unit 2. The flanges 29 at the distal end 14 or proximal end 16, or both, may be continuous around the periphery of the distal end 14 or proximal end 16 of the unit 2, or they may be discontinuous, with several independent flange lips disposed at key locations around the periphery of the distal end 14 or proximal end 16 of the unit 2.

[0132] Side panel 18 is designed to accommodate the entry of power cable cores into the interior space 8 via a through-hole in side panel 18, referred to as cable port 26. Cable port 26 includes a fitted sealing gasket on which cable seal 27 is fitted. Cable seal 27 allows the cable to slide through cable port 26 while maintaining a seal, thereby preserving the integrity of the internal atmosphere of interior space 8. In a preferred embodiment, the cable seal is a Roxtec® seal. The seal may optionally be any type of polyurethane, polyethylene, or rubber-based seal. A sealing gasket is required to hold cable seal 27 in cable port 26 as the cable moves through it. A gland gasket is designed for use both inside and outside the device 100. The gland gasket facilitates maintaining positive pressure within interior space 8 as the cable moves through the gland gasket and cable seal 27. The ability of the cable to move freely within the gland gasket and cable seal 27 during the splicing process is a key aspect of the design, as it allows any component along the cable section to be positioned optimally within the internal space 8, which allows divers to work efficiently and comfortably.

[0133] The flexibility required for high-voltage cables means that divers must be able to remove their gloves so they can make or repair cables within the equipment without being restricted by them. Unlike existing technologies that require divers to wear gloves continuously during repairs, this invention utilizes a dry-suit cuff sealing system that allows divers to remove their gloves at a point during operation, as a seal is formed around the diver's wrist that prevents decompression of the equipment through the glove outlet.

[0134] According to the present invention, the gloves are used only when divers insert or remove their hands from the internal space. During use, a seal within the glove system forms around the diver's wrist to maintain a dry environment within the internal space. The present invention combines a dry glove wetsuit system with an innovative glove check pump system. Access ports on at least one side of each top shell allow the glove system to be attached to the unit. To prevent water contained in the gloves and the external environment from entering the device, a one-way pump is connected to the gloves to pump any excess water out of the gloves before removing it. The one-way pump acts as a check valve, thus preventing water from entering the gloves from outside the device.

[0135] The following provides typical use cases of glove use as examples. It should be understood that the use of gloves is not limited to this method, and further steps and methods are possible without departing from the scope of the inventive concept.

[0136] The gloves are provided for use in seabed environments where the pressure differential within the internal space 8, used for cable intervention activities, has been reduced to a distance range. To access the gloves, the access panel 19 covering the access port must be opened or removed, exposing the inner gloves and the glove itself. Water is expelled from the gloves as the diver's arm is inserted into each glove and pushed against the glove and wrist seal. Each of the diver's hands is pushed through the rubber seal inside the glove and into the glove, creating a watertight barrier around the diver's arm to prevent further water from entering the glove beyond the diver's wrist. Once both of the diver's arms are in the gloves, the pressure stabilizes again. A one-way pump is individually connected to each glove, and an outlet on device 100 is activated by the diver to expel any water from the gloves to the outside of device 100. When the gloves are disconnected from the glove at the dry sleeve cuff system, the inner arm seal prevents water from entering the internal space 8. Once all water has been expelled from the gloves, the diver can remove one glove at a time using the dry sleeve cuff system. The diver's hands are now free to work unimpeded within the device 100. The process can be repeated by another diver or by the same diver on the other side of the device 100.

[0137] When the diver withdraws their arms from the internal space 8, gloves must first be placed on the diver's hands, and then the gloves are reattached using a dry suit cuff system. The diver then uses their other available hand, still inside the internal space 8, to withdraw their first hand from the glove and glove sleeve. The diver then places their second hand into a tool within the device, preferably a U-shaped tool, which holds the sleeve in place to allow the diver to retract their second hand. Once the diver has withdrawn both hands from the internal space 8, the access plate 19 on each access port is secured to prevent the gloves / gloves from being blown out through the access ports during overpressure or purging operations.

[0138] Visibility within the device is crucial for both high-voltage and low-voltage applications. The observation ports of this invention are not only larger than those in the prior art, but their placement within the device has also been redesigned. The observation ports are integrated into the device at an angle such that, when the diver's body position is restricted by their arms sealed within the glove system, the ports are aligned with the center of the working area inside the device and the diver's head, and are positioned midway between them. This calculated placement of the observation ports significantly increases the ergonomic suitability for divers when observing the interior of the device and represents a substantial improvement over existing technologies.

[0139] The innovative feature of this invention allows divers to adjust the helmet's free-flow valve from within the device. This is a key feature of the device, as it maintains the diver's clear visibility throughout the cable repair process.

[0140] One or more cameras 34 are installed inside the interior space 8. The cameras 34 ensure remote monitoring of activities within the interior space 8. One or more lights 38 may be installed within the interior space 8. One or more mirrors may be installed within the interior space 8 to partially conceal the view from the direct line of sight of the cameras.

[0141] Tool box 32 can be mounted on at least one side panel, allowing tools and other items to be brought into the interior space as needed.

[0142] like Figure 2 and Figure 4 As shown, to assemble at least two separate units 2 on the seabed, each unit 2 also includes a curved door 28. The door 28 is located at the proximal end 16 of the unit 2 and can be actuated by a handle 30 disposed on the exterior of the unit 2. Alternatively, the door 28 can be actuated by a motor 17 located on the exterior of the unit 2, such as... Figure 20 As shown. Motor 17 can be remotely controlled from a processing unit located on a ship or platform or on land.

[0143] The curved door 28 of this invention represents a significant innovative advancement in the technology. The curved door 28 design allows the interior space of one unit 2 to be combined with the interior space 8 of another unit 2 to bring together the ends of two cables within different units 2, and to create a larger working area by combining the two interior spaces 8 while maintaining a dry environment around the cables. The curvature angle of the curved door 28 means that, in its open position, the curved door 28 is located at a low level within the interior space 8 (e.g., below the grid floor 36), and in its closed position, the curved door 28 completely seals one end of the unit 2.

[0144] The curved door 28 is designed to open and close without significantly impairing the interior space 8 of the unit. The curved door 28 can be actuated to open or close when the side panel 18 is fixed to the proximal end 16 of the unit 2. In the closed position, the curved door 28 functions as the side panel 18, and no additional side panel is required at the proximal end 16 of the unit 2.

[0145] The curvature angle of the bend door 28 allows the units 2 to be connected to each other with the minimum spacing between the internal cable cores on each side of the bend door 28. This bend door 28 minimizes the required internal space 8 by minimizing the size of the required cable connection ferrule, which in turn affects the size of the cable connector. When two units 2 with closed bend doors 28 are placed together, the space between the two bend doors 28 needs to be evacuated before the bend doors 28 can be opened to maintain the integrity of the dry internal space 8 of each unit 2.

[0146] Furthermore, the curved door 28 is independent within the interior space 8 to avoid any potential snagging or dragging problems when deploying or retracting the device 100. In a preferred embodiment, the curved door 28 is remotely operable (from a vessel on the sea). Alternatively, in a less optimized configuration, the curved door 28 can be operated via a handle 30 located outside the unit 2.

[0147] The mechanism that enables the curved door 28 to move to the open or closed position is the rack and pinion 50 device. Figure 30 The pinion 52 is connected to and can be operated by the handle 30 or the motor 17. The rack 50 is arranged along the edge of the curved door 28 adjacent to the handle 30 or the motor 17.

[0148] As previously described, Unit 2 can be deployed assembled, partially assembled, or completely disassembled. In the case of assembled Unit 2, each Unit 2 is typically filled with water before or during deployment from the vessel to ensure that buoyancy does not unduly interfere with the deployment operation; this buoyancy can vary depending on the amount and type of gas within the internal space 8 at a specific depth. Once Unit 2 is deployed on the seabed and the side plates 18 have been attached to Unit 2, water can be removed from the internal space 8. Water is flushed out of the internal space 8 by a purging device 42. The purging device 42 may include one or more purging gas inlets connected to a purging gas supply through which purging gas is pumped into the internal space 8. The purging gas supply source may be located away from the internal space 8 (e.g., connected via a gas pipeline to a purging gas supply source on the surface vessel of Unit 2). Alternatively, Unit 2 itself may have a gas supply source, such as a weighting tank. The gas may be air or an inert gas (e.g., nitrogen). Purge the internal space 8 to provide a safe, dry repair environment and additionally to the cables being repaired.

[0149] Additionally, the purging device 42 may include a water pump for draining water contained in the internal space 8 after the assembly unit 2 is assembled.

[0150] In embodiments including the purging device 42, the device 100 may also be provided with a purging outlet through which purged water exits the internal space 8 and enters the surrounding sea. In its simplest form, the purging outlet is one or more openings in the base shell 4, top shell 6, or side plate 18 of the device 100. In a preferred embodiment, the opening is located on the base shell 4. The opening may be provided with a closure device (e.g., a cap or lid) that can be used to close the opening once seawater or other fluids or gases have been purged from the internal space 8. Several purging devices 42 may be required on a single unit 2 to empty all internal spaces.

[0151] Other embodiments of the invention may include a cleaning apparatus to allow the interior of the interior space 8 and the cable being repaired to be cleaned with a cleaning fluid (e.g., fresh water, distilled water, or solvent) capable of removing seawater deposits from the interior space 8 and the cable.

[0152] In such an embodiment, the cleaning apparatus may include one or more cleaning fluid inlets connected to a cleaning fluid supply source, through which the cleaning fluid may be pumped into the interior space 8. The cleaning fluid inlets may be located in one or more nozzles situated within the interior space 8.

[0153] Alternatively or alternatively, one or more cleaning fluid inlets may be provided in a guideable device (e.g., a spray gun) to allow the user to guide the cleaning fluid as needed.

[0154] The source of the cleaning fluid may be located remotely from the device 100, for example, via a cleaning fluid supply source (e.g., a cleaning fluid tank) on a surface vessel connected to the device 100 by a line. Additionally or optionally, the device 100 itself may be equipped with a cleaning fluid supply source, such as a tank.

[0155] Device 100 may be equipped with drying devices. These can be used after the interior of the device 100 or cable being repaired has been cleaned and / or purged to provide a dry repair environment. The drying devices may include one or more drying gas inlets connected to a drying gas supply source through which drying gas can be pumped into the contained environment. The drying gas supply source may be located remotely from device 100, for example, connected via a gas line to a drying gas supply source (e.g., a gas cylinder) on a surface container of device 100.

[0156] Additionally or optionally, the device 100 itself may be provided with a dry gas supply source, such as a weighted tank. The dry gas may be air and / or an inert gas, such as nitrogen.

[0157] The drying gas inlet can be located in one or more nozzles within the internal space. Alternatively, one or more drying gas inlets can be located in a guideable device (e.g., a spray gun) to allow the user to guide the drying gas as needed.

[0158] As will be understood, in embodiments of the invention, gas can be supplied to the containment environment within device 100 to purge water, dry the interior, and / or regulate the pressure within the interior space 8. In such embodiments, the purging, drying, and / or pressure-regulating gas can be supplied from a common supply source (e.g., a single tank). Where the common supply source is located away from device 100 (e.g., on a surface container), the purging, drying, and / or pressure-regulating gas can be supplied to device 100 via a common line. Furthermore, the common inlet can be used as a purging gas inlet, a cleaning fluid inlet, a drying gas / sand inlet, or a pressure-regulating gas inlet.

[0159] For ease of transport, the bottom shell 4 or the top shell 6, or both, may be provided with a means for attachment by a lifting device, such as a lifting ring.

[0160] The device 100 includes at least two units 2. Two or more units 2 can be used in situations requiring the repair of longer cables or where more space is needed for repair procedures. In the case of three units, two units 2 (the first unit and the second unit) can be arranged on the track 12 as described above, with their proximal ends 16 in contact with each other. The side plate 18 is not attached to the distal end 14 of the second unit 5, thus allowing the third unit to be directly connected to the second unit. In this case, the proximal end 16 of the third unit contacts the distal end 14 of the second unit.

[0161] The device 100 is equipped with a differential pressure control component. Once the unit 2 is assembled, such a device serves to maintain a controlled pressure within the internal space 8 of the device 100, thereby enabling effective and safe cleaning, purging, joining, or connecting activities.

[0162] The differential pressure control component includes multiple pressure sensors. Preferably, the differential pressure control component includes multiple pressure sensors, wherein at least one internal pressure sensor senses the pressure in the internal space 8, and at least one external pressure sensor senses the pressure outside the device 100. Readings from the internal and external sensors enable the determination of the differential pressure, i.e., the pressure difference between the internal space 8 and the outside of the device 100.

[0163] The differential pressure control component may additionally or optionally include a pressure regulating device that enables the achievement of the target differential pressure.

[0164] In embodiments of the invention, the pressure regulating device includes one or more pressure regulating gas inlets connected to a pressure regulating gas supply source, through which the pressure regulating gas can be pumped into the contained environment. The pressure regulating gas supply source can be located remotely from device 100, for example, connected via a gas pipeline to a pressure regulating gas supply source (e.g., a gas tank) on a surface vessel. Additionally or optionally, device 100 itself may be equipped with a gas supply source, such as a weighted tank. The pressure regulating gas can be air and / or an inert gas, such as nitrogen.

[0165] Additionally or optionally, the pressure regulating device may include an venting device, such as one or more controllable pressure-regulated gas outlets, which allow gas to be vented from the contained environment to the outside. One or more of the gas outlets may be equipped with a valve. This valve 31 may be configured with a predetermined threshold pressure (which may be fixed or adjustable by the user or by a control member) such that pressure is released from the internal space 8 only when a target pressure differential is reached or exceeded in the internal space 8. Pressure release from the internal space 8 may also occur as a result of gas leaving the internal space 8 via a purge outlet (if employed).

[0166] The optimal results for cable intervention activities are obtained when the pressure difference within the containment environment of the equipment 100 is equal to or greater than the external pressure.

[0167] The advancements of the invention are evident when the internal space 8 is maintained at a pressure differential below, equal to, or greater than the following ranges.

[0168] In preferred embodiments of the present invention, the pressure difference within the internal space 8 is greater than the external pressure of the device by 0 Pa, 500 Pa, 1000 Pa, 4000 Pa, 6000 Pa, 8000 Pa, 10000 Pa, 20000 Pa, and 50000 Pa.

[0169] In a preferred embodiment, the pressure differential within the internal space 8 used for repair or connection activities is in the range of 0 mbar to 100 mbar.

[0170] In a preferred embodiment, the pressure differential within the internal space 8 used for purging activities is in the range of 5 mbar to 1 bar.

[0171] In embodiments of the invention, the differential pressure control component may include a user interface, wherein any one or a combination of internal pressure, external pressure, or differential pressure may be presented to the user. The user can then control the pressure regulating device (optionally via the user interface) to ensure that the target differential pressure is maintained. In embodiments of the invention, the user interface may be located on a surface vessel. The user interface may be additionally or optionally located externally or internally to the device 100.

[0172] To prevent potentially dangerous pressure buildup in the interior space 8 (e.g., due to a malfunction in the pressure regulator), the device 100 may be equipped with an emergency pressure relief valve.

[0173] In another embodiment, the device can be used with or without a bracket to provide a dry mating environment for the cable connector. In this case, the connector can be installed at the ends of the cables within two separate units of the device (instead of a conventional cable splicing procedure). The two units can then be placed together such that the proximal ends of the two units are secured together by a latch or other suitable connecting device known in the art. Water between the two bend doors can then be drained before connecting the connector in the dry environment of the device's interior space, after opening the two bend doors.

[0174] Cable intervention activities can be mainly divided into the following two types:

[0175] - Dry-type matchable connections include new cable connections, floating offshore wind turbine connections, and induction unit connections. These connections can typically be connected and disconnected relatively easily when needed.

[0176] - Joints, including repairing cable segments less than 5 meters in length and repairing cable segments longer than 20 meters. These joints, once established, are generally not to be disconnected.

[0177] The following provides an example of a step-by-step dry-type mating connection method for cables according to the present invention. This type of connection is referred to as a click-and-connect activity, and it is suitable for activities such as adding new cables to a cable system or adding new long sections to an existing cable infrastructure.

[0178] 1.1 Connection - Disconnect the first section of cable that is not needed.

[0179] - Cut the cable at the location of the fault. Optionally, this cut can be performed using a ROV.

[0180] - Deploy the simple cradle 10 within a range of approximately 20m from the cable cut.

[0181] - Retrieve the first cable end back onto the ship.

[0182] - Remove the first 20m of cable from the first cable end.

[0183] 1.2 Connection - Attached Connector

[0184] - Prepare cable ends with connector terminals on board.

[0185] - Position the base shell 4 (which has a base side portion 22 with side plates 18) at the end of the cable segment.

[0186] - Lower the end of the cable into the base shell 4 so that the connector is almost adjacent to the bend gate 28 (at the outer end).

[0187] - Position the top shell 6 (which has a top side portion 24 provided with side plates 18) on top of the base shell 4.

[0188] - Connect the top shell 6 and the bottom shell 4 together (e.g., by latching or welding) to form unit 2.

[0189] - Close curved door 28 (at the outer end).

[0190] - Ensure all seals are watertight (cable hole seals, top / bottom shell 4 seals, and side panel components).

[0191] 1.3 Connection - Deploy the first end of the cable

[0192] - Position Unit 2 on the display pole.

[0193] - Extend the spreading rod to the seabed so that unit 2 is aligned with the cantilever track of bracket 10 on the seabed.

[0194] - Position unit 2 onto the cantilever rail of the component.

[0195] - Slide unit 2 on its cantilever track so that unit 2 is in the correct position for engagement.

[0196] 1.4 Connection - Second end of the lifting cable

[0197] - Retrieve the second cable end back onto the ship.

[0198] - Remove the first 20m of cable from the end of the cable.

[0199] - Add a new cable of approximately 40m in length to the ship (to replace the two 20m cut cables) using the following “E-connector” method, and use an in-line connector.

[0200] 1.5 Connection - First end of the attachment connector and deployment cable

[0201] Connect the connector and deploy the second end of the cable according to the methods described in 1.2 and 1.3 above.

[0202] 1.6 Connection - Connector Engagement

[0203] - Connect the two units 2 together to form a combined unit.

[0204] - Drain water from the space between the two curved doors 28.

[0205] - Open the curved door 28.

[0206] - To make the connectors mesh with each other.

[0207] The following is provided as an example of a progressively dry, matchable cable connection method according to the present invention suitable for connection to a floating offshore wind turbine.

[0208] 1.7 Connection - Floating Offshore Wind Turbine

[0209] In this method, the existing subsea anchored floating structure is in place before the activity begins, and the first cable from the floating structure includes a connector terminal that has been installed in the unit on the ship.

[0210] A second cable (from the power grid) terminated by a connector in the unit is mounted on a simple bracket 10 on the seabed. The simple bracket 10 includes a dummy unit with dummy terminals, and the dummy unit is connected to the unit on the bracket 10.

[0211] - Restore the virtual unit with the virtual terminal to the ship.

[0212] - Deploy the first cable according to method 1.3

[0213] - Slide the unit on its cantilever rail so that the unit is in the correct position for engagement.

[0214] Connect the connector according to method 1.6.

[0215] The following is an example of a step-by-step dry-matchable cable connection method suitable for installing and connecting inductor assemblies according to the present invention.

[0216] 1.8 Connection - Inductor Group

[0217] This method is suitable for high voltage over long-distance cables because it includes an inductor array in the cable system to reduce reactive power flowing in the cable. The inductor array is installed in the dry-sealed dual-unit 2 assembly on board before the activity begins.

[0218] Two cable ends are provided on the two units 2, each cable end including a connector termination. The two units 2 are each mounted on a simple bracket 10, and the two simple brackets 10 are arranged side by side on the seabed and in contact with each other, or the two units 2 are mounted on a large simple bracket 10 on the seabed.

[0219] - Slide each unit 2 on its corresponding cantilever track so that unit 2 is in the correct engagement position.

[0220] - Unfold the dual-unit 2 assembly containing the inductor group, positioning it in a position where it engages with the units 2 at both ends of the dual-unit 2 assembly.

[0221] - Following procedure 1.6, connect unit 2 to the dual unit 2 assembly and engage the connector of the inductor rear connector with each connector terminal.

[0222] The following provides an example of a step-by-step cable joining method according to the present invention.

[0223] A-connector - initial wet cable cutting, cable positioning within the gantry bracket, and dry cable cutting.

[0224] - Deploy bracket 10 onto the seabed.

[0225] - Cut the damaged cable (wet) at the location of the fault.

[0226] - Suspend the cable in bracket 10.

[0227] - The cable is prepared by splitting its constituent core wires.

[0228] - Unfold the open unit 2 into the cantilever rail of the bracket 10.

[0229] - The second open unit 2 is unfolded into the second cantilever rail of the bracket 10.

[0230] - Note: The top shell 6 is provided with a top side portion 24 of the side plate 18 in the appropriate position.

[0231] - Note: The base shell 4 is provided with a base side portion 22 of the side plate 18 located in the appropriate position.

[0232] - Note: The curved door is not closed.

[0233] - Unlock the top shell 6 from the base shell 4.

[0234] - Use an elevated gantry rail to raise the top shell 6 within the bracket 10 and slide the top shell 6 to a position above the suspended split core.

[0235] - Slide the base shell 4 of unit 2 under the suspension core.

[0236] - Place the core on each cable port 26 of the base side portion 22 of the side plate 18.

[0237] - Use the gantry rails to lower the top shell 6 onto the bottom shell 4.

[0238] - Lock the top shell 6 onto the bottom shell 4.

[0239] - Latch the first unit 2 to the second unit 2 to form two unit 2 components.

[0240] - Ensure all seals are waterproof.

[0241] - Evacuate the internal space 8 of the combination of the two unit 2 components.

[0242] - Dry-cut the cable within the two unit 2 components (approximately halfway through the internal space of the assembly).

[0243] - Raise the curved door 28 on both units 2 of the two unit 2 components.

[0244] - Restore Unit 2, which contains the redundant cable section, to the ship.

[0245] - Deploy the second bracket 10 onto the seabed.

[0246] - Repeat the method again for two or more units 2 and the second bracket, wherein the two or more units 2 and the second bracket are arranged and aligned in a mirror orientation with the first two unit 2 components.

[0247] B-connector - Submarine cable preparation

[0248] - Deploy the blank board onto unit 2 on the bracket.

[0249] - Drain the water between the blank plate and the curved door 28.

[0250] - Open the curved door 28.

[0251] - The cable core is prepared by stripping the insulation layer, etc., in order to facilitate cable intervention.

[0252] - Close the curved door 28.

[0253] - Recycle blank boards.

[0254] - Repeat the assembly procedure for the second time.

[0255] C-connector - Cable measurement

[0256] - Measure the distance between each curved door 28 of unit 2 remaining on the seabed.

[0257] D-connector - Prepare new cable segments on board for dry deployment to Subsea Unit 2.

[0258] D-1; The 5m section to be replaced - create a large internal space for 8 components, for example Figure 9 The 4-unit component shown

[0259] - Prepare a section of cable with connectors at both ends on the ship.

[0260] - Lock the two base shells 4 together to form a base shell assembly, which facilitates the entire length of the new cable.

[0261] - Lower the cable segment into the base housing assembly such that each end of the cable nearly abuts against the curved gate 28 of the base housing assembly.

[0262] - Lock the two top shells 6 together to form a top shell assembly, facilitating the full cross-section of the new cable.

[0263] - Position the top shell assembly on top of the base shell assembly.

[0264] - Latch the top shell 6 and the base shell 4 together to form two unit assemblies. Close the two curved doors 28.

[0265] - Ensure all seals are watertight (top housing 6 - bottom housing 4 seals).

[0266] - Position the two unit components on the display pole.

[0267] - The spreading rod is extended onto the seabed and onto the cantilever track of the corresponding bracket on the seabed, so that the two unit components are aligned and fitted between the two units 2 already on the seabed.

[0268] - Slide the two unit components parallel to each other on two cantilever tracks so that the two unit 2 components come into contact with each unit 2 on the seabed.

[0269] - Lock the two unit 2 components onto each unit 2 on the seabed.

[0270] - Drain water from the space between the curved doors 28 on each component of each bracket 10.

[0271] - Open the curved door 28.

[0272] D-2; The 20m section to be replaced - create two separate unit components.

[0273] - Prepare a section of cable on board with connectors at both ends (so that the main connector body is in the parking position).

[0274] - Position the base shell 4 (which is provided with the base side portion 22 of the side plate 18) at each end of the cable segment.

[0275] - Lower the ends of this cable into the two base shells 4 so that each end of the cable is almost adjacent to the bent door (at the outer end).

[0276] - Position the top shell 6 (each of which has a top side portion 24 of the side plate 18) on top of the base shell 4.

[0277] - The top shell and bottom shell 4 are latched together to form unit 2.

[0278] - Close the curved door 28. Ensure all seals are watertight (cable hole seals, top shell-base housing 4 seals, and side plate base and top side components).

[0279] - Position the two units 2 at a certain distance on the display pole.

[0280] - Extend the extension rod to the seabed so that each unit 2 is aligned with the cantilever track of the corresponding bracket 10 on the seabed.

[0281] - Position each of Unit 2 onto the relevant cantilever track.

[0282] - Each unit 2 is made to slide parallel to its cantilever track, so that unit 2 contacts unit 2 on the seabed.

[0283] - Lock each cell 2 to the adjacent cell 2 to form two cell components.

[0284] - Drain water from the space between the curved doors 28 on each component of each bracket 10.

[0285] - Open the curved door 28.

[0286] E-connector - Perform actual connector

[0287] - Connect the cable cores together.

[0288] - Slide the main connector body over the connected core body into its final position.

[0289] - Assemble the outer layer (such as a metal layer and a waterproof layer) as needed.

[0290] F-joint - Disassembly, assembly, and recycling of gantry cradles

[0291] - Remove each of the two unit components from the track and lower the component to the seabed.

[0292] - Retrieve bracket 10 back onto the ship.

[0293] It should be understood that the present invention is not limited to the specific details given herein by way of example only, and various modifications and changes are possible without departing from the scope of the invention as defined in the appended claims.

Claims

1. A modular device for high-voltage and low-voltage immersion cable intervention, comprising at least two units, each unit comprising: A bottom shell, a top shell, and at least two side plates, wherein the bottom shell, the top shell, and the at least two side plates are combined to form a sealed internal space; The side panel located at the distal end of the unit allows cables to pass through the exterior of the unit into the interior space; and the side panel at the proximal end of the unit is a movable curved door, which, when in the open position, is aligned with the longitudinal axis of the base shell, and when in the closed position, is movable to a lateral orientation to seal the proximal end. This allows the initial cable intervention to be carried out in the sealed internal space of each unit, and then the two units can be placed together with the proximal end sealed to the proximal end so that the two curved doors can be opened, thereby forming an internal space with a minimum distance between the outer edges of the two curved doors.

2. The device according to claim 1, comprising a portion of the base plate within the internal space, wherein, When the curved doors are in the open position, each curved door is aligned with the longitudinal axis of the base shell and located below the partial base plate, and when the curved doors are in the closed position, each curved door is movable to a lateral position from below the partial base plate.

3. The device according to any one of the preceding claims, comprising a bracket, wherein the base shell and the top shell of the at least two units are positioned on the bracket such that the base shell and the top shell are movable within the bracket to facilitate engagement or disengagement of the units.

4. The device according to any one of the preceding claims, wherein, The internal space includes a pressure difference relative to the outside of the device.

5. The device according to any one of the preceding claims, comprising a gas supply or gas tank for a differential pressure control component.

6. The device according to claim 5, wherein, For cable intervention activities, the pressure difference is in the range of 0 mbar to 100 mbar.

7. The device according to claim 5, wherein, For purging operations, the pressure differential is in the range of 5 mbar to 1 bar.

8. The device according to any one of the preceding claims, comprising at least one observation port.

9. The device according to any one of the preceding claims, comprising at least one access port.

10. The device of claim 9, comprising a glove and sheath seal for use in conjunction with the at least one access port.

11. The device according to any one of the preceding claims, wherein, Each curved gate can be moved by a rack and pinion mechanism, the rack being positioned along the edge of the curved gate, and the pinion being operable by a manual handle or an electric motor.

12. The device according to any one of the preceding claims, wherein, An access board is provided to selectively cover the access port.

13. The device according to any one of the preceding claims, wherein, The side plate includes a cable seal.

14. The device according to claim 13, wherein, The side plate includes a pre-assembled gasket to accommodate the cable seal.

15. A method for performing cable intervention in a seabed environment, comprising the following steps: Provided on the seabed at least a first modular device for high-voltage and low-voltage submerged cable intervention according to any of the preceding claims; Insert the cable end into the modular device and evacuate the internal space; Prepare cable ends for cable intervention, such as joints, additional connectors, etc. The second sealed modular equipment on board provides items for cable intervention, such as new cable ends, new cable segments, induction groups, etc. The second sealing modular device is deployed on the seabed and positioned adjacent to the first modular device, such that the first and second modular devices are connected to each other. Open the curved doors of the first modular device and the second modular device to form an extended interior space in which cable intervention is possible in a dry environment; as well as The cable intervention was performed in an environment where there was virtually no moisture.

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