Vessel and method for fire prevention in a vessel

Abstract

A vessel, said vessel comprising one or more lower decks (10, 20, 30, 40) where at least a part of the one or more lower decks (10, 20, 30, 40) is provided with a support surface (87), which support surface (81) comprises through-going ventilation openings allowing ventilation of the vessel, the vessel comprising at least one ventilation system, which from one hull-side of the decks (10, 20, 30, 40) has ventilation air supply openings (65) at the support surface (81) at each deck (10, 20, 30, 40), the ventilation system being configured to supply cooled air to the ventilation air supply openings (65), and the vessel further comprising a sensing device (91) configured to sense one or more of heat and gas, a control unit (92) associated with the sensing device and the ventilation system and comprising a signal processing device (93) configured to receive a signal from the sensing device (91) and to process the received signal to determine whether a predetermined threshold related to the sensed heat and gas is reached or overstepped, the control unit (92) being configured to trigger the ventilation system when it is determined that the predetermined threshold is reached or overstepped and the ventilation system being configured to supply gas to the ventilation air supply openings (65), when triggered by the control unit.

Description

[0001] Vessel and method for fire prevention in a vessel

[0002] Technical field

[0003] The present invention relates to a vessel, said vessel having one or more lower decks, where at least an area at the lower decks is provided with a support surface, which support surface comprises through-going ventilation openings, allowing ventilation of cargo the vessel having at least one ventilation system, which from one hull-side of the decks has ventilation air supply openings at the support surface of at each deck. The invention also relates to a method for fire prevention in such a vessel.

[0004] Background Art

[0005] Large ocean-going cargo vessels are the primary way to move goods internationally. Depending on the cargo, different kinds of ocean-going vessels are appropriate to use.

[0006] Refrigerated-cargo vessels are used to transport cargo, which requires controlled temperatures under transportation, such as food and like foodstuff, typically from one continent to another.

[0007] Vessels having a ramp are known as roll-on / roll-off or RO-RO ships, where cargo is driven on board of the vessel via ramps, instead of being lifted on it by a crane and lowered onto the decks through a hatch.

[0008] Car carriers are roll on / roll off vessels, RO-RO ships, loading cars and other rolling cargo, where the cargo is driven onto and from the ship via the ramp and are stored on multiple decks during transportation.

[0009] A deck may be divided into several compartments, such as by being divided by transverse bulkheads. Compartments may be refrigerated individually and independently.

[0010] A Vessel combining features of RO-RO ships and refrigerated-cargo vessels, which then is suitable for transporting fruit, such as bananas, from a first continent to a second continent, and transporting cars back, from the second continent to the first continent, is known from EP2605956B1.

[0011] In recent years there has been some catastrophic fires onboard ships, more specifically in car carriers transporting electric cars, where fires relate to lithium batteries pre-installed in the vehicles.

[0012] When a fire occurs inside lithium batteries, it is due to too high ambient temperature and eventually wrong voltage and a chemical process very quick generates heat, which can result in fires and release of toxic gases from the battery, e. g. hydrochloric acid and hydrofluoric acid and other acids released from thermal runaway. Latter is corrosive and dangerous for human beings. The battery fire process is called "Thermal runaway" because the fire itself generates heat and very important also oxygen and the fire spreads to nearby material.

[0013] The ambient temperature seems to have a decisive influence in the well- known cases onboard ships mentioned above. The higher ambient temperature the higher is the likelihood for a sudden fire in a lithium battery in a car. A car is a prerequisite for a fire in a lithium battery can spread, because a car has well-known contents of a lot of flammable materials. In a car carrier or more in general a roll on / roll off ship, the cars and other rolling equipment are parked close to each other and therefore the fire can spread very quickly.

[0014] The problem is that once fire in an electric vehicle occurs, it cannot be fought by firefighting methods like water and foam. Therefore, the fire continues until all flammable material have been consumed.

[0015] Summary of Invention

[0016] With this background it is an object of the present invention to alleviate the risk of fire in the cargo of vessels during transport at sea.

[0017] This is achieved with a vessel of the kind mentioned in the introduction, which is further characterized in that the ventilation system is configured to supply cooled air to the ventilation air supply openings, and in that the vessel further com- prises a sensing device which is located at an upper side of the deck and is configured to sense one or more of heat and gas, a control unit associated with the sensing device and the ventilation system, the control unit comprising a signal processing device, the signal processing device being configured to receive a signal from the sensing device and to process the received signal to determine whether a predetermined threshold related to the sensed one or more of heat and gas is reached or overstepped, and the control unit being configured to trigger the ventilation system when it is determined that the predetermined threshold is reached or overstepped wherein the ventilation system is further configured to supply gas to the ventilation air supply openings, when triggered by the control unit.

[0018] The ventilation system allows for blowing ventilation air in, directed in the transverse direction of the vessel, and to supply several or all lower decks from one and the same ventilation system. There is preferably provided one ventilation system for every ventilation zone.

[0019] The separation into different ventilation zones allows the cargo to be treated differently in terms of temperature, ventilation air amounts, and / or composition of the air or gas used for ventilation. In this manner it becomes simple to carry different types of refrigerated cargo, as the climate in the ventilation zone can be adjusted.

[0020] For the sake of simplicity and to allow even ventilation, draining etc. the openings in the support surface are distributed substantially evenly, but more complex configurations are also possible.

[0021] Cooling the cargo permanently using the ventilation system reduces the likelihood for a fire in a lithium battery during transportation or storage. A cooled environment during transportation is also suitable for other cargo, such as food. The vessel is suitable for different cargos and can be used for shipment of different cargo simultaneously in one shipment or respectively between two harbours in multiple shipments.

[0022] Heat and gas, such as smoke gases and / or toxic gases, are common signs of fire. Sensing heat enables early alarming of the control system independent of the cargo about a fire outbreak. Sensing for gas, besides heat in the cargo, enables fire detection in lithium batteries to be done even more reliably, as toxic gasses, e.g., hydrochloric acid and hydrofluoric acid and other acids released from thermal runaway, are released during a fire in lithium batteries. The invention is thus specifically suitable to transport goods and prevent fire in cargo with lithium batteries.

[0023] Supplying gas to the ventilation air openings removes oxygen from the atmosphere around the cargo. Without oxygen fire cannot spread. In case of a lithium battery, only that one battery "melts" instead of the fire consuming the entire cargo and potentially the entire vessel.

[0024] In an embodiment the support surface is part of one or more cargo platforms, each platform comprising an upper surface and side surfaces, which upper surface and at least one of the side surfaces comprise through-going ventilation openings, where the cargo platforms are located adjacent to one another in rows extending in the transverse direction of the vessel. Such platforms are also known as cassettes or transport cassettes. It is noted that platforms are used primarily for cargo, such as spare lithium batteries and bananas, whereas vehicles are normally not loaded on platforms. If platforms are used in a compartment or deck of the vessel, all of the compartment or deck must be covered by platforms to ensure stability at sea.

[0025] Instead of having to transport the cargo onto the vessel one-by-one, the cargo can be arranged on the platforms on shore and the loaded platforms may be taken onto the vessel. The platforms can be loaded prior to the arrival of the vessel in a harbour. This means a more continuous workload for the personnel.

[0026] By arranging cargo on platforms, and the possibility of arranging the platforms on the vessel in a highly compact manner results in a significant improvement of the capacity of the vessel. The platforms may be loaded with any type of commodities, but thanks to the ventilation openings, allowing for air circulation needed for controlling temperature and the atmosphere surrounding the cargo, the platforms are specifically suited for cargo needing refrigeration under transportation, such as food and like foodstuff, but also cargo with lithium batteries, such as electric cars.

[0027] When shipping cars on the platforms, the cars are preferably strapped down on the platforms, meaning they don't have to be driven onboard of the vessel one at a time, by their own power and are prevented from incurring damages during the loading. A common problem of crushed side-view mirrors may be eliminated.

[0028] The cargo platforms may in principle be of any configuration allowing them to be taken in and out of the ship while carrying the cargo and at the same time permitting air / gas to circulate around the cargo. To fulfil the latter requirement the openings in the upper surface may preferably be distributed substantially evenly.

[0029] In an embodiment the support surface is provided with a grating. This makes it efficient, reliable, and relatively cheap, as gratings are a standard commodity and therefore available all over the world. It is used to keep the cargo elevated above the deck surface so that air may circulate through the cargo.

[0030] The platforms should be easy to keep clean and resistant to the atmospheric conditions encountered. They are therefore advantageously made wholly or partially of steel painted with marine paints or made of a corrosion retarding material such as aluminium, stainless- or galvanised steel, plastic, composites, or combinations thereof, an example being a plastic-covered steel frame with an aluminium grate serving as the support surface.

[0031] In an embodiment the ventilation system is configured to supply a gas selected from the group consisting of helium, neon, argon, krypton, xenon, radon, nitrogen, and combinations thereof to the ventilation air supply openings, when triggered by the control unit.

[0032] Helium, neon, argon, krypton, xenon, and radon are noble gasses, or inert gasses. These gasses can be injected into the atmosphere surrounding the cargo when heat or gasses are detected in the cargo. When injected into the atmosphere, noble gasses remove the oxygen from the atmosphere. Without oxygen potential fire cannot spread in the cargo. The same is the case, when injecting nitrogen into the atmosphere surrounding the cargo.

[0033] In an embodiment the sensing device is configured to sense one or more of heat, hydrochloric acid, and hydrofluoric acid and other acids released from thermal runaway.

[0034] When a fire occurs inside lithium batteries it can result in the release of toxic gases. Examples of these toxic gases are hydrochloric acid and hydrofluoric acid and other acids released from thermal runaway. They are corrosive and dangerous for human beings. Sensing for these toxic gases specifically reduces the risk of damage, both on the vessel and surrounding cargo, as well as on the people on the vessel and handling the cargo.

[0035] In an embodiment the ventilation system is configured to supply cooled air to the air supply openings, such that a temperature of the air in the one or more lower decks stays at a temperature of less than 16 degrees Celsius, less than 15 degrees Celsius, less than 12 degrees Celsius, preferably less than 5 degrees Celsius, most preferably less than 1 degree Celsius, or of between 5 and 25 degrees Celsius, between 12 and 25 degrees Celsius, between 12 and 16 degrees Celsius, or between 15 and 16 degrees Celsius. To prevent fires in lithium batteries temperatures of lower degrees are desirable, as the ambient temperature has a decisive influence on the likelihood of a sudden fire occurring in lithium batteries. Other temperatures may also be able to achieve the desired effect.

[0036] In an embodiment the predetermined threshold for triggering the ventilation system when sensing heat is (i) the temperature of cooled air supplied by the ventilation system, or (ii) a temperature of the air in the one or more lower decks. The temperature of the air in the one or more lower decks as a threshold may be measured in a suitable unit, such as degrees Celsius. Exemplary appropriate thresholds may be 16 degrees, 15 degrees, 12 degrees, 5 degrees or 1 degree Celsius. However other temperatures may also be suitable thresholds.

[0037] In an embodiment the predetermined threshold for triggering the ventilation system when sensing gas is a predetermined amount of the sensed gas in the air in the one or more lover decks. A predetermined amount of the sensed gas may be measured in a suitable unit of volume, such as ml / m3, ppm or in percent of the total volume of air on the deck. In an embodiment the sensing device is configured to employ Al to detect one or more of heat, gas, and a person present in a vicinity of the sensing device.

[0038] Using an Al sensor may detect a sudden fire within the cargo on such a vessel earlier than traditional sensors. Using sensors based on Al may assure the safety of the personnel onboard of a vessel. By sensing a person in the vicinity of the sensor, when a fire breaks out, the person may be warned. The person is then able to remove themselves from the situation, before being damaged. By sensing a person in a vicinity of the sensor, it may also be possible to alert help early, if the person is not able to remove themselves from the situation. With an on-premises server, heat and gas detection may be performed in real time. The Al may operate based on image recognition. It may be trained based on pictures from similar situations, where fire in lithium batteries occurred in similar spaces, e.g., closed storage facilities, cargo vessels or parking spaces, with the sensing device being located beneath the lithium battery. An Al based image sensing device may be a lidar or a camera.

[0039] In an embodiment the cargo is electric cars and / or goods with lithium batteries. Sudden fire in vessels is related to the increased transport of electric cars from a first place to a second place, such as from a first continent to a second continent. These sudden fires may be related specifically to the lithium batteries in the electric cars. The sudden fires may also occur in any other cargo containing such lithium batteries.

[0040] In an embodiment, the vessel is any one of a RO-RO ship, a ferry, a ROPAX (roll-on / roll-off passenger) ship, a pure car carrier, a pure car / truck carrier and a ROCON (roll-on / roll-off container) ship. Such vessels may, but need not necessarily be, vessels.

[0041] In an embodiment, at least the ventilation system, the sensing device, and the control unit are retrofitted to the vessel.

[0042] Thereby it becomes possible to also prevent fires on board ships that are not originally build with a ventilation system, sensing device, and control unit according to the invention.

[0043] In an embodiment, the vessel may be a cargo vessel. In a second aspect there is provided a method for fire prevention on a vessel, having one or more lower decks, where at least an area at the lower decks is provided with a support surface, which support surface comprises through-going ventilation openings allowing ventilation of the vessel, and the vessel further comprises a ventilation system, which from one hull-side of the deck(s) has ventilation air supply openings at the support surface at each deck is provided. The method comprises the steps of refrigerating cargo on each lower deck using the ventilation system to supply cooled air to the ventilation air supply openings, sensing one or more of heat and gas using a sensing device, the sensing device being located at the upper side of the deck, sending a signal from the sensing device to a control unit, the control unit being associated with the ventilation system and the control unit comprising a signal processing device, processing the signal using the signal processing device to determine whether a predetermined threshold related to the sensed one or more of heat and gas is reached or overstepped, triggering the ventilation system using the control unit when it is determined that the predetermined threshold is reached or overstepped, and supplying gas to the ventilation air supply openings using the ventilation system when the ventilation system is triggered.

[0044] In a preferred embodiment of the method, the support surface forms part of one or more cargo-platforms. Each cargo platform comprises an upper surface and side surfaces. The upper surface has through-going ventilation openings. At least one of the side surfaces comprises through-going ventilation openings. The platforms are located adjacent to each other in the vessel.

[0045] In a preferred embodiment of the method, the support surface is provided with a grating.

[0046] In a preferred embodiment of the method, the ventilation system is configured to supply a gas selected from the group consisting of: helium, neon, argon, krypton, xenon, radon, nitrogen and combinations thereof to the ventilation air supply openings, when triggered by the control unit.

[0047] In a preferred embodiment of the method, the sensing device is configured to sense one or more of heat, hydrochloric acid, and hydrofluoric acid and other acids released from thermal runaway.

[0048] In a preferred embodiment of the method, the ventilation system is configured to supply cooled air at a temperature of less than 12 degrees Celsius, preferably less than 5 degrees Celsius, most preferably less than 1 degrees Celsius, to the air supply openings.

[0049] In a preferred embodiment of the method, the predetermined threshold for triggering the ventilation system when sensing heat is (i) the temperature of cooled air supplied by the ventilation system, or (ii) a temperature of the air in the one or more lower decks.

[0050] In a preferred embodiment of the method, the predetermined threshold for triggering the ventilation system when sensing gas is a predetermined amount of the sensed gas in the air in the one or more lover decks.

[0051] In a preferred embodiment of the method, the sensing device is configured to employ Al to detect one or more of heat, gas, and a person present in a vicinity of the sensing device.

[0052] In a preferred embodiment of the method, the cargo is electric cars and / or goods with lithium batteries.

[0053] In a preferred embodiment of the method, the vessel is a cargo vessel.

[0054] In a third aspect, there is provided a method for providing a vessel according to the invention, the method comprising providing a vessel, and retrofitting the vessel with a ventilation system and a sensing device.

[0055] In an embodiment, the method further comprises retrofitting the vessel with a control unit.

[0056] In a preferred embodiment of the method, the vessel is a cargo vessel.

[0057] Other embodiments and further advantages will be apparent from the subsequent detailed description and drawings.

[0058] Brief Description of Drawings

[0059] Fig. 1 illustrates a longitudinal cross-section of a vessel according to the in- vention, Figs. 2-6 illustrate decks 1-5 of the vessel in Fig. 1 seen from above,

[0060] Fig. 7 illustrates a midship cross-section of the vessel in Fig. 1,

[0061] Fig. 8 illustrates a platform according to the invention seen from the side,

[0062] Fig. 9 depicts the platform in Fig. 8 seen from above,

[0063] Fig. 10 depicts the platform in Fig. 8 seen from the end,

[0064] Fig. 11 illustrates schematically a fire prevention device, and

[0065] Fig. 12 illustrates schematically steps of a method of preventing fire on a vessel according to the invention.

[0066] Fig. 13 illustrates a midship cross-section of a vessel according to the invention in the form of a ROCON ship.

[0067] Fig. 14 illustrates a midship cross-section of vessel according to the invention in the form of a pure car carrier (PCC) or a pure car / truck carrier (PCTC).

[0068] Detailed Description

[0069] In an embodiment, the vessel may be a so-called RO-RO ship. Vessels having a ramp are known as such RO-RO ships. The cargo is driven on board of the vessel via a roll on / roll off ramp, instead of being lifted on it by a crane and lowered onto the decks through a hatch. This allows for efficient loading and unloading of cargo on the platforms. Although the below description is exemplified by reference to a RO-RO (roll on / roll off) ship, other suitable examples of a vessel according to the invention include ferries, ROPAX (roll -on / roll -off passenger) ships, pure car carriers (PCC), pure car / truck carriers (PCTC) and ROCON ships (ROCON denoting a hybrid of a RORO ship and a container ship). Also, although the below description is exemplified by reference to a cargo vessel, a vessel according to the invention may optionally further be a refrigerated-cargo vessel.

[0070] An example of a vessel according to the invention, comprising a hull 1, a roll -on / roll -off ramp 2 and a superstructure 3 is shown in Fig. 1. Here, four lower cargo decks 10, 20, 30, 40 are contained within the hull and a weather deck constitutes a fifth cargo deck 50, which is upwards open.

[0071] The roll -on / roll -off ramp 2 provides direct access to the third cargo deck 30 as may also be seen in Fig. 4 and the first deck 10, second deck 20 and fourth cargo deck 40 can be reached via internal ramps 11, 21 and 41, respectively, as may also be seen in Figs. 2-5. In this embodiment the internal ramp 21 interconnecting second and third decks is a fixed ramp, while the other internal ramps 11, 41 are lowerable. The fixed ramp is provided with hatches, or the ramps are provided with hatches, which allow the storing of cargo on the areas occupied by the ramps when not in use.

[0072] Other constellations of the internal ramps 11, 21, 41 as well as the roll- on / roll-off ramp 2 are of course also possible, but the stability of the vessel and optimisation of the loading has to be observed. Likewise, it is possible to provide elevators instead of ramps, at least on some decks, but this will usually not be feasible due to the relative logistic inefficiency and the need for maintenance. Likewise, the vessel according to one embodiment of an invention may not be a RO-RO ship. In the embodiment the cargo is lifted on board by a crane and lowered through a hatch in the deck, where it is then stowed away.

[0073] For instance, Fig. 13 shows a vessel according to the invention in the form of a ROCON ship. In the embodiment the cargo, for instance in the form of containers 71 filled with goods, is lifted on board by a crane and lowered onto the deck 50, where it is then stowed away. Decks 10, 20, 30 may be decks of the RO-RO-type, or decks of the same type as the deck 50, albeit with a hatch through which goods may be loaded onto the deck.

[0074] Another example is illustrated in Fig. 14 showing another vessel according to the invention. The vessel shown in Fig. 14 may be a pure car carrier (PCC) or a pure car / truck carrier (PCTC). Here all decks 10, 20, 30, 40 are used for transporting cars or a combination of cars and trucks according to the stye of vessel. Alternatively, the vessel shown in Fig. 14 may be a ROPAX (roll-on / roll-off passenger) ship or a ferry. In such a case, the deck 50 may be used as a passenger deck, the decks 20, 30 and 40 may be vehicle decks, and the lowermost deck 10 may be a cargo deck.

[0075] The operations of the roll-on / roll-off ramp 2 as well as the movable ramps 11, 41 are achieved with hydraulics in a manner well known to persons skilled in the art and will therefore not be described in further detail here.

[0076] In the embodiment shown in Figs. 1-5 the roll-on / roll-off ramp 2 has a width of approximately 6.5 m, a length of approximately 29 m and in the lowered, active position an angle of 0-7 degrees in relation to horizontal, depending on the quay height and the draught of the vessel. The internal ramps are somewhat narrower and longer, such as having a width of approximately 6 m and a length of approximately 32 m, and angled at approximately 8 degrees in relation to the cargo deck in the mode of operation.

[0077] The ramps are made of a durable and skid proof material, such as profiled steel plates, and various surface coatings such as paint may be applied as is well known to persons skilled in the art.

[0078] In order to further optimise the utilisation of the space available within the hull, a hatch may be provided at the opening above one or more internal ramps, so that cargo may be store on top of the hatch once the deck below it has been filled. A similar effect may be achieved by making at least one internal ramp moveable between a first position, in which it is substantially in plane with one of the decks, and a second position, in which it is inclined to interconnect two decks. Once the deck receiving platforms via the ramp has been filled the ramp may be activated to be positioned in the first position and the space thus made available may be used for cargo.

[0079] The uppermost cargo deck, here the fifth deck called the weather deck 50, can be reached only from above, i.e., by means of a crane 70. The vessel is provided with two cranes 70 and these may serve the complete weather deck during loading and unloading. The weather deck is intended for containers 71 and can be loaded independently of the lower decks. This means that it is not necessary to postpone the loading of the last containers until the lower decks have been fully loaded, as would be the case with vessel loaded through a hatch in the upper deck, and likewise, cargo can be unloaded from the lower decks without first having to unload cargo from the upper deck.

[0080] In an embodiment the cargo maybe loaded on platforms, also known as cassettes or transport cassettes. In this embodiment the cargo is taken onboard on platforms 8, which are load carriers made with means for ventilation in the form of through-going holes. It is noted that vehicles are normally not loaded on platforms, whereas other cargo, such as other devices with lithium batteries, lithium batteries and bananas normally are loaded on platforms. The individual platform 8 is sized to carry, e.g., multiple pallets, such as at least 10 pallets. An example of such a platform 8 is shown in Figs. 8-10. As may be seen, the upper surface 81 of the platform 8 is in the form of a grate, with l-profile bars 82 spanning the entire width of the platform 8. It is, however, also possible to use a grid-like structure with bars crossing each other, a perforated plate or the like. The upper surface 81 may be made from galvanized steel, aluminium, plastic, or other materials capable of withstanding wear, water contact and the load from the cargo placed on the platform 8.

[0081] In the embodiment shown, the platform 8 is downwards open and resting on four legs 83 as may be seen in Figs. 8 and 10. In this way the platform 8 is kept elevated above the surface on which it rests.

[0082] On the vessel the legs 83 provide a space between the deck and the surface of the platform 8, and this space allows very efficient ventilation where air / gas is able to be distributed underneath the cargo so that ventilation is performed in an even manner up through all cargo stored on the platforms.

[0083] In the platform 8 illustrated in Figs. 8 and 9, bars 82 forming the upper surface 81 are welded to a pair of longitudinal beams 84, which defines the two side surfaces of the platform 8, and which provides the necessary strength and stiffness to the platform 8. The beams 84 illustrated are box beams, but I-beams or solid beams may also be employed.

[0084] At the end of each beam 84 a bracket 85 is provided for guiding the sides of a trailer while the trailer is moved into the space below the platform 8 by the transport drive unit. The brackets 85 assist in positioning a trailer with respect to the platform 8. When the trailer has been fully inserted under the platform 8, brackets 85 are positioned at corresponding brackets 107 at the front and back end of the side surfaces of the trailer so that the trailer and platform are mutually guided at the four corners at the ends of the platform 8. When transporting cars 72 these are preferably secured to the platform 8, such as with lashings or flexible belts secured to the bars 82 forming the grate. The platform 8 may, however, also be provided with separate brackets and / or retainers (not shown) for this use.

[0085] The platform 8 shown in Figs. 8-10 is of a both simple and open structure and therefore easy to maintain. If using platforms of a more complex or closed design, they may advantageously be separable, for instance by attaching grates constituting the upper and lower surfaces to a frame by means of bolts or other fastening means such as latches or spring locks.

[0086] When transporting the loaded platforms on the vessel it may be advantageous that the cargo is secured. This particularly applies when transporting cars, and the platforms may therefore comprise at least one fastening device for securing a cargo item to the upper surface.

[0087] Regardless of the design chosen, the platform 8 should be sufficiently strong to carry the cargo, sufficiently stiff to not become deformed during transportation, and made from a durable material capable of withstanding both the climate and the wear associated with use in ports, warehouses, and onboard reefers.

[0088] The vessel may have a number of dummy-platforms for filling out a row in case the platforms loaded onto the vessel do not form complete rows. There may also be used inflatable bags to close one or more voids in a row.

[0089] The vessel may also not have any platforms, but instead have the cargo be placed directly on the support surface 87 of each respective lower deck. When not utilizing platforms to load cargo onto the vessel, it will be appreciated, that the support surface 87 is made with means for ventilation in the form of through-going holes and elevates the cargo from the upper side of the lower deck. The elevation from the lower deck and through-going holes of the support surface 87 allow for ventilation of the cargo despite not having any platforms. The support surface 87 may in practice be formed either by a platform or by the deck itself. The support surface 87 may thus take up the whole deck or only a part of the deck.

[0090] A ventilation unit comprising ventilating fans and air conditioning equip- merit 61 is provided at the side of the vessel possibly supplemented with a gas source for use when an artificial atmosphere, like nitrogen, is used instead of or as a supplement to ambient air. As may be seen in Fig. 7, ambient air is taken in at one side of the vessel (left side in Fig. 7) where it is cooled or heated if necessary and possibly mixed with other gasses. From here the air is passed down along the side of the hull 1 through ventilation ducts 62 and led in through ventilation air supply openings 65 located immediately above the surface of each of the lower decks. Depending on ventilation requirements, vessel size etc. it is also possible to provide duct extending across the vessel as well as auxiliary fans at each deck.

[0091] The air or air mixture is distributed along the surface of the deck and rises up through the cargo and is taken out along the ceiling formed by the deck above as indicated by arrows. From here the air or air mixture flows through exit openings 66 and enters into a second ventilation duct 63 at the opposite side of the vessel (right side in Fig. 7) and is eventually blown out by ventilation equipment 64, which may include a heat exchanger and / or a gas recovery unit.

[0092] Only a single set of ventilation units has been described, but in other embodiments several sets may be employed depending amongst others on the size and loading capacity of the vessel, on the demands for ventilation and conditioning of the atmosphere, and on the capacity of the units employed. Moreover, the decks may be divided into several individually climate-controlled cargo compartments, such as by being divided by transverse bulkheads 67, which may have access doors being open during loading and un-loading. On the lower deck provided with the transverse bulkhead there is thus one ventilation zone 68 forward of the bulkhead and another ventilation zone 69 backward of the bulkhead. It is also possible to use an uneven number of conditioning and ventilating units, where one conditioning unit works with two or more ventilating units or vice versa. It is further possible that not all but only some of the cargo compartments are climate-controlled cargo compartments.

[0093] When transporting electric cars, it is appreciated, that in the ventilation zone in which the electric cars are located during transportation, the air circulating through the cargo is cooled to around 0 degrees Celsius at all times. A cooled ambient air reduces the risk of sudden fire in the lithium batteries of electric cars. However, other, higher, temperatures are possible, such as 15 to 16 degrees, 12 degrees or 5 degrees Celsius, to reduce the risk already.

[0094] When transporting pallets of bananas on a vessel, it is appreciated, that in the ventilation zone, in which the bananas are located under transportation, the air circulating through the cargo is cooled to temperatures between 12 and 15 degrees Celsius. The atmosphere surrounding the bananas is preferably modified or controlled, meaning a partial or total replacement of the ambient air with gas, respectively. This contributes to the stalling of the ripening process and may further kill off any vermin and fungus.

[0095] Once approaching the destination, the temperature may be raised to about 17 °C and a low concentration of ethylene, which is the natural ripening agent of bananas, may be added to the atmosphere. The possibility of multiple ventilation zones on the same vessel allows for the transport of different cargo during transportation from a first harbour to a second harbour, even though the cargo may require different cooling or heating during the transport.

[0096] It is noted that depending on the cargo, not all decks and / or not all cargo compartments need be cooled.

[0097] Referring to Fig. 11, the ventilation unit 61 is further associated with a control unit 92, which is also on board of the vessel. The ventilation unit 61 and the control unit 92 may be able to communicate with each other via a wired or a wireless communication.

[0098] The control unit 92 is responsible for triggering the heating or cooling of the incoming air, and the optional addition of gas to the air, before the air circulates through the cargo and / or cargo deck. The control unit is further associated with a sensing device 91. The sensing device 91 is configured to sense heat and gas. The sensing device 91 comprises one or more sensors 94 for sensing for heat and gas. The sensing device 91 and the control unit 92 may be connected by a wired or a wireless signal communication. The sensing device 91 and the control unit 92 may be separate units as shown in Fig. 11, or they may be integrated into one unit.

[0099] The sensing device 91 may be a traditional sensor, such as a smoke alarm, or a sensor based on Al. The sensing device 91 may be located underneath the cargo at an upper side of the lower deck as shown in Fig. 7. Alternatively, or additionally, the sensing device 91 may be located above the cargo. The cargo is placed on the respective support surface 87 of the lower deck. The sensing device 91 is configured to sense heat and gas and to transmit signals with the recorded sensing data to the control unit 92. In the control unit 92, the sensing data received from the sensing device 91 is processed by a signal processing device 93.

[0100] The sensing device 91 may be based on artificial intelligence, Al. Using an Al sensor may detect a sudden fire within the cargo on such a vessel earlier than traditional sensors. Sensing devices 91 based on artificial intelligence may be trained to recognise patterns quickly. A sensing device 91 based on Al may be trained with images and / or heat data of burning car batteries, taken and / or measured from the same position as the sensing device assumes on the vessel in relation to the cargo. With a sensing device 91 based on Al, the sensing device 91 may be operating based on image recognition. Besides the sensor(s) 94 for sensing for heat and gas, the sensing device 91 may further comprise an optional image sensing device 95, such as a lidar or a camera. An Al based sensing device 91 may be trained to recognise the signs of fire or smoke formation based on pictures from similar situations. When comprising an image sensor device 95, an Al based sensing device 91 may be trained to recognise the signs of fire or smoke formation in an image taken or generated by the image sensor device 95 based on pictures from similar situations. Similar situations could be burning cargo, especially electric cars, where a sudden fire occurred in a lithium battery. The Al based sensing device 91 may be located underneath the cargo at an upper side of the lower deck as shown in Fig. 7, above the cargo and / or on bulkheads such as to enable surveillance from more than one side or from all sides. By quickly recognising the signs of a fire, a system with the sensing device 91 based on Al can react quickly to prevent the sudden fire from spreading, for instance by triggering an alarm. This may further alleviate the need for guards doing fire bills, which may in any event be insufficient for efficient fire prevention especially on large vessels.

[0101] Using a sensing device 91 based on Al may assure the safety of the personnel onboard of a vessel. By sensing a person in the vicinity of the sensing device 91, when a fire breaks out, the person may be warned. The person is then able to remove themselves from the situation, before being damaged. By sensing a person in a vicinity of the sensing device 91, it may also be possible to alert help early, if the person is not able to remove themselves from the situation. An Al based sensing device 91 may be trained to recognise the presence of a person based on pictures from similar situations. When comprising an image sensor device 95, an Al based sensing device 91 may be trained to recognise the presence of a person in an image taken by the image sensor device 95 based on pictures from similar situations, such as pictures of persons on a cargo deck or a similar structure.

[0102] The signal processing device determines whether a predetermined threshold related to the sensed one or more of heat and gas is reached or overstepped, by comparing the data received from the sensing device with said predetermined threshold. There may be a predetermined threshold when sensing for heat. There may be another predetermined threshold when sensing for gas. When sensing for heat, the threshold may relate to a temperature in a respective lower deck. When transporting electric cars this threshold may be 16 degrees Celsius, 15 degrees Celsius, 12 degrees Celsius, or 5 degrees Celsius or 1 degree Celsius. However, it is appreciated that other thresholds are possible. Likewise, different thresholds may be suitable for different cargo. For instance, a threshold of 15 degrees Celsius would be suitable when transporting bananas. When sensing for gas, the threshold may be related to the volume or amount of gas sensed in the lower deck compared to the remaining air in the lower deck.

[0103] When the predetermined threshold is overstepped, the control unit 92 triggers the ventilation system. When the ventilation system is triggered the ventilation unit 61, which is provided with a gas source, will supply a gas to the air supply openings 65. The aim is to thereby remove the oxygen from the atmosphere in a respective lower deck. Suitable gasses may be noble gasses (inert gasses) or nitrogen. Without oxygen a fire cannot spread to other cargo. In case of a lithium battery, the battery having caught fire will "melt", but the fire will be isolated, and no damage will be done to the rest of the electric cars or the surrounding cargo or people.

[0104] While only one sensing device 91 is described above, there may be other embodiments, where multiple sensing devices 91 are connected to one or more control unit(s) 92.

[0105] Also, a combination of one or more sensing devices 91 based on Al and one or more traditional sensing devices 91 may be employed. In an alternative embodiment, different ventilation zones may be employed and suitable for different cargo, and different thresholds when sensing for heat and gas may be suitable for different cargo. For instance, one sensing device 91 may be located underneath each electric car on the vessel. This provides the most reliable detection of early fire signs in the cargo. At least one sensing device 91 based on Al may be employed to assure the safety of the personnel on board the vessel in case of a potential fire.

[0106] In another embodiment the invention relates to a method for preventing fire in a vessel, such as the vessel seen in Fig. 1-7, which structural and functional features have been described in some detail above. Referring to Fig. 12, the cargo on each lower deck is refrigerated 610 by using the ventilation system. Meanwhile a sensing device 91 is used to sense 910 heat and / or gas in the lower deck. The sensing device 91 sends 911 a signal to a control unit 92.

[0107] The control unit 92 is located on board of the vessel. The control unit 92 is associated with the ventilation system responsible for circulating air in the lower deck. The control unit 92 comprises a signal processing unit 93. The signal processing unit is responsible for processing 930 the signals received from the sensing device 91. When processing the signals, the signal processing unit 93 compares the data received from the sensing device 91 with a predetermined threshold. A predetermined threshold when sensing for heat is established based on the cargo, that is transported on the vessel. Another predetermined threshold when sensing for gas is also established. When one or both thresholds are reached or overstepped the control unit 92 triggers 920 the ventilation system. When the threshold is not reached or overstepped, it is understood that the control unit 92 does not trigger the ventilation system. The sensing device 91 records data continuously and sends the data to the control unit 92 continuously. Therefore, the control unit 92 will trigger the ventilation system very quickly after a threshold is reached or overstepped.

[0108] Reaching or overstepping the threshold is a sign of fire. When the ventilation system is triggered, the ventilation unit 61 supplies 611 the ventilation supply openings 65 with a gas instead of air. The gas is supplied in order to remove any oxygen from the atmosphere in the lower deck. Removing oxygen from the atmosphere in the lower deck removes the possibility of a potential fire spreading within the cargo and / or vessel.

[0109] The vessel according to the invention may be a newbuilding vessel fitted with at least the ventilation system or unit, the sensing device, and the control unit as described above.

[0110] It is also feasible that at least the ventilation system or unit, the sensing device, and / or the control unit as described above may be retrofitted to an already existing vessel. Generally, such vessels comprise piping for conducting or supplying CO2. When retrofitting, the vessel may as a part of retrofitting the ventilation system be provided with piping for supplying a gas, such as nitrogen. The piping for supplying a gas, such as nitrogen, may be identical to and arranged parallel to the already existing piping for conducting or supplying CO2. Alternatively, the already existing piping for conducting or supplying CO2may also be used as the piping for supplying a gas, such as nitrogen.

[0111] Variations of the above-mentioned embodiments are possible within the scope of the appended patent claims.

Claims

P A T E N T C L A I M S1. A vessel, said vessel comprising one or more lower decks (10, 20, 30, 40) where at least a part of the one or more lower decks (10, 20, 30, 40) is provided with a support surface (87), which support surface (87) comprises through-going ventilation openings allowing ventilation of the vessel, the vessel comprising at least one ventilation system, which from one hull-side of the decks (10, 20, 30, 40) has ventilation air supply openings (65) at the support surface (87) at each deck (10, 20, 30, 40), the ventilation system is configured to supply cooled air to the ventilation air supply openings (65); characterised in that the vessel further comprises: a sensing device (91) located at an upper side of the deck (10, 20, 30, 40) and configured to sense one or more of heat and gas; a control unit (92), associated with the sensing device and the ventilation system, the control unit (92) comprising a signal processing device (93), the signal processing device (93) being configured to receive a signal from the sensing device and to process the received signal to determine whether a predetermined threshold related to the sensed one or more of heat and gas is reached or overstepped, and the control unit (92) being configured to trigger the ventilation system when it is determined that the predetermined threshold is reached or overstepped; wherein the ventilation system is further configured to supply gas to the ventilation air supply openings (65) when triggered by the control unit.

2. A vessel according to claim 1, wherein the support surface (87) forms part of one or more cargo platforms (8), each cargo platform comprising an upper surface (81) and side surfaces, the upper surface and at least one of the side surfaces comprising through-going ventilation openings, wherein the cargo platforms (8) are located adjacent to one another in rows extending in a transverse direction of the vessel.

3. A vessel according to any preceding claim, wherein the support surface (87) is provided with a grating.

4. A vessel according to any preceding claim, wherein the ventilation system is configured to supply a gas selected from the group consisting of: helium, neon, argon, krypton, xenon, radon, nitrogen, and combinations thereof to the ventilation air supply openings (65), when triggered by the control unit.

5. A vessel according to any preceding claim, wherein the sensing device (91) is configured to sense one or more of heat, hydrochloric acid, and hydrofluoric acid and other acids released from thermal runaway.

6. A vessel according to any preceding claim, wherein the ventilation system is configured to supply cooled air to the air supply openings (65), such that a temperature of the air in the one or more lower decks (10, 20, 30, 40) stays at a temperature of less than 16 degrees Celsius, less than 15 degrees Celsius, less than 12 degrees Celsius, preferably less than 5 degrees Celsius, most preferably less than 1 degree Celsius, or of between 5 and 25 degrees Celsius, between 12 and 25 degrees Celsius, between 12 and 16 degrees Celsius, or between 15 and 16 degrees Celsius.

7. A vessel according to any one of the above claims, wherein the predetermined threshold for triggering the ventilation system: when sensing heat is (i) the temperature of cooled air supplied by the ventilation system, or (ii) a temperature of the air in the one or more lower decks, when sensing gas is a predetermined amount of the sensed gas in the air in the one or more lover decks.

8. A vessel according to any preceding claim, wherein the sensing device (91) is configured to employ Al to detect one or more of: heat, gas, anda person being present in a vicinity of the sensing device.

9. A vessel according to any preceding claim, wherein the vessel is configured for the cargo of electric cars and / or goods with lithium batteries.

10. A vessel according to any preceding claim, wherein the vessel is any one of a RO-RO ship, a ferry, a ROPAX (roll-on / roll-off passenger) ship, a pure car carrier, a pure car / truck carrier and a ROCON (roll-on / roll-off container) ship.

11. A vessel according to any preceding claim, wherein the ventilation system, the sensing device (91) and / or the control unit (92) are retrofitted to the vessel.

12. A vessel according to any preceding claim, wherein the vessel is a cargo vessel.

13. A method for preventing fire in a vessel, wherein the vessel comprises one or more lower decks (10, 20, 30, 40), where at least a part of the one or more lower decks (10, 20, 30, 40) is provided with a support surface (87), which support surface (87) comprises through-going ventilation openings allowing ventilation of the vessel, and the vessel further comprises a ventilation system, which from one hull-side of the deck(s) (10, 20, 30, 40) has ventilation air supply openings (65) at the support surface (87) at each deck (10, 20, 30, 40); the method comprising the steps of: refrigerating (610) cargo on each lower deck (10, 20, 30, 40) using the ventilation system to supply cooled air to the ventilation air supply openings (65); sensing (910) one or more of heat, and gas using a sensing device (91), the sensing device being located at the upper side of the deck (10, 20, 30, 40); sending (911) a signal from the sensing device to a control unit (92), the control unit being associated with the ventilation system and the control unit com-prising a signal processing device (93); processing (930) the signal using the signal processing device to determine whether a predetermined threshold related to the sensed one or more of heat, smoke, and gas is reached or overstepped; triggering (920) the ventilation system using the control unit when it is determined that the predetermined threshold is reached or overstepped; and supplying (611) gas to the ventilation air supply openings using the ventilation system when the ventilation system is triggered.

14. A method for providing a vessel according to any one of claims 1-12, the method comprising: providing a vessel, and retrofitting the vessel with a ventilation system and a sensing device (91).

15. A method according to claim 14 and further comprising retrofitting the vessel with a control unit (92).

16. A method according to any one of claims 13-15, wherein the vessel is a cargo vessel.

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