System and method for performing an operation

Abstract

A system for performing an operation on a partially submerged body (600) of a structure or vessel comprises: a primary vehicle (100) configured to traverse the body (600) above a splash zone, the primary vehicle (100) using magnetic or vacuum attachment (120a, 120b) to secure itself to the body; and a secondary vehicle (200) configured to move within or below the splash zone, the second vehicle (200) being tethered to the primary vehicle (100), and the secondary vehicle (200) comprising at least one tool (230) for performing the operation on the body (600).

Description

[0001] SYSTEM AND METHOD FOR PERFORMING AN OPERATION

[0002] The present invention relates to a system for performing operations, particularly repairs, on the body of a structure or vessel that is partially submerged in water, and to a method of performing operations using the system.

[0003] Today, in order to repair damage to the hull of a vessel, where the damage is below the water line, it is necessary to take the ship into a dry dock or use a bespoke cofferdam.

[0004] A dry dock is a narrow basin, which can be flooded to allow a ship to be floated in, and then drained to allow the ship to rest on a dry platform. This permits all types of repair to be performed on the hull. However, this process is time consuming, financially costly, and can only be performed at a limited number of locations.

[0005] A cofferdam is a temporary sealed-off space below the water's surface that allows for underwater repair and maintenance. Cofferdams allow the vessel to remain on its scheduled itinerary by allowing repairs to be done in-situ. However, their use is again costly, as they must be designed and manufactured specifically for the repair being performed.

[0006] For certain types of damage, divers can perform repairs on the hull in-situ, for example using underwater welding equipment or the like. However, divers can only work on regions of the hull that are well below the water line. Where damage is close to the water line, waves mean that it is unsafe or impossible for divers to work. Additionally, only certain types of repair operations can be performed when they are exposed to water, which limits the types of repair that can be performed by divers.

[0007] Similar considerations apply also to partially submerged structures, such as floating or fixed offshore platforms.

[0008] A need therefore exists for an improved system for performing such operations.

[0009] The present invention provides a system for performing an operation on a body of a structure or vessel whilst the body is partially submerged in water, the system comprising: a primary vehicle configured to traverse the body above a splash zone, the primary vehicle using magnetic or vacuum attachment to secure itself to the body; and a secondary vehicle configured to move within or below the splash zone, the second vehicle being tethered to the primary vehicle, and the secondary vehicle comprising at least one tool for performing the operation on the body.

[0010] By using this design, the primary vehicle can carry heavy or bulky supplies and equipment that are required for the operation and must be located close to the operation site on the body, but do not need to be located directly at the operation site. This means that the secondary vehicle, which actually performs the operation and must enter the splash zone, can be much smaller and lighter. This simplifies its design to allow it to resist the high dynamic forces that is subject to within the splash zone.

[0011] The body may be a metallic body, and particularly a magnetic metallic body. The body may be a hull of the structure or vessel.

[0012] The vessel may be a ship, optionally having a length of at least 100 meters, or at least 150 meters, or at least 200 meters or at least 400 meters.

[0013] The structure or vessel may be a floating structure or vessel, which may be floating in the water and / or tethered to a sea bed.

[0014] The structure may be a fixed structure extending from a sea bed.

[0015] The secondary vehicle may be configured to traverse the body within or below the splash zone. The secondary vehicle may be configured to use magnetic or vacuum attachment to secure itself to the body.

[0016] The secondary vehicle may be configured to perform the operation on a component of the body having a complex shape. The component may be one of a rudder, a thruster, a propeller, a water outlet, a valve, a sea chest, and a bilge keel.

[0017] The primary vehicle and / or the secondary vehicle may be configured to traverse a substantially flat portion of the body, i.e. which does not comprise any anchor point, such as hooks, protrusions, rails or the like.

[0018] The primary vehicle and / or the secondary vehicle may be configured to traverse the body without use of any anchor point on the body.

[0019] The primary vehicle and / or the secondary vehicle may be configured to traverse the body both in a first direction parallel to a surface of the body (e.g. a substantially horizontal direction, such as a fore-aft direction) and a second, perpendicular direction parallel to the surface of the body (e.g. a substantially vertical direction, or a substantially port-starboard direction if beneath a vessel).

[0020] The primary vehicle and / or the secondary vehicle may comprise a crawler assembly for traversing the body, for example comprising a belt or track assembly The primary vehicle and / or the secondary vehicle may be configured to secure itself to the body. The primary vehicle and / or the secondary vehicle may be capable of securing itself at least to a surface of the body that is within 30° of vertical, or within 15° of vertical, or that is substantially vertical.

[0021] The secondary vehicle may be capable of securing itself at least to an underside of a surface of the body, such as beneath a vessel.

[0022] The primary vehicle and / or the secondary vehicle may comprise at least one crawler assembly for securing the respective vehicle to the body. The crawler may comprise a magnet belt or a suction belt / device.

[0023] A mass of the primary vehicle is preferably larger than a mass of the secondary vehicle. Optionally, the secondary vehicle has a mass of less than 50% of a mass of the primary vehicle.

[0024] The primary vehicle may be configured to carry the secondary vehicle, when the primary vehicle traverses the body above the splash zone.

[0025] The primary vehicle may be tethered to the structure or vessel, for example to a deck of the structure or vessel, optionally via a launch and recovery system.

[0026] A maximum tethered distance between the primary vehicle and the structure or vessel may be longer than a maximum tethered distance between the secondary vehicle and the primary vehicle.

[0027] The maximum tethered distance between the primary vehicle and the structure or vessel may be at least 50 meters, or at least 100 meters, or at least 150 meters, or at least 300 meters.

[0028] The maximum tethered distance between the secondary vehicle and the primary vehicle may be at least 1 meter, or at least 2 meters, or at least 5 meters, or at least 10 meters.

[0029] The maximum tethered distance between the secondary vehicle and the primary vehicle may be less than less than 30 meters.

[0030] The operation may comprise one or more of an inspection operation, a repair operation, and an installation operation.

[0031] The operation may include a preparation step. The preparation step may include one or more of a heating step, a cutting step, a grinding step, a milling step and a sandblasting step.

[0032] The operation may include a finishing step. The finishing step may include one or more of a washing step, a brushing step, a coating step, e.g. spray coating or painting, a grinding step, a polishing step, a shot peening step, a chemical or electrochemical finishing step and a heat-treating step

[0033] The operation may comprise an additive manufacture step. The additive manufacture step may be performed after a preparation step. The additive manufacture step may be performed before a finishing step. The additive manufacture step may be part of a repair operation, for example to restore a part of the body to an original condition, or part of an installation operation, for example to install a new feature on the body.

[0034] The additive manufacture step may be a directed energy deposition additive manufacture step. Alternatively, the additive manufacture step may be a material extrusion additive manufacture step or a material jetting additive manufacture step.

[0035] The additive manufacture step may comprise sequential deposition of material in layers.

[0036] The at least one tool may comprise an additive manufacture tool, and particularly a directed energy deposition additive manufacturing tool, a material extrusion additive manufacture tool or a material jetting additive manufacture tool.

[0037] The at least one tool may comprise heating tool, a cutting tool, a grinding tool, a milling tool or a sandblasting tool.

[0038] The at least one tool may comprise a washing tool, a brushing tool, a coating tool, a grinding tool, a polishing tool, a shot peening tool, a chemical or electrochemical finishing tool and a heat-treating tool.

[0039] The at least one tool may be movable relative to a housing of the secondary vehicle, preferably in at least two directions and preferably at least three directions.

[0040] The secondary vehicle may comprise a housing configured to establish a controllable environment against a portion of the body. The secondary vehicle may be configured to control the controllable environment to provide a desired operation environment.

[0041] The at least one tool may be inside the housing.

[0042] The at least one tool may be configured to perform the operation within the controllable environment.

[0043] The housing may comprise at least one inlet for supply of fluid into the controllable environment. The fluid comprises a liquid, such as clean or distilled water, or a gas, such as air, nitrogen or another inert gas, such as argon or helium.

[0044] The housing may comprise at least one outlet for removal of fluid from the controllable environment, which may be water and / or air. The housing may comprise one or more sensor for monitoring the controllable environment. The one or more sensor may comprise a temperature sensor and / or a pressure sensor and / or a gas sensor.

[0045] The housing may comprise a camera and / or a light source.

[0046] The system may comprise an umbilical connecting the primary vehicle and the secondary vehicle. The umbilical may be configured to carry one or more of power, control signals, one or more fluid for maintaining a controllable environment, and feed material for performing the operation.

[0047] The primary vehicle may comprise a primary vehicle control module. The primary vehicle control module may be connected to the umbilical.

[0048] The secondary vehicle may comprise a secondary vehicle control module. The secondary vehicle control module may be connected to the umbilical.

[0049] The primary vehicle may be configured to supply a fluid to the secondary vehicle, via the umbilical, such as for maintaining the controllable environment. The fluid may be a liquid, such as clean or distilled water, or a gas, such as air, nitrogen or another inert gas. The fluid may be for supply to the controllable environment.

[0050] The primary vehicle may comprise a compressor for compressing ambient air for supply to the secondary vehicle, via the umbilical.

[0051] The primary vehicle may comprise a source of the fluid, such as a tank. The tank may be a pressurised gas tank.

[0052] The primary vehicle may be configured to receive the fluid from another source, such as from a deck of the structure or the vessel.

[0053] The primary vehicle may comprise a pump for pumping the fluid to the secondary vehicle, via the umbilical.

[0054] The primary vehicle may comprise a transformer.

[0055] The transformer may be configured to receive power at a first voltage from another source, such as from a deck of the structure or the vessel, and to supply power at a second, lower voltage to the secondary vehicle.

[0056] The second voltage may be suitable for directed energy deposition additive manufacturing.

[0057] The primary vehicle and / or the secondary vehicle may comprise a cleaning tool. The cleaning tool may be configured to remove marine growth to clean a trajectory of the primary vehicle. The cleaning tool may comprise one or more of a brush, a hydro-blast cleaning tool, and a cavitation cleaning tool. The primary vehicle may comprise a source of feed material. The feed material may be for an additive manufacture operation. The primary vehicle may be configured to supply the feed material to the secondary vehicle, via the umbilical, for performing the operation.

[0058] The system may comprise a security cable connecting the primary vehicle and the secondary vehicle.

[0059] The security cable may have sufficient tensile strength to support the weight of the secondary vehicle. The security cable has sufficient tensile strength to support the secondary vehicle when falling a height of at least 1 meter, or at least 2 meters, or at least 5 meters.

[0060] The primary vehicle may comprise a least one retraction assembly, such as winch. The at least one retraction assembly may be configured to retract the umbilical and / or the security cable.

[0061] The primary vehicle may be configured to operate the at least one retraction assembly to maintain a length of the umbilical and the security cable approximately equal to a distance between the primary vehicle and the secondary vehicle.

[0062] The system may further comprise a launch and recovery system for mounting to the structure or vessel, such as to a deck of the structure or vessel.

[0063] The launch and recovery system may be configured for detachable mounting to the structure or vessel.

[0064] The primary vehicle may be tethered to the launch and recovery system. The system may comprise an umbilical connecting the launch and recovery system to the primary vehicle.

[0065] The system may comprise a security cable connecting the launch and recovery system and the primary vehicle.

[0066] The launch and recovery system may comprise a least one retraction assembly, such as winch. The at least one retraction assembly may be configured to retract the umbilical and / or the security cable.

[0067] The launch and recovery system may be configured to operate the at least one retraction assembly to maintain a length of the umbilical and the security cable approximately equal to a distance between the launch and recovery system and the primary vehicle.

[0068] The system may comprise a control container, which may be configured to rest on a deck of the structure or vessel. The control container may be configured to send control signals to the primary vehicle and / or the secondary vehicle via the umbilical.

[0069] The secondary vehicle may be a first secondary vehicle, and wherein the system may further comprise a second secondary vehicle.

[0070] The second secondary vehicle may also be configured to move within or below the splash zone. The second secondary vehicle may also be tethered to the primary vehicle. The second secondary vehicle may comprise at least one tool for performing the operation on the body.

[0071] The first secondary vehicle and the second secondary vehicle cooperate to perform at least part of the operation. For example, the first and secondary vehicle may perform an inspection operation by transmitting one or more signal between one another through the body.

[0072] The first secondary vehicle may be configured to perform a first step of the operation, such as an additive manufacture step, and the second secondary vehicle is configured to perform a second, different step of the operation, such as an inspection, preparation or finishing step.

[0073] The present invention also provides a method of performing an operation on a body of a structure or vessel whilst the body is partially submerged in water using the system described above, the method comprising: traversing the body above a splash zone by the primary vehicle, the primary vehicle using magnetic or vacuum attachment to secure itself to the body; moving within or below the splash zone by the secondary vehicle, so as to position the secondary vehicle adjacent an operation site on the body that is above, within or below the splash zone; and performing an operation on the body at the operation site using the at least one tool.

[0074] The method may comprise: establishing a controllable environment enclosing the operation site on the body; and controlling the controllable environment by removing at least one fluid from the controllable environment and / or supplying at least one outlet to the controllable environment.

[0075] The method may comprise: supplying, from the primary vehicle to the secondary vehicle, one or more of: control signals, power, a fluid for maintaining an operation environment within the controllable environment, and feed material for performing the operation.

[0076] The operation may comprise a repair operation including an additive manufacture step. The method may comprise controlling the operation from a remote location, for example via satellite communication.

[0077] The method may comprise deploying the primary vehicle and the secondary vehicle. The primary vehicle may be deployed whilst the secondary vehicle is carried by the primary vehicle. The primary vehicle may be deployed from a vessel or structure that is different from the structure or vessel comprising the body on which the operation is performed.

[0078] In further aspects, the present invention also provides a primary vehicle of the system described above, and / or a secondary vehicle of the system described above.

[0079] Thus, the preset invention provides a primary vehicle of a system for performing an operation on a body of a structure or vessel whilst the body is partially submerged in water, the primary being configured to traverse the body above a splash zone, the primary vehicle using magnetic or vacuum attachment to secure itself to the body; and the primary vehicle being configured to be tethered to the secondary vehicle, the primary vehicle being configured to be tethered to a secondary vehicle that will perform the operation.

[0080] The present invention also provides a secondary vehicle of a system for performing an operation on a body of a structure or vessel whilst the body is partially submerged in water, the secondary vehicle being configured to move within or below a splash zone, the secondary vehicle being configured to be tethered to a primary vehicle secured to the body above the splash zone, and the secondary vehicle comprising at least one tool for performing the operation on the body.

[0081] It will be appreciated that the primary vehicle and the secondary vehicle may comprise any one or more of all of the features, respectively, of the primary vehicle or the secondary vehicle described above.

[0082] Certain preferred embodiments will now be described in greater detail, by way of example only, and with reference to the accompanying drawings, in which:

[0083] Figure 1 shows a primary vehicle of a system for performing repairs;

[0084] Figure 2 shows a secondary vehicle of the system for performing repairs; Figure 3 shows details of an operation module of the secondary vehicle; Figures 4a to 4c show a cross-sectional view of the secondary vehicle in operation;

[0085] Figure 5a to 5d shown schematically a repair operation performed by the system; Figure 6 shows photographs taken before and after a first repair operation; Figure 7 shows photographs taken before and after a second repair operation;

[0086] Figure 8 shows photographs taken before and after a third repair operation; and

[0087] Figures 9a to 9d show deployment of the system for performing repairs. Described herein is a system capable of performing operations, such as repairs, on a body 600 of a structure or vessel whilst the body 600 is partially submerged in water.

[0088] The system is particularly capable of performing operations within the splash zone 640, where divers cannot operate. The splash zone 640 of a vessel or structure refers to the region that is alternately in and out of the water during normal conditions, for example because of the influence of tides, winds and waves. The splash zone 640 does not include surfaces that only get wet during exceptional circumstances, such as major storms.

[0089] The system is principally envisaged for application on the hulls of large vessels, such as cargo ships or warships, for example having a length of over 300 meters, such as around 500 meters. For such large vessels, there are a limited number of dry docks available to perform repairs, which means that repair processes can be even more costly than for smaller vessels, and may have a long lead time due to the limited availability of the dry docks.

[0090] The system described herein allows repairs to be performed in-situ and with minimal disruption to the operations of the vessel. This avoids the need to use a dry dock or cofferdam solution. Furthermore, it minimises downtime of the vessel whilst it is being repaired, as the repair process described herein requires minimal preparation time and can be performed without needing the vessel to be moved to a specific location.

[0091] The system may alternatively be applied to other bodies that are at least partially submerged in water, and thus have a splash zone. Examples may include the column of a floating or fixed offshore wind turbine, or a floating or fixed offshore platform, such as used for oil and gas production. Other examples might include partially submerged structures, such as dams or the like.

[0092] Furthermore, the system is not limited to performing operations on substantially flat bodies, such as hulls or walls, but may perform operations on bodies of any shape. Such bodies may include curved or tubular bodies, such as a tower of a wind turbine or legs of an offshore structure. Yet further the system may perform operation on components of the body having a complex shapes, such as rudders, thrusters, propellers, water outlets, valves, sea chests, and bilge keels. Those skilled in the art will appreciate how the geometry of the system may be adapted to the specific geometry required.

[0093] Figures 1 and 2 show a primary vehicle 100 and a secondary vehicle 200, respectively, of the system.

[0094] The secondary vehicle 200 is configured to perform the operation. It is design to be relatively lightweight, with a relatively strong means for attaching itself to the body 600 of the vessel or structure, such that it can operate on the body 600 within the splash zone 640. Within this zone, the secondary vehicle 200 will be subject to high forces from the water.

[0095] The primary vehicle 100 is configured to secure itself to the body 600 of the vessel or structure above the splash zone 640. Thus, the primary vehicle 100 will be subject to much lower forces than the secondary vehicle 200. The primary vehicle 100 carries supplies and equipment required for the secondary vehicle 200 to perform the operation. However, by carrying these on the primary vehicle 100, they do not need to be carried into the splash zone 640 by the secondary vehicle 200, thereby allowing the overall system to be smaller.

[0096] The primary vehicle 100 can also act as an anchor for the secondary vehicle 200, in the event that it is dislodged from the vessel or structure by the high forces within the splash zone 640.

[0097] In the illustrated example, which is intended for application to large ships, the primary vehicle 100 has a mass of approximately 1.5 tonnes, whilst the secondary vehicle 200 has a mass of between 250 and 750 kilograms, depending on its specific loadout. However, it will be appreciated that the design may be scaled for smaller applications.

[0098] The primary vehicle 100 is connected to a primary vehicle umbilical 310 and a primary vehicle safety cable 320. The primary vehicle umbilical 310 and the primary vehicle safety cable 320 connect (tether) the primary vehicle 100 to a launch and recovery system 500.

[0099] A length of the primary vehicle umbilical 310 and the primary vehicle safety cable 320 is selected based on the desired application. However, in the case of a large ship, such as described above, the length may be up to 500 meters. The primary vehicle umbilical 310, in the illustrated embodiment, acts to carry control signals and power to the primary vehicle 100. However, in other embodiments (not shown), the primary vehicle 100 may be controlled by wireless communication, for example via a wireless receiver, and / or the primary vehicle 100 may comprise a local power source. Thus, the primary vehicle umbilical 310 may not be required in some embodiments.

[0100] The primary vehicle safety cable 320 has a tensile capacity sufficient to carry the weight of both the primary vehicle 100 and the secondary vehicle 200. Thus, in the event that the primary vehicle 100 becomes dislodged from the body 600, the primary vehicle safety cable 320 will allow the primary vehicle 100 (and the secondary vehicle 200) to be recovered.

[0101] The primary vehicle 100 and the secondary vehicle 200 are connected (tethered) by a secondary vehicle umbilical 410 and by a secondary vehicle safety cable 420.

[0102] A length of the secondary vehicle umbilical 410 and the secondary vehicle safety cable 420 is again selected based on the desired application. However, in the case of a large ship, such as described above, the length may be up to 30 meters.

[0103] The secondary vehicle umbilical 410, in the illustrated embodiment, acts to carry control signals, power, fluid for maintaining an operation environment, and feed material for performing the operation from the primary vehicle 100 to the secondary vehicle 200.

[0104] The secondary vehicle umbilical 410 further acts to carry waste products from the secondary vehicle 100 to the primary vehicle 200.

[0105] The secondary vehicle safety cable 420 has a tensile capacity sufficient to prevent the primary vehicle 100 and the secondary vehicle 200 becoming separated when the secondary vehicle 200 is detached from the body 600. Thus, in the event that the secondary vehicle 200 becomes dislodged from the body 600 by the high dynamic forces within the splash zone 640, the secondary vehicle safety cable 420 will allow the secondary vehicle 200 to be recovered to the primary vehicle 100.

[0106] With reference to Figure 1, the primary vehicle 100 will now be described. The primary vehicle 100 comprises a frame carrying the following components. The frame of the primary vehicle 100 defines a bay 110 configured to receive the secondary vehicle 200, such that the secondary vehicle 200 can be carried by the primary vehicle 100. The bay 110 may comprise one or more electromechanical fasteners for releasably securing the secondary vehicle 200, such that the secondary vehicle 200 can be released from the bay 110 remotely.

[0107] The primary vehicle 100 comprises a pair of continuous magnetic belts 110a, 110b for securing the primary vehicle 100 to the body 600. The magnet belts are permanent magnetic and are sufficiently strong to carry the weight of the primary vehicle 100 and the secondary vehicle 200, and optionally to resist the load of the secondary vehicle 200 dropping, in the event it is dislodged from the body 600.

[0108] In other embodiments, the primary vehicle 100 may use electromagnets or may use vacuum attachments. Furthermore, instead of a belt, the primary vehicle 100 may use other crawler designs, such as movable grippers, to walk across the body 600.

[0109] The primary vehicle 100 comprises an umbilical termination head 130 connected to the primary vehicle umbilical 310. The umbilical termination head 130 is also in communication with the secondary vehicle umbilical 410

[0110] The umbilical termination head 130 includes a control module that is configured to send control signals to the secondary vehicle 200, for example by relaying control signals received from the primary vehicle umbilical 310 and / or received wirelessly to the secondary vehicle umbilical 410.

[0111] The umbilical termination head 130 further comprises a transformer, which is configured to receive power from the primary vehicle umbilical 310 at a first voltage, to transform the received power to a second, lower voltage, and to supply the transformed power to the secondary vehicle umbilical 410.

[0112] This arrangement is important because the secondary vehicle 200 may require low voltage, high current power to perform the operation on the body 600, for example where the operation comprises directed energy deposition additive manufacturing (or other similar operations, such as welding). Such low voltage power cannot be transmitted long distance, such as hundreds of meters between a deck of the vessel or structure and the primary vehicle 100 or the secondary vehicle 200. However, it may be transmitted shorter distances such as tens of meters between the primary vehicle 100 and the secondary vehicle 200. The transformer for such operations is typically large and heavy, and so by positioning it on the primary vehicle 100, significantly less weight needs to be carried into the splash zone 640.

[0113] The primary vehicle 100 further comprises a repository 140. The repository 140 is connected to the secondary vehicle umbilical 410, and is configured to store and supply one or both of fluid for maintaining an operation environment, and feed material for performing the operation.

[0114] The repository 140 may comprise a pressure container for storing gas, which may be filled with a compressed or liquified gas for maintaining the operation environment. The gas might be air, such as dry air, or an inert gas, such as nitrogen. Where the operation is a directed energy deposition or welding operation, the gas may be a metal-inert gas, such as argon or helium.

[0115] The repository may comprise a supply of feed material for the operation, such as a reel of feed metal, for example for use in a directed energy deposition operation or a welding operation. Other materials for the operation might include one or more of: flux, a coating material, a paint, a lubricant, a coolant, an abrasive, and peening shot.

[0116] The repository 140 may further comprise a waste container, which may be configured to receive one or more waste products from the secondary vehicle 200. Exemplary waste products may comprise fumes generated from the operation, or solid debris, such as grit, slag, or material removed from the body 600 during a milling, grinding or polishing operation.

[0117] By collecting the waste products on the primary vehicle 100, the system can carry them back up to the surface to be disposed of appropriately.

[0118] Optionally, the waste products may be filtered from another fluid at the primary vehicle 100, which may be discharged. For example, solid waste products may be filtered from water that can be discharged into the sea, or gaseous and / or particulate waste products may be filtered from a gas that can be discharged into the atmosphere, such as air or nitrogen.

[0119] The primary vehicle 100 comprises a winch 150 connected to the secondary vehicle safety cable 420. The primary vehicle can use the winch 150 to recover the secondary vehicle 200 by retracting the secondary vehicle safety cable 420.

[0120] The primary vehicle 100 comprises an umbilical reel 160 for storing an excess length of the secondary vehicle umbilical 410. The primary vehicle 100 is configured to control the winch 150 and the umbilical reel 160 so as to extend and retract the secondary vehicle umbilical 410 and the secondary vehicle security cable 420 so as to maintain their respective length approximately equal to a distance between the primary vehicle 100 and the secondary vehicle 200.

[0121] This may be achieved by active control. Alternatively, the winch 150 and / or the umbilical reel 160 may be biased towards a wound position, such that the umbilical or safety cable is released by the application of tension, and wound back as that tension is released.

[0122] The primary vehicle 100 may comprise a cleaning tool, such as a brush, configured to remove marine growth from the body 600 in the path of the primary vehicle 100. This ensures that the primary vehicle 100 can achieve a strong attachment to the body 600.

[0123] Further exemplary cleaning tools that may be provided on the primary vehicle 100 include a hydro-blast cleaning tool or a cavitation rotor cleaning tool.

[0124] A hydro-blast cleaning tool comprises a spraybar or manifold configured with a plurality of high-pressure liquid nozzles (e.g. between 100 and 690 bar). To remove marine fouling, such as algae, barnacles, and other organisms from surfaces like hulls and underwater parts, typical pressures range from 200 to 300 bar (20-30 MPa), but in some cases, pressures as high as 400 bar (40 MPa) are used for more intensive cleaning. A typical flow rate would range from 15 to 60 L / min for standard applications, with about 20-40 L / min providing a good balance between cleaning efficiency and pressure needs.

[0125] A cavitation rotor cleaner is an underwater cleaning tool that uses high-pressure waterjets to create and collapse microscopic vapor bubbles, generating shockwaves that remove marine growth, fouling, and corrosion from surfaces.

[0126] These tools feature a rotating nozzle inside a dome, which pulls towards the surface to be cleaned and covers a wide area for fast, efficient cleaning with minimal surface impact.

[0127] With reference to Figure 2, the secondary vehicle 200 will now be described. The secondary vehicle 200 comprises a frame carrying the following components.

[0128] The secondary vehicle 200 comprises a pair of continuous magnetic belts 110a, 110b for securing the secondary vehicle 100 to the body 600. The magnetic belts are permanently magnetic and are sufficiently strong to carry the weight of the secondary vehicle 200 within the splash zone 640. In other embodiments, the secondary vehicle 200 may use electromagnets or may use vacuum attachments. Furthermore, instead of a belt, the secondary vehicle 200 may use other crawler designs, such as movable grippers to walk across the body 600.

[0129] Optionally, the secondary vehicle 200 may comprise a further means for securing the secondary vehicle 200 to the body 600 during the operation. For example, the secondary vehicle 200 may comprise fixed electromagnets that, when energised, hold the secondary vehicle 200 tightly against the body 600. This can both help establish a controllable environment, and also prevent the secondary vehicle 200 from becoming disengaged during the operation.

[0130] The secondary vehicle 200 comprises an operation module 220.

[0131] The operation module 220 is configured to establish a controllable environment around an operational site on the body 600 of the vessel or structure, and to perform the operation on the body 600. The operation module 220 is further configured to control the controllable environment to provide a suitable operation environment for the operation.

[0132] The operation module 220 is connected to the secondary vehicle umbilical 410, so as to receive from the primary vehicle 100 the control signals, the power, the fluid for maintaining the operation environment, and the feed material for performing the operation.

[0133] The secondary vehicle 200 may comprise a cleaning tool, such as a brush, configured to remove marine growth from the body 600 in the path of the secondary vehicle 200. This ensures that the secondary vehicle 200 can achieve a strong attachment to the body 600. The cleaning tool may be located outside of the housing 222 of the operation module 220.

[0134] Further exemplary cleaning tools that may be provided on the secondary vehicle 200 include a hydro-blast cleaning tool or a cavitation rotor cleaning tool, as described previously.

[0135] With reference to Figure 3, the operation module 220 of the secondary vehicle 200 will now be described in greater detail.

[0136] The operation module 220 comprises a housing 222. The housing 222 is configured to seal against the body 600 to establish the controllable environment.

[0137] In the case of a large ship, the housing 222 may comprise a substantially planar opening on an inboard side of the operation module 220, which is suitable for abutting against a substantially planar part of the hull of a ship. For different bodies, the opening may have a different shape, such as a curved shape for abutting a tubular body 600.

[0138] The housing 222 may comprise a seal member (not shown), such as a compressible or inflatable seal member, which may extend around part or all the opening, so as to more effectively maintain the controllable environment.

[0139] Alternatively, or additionally, the operation module 220 may be configured to maintain a positive pressure within the controllable environment, relative to an external pressure, so as to resist ingress of ambient fluid into the controllable environment.

[0140] The operation module 220 comprises an inlet 224 for connection to the secondary vehicle umbilical 410.

[0141] The operation module 220 further comprises and outlet 226 for connection to the secondary vehicle umbilical 410

[0142] In the illustrated embodiment, the inlet 224 and the outlet 226 are formed as a pipe-in-pipe arrangement, whereby a tube forming the outlet 226 passes inside a tube forming the inlet 224. However, it will be appreciated that a separate inlet and outlet design may also be used.

[0143] The operation module 220 comprises an operational head 228 comprising at least one operational tool 230.

[0144] The operational head 228 is configured to perform one or more operation on the body 600 of the vessel or structure. In the illustrated embodiment, the operational head 228 is configured to perform a directed energy deposition additive manufacture operation, and the operational tool 230 is a directed energy deposition additive manufacture tool 230. However, the operational tool 230 is not limited to this particular tool, nor is the operational head 228 limited to performing only this operation.

[0145] In some embodiments, not shown, the operational head 228 may comprise a plurality of operational tools, each configured to perform a different operation, or operational stage.

[0146] Exemplary alternative or additional operational tools 230 may comprise: any suitable additive manufacture tool, such as a material jetting additive manufacture tool or a material extrusion additive manufacture tool;

[0147] a welding tool;

[0148] an inspection tool, such as an optical inspection tool, e.g. a visual inspection tool or an infrared inspection tool, a vibration inspection tool, e.g. an ultrasound inspection tool, an electrical inspection tool, a magnetic inspection tool, and a pressure inspection tool;

[0149] a preparing tool, such as a pre-heating tool, a cutting tool, a grinding tool, a milling tool, and a sandblasting tool; and

[0150] a finishing tool, such as a washing tool, a brushing tool, a coating tool, e.g. a spray coating tool or a painting tool, a grinding tool, a polishing tool, a shot peening tool, a chemical or electrochemical finishing tool and a heat-treating tool.

[0151] The operation module 220 comprises a positioning system 232 for positioning the operational head 282, and particularly the operational tool 230, within the housing 222 and relative to the body 600. The illustrated embodiment uses a two-axis positioning system 232, which is capable of independent movement of the operational head 228 in two perpendicular directions, both of which are substantially parallel to the body 600. However, it will be appreciated that other positioning system designs can be used.

[0152] The operational head 228 is further configured to move the operational tool 230 in a third direction, towards and away from the body 600. Thus, the operational tool 230 can be moved in three axial directions relative to the body 600. This permits the three-dimensional deposition of material in layers, thereby facilitating additive manufacture.

[0153] In the illustrated embodiment, the inlet 224 and the outlet 226 are both connected to the controllable environment via the operational head 228. Thus, fluid is supplied to and removed from the controllable environment via the operational head 228, so as to establish the operation environment and maintain the operation environment during the operation. However, it will be appreciated that other designs are possible.

[0154] The operation module 220 further comprises a plurality of sensors (not shown) within the housing 222 for monitoring the controllable environment.

[0155] The sensors may comprise one or more of: a temperature sensor for monitoring a temperature within the controllable environment, a pressure sensor for monitoring a pressure within the controllable environment, a gas sensor for monitoring for the presence and / or monitoring a concentration of one or more predetermined gas.

[0156] The operation module 220 may comprise a camera and / or a light source, such that the operation may be monitored visually by an operator. The secondary vehicle 200 may comprise a pump within or connected to housing 222 for pumping a fluid out of the controllable environment. The pump may be located at or connected to a bottom side (in use) of the housing 222, so as to drain water from the controllable environment.

[0157] Referring now to Figures 4a to 4c, and exemplary operation will be described.

[0158] First, as shown in Figure 4a, the secondary vehicle 200 is positioned at an operational site on the body 600 and the housing 222 of the operation module 220 is brought against the body 600 to establish the controllable environment.

[0159] As can be seen, if this is done within the splash zone 640, then a quantity of water will be captured within the controllable environment. In order to establish a suitable operation environment within the controllable environment for performing the operation, this water is at least partially displaced from the controllable environment. This may be done by one or a combination of injection of pressurised gas into the controllable environment and / or use of a pump to suck the water out of the controllable environment.

[0160] Depending on the operation to be performed, a small quantity of water may be left in the controllable environment as the operation is performed.

[0161] Next, as shown in Figure 4b, after the desired operation environment has been established within the controllable environment, the operational head 228 is controlled to perform the desired operation using the operational tool 230. In the illustrated example, this operation comprises a directed energy deposition additive manufacture operation.

[0162] During the operation, a continuous supply of gas may be supplied to the controllable environment. This may serve as top-up gas to replace any gas escaping through a boundary between the housing 222 and the body 600, so as to maintain a desired pressure within the controllable environment. Additionally, or alternatively, the gas may be supplied to cycle the gas within the controllable environment, for example to prevent accumulation of waste gases or the like.

[0163] Finally, as shown in Figure 4c, the controllable environment may be returned to a neutral condition, whereby the operation module 220 can be released from the body 600.

[0164] This step may include pumping water back into the controllable environment. Optionally, the controllable may be completely or substantially filled with water to displace any waste gases that have accumulated within the operation module 220, such that they are not released to the atmosphere when the operation module 200 is released.

[0165] Where the operation is performed at an operation site that is partially or fully submerged, the operation module 220 may be partially or fully filled with water to a level corresponding to the average water level outside of the operation module 220. Thus, when the operation module 220 is released, there is not a rapid inrush or egress of water, which might damage components within the operation module.

[0166] The system is particularly applicable to additive manufacture operations. Additive manufacture, sometimes known as 3D printing, refers to the manufacture of three-dimensional structures by sequentially depositing layer-upon-layer of material according to a digital, 3D model. ISO / ASTM52900-15 defines seven categories of additive manufacture processes within its meaning: binder jetting, directed energy deposition, material extrusion, material jetting, powder bed fusion, sheet lamination and vat photopolymerization.

[0167] The exemplary embodiments utilise directed energy deposition additive manufacture. However, it is envisaged that material extrusion additive manufacture and material jetting additive manufacture might also be employed.

[0168] With reference to Figures 5a to 5d, an exemplary operation will be discussed.

[0169] A pin hole fault 610 in a body 600 is illustrated in Figure 5a. Upon detection and location of a pin hole in the body 600 the system will be deployed to establish a sealed chamber around the pin hole. This sealed chamber will provide a controllable environment to permit stable control of the operation environment.

[0170] Once the operation environment is established within the controllable environment, the first stage is to remove any coatings on the body 600 and perform a thorough inspection of the fault 610 to establish what repair is required. The repair operation is then planned.

[0171] Next, the planned repair is executed.

[0172] First, the pin hole 610 is machined to a larger cone 620 as illustrated in Figure 5b. This permits the operational tool 230 to access the full depth of the fault 610.

[0173] Once the pin hole 610 has been machined to a larger cone 620, it is then repaired using additive manufacture. For example, as shown in Figure 5c, the conical hole 620 may be filled by a directed energy deposition additive manufacture process. Whilst not shown, the directed energy deposition repair may optionally be polished and / or coated as appropriate.

[0174] Optionally, as shown in Figure 5d, a background locking plate 630 may be installed (screwed, riveted or welded) on the opposite side of the body 600. This background plate 630 may frame and limit the extension of the additive manufacture operation.

[0175] Whilst the illustrated example shows an additive manufacture operation that restores a substantially flat surface of the body 600, the techniques disclosed herein may also be used for more complex additive manufacture operations. For example, three dimensional structures may be formed, either that extend into the body 600 or protrude from the body 600.

[0176] Figures 6 to 8, illustrate before and after images of exemplary operations conducted using the described system.

[0177] Figure 6 shows a hairline crack fault. The hairline crack fault was first expanded, as shown in Figure 5b, and was then repaired by directed energy deposition additive manufacture, following the contour of the hairline crack fault.

[0178] Figure 7 shows a larger fault that, where the body was milled to remove the region containing the fault. The milled region was then filled by directed energy deposition additive manufacture by application of material in layers to filly fill the milled region.

[0179] Figure 8 shows a hole fault that has completely penetrated the body 600. One advantage of directed energy deposition additive manufacture is that it can bridge a hole, such as shown, without the need for backing material (such as used in Figure 5d).

[0180] It will be appreciated that the static mode of operation described above is merely one exemplary mode of operation. In some embodiments, the system may be operated in a continuously moving mode of operation. For example, certain operations may be performed without fully isolating the controllable environment, but may instead be performed in a semi-isolated environment, where the housing 222 at least partially shields the operation, or even in an exposed environment. Exemplary such operations may include sandblasting, either underwater or in the splash zone, or painting in the splash zone.

[0181] The operations described above do not need to be performed whilst the vessel is stationary. For example, it will be appreciated that the system may be deployed and / or the operation may be performed whilst the vessel is sailing. The operation may comprise repair of damage to the vessel. In one example, the damage may comprise a torpedo perforation.

[0182] Figures 9a to 9d, illustrate deployment of the system within the context of a large ship.

[0183] As shown in Figure 9a, a launch and recovery system 500 is provided on the deck of the ship. The launch and recovery system 500 is preferably secured to the deck by means of a temporary attachment. Advantageously, a movable launch and recovery system 500 means that the system can be deployed from various locations on the ship (e.g. port and starboard sides of the ship). Additionally, it does not need to be present at all times, and indeed may be sent to a particular ship only when a repair (or other operation) is required. Of course, a permanently installed launch and recovery system 500 could be used.

[0184] The launch and recovery system 500 comprises a control container 510 connected to the primary vehicle umbilical 310. The control container 510 is configured to send power and control signals to the primary vehicle 100, for example via the primary vehicle umbilical 310.

[0185] The control signals may be generated at the launch and recovery system 500, for example by a local operator, or may be received from a remote location. For example, the launch and recovery system 500 may be configured to receive control signals wirelessly (e.g. via satellite) from an operator on shore or another remote location.

[0186] As can be seen, the primary vehicle 100 and the secondary vehicle 200 are launched together, with the secondary vehicle 200 being carried by the primary vehicle 100.

[0187] With reference to Figure 9b, the launch and recovery system 500 initially lower the primary vehicle 100 using the primary vehicle safety cable 320 to allow it to pass any obstacles or uneven portions of the hull of the ship. Once the primary vehicle 100 has passed these obstacles, the magnetic belts engage with the hull of the ship to allow the primary vehicle 100 to carry its own weight.

[0188] As shown in Figure 9c, the primary vehicle 100 can traverse the hull of the ship in both a vertical and horizontal direction, thereby allowing the primary vehicle 100 to move freely along the length of the ship. This allows for operations to be performed at a wide range of locations, even where there are only a limited number of launch sites from the deck of the ship. Turning now to Figure 9d, once the primary vehicle 100 reaches a desired location, it secures itself to the hull of the ship above a splash zone 640, and deploys the secondary vehicle 200. During the operation, the primary vehicle 100 remains above the splash zone 640, such that it is no subject to the high dynamic loading occurring within the splash zone 640.

[0189] The secondary vehicle 200, once deployed, traverses the hull of the ship from the primary vehicle 100 down into the splash zone 640, and optionally (not shown) below the splash zone such that it is fully submerged within the water.

[0190] Once the secondary vehicle 200 reaches the target operation site, it will proceed to perform the desired operation, as described above.

[0191] Once the operation is complete, the secondary vehicle 200 returns to the primary vehicle 100, and the primary vehicle 100 carries the secondary vehicle back to the launch and recovery system 500.

[0192] In other embodiments, the launch and recovery system 500 may be mounted to another vessel or structure that is proximate the vessel or structure on which the operation is to be performed. For example, the launch and recovery system 500 may be mounted on one ship to perform operations on another ship or a partially submerged structure, such as a mateskip or feeder ship, or the launch and recovery system 500 may be mounted on a dock of a harbour to perform operations on a ship at the dock.

[0193] Thus, in such an embodiment, the primary and secondary vehicles 100, 200 may be transferred from the structure or vessel having the launch and recovery system 500 to the vessel or structure on which the operation is to be performed.

[0194] In further embodiments, the primary vehicle 100 may be mounted on one structure or vessel and the secondary vehicle 200 may be mounted on, and perform an operation on, another structure or vessel.

[0195] Whilst certain preferred embodiments have been described, it will be understood that the invention is not limited thereto.

[0196] In some embodiments, a single primary vehicle 100 may be configured to receive a plurality of different secondary vehicles 200 and / or the loadout of the secondary vehicle 200 may be changed. Thus, depending on the specific operation required, the system may be configured for that specific operation by selecting a specific secondary vehicle 200 and / or selecting a specific loadout of the secondary vehicle 200. Optionally, this step may be done after performing inspection of the operation site. In one exemplary embodiment, the primary vehicle 100 may be configured to carry two or more secondary vehicles 200. For example, different secondary vehicles 200 may be deployed for performing different operations, or different stages of a single operation. For example, a first secondary vehicle 200 may perform an inspection operation, whilst a second secondary vehicle 200 may perform a repair operation.

[0197] In another example, use of two secondary vehicles 200 may permit certain types of inspection operation to be performed, for example where a first secondary vehicle 200 generates a signal that is transmitted through the body 600, such as a vibration or electrical signal, and a second secondary vehicle 200, spaced apart from the first secondary vehicle 200 may detect the signal. This type of inspection may allow large regions of the body to be rapidly inspected for particular types of fault.

[0198] In some embodiments, the secondary vehicle 200 may be equipped with thrusters or propellers for movement underwater. Such systems may be useful for positioning the secondary vehicle 200 and holding it against the body 600, when it is used in a fully submerged manner, i.e. below the splash zone 640.

[0199] In some embodiments, the secondary vehicle 200 may be configured to additionally or alternatively carry other types of load.

[0200] For example, the secondary vehicle 200 may be provided with a docking head configured to receive a tertiary vehicle (not shown). The tertiary vehicle may comprise a drone or an unmanned operated underwater vehicle. The tertiary vehicle may be an autonomous or remotely operated vehicle. Thus, the secondary vehicle 200 may act as a carrier vehicle to carry the tertiary vehicle through the splash zone and act as a mobile launchpad to allow the tertiary vehicle to be smoothly deployed and recovered, such as described in WO 2018 / 016970 A1. The tertiary vehicle may be configured to perform inspection or monitoring, for example before, during or after the operation performed by the secondary vehicle 200.

[0201] In another example, the secondary vehicle 200 may be equipped with a person carrying attachment, which may enable it to softly carry a person, such as a wounded seamen, from a deck of the ship to a smaller vessel, such as an ambulance dingy, at water level.

[0202] In another example, the primary vehicle 100 or the secondary vehicle 200 may be equipped with a water-jet tool. Such a tool could be used by coastguards to control a trawler or to keep a pirate at bay. In one example, the secondary vehicle 200 may be deployed below the surface of the water to supply water via the secondary vehicle umbilical 410 to a water-jet tool on the primary vehicle 100. The scope of the invention is defined by the following claims.

Claims

CLAIMS1. A system for performing an operation on a body of a structure or vessel whilst the body is partially submerged in water, the system comprising:a primary vehicle configured to traverse the body above a splash zone, the primary vehicle using magnetic or vacuum attachment to secure itself to the body; anda secondary vehicle configured to move within or below the splash zone, the secondary vehicle being tethered to the primary vehicle, and the secondary vehicle comprising at least one tool for performing the operation on the body.

2. A system according to claim 1, wherein the secondary vehicle is configured to traverse the body within or below the splash zone, the secondary vehicle using magnetic or vacuum attachment to secure itself to the body.

3. A system according to claim 1 or 2, wherein the primary vehicle is configured to carry the secondary vehicle whilst traversing the body above a splash zone.

4. A system according to any preceding claim, wherein the operation comprises one or more of: an inspection operation, a repair operation, and an installation operation.

5. A system according to claim 4, wherein the operation comprises a repair or an installation operation including an additive manufacture step.

6. A system according to claim 5, wherein the operation includes a preparation step before the additive manufacture step and / or a finishing step after the additive manufacture step.

7. A system according to any preceding claim, wherein the secondary vehicle comprises a housing configured to establish a controllable environment against a portion of the body, the housing comprises at least one inlet for supply of fluid into the controllable environment and at least one outlet for removal of fluid from the controllable environment.

8. A system according to any preceding claim, wherein the system comprises an umbilical connecting the primary vehicle and the secondary vehicle, the umbilical being configured to carry one or more of: control signals, power, a fluid for maintaining a controllable environment, and feed material for performing the operation.

9. A system according to claim 8, wherein the primary vehicle comprises a transformer configured to receive power at a first voltage and to supply power at a second, lower voltage to the secondary vehicle via the umbilical, the second voltage being suitable for directed energy deposition additive manufacturing.

10. A system according to claim 8 or 9, wherein the primary vehicle comprises a source of fluid and is configured to supply the fluid to the secondary vehicle via the umbilical for maintaining the controllable environment.

11. A system according to claim 8, 9 or 10, wherein the primary vehicle comprises a source of feed material and is configured to supply the feed material to the secondary vehicle via the umbilical for performing the operation.

12. A system according to any of claims 8 to 11 , further comprising a security cable connecting the primary vehicle and the secondary vehicle, the primary vehicle comprising at least one retraction assembly configured to retract the umbilical and the security cable so as to maintain a length of the umbilical and the security cable approximately equal to a distance between the primary vehicle and the secondary vehicle.

13. A system according to any preceding claim, wherein one or both of the primary vehicle and the secondary vehicle comprises a cleaning tool configured to remove marine growth from the body to clean a trajectory of that vehicle.

14. A system according to any preceding claim, further comprising a launch and recovery system for detachable mounting to the structure or vessel, the primary vehicle being tethered to the launch and recovery system.

15. A system according to any preceding claim, wherein the secondary vehicle is a first secondary vehicle, and wherein the system further comprises a second secondary vehicle configured to move within or below the splash zone, the second secondary vehicle also being tethered to the primary vehicle, and the second secondary vehicle comprising at least one tool for performing the operation on the body.

16. A system according to claim 15, wherein the first secondary vehicle and the second secondary vehicle cooperate to perform at least part of the operation.

17. A system according to claim 15, wherein the first secondary vehicle is configured to perform a first step of the operation, and the second secondary vehicle is configured to perform a second step of the operation.

18. A method of performing an operation on a body of a structure or vessel whilst the body is partially submerged in water using the system of any preceding claim, the method comprising:traversing the body above a splash zone by the primary vehicle, the primary vehicle using magnetic or vacuum attachment to secure itself to the body;moving within or below the splash zone by the secondary vehicle, so as to position the secondary vehicle adjacent an operation site on the body that is above, within or below the splash zone; andperforming an operation on the body at the operation site using the at least one tool.

19. A method according to claim 18, further comprising:establishing a controllable environment enclosing the operation site on the body; andcontrolling the controllable environment by removing at least one fluid from the controllable environment and / or supplying at least one fluid to the controllable environment.

20. A method according to claim 18 or 19, further comprising:supplying, from the primary vehicle to the secondary vehicle, one or more of: control signals, power, a fluid for maintaining an operation environment within the controllable environment, and feed material for performing the operation.

21. A method according to claim 18, 19 or 20, wherein the operation comprises a repair or installation operation including an additive manufacture step.

22. A primary vehicle of a system for performing an operation on a body of a structure or vessel whilst the body is partially submerged in water, the primary being configured to traverse the body above a splash zone, the primary vehicle using magnetic or vacuum attachment to secure itself to the body; and the primary vehicle being configured to be tethered to a secondary vehicle that will perform the operation.

23. A secondary vehicle of a system for performing an operation on a body of a structure or vessel whilst the body is partially submerged in water, the secondary vehicle being configured to move within or below a splash zone, the secondary vehicle being configured to be tethered to a primary vehicle secured to the body above the splash zone, and the secondary vehicle comprising at least one tool for performing the operation on the body.

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