EP4244129A1

EP4244129A1 - Inflatable salvage bag

Info

Publication number: EP4244129A1
Application number: EP21802028.7A
Authority: EP
Inventors: Cato ISENE STOLL; Nikolai MICHELSEN
Original assignee: Miko Marine AS
Current assignee: Miko Marine AS
Priority date: 2020-11-16
Filing date: 2021-10-01
Publication date: 2023-09-20
Also published as: NO20201247A1; WO2022103271A1; US20230415861A1; NO347010B1

Abstract

The present invention concerns an inflatable salvage bag (1), for reducing fluid flow through a hole in the hull structure of a marine vessel or in a storage tank. The inflatable salvage bag (1) includes an inner bag (9), wherein the inner bag (9) is inflatable, a reinforcing bag (10), wherein the reinforcing bag (10) surrounds the inner bag (9) and is configured to be tear and puncture resistant and an outer bag (2), wherein the outer bag (2) surrounds the reinforcing bag (10). The inflatable salvage bag (1) further includes a valve (5), configured to connect the inner bag (9) with an external source of pressurized gas, in order to inflate the inflatable salvage bag (1).

Description

Inflatable salvage bag

Technical Field

[0001] The present invention is concerned with means for reducing fluid flow through a hole in a hull structure of a marine vessel or in a storage tank. Specifically, the invention is concerned with a novel salvage bag, a portable salvage system and a method of using the portable salvage system.

Background

[0002] Holes in a hull structure of a marine vessel or in a storage tank may occur due to collisions, due to constructional failures, due to impact from a projectile or an explosion or simply due to material fatigue. A marine vessel, such as a ship or a floating structure, may, for instance, collide with another vessel, with a fixed structure or with nearshore rocks. In each case, a hole below or at the waterline may occur, allowing water to flow freely into the marine vessel, thereby threatening the floating capability of the vessel.

A storage tank for fluid or granular materials, such as a tank on a transport vehicle or a land-based tank, may similarly experience damage resulting in a hole in a wall of the storage tank. The fluid or granular contents of the storage tank may, consequently, freely flow out of the tank and into the outside environment, causing loss of the stored material and possibly, environmental damage or personal injuries.

[0003] Emergency salvaging equipment for reducing flow through a hole in a marine vessel or in a storage tank is known in the art. The purpose of such emergency salvaging equipment is to reduce or stop the inflow of water into a marine vessel or the outflow of fluid or granular material from a damaged storage tank. Such emergency salvaging equipment usually comprises a set of wood- or polymer-based plugs of different sizes, together with a hammering implement, such as a brass hammer. In use, an operator or a damage control crew selects a plug with an appropriate diameter and hammers the plug into the hole. The plug, if inserted properly, may stop, or partially stop, the flow through the hole. In marine environments, reducing the flow through the hole by 70% is considered a successful result.

[0004] A disadvantage of the known wood- or polymer-based plugs is that a large set with different plug diameters is required, in order to handle holes of different sizes. Such a large set of plugs is both heavy and voluminous, having a negative impact on handling and on storage requirements. Especially during, for instance, a post-collision emergency, cumbersome handling may critically slow down the emergency salvaging operation. Another disadvantage is that significant force is required to hammer the wood- or polymer-based plug into the hole. Such force is required as the hole is likely to have an irregular geometry, not matching that of the plug. Furthermore, force is required to insert the plug against the fluid or granular material pressure acting opposite to the direction of insertion of the plug. Especially for larger holes this may mean that several persons are required to perform the emergency salvaging operation, in order to hold the plug in-place and when hammering. A further disadvantage is that, due to a likely irregular geometry of the hole, the wood- or polymer-based plug may never be completely form-fittingly inserted into the hole.

Consequently, the hole is not satisfactorily closed-off and the flow through the hole may not be reduced sufficiently.

[0005] Consequently, there is a clear need for an improved emergency salvaging means, which is portable, having a small weight and volume, which allows for improved handling, also in an emergency situation and when handled by a single operator, and which has an improved ability to reliably reduce the flow through holes of different sizes and geometries in a hull structure of a damaged marine vessel or in a storage tank.

Summary of the invention

[0006] The present invention concerns an inflatable salvage bag according to claim 1 . The present invention also concerns a portable salvage system according to claim 13. Finally, the present invention also concerns the use of a salvage system according to claim 16 and a method for producing an inflatable salvage bag according to claim 17. The inflatable salvage bag, the portable salvage system and use of the portable salvage system according to the present invention are applicable to marine vessels and to storage tanks. Advantageously, the inflatable salvage bag and portable salvage system of the present invention are easy to handle, require less force to apply than conventional systems and provide improved capacity for reducing fluid flow through a hole in a hull structure. A further advantage is that the speed of deployment of the portable salvage system of the present invention is significantly increased as compared conventional systems.

Figures

[0007] Figure 1A schematically shows a salvage bag according to the invention in a deflated state.

[0008] Figure 1 B schematically shows a salvage bag according to the invention in an inflated state.

[0009] Figure 2A schematically shows a longitudinal cross-section of a salvage bag according to the invention in a partially inflated state.

[0010] Figure 2B schematically shows a more detailed cross-section of a valve of an inflatable salvage bag according to the invention.

[0011] Figure 3 schematically shows a portable salvaging system.

Detailed description

[0012] Figure 1A schematically shows an inflatable salvage bag 1 according to the invention, where the inflatable salvage bag 1 is in a deflated state. As described in further detail below, the inflatable salvage bag 1 , in deflated or partially inflated state, can be inserted into a hole in a hull structure of a marine vessel or in a storage tank. The storage tank may be a movable storage tank, such as a storage tank mounted on a lorry, a railway carriage, in an airplane or on a vessel. Alternatively, the storage tank may comprise a fixed structure, such as a land-based fuel tank, a silo, or an industrial tank. Following insertion, the inflatable salvage bag 1 can be fully inflated, thereby conforming to the perimeter of the hole and securely reducing fluid flow through the hole.

[0013] The outer surface of the inflatable salvage bag 1 is formed by an outer bag 2. In the deflated state, the outer bag 2 may have a generally rectangular shape, with a transversal leading side 3 and a transversal trailing side 4 and two longitudinal sides extending from the transversal trailing side 4 to the transversal leading side 3. Other shapes may also be possible for the outer bag 2 in the deflated state, such as an oval, triangular or multisided shape. The dimension of the inflatable salvage bag 1 along the trailing side 4, may be up to about 150 cm, preferably up to 100 cm, most preferably up to about 50 cm. The dimension of the inflatable salvage bag 1 along the longitudinal sides may range from about 20 - 150 cm, preferably from about 30 - 100 cm. The inflated volume of the inflatable salvage bag 1 is preferably less than about 2000 liters, more preferably less than about 500 liters, most preferably less than about 100 liters. Advantageously, portability of the portable salvage system, detailed below, in which the inflatable salvage bag is included is thereby maintained.

[0014] Protruding from the surface of the outer bag 2 is a valve 5. The valve 5 allows the inflatable salvage bag 1 to be inflated or deflated, as detailed below. One or more friction bands 6, detailed below, may be fixed onto the surface on one or either side of the outer bag 2. An elongated sleeve 7, detailed below, may optionally be fixed onto the surface of the outer bag 2. At the leading side 4, the outer bag 2 may optionally have a tapered shape. The tapered shape may facilitate easier insertion of the inflatable savage bag 1 into a hole in a hull structure, as detailed below. Finally, the outer bag 2 may be provided with an eyelet 8. The eyelet 8 may allow the inflatable salvage bag 1 to be releasably attached to an attachment line or clip, for attaching the inflatable salvage bag 1 to another element or to a fixed structure. The eyelet is preferably a plastic or metal ring, such as a D-ring, which may be attached to the outer bag 2 by means of a fabric attachment loop.

[0015] Figure 1 B schematically shows an inflatable salvage bag 1 in the inflated state, where like reference numbers in figure 1 B denote the same features as in figure 1A. In figure 1 B the inflatable salvage bag 1 has a generally cylindrical shape in the inflated state. The inflatable salvage bag 1 may be configured to be inflated up to a pressure of about 2 bar, preferably about 1 ,5 bar.

[0016] Figure 2A shows a schematic longitudinal cross-section of the inflatable salvage bag 1. Like reference numbers in figure 2A denote the same features as in figures 1 A and 1 B. Moving from inside to outside, the inflatable salvage bag 1 includes an inner bag 9, a reinforcing bag 10 and the outer bag 2. The inner bag 9 is inflatable and is preferably airtight. The inner bag 9 functions as an air chamber, holding a pressurized gas when the inflatable salvage bag 1 is in the inflated state. The inner bag 9 preferably comprises a polymer foil material, where the polymer may be a polyurethane, preferably a transparent polyurethane. Alternatively, the polymer foil material may be any other suitable polymer, such a polyvinylchloride or polyethylene. The polymer foil material achieves a high tear strength, allowing the inflatable salvage bag 1 to be inflated up to a required pressure, preferably up to at least 2 bar. The polymer foil material may be glued, sewn, or welded to form the inner bag 9. The valve 5 is configured to fluidly connect the inner bag 9 with a source of pressurized gas or with the outside environment, as detailed below.

[0017] Surrounding the inner bag 9 is the reinforcing bag 10, as shown in figure 2A. The reinforcing bag 10 protects the inner bag 9 from damage due to impact from external objects, such as the sharp edges of a hole in a hull structure. Thereby, possible piercing, rupturing or tearing of the inner bag 9 during handling or inflation of the inflatable salvage bag 1 may securely be prevented. Preferably, the reinforcing bag 10 comprises a double-walled or triple-walled tear and puncture resistant material, such as Kevlar. The reinforcing bag 10 is preferably sewn around the inner bag 9. The reinforcing bag 10 is configured to allow inflation of the inner bag 9. As shown in figure 2A, the reinforcing bag 10 is provided with an aperture, accommodating the valve 5.

[0018] With further reference to figures 2A and with reference to figure 2B, where like references denote the same features as in figures 1 A - 2A, the reinforcing bag 10 is surrounded by the outer bag 2. The outer bag 2 preferably comprises an inner backing 11 covered with an outer coating 12. This configuration of the outer bag 2 achieves a high resistance against damage from external objects, such as the sharp edges of a hole in a hull structure. The inner backing 11 forms the inner surface of the outer bag 2 and may comprise a polymer material in the form of a foil, a woven fabric, or a non-woven fabric, of, for instance a polyester material or any other suitable polymer material. The outer coating 12 forms the outer surface of the outer bag 2 and may comprise a polyurethane or a thermoplastic polyurethane material. Alternatively, the outer coating 12 may comprise any other suitable polymer material. The outer coating 12 is preferably adhered to the inner backing 11 . The outer bag 2 is preferably sewn around the reinforcing bag 10. The outer bag 2 is configured to allow inflation of the inner bag 9 together with the reinforcing bag 10. As shown in figures 2A and 2B, the outer bag 2 is provided with an aperture, accommodating the valve 5. The outer bag 2 may be waterproof.

[0019] Referring to figures 1A and 1 B, one or more friction bands 6 may optionally be fixed onto the outer bag 2. The one or more friction bands 6 are configured to enhance the friction between the inflatable salvage bag 1 and a hole in which the inflatable salvage bag 1 is inserted. Thereby the one or more friction bands 6 prevent the inflatable salvage bag from accidentally slipping out of the hole during inflating and afterwards. Preferably, two friction bands 6 are present on at least one surface of the outer bag 2. The two friction bands 6 are preferably arranged in a cross shape, or an X shape, as shown in figures 1A and 1 B. Such an X shape maximizes the chance that at least one of the friction bands 6 remains into contact with the perimeter of the hole, while simultaneously minimizing the amount of friction band material required. Furthermore, the X shape may serve as a visual guide for an operator, when inserting the inflatable salvage bag 1 into a hole in a hull structure. The midpoint of the X shape preferably coincides with the lengthwise middle of the outer bag 2. When a tapered shape is present at the leading side 4, the midpoint of the X shape preferably coincides with the midpoint of the main portion of the outer bag 2, excluding the tapered shape. Consequently, an operator can securely insert the inflatable salvage bag 1 such that the lengthwise middle of the inflatable salvage bag 1 is placed within the perimeter of a hole in a hull structure. The one or more friction bands comprise a friction enhancing material, for example a polyester, a non-slip rubber, a silicone gel, or a urethane foam. The one or more friction bands 6 may be fixed to the outer bag 2 by gluing, sewing, or welding.

[0020] Referring to figures 1 A and 1 B, an elongated sleeve 7 may optionally be fixed onto the outer bag 2. A stiffening element, not shown, may be inserted into the elongated sleeve 7, to temporarily provide rigidity to the inflatable salvage bag 1 when the latter is in a deflated state. Thereby the ease of insertion of the inflatable salvage bag 1 into the hole is improved. The elongated sleeve 7 is preferably closed towards the leading side 4 and open towards the trailing side 3. Consequently, a stiffening element may be inserted in the elongated sleeve from the trailing side towards the leading side. The elongated sleeve 7 may be fixed to the outer bag 2 by gluing, sewing, or welding. Preferably, the sleeve 7 extends parallel to one of the longitudinal sides of the outer bag 2.

[0021] The valve 5 is schematically shown in a cross-section in figure 2B and is configured to allow inflating and deflating of the inflatable salvage bag 1 . The valve 5 includes a coupling 13 comprising an outlet nozzle, configured to be connected in a gas tight manner to a source of pressurized gas. The valve 5 further includes an inner passage 14, configured to allow gas to flow from a pressurized gas source into the inner bag 9, in order to inflate the inflatable salvage bag1 , or from the inner bag 9 to the outer environment, in order to deflate the inflatable salvage bag 1 . A valve element, not shown, located in the inner passage 14 blocks pressurized gas from inadvertently escaping from the inner bag 9. The valve 5 also includes a first release lever 15, preferably positioned on the coupling 13. The first release lever 15 is configured to open the outlet nozzle to the outside environment and thereby release pressurized gas contained within the inflatable inner bag 9. The first release lever 15 can be operated manually, to thereby deflate or partially deflate the inflatable salvage bag 1 . The valve 5 is preferably placed near the trailing side 3 of the outer bag 2. Consequently, the valve 5 and thereby the first release lever 15, remains accessible to an operator, even when the inflatable salvage bag 1 has been inserted in a hole in a hull structure, as explained further below.

[0022] The inflatable salvage bag 1 may optionally be provided with a light source, not shown, such as a battery-operated light or a chemiluminescence-based glowstick. The light source may releasably be attached to the eyelet 8. By activating the light source, the inflatable salvage bag 1 can securely be used in a dark environment.

[0023] A method for producing an inflatable salvage bag 1 includes providing an inner bag 9, arranging a reinforcing bag 10 around the inner bag 9 and arranging an outer bag 2 around the reinforcing bag 10 to provide an initial bag and attaching a valve 5 to the initial bag. Arranging the reinforcing bag 10 around the inner bag 9 may include gluing, sewing, or welding the reinforcing bag 10 around the inner bag 9. Arranging the outer bag 2 around the reinforcing bag 10 may include gluing, sewing, or welding the outer bag 2 around the reinforcing bag 10. In each case, welding may include ultrasonic welding or heat welding. Attaching the valve 5 includes fitting the valve 5 through dedicated apertures in the inner bag 9, the reinforcing bag 10 and the outer bag 2 and attaching the valve 5 thereto.

[0024] A portable salvage system 16 is schematically shown in figure 3, where like references refer to the same features as in figures 1 A - 2B. The portable salvaging system 16 includes one or more inflatable salvage bags 1 , a flexible tube 18 and a pressurized gas source 19. The portable salvage system may further include a holding plate 17. The portable salvage system may also include at least one attachment line 20. Finally, the portable salvage system 16 preferably includes a carrying bag, not shown, for storage and transportation of the portable salvage system 16. The carrying bag may preferably be in the form of a backpack or a pack with carrying hinges. Thereby, the carrying bag improves the portability of the portable salvage system 16, allowing an operator to easily carry the portable salvage system 16 to and from the emergency salvaging site. Both the volume and weight of the portable salvage system 16 are much reduced, as compared to conventional wooden- or polymer-plug based systems. Thereby handling, transport and speed of deployment are improved, which is beneficial during an emergency salvaging operation, where time is a critical factor. The carrying bag may optionally be provided with one or more magnets, not shown, fixed onto the outside of the carrying bag.

Preferably, one magnet is placed in each corner of the carrying bag. The one or more magnets allow the carrying bag to be releasably attached to any metal element in its environment. Thereby the carrying bag can temporarily be stored at an easy-accessible spot during an emergency salvaging operation or suspended to dry after use.

[0025] The portable salvage system 16 includes one or more inflatable salvage bags 1 , preferably two to ten inflatable salvage bags 1 . For the sake of legibility only one inflatable salvage bag 1 is shown in figure 3. The one or more inflatable salvage bags 1 included in the portable salvage system 16 may each have different dimensions. Alternatively, some, or even all of the inflatable salvage bags 1 may have the same dimensions. Including one or more inflatable salvage bags 1 of different dimensions provides greater flexibility for reducing fluid flow through holes of different diameters and shapes.

[0026] The portable salvage system may include a holding plate 17, serving as an organizing and handling element, from which each of the one or more inflatable salvage bags 1 may be suspended. Thereto, the portable salvage system 16 preferably includes one or more attachment lines 20. Each attachment line 20 may be provided with a quick-release clip at both ends thereof. Thereby, an inflatable salvage bag 1 may be quickly attached to, or released from, the holding plate 17. A quick release and attachment improve handling, for instance, when choosing the right inflatable salvage bag 1 during an emergency salvaging operation or when moving around the one or more inflatable salvage bags 1 at the emergency salvaging site.

The holding plate 17 includes one or more apertures 25 for attaching of one or more inflatable salvage bags 1 by means of attachment lines 20. The holding pate 17 also includes a central aperture 26, allowing an operator to grab the holding plate 17. The holding plate 17 further includes one or more apertures 27 for suspending the holding plate 17 from a fixed point. Such a suspension of the holding plate 17 may, for instance, be desirable when an operator needs to work hands-free during an emergency salvaging operation. The holding plate 17 preferably comprises a lightweight material of sufficient strength, such as a lightweight metal material or a reinforced polymer composite material.

[0027] The portable salvage system 16 includes a pressurized gas source 19, such as a tank, a cylinder or a cannister, preferably a lightweight composite cylinder. The pressurized gas source 19 may have a volume of up to about 12 liters, preferably about 1 - 5 liters, most preferably about 3 liters. The gas comprised in the pressurized gas source 19 is preferably air or a mixture including air. When filled, the pressurized gas source 19 may comprise a pressurized gas with a pressure of about 100 - 300 bar, preferably about 200 - 300 bar, most preferably about 300 bar. The pressurized gas source 19 may, for example, have a volume of 3 liters and comprise pressurized air at 300 bars, equating to about 900 liters of air. The pressurized gas source 19 may be provided with carrying straps. Alternatively, the pressurized gas source 19 may be releasably held in the carrying bag, which may be a backpack. Advantageously, the pressurized gas source 19 can easily be carried on the back of an operator, thereby allowing the operator freedom of movement during an emergency salvaging operation.

[0028] The pressurized gas source 19 includes a valve 22, releasably attached to the pressurized gas source 19 and schematically shown in figure 3. The valve 22 is configured to allow filling and emptying of the pressurized gas source 19. The valve 22 includes a coupling comprising an outlet nozzle. An inner passage with a valve element, not shown, within the valve 22, allows gas to flow into or out from the pressurized gas source 19, when the valve 22 is opened. The valve 22 is manually operable, preferably including a lever for opening and closing, not shown. The valve 22 further includes an overpressure valve 24, configured to automatically release pressurized gas to the environment when a threshold pressure is reached in the inflatable salvage bag 1 , when the pressurized gas source 19 is connected to an inflatable salvage bag 1. Preferably, the threshold pressure for activating the overpressure valve 24 is about 2 bar or above. During operation, the overpressure valve 24 prevents an overfilling of the inflatable salvage bag 1 to which the pressurized gas source 19 is connected.

[0029] The flexible tube 18 includes first and second connection pieces 21 A and 21 B, fixed at the opposite ends thereof. The first connection piece 21 A is configured to form a releasable gas tight connection with the coupling 13 of the valve 5 on the inflatable salvage bag 1. The second connection piece 21 B is configured to form a releasable gas tight connection with the coupling of the valve 22 of the pressurized gas source 19. The flexible tube 18 thereby allows the pressurized gas source 19 to be connected to an inflatable salvage bag 1 . When not in use, the flexible tube 18 may remain connected to the valve 22 of the pressurized gas source 19 by means of the second connection piece 21 B, with the first connection piece 21 A of the flexible tube 18 remaining unconnected. The second connection piece 21 B includes a second release lever 23, configured to open the inner passage of the flexible tube 18 to the outside environment. When the pressurized gas source 19 is connected to an inflatable salvage bag 1 , the second release lever 23 can be operated to release pressurized gas from the inflatable salvage bag 1. Advantageously, the second release lever 23 may be activated by an operator positioned close to, or carrying, the pressurized gas source 19. Advantageously, the first release lever 15 may be operated by another or the same operator, positioned close by the hole in a hull structure, in which the inflatable salvage bag 1 is inserted. [0030] The portable salvage system 16 may further include a stiffening element. The stiffening element may comprise multiple sections and may preferably be collapsible, for ease of transportation and handling. At least one section is configured to be inserted into the elongated sleeve 7. The multiple sections may comprise telescoping tube-elements. The telescoping tube elements can manually be retracted or extended in a telescoping manner. The telescoping tube elements may comprise a locking mechanism, to prevent accidental collapse of the tube during use. The tube-element with the smallest diameter is configured to be inserted in the elongated sleeve 7. Alternatively, the multiple sections may be hinged sections, which can be unfolded to extend the stiffening element. The hinges may comprise a locking mechanism, to prevent accidental collapse of the stiffening element during use. Yet alternatively, the multiple sections may be connectable by screw connections, snap connections, or shock-cord connections. Advantageously, by utilizing a stiffening element, an operator may insert an inflatable salvage bag into a hole in a hull structure from a safe distance, thereby remaining out of reach from the flow through the hole. This is especially advantageous when the flow comprises a hazardous material.

[0031] Use of a portable salvage system 16 is detailed below. An inflatable salvage bag 1 is selected from the one or more inflatable salvage bags 1 in the portable salvage system 16. Preferably the selected inflatable salvage bag 1 matches or approximately matches the size of the hole in a hull structure.

[0032] Next, the inflatable salvage bag 1 is inserted into the hole. During insertion, the leading side 3 of the inflatable salvage bag 1 is passed through the hole. The inflatable salvage bag 1 is preferably in the deflated state during insertion. Preferably, a part of the stiffening element is inserted into the elongated sleeve 7, before the inflatable salvage bag 1 is inserted into the hole in a hull structure. Thereby the insertion of the inflatable salvage bag 1 against the pressure of fluid flowing through the hole is improved. Preferably, two friction bands 6 arranged in an X shape serve as a visual guide to align the lengthwise middle of the inflatable salvage bag 1 with the perimeter of the hole during insertion. Before or after insertion of the inflatable salvage bag 1 , the valve 5 is connected to the first connection piece 21 A of the flexible tube 18 and the valve 22 is or remains connected to the second connection piece 21 B of the flexible tube 18.

[0033] Next, the inflatable salvage bag 1 is inflated, by letting gas flow from the pressurized gas source 19 into the inflatable salvage bag 1. The inflatable salvage bag 1 expands, preferably within a few seconds. During inflation, the outer surface of the inflatable salvage bag 1 expands, restrained by the perimeter of the hole in a hull structure. Therefore, the inflatable salvage bag 1 forms a secure fit with the perimeter of the hole in a hull structure. The parts of the inflatable salvage bag 1 protruding from either side of the hole preferably expand to a larger diameter than the part restrained by the perimeter of the hole. Thereby a secure placement of the inflatable salvage bag 1 is achieved. The securely placed and expanded inflatable salvage bag 1 reduces the fluid flow through the hole in a hull structure. Preferably the inflatable salvage bag 1 reduces at least 90% of the fluid flow through the hole, more preferably at least 95% of the fluid flow. Thereby the inflatable salvage bag 1 achieves an improved reducing of fluid flow through a hole in a hull structure of a marine vessel or a moveable storage tank. As the expansion is driven by pressurized gas, no operator force is required other than the force needed to hold the inflatable salvage bag 1 in place during expansion. Thereby a much-improved handling is achieved. Advantageously, the speed of deployment of the portable salvage system according to the invention is much improved over conventional systems. The application of wooden plugs may, for instance, take minutes, as opposed to the few seconds needed for expanding the inflatable salvage bag of the invention. This is an important advantage during emergency salvaging operations when time is a critical factor.

[0034] Gas can be released from the inflatable salvage bag 1 in the inflated state, by activating the first release lever 15 or the second release lever 23. Either of the release levers 15, 23 may be activated in order to prevent overfilling of the inflatable salvage bag, or to partially or fully deflate an inflatable salvage bag 1. Advantageously, deflating can thereby be performed by an operator positioned close to the inflatable salvage bag 1 inserted in the hole in a hull structure or by an operator carrying the pressurized gas source 19, possibly at a distance from the hole. Overfilling of the inflatable salvage bag 1 is further prevented by over pressure valve 24. Thereby, possible failure of the inflatable salvage bag 1 due to overfilling may securely be prevented. During or after expansion, the stiffening element may be removed from the elongated sleeve 7. Alternatively, a section of the stiffening element may be left in place in the elongated sleeve 7.

[0035] Once the inflatable salvage bag 1 is securely expanded in place, the flexible tube 18 can be disconnected from the expanded inflatable salvage bag 1 . Should the hole have an elongated or irregular shape, it may be necessary to apply two or more inflatable salvage bags 1 to the hole, in order to reliably reduce the flow therethrough. Finally, in an emergency salvaging operation with little or no ambient light, the optional light source on the inflatable salvage bag 1 may have to be activated by an operator.

[0036] After use, the inflatable salvage bag 1 can be deflated, retrieved from the hole, optionally washed, dried, checked for damage and preferably reattached to the holding plate 17. Furthermore, the pressurized gas source 19 may be refilled. Refilling can be performed at any filling station comprising a source for compressed gas, where the gas preferably is air or a mixture including air. The optional light source may have to be replaced or refitted with batteries. The portable salvage system 16 can then be reassembled and preferably stored in the carrying bag, ready for renewed use.

[0037] The portable salvage system 16 may be used for reducing flow through a hole in a hull structure of a marine vessel or in a storage tank. Alternatively, or additionally, the portable salvage system 16 may be used to reduce flow through man-holes in an industrial structure or in a vessel. Thereby, ingress of seawater may, for instance, be limited to a lower deck of a ship only. Further alternatively, the portable salvage system 16 may be used to reduce or prevent flow through storm drain inlets or sewer inlets, such as found in streets or other public spaces. For instance, water in a sewer system may be prevented from exiting through a sewer inlet and flooding a street. List of references

[0038]

1 inflatable salvage bag

2 outer bag

3 transversal leading side

4 transversal trailing side

5 valve

6 friction band

7 elongated sleeve

8 eyelet

9 inner bag

10 reinforcing bag

11 inner backing

12 outer coating

13 coupling

14 inner passage

15 first release lever

16 portable salvage system

17 holding plate

18 flexible tube

19 pressurized gas source

20 one attachment line

21 A first connection piece

21 B second connection piece

22 valve

23 release lever

24 over pressure valve

Claims

1 . An inflatable salvage bag (1), for reducing fluid flow through a hole in a hull structure of a marine vessel or in a storage tank, the inflatable salvage bag (1 ) including:

- an inner bag (9), wherein the inner bag (9) is inflatable;

- a reinforcing bag (10), wherein the reinforcing bag (10) surrounds the inner bag (9) and is configured to be tear and puncture resistant;

- an outer bag (2), wherein the outer bag (2) surrounds the reinforcing bag (10);

- a valve (5), configured to connect the inner bag (9) with an external source of pressurized gas, in order to inflate the inflatable salvage bag (1 ); and

- optionally, one or more friction bands (6), configured to enhance the friction between the inflatable salvage bag (1) and the perimeter of the hole in which the inflatable salvage bag (1) is inserted.

2. The inflatable salvage bag (1) according to claim 1 , wherein the inner bag includes a polyurethane material, preferably a transparent polyurethane material.

3. The inflatable salvage bag according to any of claims 1 - 2, wherein the reinforcing bag (10) includes a double-walled or triple-walled tear and puncture resistant material, such as Kevlar.

4. The inflatable salvage bag (1) according to any of claims 1 - 3, wherein the outer bag (2) includes an inner fabric backing, such as a polyester, and an outer coating, such as a polyurethane or a thermoplastic polyurethane.

5. The inflatable salvage bag (1) according to any of claims 1 - 4, wherein the inflatable salvage bag (1 ) has a generally rectangular shape when in the deflated state, with a transversal leading side (4), a transversal trailing side (3) and two longitudinal sides extending therebetween. The inflatable salvage bag (1) according to claim 5, wherein the leading side (4) of the inflatable salvage bag (1) has a tapered shape. The inflatable salvage bag (1) according to any of claims 1 - 6, wherein two friction bands (6) are fixed onto at least one surface of the outer bag (2), the two friction bands being arranged in an X shape, preferably wherein the midpoint of the X shape coincides with the longitudinal middle of the outer bag (2). The inflatable salvage bag (1) according to any of claims 1 - 7, wherein the valve (5) includes a first release lever (15), configured to release pressurized gas from the inner bag (9) when activated. The inflatable salvage bag (1) according to any of claims 1 - 8, wherein an elongated sleeve (7) is fixed onto the outer bag (2), preferably extending along a longitudinal side thereof. The inflatable salvage bag (1) according to any of claims 1 - 9, wherein the inflatable salvage bag (1) is configured to comprise a pressurized gas with a pressure of up to 2 bar, preferably up to 1 .5 bar. The inflatable salvage bag (1 ) according to any of claims 1 - 10, wherein the inflatable salvage bag (1) includes an eyelet (8). The inflatable salvage bag (1) according to any of claims 1 - 11 , wherein the inflatable salvage bag (1) includes a light source, such as a battery- operated light or a chemiluminescence-based glowstick. A portable salvage system (16) for reducing fluid flow through a hole in a hull structure of a marine vessel or in a storage tank, the portable salvage system (16) including: one or more inflatable salvage bags (1 ) according to any of claims 1 - 12; a pressurized gas source (19); and 18 a flexible tube (18) for connecting the one or more inflatable salvage bags (1 ) to the pressurized gas source (19) in a gas tight manner. Portable salvage system (16) according to claim 13, further comprising a holding plate (17), to which the one or more inflatable salvage bags (1 ) are releasably attached. Portable salvage system (16) according any of claims 13 - 14, further including a stiffening element comprising multiple sections, wherein at least one section is configured to be inserted into the elongated sleeve (7). Portable salvage system (16) according to any of claims 13 - 15, wherein the pressurized gas source (19) includes a valve (22) and wherein the flexible tube (18) includes a first connection piece (21 A), configured to be connected to the valve (5) on an inflatable salvage bag (1 ), and a second connection piece (21 B), configured to be connected to the valve (22) on the pressurized gas source (19). Portable salvage system (16) according to claim 16, wherein the valve (22) further includes an over pressure valve (24), configured to automatically release pressurized gas to the environment when a threshold pressure is reached in the inflatable salvage bag (1 ), and wherein the second connection piece (21 B) includes a second release lever (23), configured to release pressurized gas from the inflatable salvage bag (1 ) when activated. Portable salvage system (16) according to any of claims 13 - 17, wherein the pressurized gas source (19) is a cylinder, preferably a refillable cylinder, with a volume of about 1 - 5 liters. Portable salvage system (16) according to any of claims 13 - 18, further including a carrying bag, such as a backpack, for storage and transportation of the portable salvage system (16). 19 Use of the portable salvage system (16) according to any of claims 13 - 19, for reducing fluid flow through a hole in a hull structure of a marine vessel or in a storage tank, for reducing flow through a man-hole in an industrial structure or in a vessel, or for reducing flow through a storm drain inlet or a sewer inlet. A method for producing an inflatable salvage bag (1 ) according to any of claims 1 - 12, the method including: providing an inner bag (9); arranging a reinforcing bag (10) around the inner bag (9); arranging an outer bag (2) around the reinforcing bag (10); and attaching a valve (5) to the inner bag (9), reinforcing bag (10) and outer bag (2).