System and method for fumigating a ship with crew protection

Abstract

A method and system for fumigating a vessel includes delivering a fumigation agent to a cargo area of ​​the vessel. In particular, the vessel may be a roll-on / roll-off vessel. In such a system, a pneumatic system is provided for maintaining a selected minimum pressure differential between a selected area of ​​the vessel above the cargo area and the cargo area such that the pressure in the selected area is greater than the cargo area. A control system may maintain the pressure differential.

Description

Detailed Description of the Invention

[0001] [Technical field] The present invention relates to systems and methods for fumigating vessels. The present invention has particular application to the fumigation of roll-on / roll-off vessels. The present invention is also directed to methods of fumigating roll-on / roll-off vessels. Furthermore, the present invention relates to temporary bulkheads. Although the present invention is directed to roll-on / roll-off vessels, some aspects of the invention are by no means limited to these types of vessels and may have broad application to cargo ships and other types of marine vessels.

[0002] The reader is also directed to another co-filed application entitled "System and method for fumigating a vessel with exhaust" which relates to aspects of the invention described but not claimed herein, the entire contents of which are incorporated herein by reference. [Background technology]

[0003] It is a requirement in many jurisdictions that cargo on board cargo-carrying ships be fumigated prior to unloading. Fumigation of infested ships may also be necessary. The fumigation process involves releasing a fumigant into the cargo area of ​​the ship to eliminate, reduce, or prevent infestation of the cargo by insects or other undesirable pests. The fumigant may be provided in solid form and placed in the cargo area, or in gaseous form and piped into the cargo area. The fumigant is typically toxic to humans.

[0004] The fumigation process may be carried out en route, at anchor, or when moored at a pier, and is usually carried out by specially trained personnel with specialized equipment. In most cases, members of the vessel's crew will be present on board the vessel during the fumigation process, and it is therefore essential that the fumigation process be carried out in a manner that ensures that the crew (and specially trained fumigation personnel) are not exposed to toxic fumigants. Access to parts of the vessel, such as engine rooms and mooring lines, may also be required during fumigation.

[0005] A bulk carrier is a ship specially designed to carry loose bulk cargo such as grain, coal, ore, or other similar loose cargoes. A bulk carrier typically includes one or more separate cargo holds arranged from bow to stern of the ship. Grain or other loose bulk goods may be loaded into and unloaded from the holds by, for example, one or more cranes located on the deck of the ship. Alternatively, conveyor loaders, shore cranes, or pneumatic loaders may be used to load and unload the cargo. Each of the cargo holds also typically includes a hatch for closing the opening to the cargo hold.

[0006] In bulk carriers, the ship's accommodation areas and the ship's engine room are typically located aft of the cargo holds, with the accommodation areas located above the engine room. The cargo holds are separated from the engine room by a vertically extending bulkhead. The accommodation areas are physically separated from the cargo holds by two physical barriers, including an intervening engine room, physically removed from the cargo holds, and a vertically extending bulkhead and a deck between the engine room and the accommodation areas. Due to this physical separation, it has generally been relatively safe to fumigate each of the cargo holds of a bulk carrier subject to ship inspection.

[0007] New challenges arise when attempting to safely fumigate roll-on / roll-off ships (also known as RORO ships). In this type of ship, the cargo area typically extends over most of the ship's length and is located within decks within the ship. The decks are interconnected by upright walkways, such as stairs and ladders, and the decks are linked by ramps. Furthermore, the decks are grouped into watertight or gastight zones, with each zone typically having two decks, although some ships may contain more than two decks per zone. Typically, RORO ships are arranged into approximately four zones, each of which is independently ventilated. The cargo areas are configured in such a way that bulk cargo, such as wheeled cargo, can be rolled onto or driven into the cargo area.

[0008] On RORO ships, accommodation areas are typically located on the vessel's open deck, with only flat steel plates and flooring separating the accommodation areas from the top deck of the cargo area. Any openings or small cracks in this flat steel structure could therefore allow fumigants to enter the accommodation areas from the top deck of the cargo area. Openings and small cracks are common on sea-going ships due to the stresses on the vessel during its voyage.

[0009] The arrangement of accommodation areas on a RORO ship presents another challenge for venting fumigants from cargo areas. Ventilation systems serving deck cargoes have been specifically designed to ventilate fuel vapors from cargo areas. Each zone of the ship (watertight or gastight deck cargo group) is served (supply and exhaust as discussed below) by its own group of mechanical fans, which may be controlled as a group, or each fan within a group may be controlled individually, independent of any other fan within that group. In general, the systems have typically been designed to provide 20 to 30 air changes in each zone during loading / unloading operations and 10 air changes per hour while underway.

[0010] RoRo ships usually have one of two types of ventilation systems for the cargo area: 1. Air supply and exhaust mechanical ventilation: The supply and exhaust fans are located around the periphery of the open deck. Some ships may have as many as 70 or more mechanical fans. The mechanical fans may act as supply mechanical fans, exhaust mechanical fans, or reversible supply mechanical fans. Each zone of the ship is ventilated by a group of supply and exhaust mechanical fans that work together to exchange air within the zone. Each zone has multiple ducts (supply and exhaust ducts) that connect to the group of mechanical fans through which the air is exchanged. - A supply mechanical ventilation fan supplies air from the open deck into the area. - Exhaust mechanical ventilation fans exhaust air from the area to the atmosphere above the open deck.

[0011] Ventilation fans may in some cases be dedicated supply and exhaust fans. Some fans may alternate between supply and exhaust modes, with the mode controlled by the operator. Such fans are called reversible supply fans. Depending on how much ventilation needs to be achieved during navigation or loading / unloading, some mechanical fans may or may not be used.

[0012] Mechanical fans are usually located in close proximity (sometimes just a few metres) to accommodation and engine room supply ventilation intakes. Type 1 is prevalent on newer RORO ships.

[0013] 2. Air supply mechanical ventilation and ventilation enclosures: Supply air mechanical ventilation fans are located around the periphery of the forward and amidships of the ship. - Ductwork connected to these supply air mechanical ventilators supplies fresh air into the cargo area. - Ventilation enclosures are located at the aft end of the vessel (also on the port and starboard edges). Each zone has its own dedicated ventilation enclosure. - Piping connects each area to the ventilation housing.

[0014] Fresh air is drawn into each zone by supply mechanical ventilation fans, and atmospheric air is exhausted through vented enclosures.

[0015] In either case, the mechanical ventilation / ventilation enclosures are located near the engine room air intakes and the air conditioning intakes for the crew accommodations. This relative proximity therefore presents a risk to the crew if the mechanical ventilation / ventilation enclosures vent the fumigant during fumigation.

[0016] In addition, mechanical ventilation fans are designed with mechanically operated vents that open and close but in any case are directed downwards to avoid rain intrusion. The mechanical ventilation fans therefore blow down onto the open deck. Venting the fumigant from the cargo area via the mechanical ventilation fans creates the likelihood that the fumigant will stratum and remain on the open deck. This presents a risk to the crew needing access to the engine room, moorings or in the event of an evacuation.

[0017] Another special feature of ro-ro ships that distinguishes them from bulk carriers is that ro-ro ships rise above the waterline compared to bulk carriers due to the lower density of the cargo inside the ro-ro ship. Mooring lines are therefore lowered (usually on deck 4 or 5) and therefore require stairwell access so that the crew can adjust the mooring lines to take tidal movements into account. In contrast, the mooring lines of bulk carriers are located on the open deck.

[0018] Other areas of the ship may require access during fumigation. For example, engine rooms sandwiched between cargo areas may require access during fumigation. For example, auxiliary generators typically run during fumigation. If an alarm condition occurs, the crew will require access to the engine room. Fumigants entering the engine room or access ways will be hazardous to the health of the crew.

[0019] It is an object of the present invention to provide a system / method for fumigating a RORO vessel. It is also an object of the present invention to provide a temporary bulkhead configured to fluidly seal an entryway of a vessel. It is also an object of the present invention to at least provide the public with a useful choice over known systems, methods and equipment.

[0020] As used herein, the term "roll-on / roll-off vessel" or "RORO vessel" refers to any vessel on which car or towable cargo is rolled or driven, usually via a stern ramp or side ramp, onto the cargo deck of the vessel. Examples of such vessels include pure car and truck carriers (PCTCs), large car and truck carriers (LCTCs), and pure car carriers (PCCs).

[0021] The reference herein to any prior art is not an admission or implication that this prior art forms part of the common general knowledge in any legal sense, or that this prior art could reasonably be expected to be understood, regarded as relevant, and / or combined with other prior art by a person skilled in the art. [Summary of the Invention] [Means for solving the problem]

[0022] 1. Systems for fumigating ships In a first aspect, there is provided a system for fumigating a vessel, the system being incidental to the vessel. The system comprises: a fumigant delivery system for delivering the fumigant to a cargo area of ​​the vessel; and A pneumatic system is included for maintaining a selected minimum pressure differential between a selected area of ​​the vessel above the cargo area and the cargo area such that the pressure in the selected area is greater than the cargo area.

[0023] In one embodiment, the vessel is a roll-on / roll-off (RORO) vessel. Preferably, the pneumatic system includes a controller for maintaining a pressure differential throughout the fumigation and exhaust.

[0024] The system is preferably ancillary in that it is not within the body of the vessel, nor is it part of the vessel's machinery, rigging, gear, and other accessories. The control system is also preferably ancillary equipment brought in to fumigate the vessel. As described, many of these aspects are used at the wharf. Components of the pneumatic system are preferably portable. For example, the pneumatic system may include one or more controllers, one or more fans, one or more variable speed drives, and associated sensors, some or all of which may be portable.

[0025] Preferably, the selected areas include the living areas of the vessel, but the selected areas may alternatively or additionally include other areas intended for human occupancy (such as engine rooms, access corridors, and stairwells to engine rooms or moorings).

[0026] The fumigation agent may be an insecticide. Alternatively, the fumigation agent may comprise an insecticide, disinfectant, sanitizer, bactericide, decontaminant, antiseptic, sanitizer, vaccine, antiviral, or vapor.

[0027] Suitably, the fumigation agent delivery system includes one or more first conduits for delivering the fumigation agent in gaseous form, a first end of the one or more first conduits connected to a source of fumigation agent and a second end of the one or more first conduits connected to a cargo area of ​​the vessel for delivering the gaseous fumigation agent to the cargo area of ​​the vessel.

[0028] Preferably, the pneumatic system includes one or more second conduits for delivering air, a first end of the one or more second conduits being connected to a source of air and a second end of the one or more second conduits being connected to a selected area of ​​the vessel, which, as noted above, is preferably a living area of ​​the vessel.

[0029] Preferably, the one or more second conduits are configured to deliver air to the accommodation area so as to substantially maintain a pressure differential between the accommodation area and the cargo area. The pressure differential is preferably at least 50 Pa, more preferably between 50 Pa and 100 Pa. The pressure differential may be a predetermined or preselected pressure differential, or alternatively may be determined in accordance with measurement parameters or operational guidelines. The pressure differential may be constant. Alternatively, the pressure differential may vary throughout the course of the fumigation, provided that a minimum pressure differential is maintained. The pressure differential may vary in accordance with other measured parameters. The selected minimum pressure differential may be maintained throughout the fumigation, and preferably extend beyond the fumigation (at least until removal of the fumigation agent from the cargo area).

[0030] In one embodiment, the pneumatic system may maintain a pressure differential by maintaining a relatively high pressure in the accommodation area, thereby ensuring that a pressure differential exists between the accommodation area and the cargo area (which is typically at atmospheric pressure).

[0031] The pneumatic system and / or fumigation agent delivery system are preferably controlled by the or each controller, which preferably forms part of a control system, and the or each controller is pre-configured at the time of manufacture or during routine servicing or calibration, which calibration includes re-calibration.

[0032] The one or more first conduits of the fumigation agent delivery system are preferably sealingly connected at second ends of the plurality of first conduits to a first bulkhead located at the entrance to the cargo area. The first bulkhead is preferably configured to fluidly receive and deliver the gaseous fumigation agent to the cargo area. In one embodiment, the first bulkhead includes one or more openings therein configured to be respectively connected to the one or more first conduits, thereby delivering the gaseous fumigation agent to the cargo area. The one or more openings may include one or more respective valves. The one or more valves may be one-way valves. The one or more openings may also be used to transfer a gas sample from the cargo area across the first bulkhead for analysis of the gas sample outside the cargo area. Preferably, the first bulkhead includes a seal configured to fluidly seal the entrance to the cargo area. The seal is preferably in the form of a rubber extrusion. The seal is preferably positioned on the bulkhead according to the style and type of entrance passage to be sealed. The first bulkhead may include one or more other openings configured to transmit power and / or data across the first bulkhead. The first bulkhead may be fitted into a watertight steel doorway. This type of door almost always has a protruding steel flange that runs around the periphery of the doorway. Typically, the protruding steel flange fits into a rubber gasket frame on the door to create a seal. There are two preferred options for creating a seal using a temporary bulkhead: 1) Fitting a rubber extrusion into a protruding steel flange that runs around the perimeter of the doorway, which creates a seal with a flat surface on the bulkhead, or 2) A flat rubber or foam (butyl tape) flat extrusion is attached to the bulkhead using adhesive. A protruding steel flange running around the doorway then fits into the rubber surface frame on the back of the bulkhead.

[0033] The system preferably further includes one or more other temporary bulkheads, where the access way needs to be sealed but penetrates appurtenances (such as conduits or power cables). The one or more other bulkheads may be similar to the first bulkhead. For example, there may be multiple entry points into each cargo area. Each escape trunk (a vertical access way located around the periphery of the ship) will have a watertight door or hatch between the cargo areas. The bulkheads are preferably fitted over the access ways (doors / hatches) where appurtenances need to be attached. Preferably, a bulkhead is located at at least one entrance into each cargo area of ​​the ship, so that each cargo area can be fumigated independently of any other cargo area, as required. For example, a first bulkhead may be located at the entrance to a first cargo area and fluidly connected via a conduit to another bulkhead located at the entrance to a second cargo area, so that the fumigation agent can be delivered to the second cargo area.

[0034] The system may preferably further include a plurality of recirculation fans disposed within each cargo area. The plurality of recirculation fans are configured to distribute the gaseous fumigation agent throughout the respective cargo areas. The one or more first conduits are preferably fluidly connected to the plurality of recirculation fans through the first bulkhead (or through respective bulkheads disposed at the entrances to the respective cargo areas), thereby distributing the fumigation agent throughout the cargo areas. In a preferred embodiment, each deck within the cargo area includes two recirculation fans, with the first fan disposed amidships on the starboard side of the vessel and the second fan disposed amidships on the port side of the vessel. The first and second fans preferably face in opposite directions within the vessel. For example, the first fan faces toward the aft end of the vessel and the second fan faces toward the forward end of the vessel. The plurality of recirculation fans may be powered by power delivered through a plurality of other openings in the first bulkhead (or one or more openings in one or more other bulkheads). The multiple recirculation fans may be powered by a power source located on board the vessel or by a power source located remotely from the vessel.

[0035] The one or more second conduits are preferably sealingly connected at their second ends to a second bulkhead disposed at the inlet to the living area. The second bulkhead is preferably configured to fluidly receive and deliver air to the living area. In one embodiment, the second bulkhead includes one or more openings therein configured to respectively connect to the one or more second conduits, thereby delivering air to the living area. The one or more openings may include one or more respective valves. The one or more valves may be one-way valves. Preferably, the second bulkhead includes a seal configured to fluidly seal the inlet to the living area. The second bulkhead may include one or more other openings configured to deliver power and / or data across the second bulkhead.

[0036] Gaseous fumigants may include any one or more of the following: sulfuryl fluoride, formaldehyde, methyl bromide, chloropicrin, iodoform, hydrogen cyanide, nitrogen, ethyl formate, and ethanedinitrile. Fumigants may also be delivered with a carrier gas such as nitrogen or carbon dioxide.

[0037] The source of the fumigation agent may vary. In one embodiment, the fumigation agent may be provided by a mobile vehicle containing the gaseous fumigation agent. The gaseous fumigation agent is typically stored in gas cylinders within the mobile vehicle. The gas cylinders may be arranged in separate groups. Each of the gas cylinders within a group may be fluidly connected via a manifold. Two first conduits may extend from each manifold to deliver the gaseous fumigation agent into each cargo area. Each of the first conduits may have a diameter of approximately 1 / 4 inch (6.35 mm) to 1 inch (25.4 mm), but is preferably approximately 3 / 8 inch (9.53 mm).

[0038] In an alternative arrangement, the fumigant may be provided in liquid form and vaporized at the wharf or on board the ship. Vaporization methods include: a) Introduction of liquid fumigant into the jet stream of recirculating fans on each deck. This is appropriate for sulfuryl fluoride; b) Heat exchanger vaporizer: Such an arrangement may be provided on each cargo deck. c) Air-assisted atomization: whereby the liquid fumigant is pressurized before being introduced into the jet stream of the recirculation fan. Such an arrangement may be provided on each cargo deck adjacent to the recirculation fan. d) The fumigant liquid ethyl formate is dissolved in liquid CO2 and delivered as a mixture from the wharf to the ship, this release generating heat from the atmosphere and evaporation.

[0039] In a preferred embodiment, each of the one or more secondary conduits is connected at its first end to a respective one or more fans. The one or more fans are configured to draw air into the respective one or more secondary conduits so that the air may be delivered by the one or more secondary conduits to selected areas of the vessel, such as accommodation areas. The one or more fans are preferably controlled by a controller via a variable speed drive (VSD). Preferably, the controller controls the speed of at least one of the one or more fans via the variable speed drive. In one embodiment, the VSD may be integrated with the controller. Alternatively, the VSD may be separate from the controller and operably controlled by the controller.

[0040] In a preferred embodiment, the pneumatic system includes three second conduits configured to deliver air to selected areas of the vessel, such as accommodation areas. In this embodiment, the pneumatic system further includes three fans, each connected to a first end of a respective one of the three second conduits. The second conduits are preferably respective ducts each having a diameter of 450 mm.

[0041] Preferably, the source of air is ambient air located at the vessel's wharf. Alternatively, the source of air may be drawn from below the vessel's deck or above the deck at the forward end of the vessel. In this embodiment, one or more fans may be located on the vessel's deck, and each one or more conduits may be connected at a first end thereof to the one or more fans. The second ends of the one or more conduits may be routed across the side of the vessel to draw fresh air from below the deck.

[0042] Preferably the source of air is located remotely from the source of fumigation agent. Preferably the source of air is located remotely on the vessel.

[0043] The system preferably further includes a low-range monitoring system including an air quality monitor disposed at or adjacent to the source of air. Preferably, the air quality monitor is disposed substantially adjacent to at least one of the first ends of the one or more second conduits. The air quality monitor may be configured to detect the presence or absence of one or more of the gaseous fumigation agent, carbon dioxide, carbon monoxide, and other volatile organic compounds (VOCs). The low-range monitoring system may further include one or more other monitors or sensors disposed in other areas typically occupied by the vessel's crew (e.g., engine rooms, etc.). Each of the monitors or sensors of the low-range monitoring system may be configured to detect the presence or absence of each of the aforementioned compounds. For a gaseous fumigation agent including sulfuryl fluoride, each of the monitors or sensors of the low-range monitoring system is configured to detect sulfuryl fluoride at concentrations ranging from approximately 0.5 ppm to 230 ppm with a resolution of 0.1 ppm. However, different levels will apply to a variety of different fumigation agents. Each of the monitors or sensors of the low range monitoring system preferably transmits its respective measurements to the controller.

[0044] The fumigation agent delivery system may further include a high-range monitoring system. The high-range monitoring system may include a plurality of monitors or sensors disposed within each of the cargo areas of the ship. Each of the monitors or sensors in the high-range monitoring system may be configured to detect the presence or absence of gaseous fumigation agent within the cargo area to determine the efficacy of the fumigation operation. For gaseous fumigation agents including sulfuryl fluoride, each of the monitors or sensors in the high-range monitoring system is configured to detect sulfuryl fluoride at concentrations ranging from approximately 5,000 ppm to 15,000 ppm to determine the efficacy of the fumigation operation. However, various levels will be applicable for various different fumigation agents. Each of the monitors or sensors in the high-range monitoring system preferably transmits its measurement results to an associated controller.

[0045] The controllers for the pneumatic system and the low-range monitoring system may be integrated and operable to maintain a pressure differential to ensure continued operation of the pneumatic system, with the low-range monitoring system detecting levels of gaseous fumigation agent in a staffed area (e.g., a living area) and / or at the intake to the pneumatic system. If the low-range monitoring system detects fumigation agent at the intake to the pneumatic system, a safety mechanism may prevent the pneumatic system from being shut down. Another safety feature may consist in increasing the pressure in a staffed area, such as a living system, if the low-range monitoring system detects fumigation agent in the staffed area. For example, a pressure of up to 250 Pa (relative to the top cargo hold or the external environment) may be tolerable in a staffed area. In an alternative embodiment, the high-range monitoring system may include a single monitor or sensor. In this embodiment, one or more gas sampling lines may be distributed throughout the cargo area and connected at one end to a manifold. The manifold may be connected to the monitor or sensor, and a pump may be used to pump gas samples through the one or more gas sampling lines to the monitor or sensor. In this embodiment, the monitor or sensor may be located within the cargo area or outside the cargo area. In either case, the monitor or sensor preferably transmits its measurements to an associated controller. If the monitor or sensor is located outside the cargo area, one or more gas sampling lines may be routed through any of the temporary bulkheads as needed.

[0046] The pneumatic system preferably further includes a first pressure sensor disposed in the cargo area and a second pressure sensor disposed in a selected area, such as the accommodation area. In an embodiment in which the ship is a roll-on / roll-off ship, the cargo area may include multiple cargo areas arranged generally vertically within the ship. In this embodiment, the accommodation area may be located at least partially above an uppermost cargo area of ​​the multiple cargo areas. In a preferred embodiment, the first pressure sensor is located in the uppermost cargo area of ​​the multiple cargo areas. More preferably, the first pressure sensor is located at a location in the uppermost cargo area generally adjacent to the accommodation area.

[0047] The first and second pressure sensors are configured to sense the pressures in the cargo area and the accommodation area, respectively, and transmit the first and second pressures to an associated controller. The controller is configured to determine a difference between the first pressure and the second pressure. The controller is further preferably configured to control operation of the one or more fans to ensure that the difference between the first pressure and the second pressure is maintained above a certain pressure differential. As noted above, the pressure differential is preferably at least 50 Pa, more preferably 50-100 Pa. Accordingly, the second pressure preferably exceeds the first pressure by at least 50 Pa.

[0048] In an alternative embodiment, the pneumatic system may include a differential pressure sensor. A first pressure sensing end of the differential pressure sensor may be located in or fluidly connected to the accommodation area of ​​the vessel, and a second pressure sensing end of the differential pressure sensor may be located in or fluidly connected to the top cargo area. The first and second pressure sensing ends may be fluidly connected to the accommodation area and the top cargo area, respectively, by respective conduits extending from the first and second pressure sensing ends. The first and second ends of the differential pressure sensor are configured to sense pressures in the accommodation area and the top cargo area, respectively, and transmit the respective pressures to an associated controller. As above, the controller is then configured to determine a difference between the respective pressures and to control operation of one or more fans to ensure that the pressure differential is maintained.

[0049] In an alternative embodiment, a first pressure sensing end of the differential pressure sensor may be fluidly connected to a controller or to a controller integrated with a variable speed drive (VSD) via a conduit, and a second pressure sensing end may be fluidly connected to the top cargo area via a conduit extending to the top cargo area.

[0050] In yet another alternative embodiment, the pneumatic system may include a pressure sensor disposed in, on, or adjacent to one or more fans, the pressure sensor configured to measure a resistance applied to the one or more fans during operation. The resistance applied to the one or more fans may be interpolated in a manner known to those skilled in the art to determine a pressure differential between the pressure in the accommodation area and the external air pressure outside the accommodation area. An associated controller may be configured to control the pressure differential to ensure that the accommodation area is at a greater relative pressure than the cargo area.

[0051] The system preferably includes at least one first power source that is independent of the vessel's power. Alternatively, the system may derive its power from the vessel's power. The power source is configured to provide power to at least the controller, the first and second pressure sensors, the one or more fans of the pneumatic system, the one or more recirculation fans, the low-range monitoring system, and the high-range monitoring system. The air quality monitor of the low-range monitoring system (located adjacent to the source of air) may alternatively be powered by a separate power source, such as a battery.

[0052] The system may include a first power source and a second power source. The second power source is preferably a backup power source and may provide power to components powered by the first power source if the first power source becomes inoperable. The first and second power sources may be first and second mobile generators, respectively. Alternatively, the first and second power sources may be first and second batteries, respectively, or any combination of mobile generators and batteries.

[0053] The gaseous fumigant is suitably configured to exit the cargo area through one or more openings located on the deck of the vessel. In a preferred embodiment, a flexible stack or chimney is disposed around each of the one or more openings and configured to direct the exiting gaseous fumigant generally upwardly and away from the deck of the vessel. The one or more openings may comprise a combination of mechanical ventilation fans, vent enclosures or escape trunks.

[0054] Any of the features described in connection with other aspects described in the Summary may also have application to this aspect.

[0055] According to a second aspect, there is provided a system for fumigating a vessel, the system being incidental to the vessel, the system including: a fumigation agent delivery system for delivering a fumigation agent to a cargo area of ​​the vessel at one or more delivery sites; and a pneumatic system for maintaining a pressure in a selected area of ​​the vessel that is greater than the pressure in the cargo area of ​​the vessel, wherein an air intake of the pneumatic system is remote from the one or more fumigation agent delivery locations and the one or more exhaust sites.

[0056] Suitably the air intake is more than 30 metres from the fumigation agent delivery location or locations.

[0057] An exhaust system may be provided to exhaust the fumigation agent from the cargo area following fumigation from one or more exhaust sites, preferably with an air intake more than 30m from the exhaust site or sites.

[0058] The air intake may be located on the pier outside the hull of the vessel or at the forward end of the vessel.

[0059] Preferably the pneumatic system includes a controller to maintain pressure throughout fumigation and exhaust.

[0060] Any of the features described in connection with other aspects described in the Summary may also have application to this aspect.

[0061] 2. Methods for fumigating RORO vessels In another aspect, a method of fumigating a vessel is provided, the method comprising delivering a fumigation agent to a cargo area of ​​a roll-on / roll-off vessel.

[0062] Preferably, the method further comprises delivering air to a selected area on the vessel above the cargo area to maintain a selected minimum pressure differential between the selected area and the cargo area so that the pressure in the selected area is greater than the cargo area. Preferably, the method further comprises delivering a fumigation agent to the cargo area at one or more delivery sites, the method further comprising exhausting the fumigation agent from the cargo area following fumigation from one or more exhaust sites, and delivering air to the selected area on the vessel to maintain a selected minimum pressure differential between the selected area and the cargo area so that the pressure in the selected area is greater than the cargo area, wherein an air intake for the air delivery is remote from the one or more fumigation agent delivery locations and the one or more exhaust sites.

[0063] Suitably the air intake is more than 30 metres from the one or more fumigation agent delivery locations and one or more exhaust site(s). In a more preferred form of the invention the air intake is located on the quay outside the hull of the vessel or at the forward end of the vessel.

[0064] The method may further include delivering a fumigation agent to fumigate the cargo area; venting the fumigation agent from the cargo area following fumigation; and delivering air to the selected area of ​​the vessel to maintain a pressure in the selected area greater than the pressure in the cargo area, the air delivery being maintained throughout the fumigation and venting.

[0065] Any of the features described in connection with other aspects described in the Summary may also have application to this aspect.

[0066] 3. How to configure a fumigation system In another aspect, there is provided a method of configuring a system for fumigating a vessel, the system being incidental to the vessel, the method comprising configuring an air intake of a pneumatic system operable to maintain a minimum selected pressure differential between a selected area of ​​the vessel and a cargo area such that the pressure in the selected area is greater than the pressure in a cargo area of ​​the vessel, the air intake configured to draw air from a wharf or at a location outwardly over the hull of the vessel.

[0067] Preferably, the pneumatic system includes one or more fans, and the method further includes configuring the fans at the wharf. The pneumatic system may include a variable speed drive, and the controller controls the speed of the one or more fans via the variable speed drive, and the method further includes configuring the variable speed drive at the wharf.

[0068] The method may further include providing a source of fumigation agent for fumigating the vessel, the source of fumigation agent being located at the wharf.

[0069] The method may further include configuring a movable crew escape boom at the wharf.

[0070] Any of the features described in connection with other aspects described in the Summary may also have application to this aspect.

[0071] 4. Control System According to yet another aspect, there is provided a control system incidental to a roll-on / roll-off vessel (RORO vessel). The associated control system includes a controller configured to receive pressure or pressure differential measurements from selected areas and / or cargo areas of the vessel during fumigation and, in response to such measurements, control air delivery to selected areas of the vessel to maintain a selected minimum pressure differential between the selected areas and the cargo areas, the pressure in the selected areas being greater than the cargo areas. The controller is further configured to maintain the pressure differential throughout fumigation and subsequent evacuation of the fumigation agent from the cargo areas.

[0072] Preferably, the selected minimum pressure differential is at least 50 Pa, or between 50 Pa and 100 Pa. The selected minimum pressure differential may be preselected. The associated control system may be responsive to the one or more pressure sensors and / or differential pressure sensors and is preferably further configured to control one or more supply air fans to supply air to the selected area to maintain the selected minimum pressure differential. The associated control system is preferably configured to control at least the speed of the one or more fans via a variable speed drive.

[0073] The associated control system may further be configured to perform low range monitoring to detect one or more of gaseous fumigants; carbon dioxide; carbon monoxide; and other volatile organic compounds (VOCs) within the selected area and / or at the air intake of the delivered air.

[0074] Any of the features described in connection with other aspects described in the Summary may also have application to this aspect.

[0075] According to yet another aspect, there is provided a method of pre-configuring a control system associated with a roll-on / roll-off vessel (RORO vessel). The method includes pre-configuring a controller of the associated control system. The controller is operable to receive pressure or pressure differential measurements from selected areas and / or cargo areas of the vessel during fumigation and, in response to such measurements, control air delivery to selected areas of the vessel to maintain a selected minimum pressure differential between the selected areas and the cargo areas, the pressure in the selected areas being greater than the cargo area. The controller is further operable to maintain the pressure differential throughout fumigation and subsequent evacuation of the fumigation agent from the cargo areas.

[0076] Preferably, the method further includes pre-configuring the associated control system to maintain a selected minimum pressure differential of at least 50 Pa, or between 50 Pa and 100 Pa. The method may further include pre-configuring the associated control system to maintain at least one pre-selected minimum pressure differential. Preferably, the method further includes pre-configuring the associated control system to control one or more supply air fans to deliver air to the selected area.

[0077] The method further includes pre-configuring the associated control system or additional associated control systems to perform low range monitoring to detect one or more of the gaseous fumigant; carbon dioxide; carbon monoxide; and other volatile organic compounds (VOCs) within the selected area and / or at the air intake of the delivered air, wherein the controller controls the air delivery in response to an output of the low range monitoring.

[0078] Any of the features described in connection with other aspects described in the Summary may also have application to this aspect.

[0079] 5. Temporary bulkhead In another aspect, a temporary bulkhead configured to fluidly seal an inlet passage of a vessel is provided, the bulkhead including: a body configured to be disposed within the inlet passage of the vessel; a seal disposed about the body and configured to contact the inlet passage to fluidly seal the inlet passage; and one or more openings in the body, the one or more openings adapted to connect with a fluid conduit.

[0080] The body containing the seal is preferably sized to be larger than the opening of the inlet passage.

[0081] The opening in the body preferably includes mating features to facilitate connection to a fluid conduit.

[0082] The one or more openings may be configured to allow a fluid to pass through the bulkhead. The fluid may be a gaseous fluid. The bulkhead may include one or more other openings configured to allow the passage of power, data, and / or other ancillary equipment through the bulkhead.

[0083] At least some of the one or more openings include a respective valve.

[0084] Preferably, the septum is configured to be sealingly connected to one or more air conduits as described above in relation to the previous embodiment.

[0085] The bulkhead preferably forms part of the above-mentioned system for fumigating a vessel. Any of the features described in relation to other aspects set out in the Summary may also have application to this aspect.

[0086] As used herein, unless the context requires otherwise, the term "comprises" and its variations (progressive tense, third person singular, etc.) is not intended to exclude further additional items, parts, integers or steps.

[0087] Further aspects and embodiments of the above-described aspects will become apparent from the following description, given by way of example with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0088] [Figure 1] FIG. 1 is a side cross-sectional view of a RORO vessel that may be fumigated in accordance with one embodiment, illustrating a fumigation operation, a fumigation agent delivery system, a pneumatic system and temporary flexible exhaust vents in accordance with one embodiment; [Figure 2] Similar to Figure 1, but showing ventilation operation (occurring after fumigation operation). [Figure 3] FIG. 10 is a side cross-sectional view of an alternative RORO vessel that may be fumigated in accordance with one embodiment, illustrating a fumigation operation, a fumigation agent delivery system, a pneumatic system and temporary flexible exhaust vents in accordance with one embodiment; [Figure 4]Similar to Figure 3, but showing ventilation operation (occurring after fumigation operation). [Figure 5] FIG. 10 is a side cross-sectional view of an alternative RORO vessel that may be fumigated in accordance with one embodiment, illustrating a fumigation operation, a fumigation agent delivery system, a pneumatic system and temporary flexible exhaust vents in accordance with one embodiment; [Figure 6] Similar to Figure 5, but showing ventilation operation (occurring after fumigation operation). [Figure 7] FIG. 3 is a front perspective view of a portion of the accommodation area of ​​the vessel of FIG. 2, further showing temporary bulkheads and other components of the pneumatic system of FIG. 2. [Figure 8] Similar to FIG. 7, but showing only some parts of the temporary bulkhead. [Figure 9] 9 is a rear perspective view similar to FIG. 8. [Figure 10] FIG. 8 is a front view of the bulkhead of FIG. 7. [Figure 11] 11 is a side cross-sectional view of the septum of FIG. 10 taken along line 11-11. [Figure 12] FIG. 9 is a rear perspective view of the bulkhead of FIG. 8. [Figure 13] FIG. 2 is a rear front view of another bulkhead associated with the fumigation agent delivery system of FIG. 1; [Figure 14] FIG. 14 is a side cross-sectional view of the partition wall of FIG. 13. [Figure 15] FIG. 2 is a side perspective view of another bulkhead associated with the fumigation agent delivery system of FIG. 1 and used internally throughout the cargo area; [Figure 16] FIG. 2 is a side perspective view of a hatch bulkhead associated with the fumigant delivery system of FIG. 1 and used internally throughout the cargo area; [Figure 17] FIG. 1 is a perspective view of a flexible temporary vent according to one embodiment. [Figure 18] 18 is a cutaway view similar to FIG. 17. [Figure 19] FIG. 18 is a front cutaway view of the flexible temporary vent of FIG. 17. [Figure 20] FIG. 20 is a side cross-sectional view of the flexible temporary vent of FIG. 19 taken along line 20-20. [Figure 21] FIG. 10 is a side cross-sectional view of a RORO vessel that may be fumigated in accordance with an alternative embodiment, showing the fumigation agent delivery system, pneumatic system, temporary flexible exhaust vents, and illustrating both fumigation and ventilation operations in accordance with one embodiment; [Figure 22] This is a mechanical exhaust ventilation fan with a housing that can be installed on the open deck of a RORO ship. [Figure 23] 23 is a flexible exhaust outlet (Type II) according to one embodiment installed on the mechanical ventilation fan of FIG. 22. [Figure 24] FIG. 24 is a side view of the flexible vent of FIG. 23. [Figure 25] FIG. 24 is a side view of the flexible exhaust port of FIG. 23 during ventilation operation. [Figure 26] This is an exhaust vent housing that can be installed on the open deck of a RORO ship. [Figure 27] 27 is the vented enclosure of FIG. 26 showing the location of a flexible exhaust vent according to one embodiment. [Figure 28] 28 shows the exhaust housing and flexible exhaust of FIG. 27 during ventilation operation. DETAILED DESCRIPTION OF THE INVENTION

[0089] Typical RORO vessel Referring to FIG. 1 , a roll-on / roll-off vessel 10 (hereinafter "RORO vessel") is shown including a hull 12 and a cargo area 13 including a plurality of separate cargo areas 14. Each of the cargo areas 14 is watertight or gastight and includes a respective cargo deck 16. As shown in FIG. 1 , each cargo area 14 includes a single cargo deck 16. However, it will be understood that the RORO vessel shown in FIG. 1 is merely exemplary and that a RORO vessel may include more than one cargo deck 16, such as two or three cargo decks within each separate cargo area 14. A typical RORO vessel may include a total of 13 cargo decks distributed among four separate cargo areas. Each of the cargo decks within a single cargo area is typically interconnected by a ramp.

[0090] The RORO vessel 10 further includes an open deck 18 disposed above the uppermost cargo area of ​​the plurality of cargo areas 14 and an accommodation area 20 disposed on the open deck 18 generally adjacent a bow end 22 of the vessel 10. The accommodation area 20 is positioned to provide accommodation for the crew or personnel of the vessel 10 and includes various living quarters of the vessel 10. A bridge 23 is positioned above and generally fluidly connected to the accommodation area 20. The bridge 23 houses various controls, navigation instruments, and other equipment necessary for command of the vessel 10.

[0091] The cargo areas 14 of the RORO vessel 10 are disposed one on top of the other and extend substantially along the entire length of the vessel 10. In the illustrated embodiment, the vessel 10 includes four such cargo areas 14. As described above, each of the cargo areas 14 is configured to be watertight or gastight and is further connectable to an adjacent cargo area 14 via one or more movable or sealable ramps. The movable ramps are movable between an open position and a closed position. In the open position, the ramps connecting adjacent cargo areas 14 allow for the passage of crew, other personnel, and cargo between the adjacent connected cargo areas 14. As will be appreciated, in the open position, the adjacent connected cargo areas 14 are fluidly connected to one another such that, for example, gaseous fumigant in one cargo area 14 can flow into the adjacent connected cargo area 14. However, in the closed position, the ramps act as seals between adjacent cargo areas 14 such that the adjacent cargo areas are watertight or gastight.

[0092] The top cargo area 14 may be accessed by crew members or other personnel (such as specially trained fumigation personnel) via one or more escape trunks located within the open deck 18. The RORO vessel 10 shown in Figure 1 includes eight to ten such escape trunks (only four escape trunks are shown in Figure 1) generally located around the periphery of the open deck 18. The escape trunks define respective openings or access ways into the top cargo area 14 through the open deck 18 and include ladders or combinations of ladders and staircases extending downward through each cargo deck 16 to the bottom cargo deck 16 within the bottom cargo area 14.

[0093] The openings or accessways into the uppermost cargo area 14 through the open deck 18 can be in the form of hatches 29 (see, for example, FIG. 1) or staircases 31 (see, for example, FIG. 5). In addition, the escape trunks define hatches 19 and / or staircases distributed throughout the cargo area 13. The hatches 19 and / or staircases connect adjacent cargo decks 16 within the cargo area 14 and connect adjacent cargo areas 14. The hatches 19 define respective hatch openings that can be selectively closed as desired to fluidly seal the cargo area 14 from adjacent cargo areas 14. The staircases include respective doors at their upper and lower ends that can also be selectively closed as desired to fluidly seal the cargo area 14 from adjacent cargo areas 14. As will be explained below, during fumigation and subsequent ventilation operations, each of the hatches 19 and / or staircases connecting adjacent cargo areas 14 (except for the hatches 19 and / or staircases of a single escape trunk selected as the "elevator" which allows various appurtenances (such as conduits containing gaseous fumigant) to be routed throughout the cargo area 13) are closed. For reasons explained below, the escape trunk located approximately closest to the amidships of the vessel 10 is preferably selected as the elevator. For convenience, this particular escape trunk will hereinafter be referred to as the "elevator escape trunk." To allow for the routing of appurtenances, such as conduits containing gaseous fumigant, throughout the cargo area 13, each of the hatches 19 of the elevator escape trunks is mounted in a hatch bulkhead 115 (see Figure 16), and each of the doors of each staircase of the elevator escape trunk is mounted in a door bulkhead 111 (see Figure 15). As mentioned above, each staircase includes an upper door and a lower door. Figure 1 shows various interior hatches 19 within cargo area 13 that, if used as elevator escape trunks, would be attached to hatch bulkheads 115. Figure 5 shows interior doors 111a within cargo area 13 that, if used as elevator escape trunks, would be attached to door bulkheads 111. Hatch bulkheads 115 and door bulkheads 111 are described in detail below.

[0094] The RORO vessel 10 shown in Figure 1 includes multiple escape trunks in the form of hatches 29 that include only ladders. Figure 5 shows an alternative RORO vessel 10''' that includes multiple escape trunks in the form of hatches 29 and stairs 31, with at least one escape trunk including a combination of ladders and stairs. Specifically, it can be seen in Figure 5 that the second-most escape trunk from the right includes a combination of stairs and ladders.

[0095] Mechanical supply and exhaust fans The vessel 10 further includes a plurality of supply mechanical ventilators 24 and a plurality of exhaust mechanical ventilators 26. Specifically, each cargo area 14 includes a respective dedicated supply mechanical ventilator 24 and a dedicated exhaust mechanical ventilator 26. Each of the supply mechanical ventilators 24 is configured to supply fresh air into each cargo area 14 via a respective duct 25 extending from around the open deck 18 to the respective cargo area 14 (as shown by the direction of the arrows in FIG. 2). Each of the exhaust mechanical ventilators 26 is configured to exhaust air from each cargo area 14 via a respective duct 27 to the atmosphere above the open deck 18 (as shown by the direction of the arrows in FIG. 2). Although FIG. 1 shows each cargo area 14 including only a single supply mechanical ventilator 24 and a single exhaust mechanical ventilator 26, those skilled in the art will recognize that each cargo area 14 will typically include multiple supply mechanical ventilators and exhaust mechanical ventilators. Each of the supply mechanical ventilators 24 and the exhaust mechanical ventilators 26 can be selectively opened and closed as desired to control the supply and exhaust of air, respectively, to the cargo area 14. Additionally, each of the supply mechanical ventilators 24 includes a respective fan 24a configured to assist in moving air into the cargo area 14, as desired. Alternatively, air can be passively drawn into the cargo area 14 via the supply mechanical ventilators 24. Each of the exhaust mechanical ventilators 26 includes a respective fan 26a configured to assist in removing air from the cargo area 14, as desired.

[0096] As further shown in FIG. 1 , disposed on each of the decks 16 of the cargo areas 14 is cargo 30. The cargo 30 may be any type of cargo, typically wheeled or tracked cargo, that is rolled onto or driven into the cargo areas 14 of the vessel 10 via a selectively openable stern ramp 32 located at the aft end 34 of the vessel 10. After loading of the cargo 30 and while the vessel 10 is in operation, access to the cargo areas 14 may be achieved via an accommodation ladder landing watertight door 36 adjacent to the gangway 11 on the starboard side of the hull 12. As noted above, the uppermost cargo area 14 may also be accessed via one or more escape trunks (either in the form of hatches 29 or stairs 31) in the open deck 18. As shown throughout the accompanying drawings, the accommodation ladder landing watertight door 36 provides direct access to the second-lowest cargo area 14. However, it will be recognized that on other RORO vessels the accommodation ladder landing watertight door may provide direct access to another cargo area other than the second-lowest cargo area.

[0097] The vessel 10 further includes an engine room 38 located adjacent to the lowest cargo area of ​​the plurality of cargo areas 14 generally adjacent the aft end 34 of the vessel. The engine room 38 is physically separated from the lowest cargo area 14 via a vertically extending flat steel bulkhead 40 and is further separated from the second-lowest cargo area 14 by the flat steel deck floor of the second-lowest cargo area 14. As will be appreciated, the engine room 38 houses the engines and other associated equipment used to power and propel the vessel 10 and is controlled by various controls located within the bridge 23. Crew members may be located within the engine room 38 from time to time during operation of the vessel 10 and potentially during fumigation and subsequent ventilation. Exhaust gases generated during engine use are vented via a funnel 42 located on the open deck 18 generally adjacent the aft end 34 of the vessel 10.

[0098] A travel tower 300 is located at the pier to provide an alternative means of embarking or disembarking the RORO vessel 10 during emergencies or fumigation operations when access to the RORO vessel 10 is not possible through the accommodation ladder landing watertight door 36. The travel tower 300 is a cherry picker-style vehicle that can lift passengers from the pier onto the open deck 18 of the RORO vessel 10.

[0099] It will be understood that the RORO vessel 10 shown in FIG. 1 and described above is merely exemplary, and that the particular type and configuration of the RORO vessel may be varied without affecting the scope of the present invention.

[0100] Incidental fumigation system As discussed above, there is an ongoing need to ensure that cargo 30 aboard a vessel 10 is properly fumigated prior to offloading while ensuring the safety of the vessel's crew and any specially trained fumigation personnel. To achieve this objective, the present disclosure provides systems and methods for fumigating a vessel, embodiments of which are shown in Figures 1-28 and described in detail below.

[0101] 1 , there is shown a fumigant delivery system 50 for delivering a fumigant to the cargo area 14 of the vessel 10 and a pneumatic system 60 for maintaining a pressure in the accommodation area 20 greater than the pressure in the cargo area 13. Thus, by maintaining a greater relative pressure in the accommodation area 20 compared to the cargo area 13, any gaseous fumigant present in the cargo area 14 is prevented from entering the accommodation area 20 through, for example, an unintended opening or crack in the flat steel decking below the accommodation area 20.

[0102] The fumigation agent delivery system 50 includes a plurality of first conduits 52 (shown schematically in FIG. 1 ) connected at their first ends to fumigation agent-containing gas cylinders 54 stored within a mobile vehicle 56 located at the wharf of the vessel 10. Typically, the gas cylinders are arranged in separate groups. Each of the gas cylinders within a group may be fluidly connected via a manifold. Two first conduits may extend from each manifold to deliver the gaseous fumigation agent into each cargo area 14. The fumigation agent delivery system may typically include between 20 and 36 first conduits 52. Each of the first conduits 52 may have a diameter of approximately 1 / 4 inch (6.35 mm) to 1 inch (25.4 mm). However, the preferred diameter of each of the conduits 52 is 3 / 8 inch (9.53 mm).

[0103] The fumigation agent may be any one or more of a pesticide, insecticide, disinfectant, sanitizer, bactericide, decontaminant, antiseptic, sanitizer, vaccine, antiviral or vapor and may include any one or more of sulfuryl fluoride, ethyl formate, ethanedinitrile, formaldehyde, methyl bromide, chloropicrin, iodoform, hydrogen cyanide (blue fume), nitrogen and carbon dioxide. While this disclosure includes reference to sulfuryl fluoride, it will be understood that other fumigation agents may be incorporated into some embodiments. Additionally, the mode and level of fumigation agent delivery detected by the high-range and low-range detection systems may vary according to the fumigation agent selected.

[0104] A second end of each of the plurality of first conduits 52 is fluidly connected to the cargo area 14 via a fumigation bulkhead 110 disposed within the accommodation ladder landing watertight door 36. The fumigation bulkhead 110 (see Figures 13 and 14), described in detail below, is configured to fluidly seal the accommodation ladder landing watertight door 36 to ensure that any gaseous fumigant delivered to the cargo area 14 via the plurality of first conduits 52 is prevented from escaping from the cargo area 14 through the accommodation ladder landing watertight door 36 into the environment.

[0105] In addition to the fumigation bulkheads 110 located within the accommodation ladder landing watertight doors 36, a number of other bulkheads are located throughout the cargo area 13. As noted above, there is a hatch bulkhead 115 (FIG. 16) located at each hatch 19 connecting adjacent cargo areas 14 within the elevator escape trunk. Additionally, there is a door bulkhead 111 (FIG. 15) at each door (such as at door 111a shown in FIGS. 5 and 6) at each stairway connecting adjacent cargo areas 14 within the elevator escape trunk. The door bulkheads 111 are generally rectangular in overall form and include seals 84 configured to seal their respective door openings. The door bulkheads 111 also include a generally rectangular opening 113 within their lower half that is configured to receive a plurality of first conduits 52 for delivering gaseous fumigation agent across the bulkhead 111. The hatch bulkheads 115 (FIG. 16) are generally square in cross section and are sized to be larger than the generally square hatch openings 19a. The hatch bulkhead 115 is therefore configured to fluidly seal the hatch 19 by seating over and covering the hatch opening 19a. It should be noted that Figure 16 shows an exploded view of the hatch bulkhead 115 partially positioned over the opening 19a in the hatch 19. Similar to the door bulkhead 111, the hatch bulkhead 115 includes a generally rectangular opening 117 configured to receive the plurality of first conduits 52 to thereby deliver the gaseous fumigation agent across the hatch bulkhead 115.

[0106] The combination of fumigation bulkheads 110, door bulkheads 111, and hatch bulkheads 115 used throughout the cargo area 13 allows the entire cargo area 13 to be fumigated at approximately the same time, or alternatively, allows a particular cargo area 14 to be fumigated separately from any other cargo area 14, or yet alternatively, allows multiple cargo areas 14 to be fumigated separately from any other cargo area 14.

[0107] Fumigation Mode Fumigating the entire cargo area 13 substantially simultaneously is achieved in the following manner. First, a plurality of first conduits 52 are fluidly connected at their first ends to the mobile fumigation agent-containing vehicle 56 and at their second ends to the exterior of the fumigation bulkhead 110 located within the accommodation ladder landing watertight door 36. Next, another plurality of first conduits 52 are connected at their first ends to the interior of the fumigation bulkhead 110 and at their second ends to respective recirculation fans 33 located within the second-lowest cargo area 14 (as explained above, the accommodation ladder landing watertight door 36 provides direct access to the second-lowest cargo area 14). The recirculation fans 33 are configured to distribute the gaseous fumigation agent throughout the second-lowest cargo area 14. There are preferably two recirculation fans 33 located within each cargo deck 16 in each cargo area 14 to distribute the gaseous fumigation agent throughout each cargo area 14. A preferred arrangement has a first fan 33 located approximately amidships on the starboard side of the vessel 10 and a second fan located approximately amidships on the port side of the vessel 10. The first and second fans 33 preferably face in opposite directions within the vessel 10. For example, the first fan 33 may face towards the aft end of the vessel 10 and the second fan 33 may face towards the forward end of the vessel 10 to thoroughly distribute the gaseous fumigant throughout each cargo area 14.

[0108] Each of the recirculation fans 33 is preferably a direct drive axial fan. Preferably, each of the recirculation fans 33 is a 7.5 kW direct drive axial fan. Furthermore, each of the recirculation fans 33 preferably has a diameter of 760 mm and a centreline located 1.5 m above the cargo deck 16 to ensure sufficient distribution of the gaseous fumigant throughout each cargo deck 16. The recirculation fans 33 are located at a height of approximately 4 to 16 m. 3 The preferred air volume flow rate for the recirculation fan 33 is about 10 m / s. 3 / s.

[0109] To fumigate cargo areas other than the second-lowest cargo area 14, another plurality of first conduits 52 are connected at their first ends to the inside of the fumigation bulkhead 110 and at their second ends to recirculation fans 33 located within each of the other cargo areas 14. The plurality of first conduits 52 may be routed to a particular cargo area 14 through one or more door bulkheads 111 (Figure 15) and / or through one or more hatch bulkheads 115 (Figure 16) in the escape trunk elevator. As mentioned above, the door bulkheads 111 and hatch bulkheads 115 include respective openings 113 and 117 through which the first conduits 52 may be routed. In this manner, a plurality of first conduits 52 extend from the inside of the fumigation bulkheads 110 located within the accommodation ladder landing watertight doors 36 within each of the cargo areas 14 to the recirculation fans 33, thereby creating separation between the cargo areas 14 while allowing the entire cargo area 13 to be fumigated substantially simultaneously.

[0110] To fumigate only a single cargo area 14 or only a specific plurality of cargo areas 14, the multiple first conduits 52 are connected at their first ends to the inside of the fumigation bulkhead 110 and at second ends to the recirculation fans 33 within the specific cargo area 14 or groups of cargo areas 14 desired to be fumigated. Any specific cargo area 14 not desired to be fumigated is fluidly sealed by closing openings 113 and 117 in the respective door bulkhead 111 and hatch bulkhead 115 leading into that cargo area 14 via the escape trunk elevator. As shown in Figure 15, the door bulkhead 111 includes a pair of flaps 114 disposed around the opening 113, which are configured to close and fluidly seal the opening 113. The flaps 114 preferably include a rubber sealant and are biased to a closed position in which the flaps 114 close the opening 113. 16, the hatch bulkhead 115 includes a flap 118 disposed about the periphery of the opening 117, the flap 118 being configured to close and fluidly seal the opening 117. The flap 117 is similar to the pair of flaps 114 and includes a rubber sealant that is biased to a closed position. In this manner, one or more cargo areas 14 can be individually fumigated as desired by fluidly sealing off specific cargo areas 14 by closing the openings 113 and 117 in the respective door bulkheads 111 and hatch bulkheads 115 leading from the escape trunk elevators to those cargo areas 14.

[0111] As shown in Figures 15 and 16, two first conduits 52 penetrate the door bulkhead 111 and / or hatch bulkhead 115 to fumigate each cargo area 14. However, one skilled in the art will recognize that a different number of conduits 52 may be used to fumigate each specific cargo area 14. For example, two to four conduits 52 may be used to fumigate each cargo deck 16 within a cargo area 14, with one or two conduits 52 connected to each recirculation fan 33 on each cargo deck 16. In the illustrated arrangement, two first conduits 52 are used to fumigate each cargo area 14. A first one of the conduits 52 is connected to a first fan 33 located within the specific cargo area 14, and a second one of the conduits 52 is connected to a second fan 33 located within the specific cargo area 14. As mentioned above, the escape trunk located approximately closest to amidships of the ship 10 is selected as the riser escape trunk with appurtenances such as conduits 52 routed throughout the cargo area 13. Advantageously, this positioning allows the shortest possible conduits 52 to be used throughout the cargo area 13, as the fumigation bulkheads 110 are also located approximately amidships of the ship 10, as are the recirculation fans 33 in each cargo zone 14.

[0112] High Range Monitoring System Other features of the fumigation system 50 will now be described. Referring back to Figure 1, a high range monitoring system is used to determine the efficacy of the fumigation operation. The high range monitoring system includes a plurality of sensors 35 located within each of the cargo areas 14. The sensors 35 detect a gaseous fumigant in the form of sulfuryl fluoride in a concentration range of approximately 5,000 ppm to 15,000 ppm. The sensors 35 in the high range monitoring system provide feedback to a controller 41. The high range monitoring system may be activated during fumigation and ventilation.

[0113] During a fumigation operation, the supply mechanical ventilators 24 and the exhaust mechanical ventilators 26 are maintained in a closed position to prevent the escape of the gaseous fumigation agent into the environment above the open deck 18. Mounted around each of the exhaust mechanical ventilators 26 is a respective flexible temporary vent 58, described in detail below. The flexible temporary vents 58 assist in the safe removal of the gaseous fumigation agent from the cargo area 14 after a fumigation operation is completed. In the embodiment shown in Figure 1, the temporary flexible vents 58 are shown in a non-operational retracted position due to the exhaust mechanical vents 26 being in a closed or non-operational position.

[0114] Overpressure in the passenger area As mentioned above, during fumigation operations, the air pressure system 60 is configured to maintain the air pressure in the accommodation area 20 higher than the air pressure in the cargo area 14. In the embodiment shown, the bridge 23 is also maintained at a greater relative pressure than the cargo area 14 due to its fluid connection to the accommodation area 20.

[0115] The pneumatic system includes three second conduits 62 (shown schematically in FIG. 2 ) configured to deliver air to the accommodation area 20 of the vessel 10. Each of the conduits 62 is connected at their first end to a source of air located at the wharf of the vessel 10 (i.e., remote from the vessel 10) and connected at their second end to an accommodation bulkhead 80 ( FIG. 7 ) located within an inlet way 64 (described below) into the accommodation area 20. The accommodation bulkhead 80 is fluidly connected to each of the three conduits 62 and configured to thereby deliver air into the accommodation area 20, and is further configured to fluidly seal the inlet way 64 to prevent air from escaping via the inlet way 64. During fumigation operations, the accommodation area 20 is preferably significantly airtight, or at least sufficiently airtight, to prevent the escape of a relatively significant amount of air from the accommodation area 20 that would otherwise make it difficult to maintain the accommodation area 20 at a greater relative pressure compared to the cargo area 14. To this end, any vents or openings into the occupied area are preferably closed and any air conditioning devices supplying and / or removing air from the occupied area 20 are preferably shut down during fumigation operations.

[0116] 2, each of the first ends of the conduits 62 is connected to a respective fan 66 configured to draw air into a respective conduit 62 so that the air may be delivered to the living area 20 via the respective conduit 62. The fans 66 are controlled by a controller 41 that controls at least the speed of the fans 66 via a variable speed drive (VSD) 43, thereby adjustably controlling the volumetric flow rate of air delivered to the living area 20 through each of the conduits 62. The VSDs 43 and the fans 66 are powered by first and second mobile generators 45. Preferably, the second generator 45 serves as a backup power source for the first generator 45 in the event that the first generator 45 is inoperable.

[0117] Pressure Difference Sensing The pneumatic system 60 further includes a differential pressure sensor 70 including a first pressure sensing end 72 located in the accommodation area 20 of the vessel and a second pressure sensing end 74 located in and adjacent to the uppermost cargo area 14. The first and second ends 72 and 74 of the differential pressure sensor 70 are configured to sense the pressure in the accommodation area 20 and the uppermost cargo area 14, respectively, and transmit the respective pressures to the controller 41. The controller 41 is configured to determine the difference between the respective pressures and to control the operation of a fan 66 connected to the conduit 62 to ensure that a predetermined desired pressure differential is maintained. Preferably, the pressure in the accommodation area 20 is maintained at least 50 Pa above the pressure in the cargo area 14. More preferably, the pressure in the accommodation area 20 is maintained between 50 and 100 Pa above the pressure in the cargo area 14. As will be appreciated by those skilled in the art, if the pressure differential falls below a predetermined desired pressure differential, the controller controls fan 66 via VSD 43 to increase the speed of fan 66, thereby increasing the volumetric flow rate of air drawn through conduit 62 and into living area 20. Conversely, if the pressure differential exceeds the maximum desired pressure differential, the controller controls fan 66 via SD 43 to decrease the speed of fan 66, thereby reducing the volumetric flow rate of air drawn through conduit 62 and into living area 20.

[0118] Air Quality Monitoring The pneumatic system 60 further includes an air quality monitor 76 located on the wharf generally adjacent to the fan 66 (and thus the intake end of the conduit 62). The air quality monitor is configured to detect the presence or absence of one or more of the gaseous fumigants, carbon dioxide, carbon monoxide, and other volatile organic compounds (VOCs), and may report the presence or absence of these gases to a controller and / or operator so that the pneumatic system 60 may be shut down if necessary. The air quality monitor 76 forms part of a low-range monitoring system used to detect fumigation gases, including sulfuryl fluoride, in the range of 0.5 ppm to 230 ppm with a resolution of 0.1 ppm. Other sensors 37 forming part of the low-range monitoring system may be used at specific locations to detect gas leaks. For example, sensors 37 may be located in the engine room 38, the corridors, and the crew access and accommodation areas 20. The sensors 37 may be daisy-chained by cable feeds that feed back to the control system. The low-range monitoring system is activated during fumigation and ventilation.

[0119] A fumigation operation may last for several hours, such as about 12 to 48 hours or more, depending on the treatment requirements. Throughout the fumigation operation, the pneumatic system 60 is operated to maintain a predetermined desired pressure differential between the accommodation area 20 and the cargo area 14, and optionally is operated until the end of the fumigation operation or beyond (at least until removal of the gaseous fumigant from the cargo area 14 and cargo 30).

[0120] Ventilation operation After the fumigation operation is completed, a ventilation operation is initiated to safely remove the gaseous fumigant from the cargo area 14 and cargo 30. The ventilation operation may last for several hours, such as approximately 10 to 36 hours. During a ventilation operation, the supply mechanical ventilation fans 24 are opened and their associated fans 24a are operated to allow a fresh supply of air to be drawn into the cargo area 14. In addition, the exhaust mechanical ventilation fans 26 are opened and their associated fans 26a are operated to actively remove air containing the gaseous fumigant from the cargo area 14. This ventilation operation is illustrated in FIG. 2. As can be seen in FIG. 2, during a ventilation operation, the flexible temporary exhaust vent 58 is in a generally upright operating position to expel air containing the gaseous fumigant generally upward and away from the open deck 18. As explained below, the flexible temporary exhaust vent 58 extends above the accommodation area 20 when in an operating position to ensure as much as possible that escaping gaseous fumigant is directed away from the accommodation area 20.

[0121] bulkhead 7-14 provide details relating to the fumigation bulkhead 110 located at the accommodation ladder landing watertight door 36, details relating to the accommodation bulkhead 80 located within the entryway 68 into the accommodation area 20, and details relating to the flexible temporary exhaust vent 58 and other potential ventilation methods.

[0122] 7, there is shown a temporary bulkhead 80 located in the starboard entryway 68 into the accommodation area 20. Each of the three conduits 62 of the pneumatic system 60 is fluidly and sealingly connected to the accommodation bulkhead 80 for delivering air through the accommodation bulkhead 80 and into the accommodation area 20.

[0123] 8 and 9, the temporary habitation bulkhead 80 is installed by first positioning the bulkhead 80 within the entryway 68 inside the habitation area 20 (inside as shown in FIG. 9). The bulkhead 80 includes a rectangular body 82 (FIG. 9) sized to be slightly larger than the generally rectangular opening of the entryway 68. The bulkhead 80 further includes a seal 84 (FIG. 9) on a first or outer surface 86 of the body 82. The seal 84 is generally rectangular in cross section throughout its length and extends along the periphery of the rectangular body 82 on the outer surface 86, being slightly recessed from the outer end of the body 82 (see FIGS. 9 and 11). The outer surface 86 of the body 82 is positioned so that the seal 84 faces away from the interior of the habitation area so that it contacts and seals the opening in the entryway 68. The habitation bulkhead 80 is maintained in this position by a series of generally rectangular brackets 88 (FIG. 7) secured to an outer wall 90 of the habitation area 20 surrounding the entryway 68.

[0124] Referring to FIG. 8 , the habitation bulkhead 80 includes four generally rectangular brackets 88 configured to be positioned generally horizontally across the entryway 68. Each of the brackets 88 includes a laterally projecting, outwardly flanged longitudinal end 92 configured to contact the exterior wall 90 of the habitation area 20. Each of the brackets 88 further includes an elongated opening or slit 94 extending generally along the entire length of the bracket 88. The elongated openings 94 are configured to receive a pair of generally T-shaped tubular rods 96. The distal ends of the rods 96 are configured to be received within respective generally circular apertures 98 ( FIG. 15 ) extending through the body 82 of the bulkhead 80 such that the distal ends of the rods 96 protrude from the inner surface of the body 82 ( FIG. 9 ). A respective nut 100 is disposed around each of the distal ends of the rods 96 to secure the position of the rods 96 relative to the body 82 of the bulkhead 80. The proximal ends of the rods 96 include respective generally annular plates ( FIG. 8 ) sized to be wider than the elongated openings 94 and configured to contact the brackets 88 to adjust the position of the brackets 88 relative to the body 82. As will be understood by those skilled in the art, the generally T-shaped proximal ends of the rods 96 can be manually rotated to adjust the position of the rods 96 relative to the body 82 of the septum 80, and therefore the position of the seal 84 relative to the opening in the inlet passage 68. For example, during tightening, the generally circular plate 102 of the rods 96 contacts the outer surface of the brackets 88 to move the brackets 88 toward the body 82 of the septum 80 relative to each other.

[0125] 9-12 , the body 82 of the bulkhead 80 includes three generally circular openings 104 disposed perpendicular to one another along a transverse centerline of the body 82 and extending therethrough. Each of the openings 104 is configured to be fluidly and sealingly connected to a respective one of the second conduits 62 of the pneumatic system 60. The openings 104 may include respective valves (not shown) that may operate as one-way valves to allow air to enter the living area 20 through the openings 104 but prevent the backflow of air.

[0126] 13 and 14 show a temporary fumigation bulkhead 110 configured to be positioned at the accommodation ladder landing watertight door 36. However, it will be recognized that the fumigation bulkhead 110 may instead be fitted to any other suitable opening into the cargo area 13 (such as at the door leading to the staircase (escape trunk) 31 (FIG. 5) on the open deck 18 or via the aft aft access door). However, the fumigation bulkhead 110 is preferably fitted to the accommodation ladder landing watertight door due to its approximately central location within the cargo area 13.

[0127] Fumigation bulkhead 110 is similar in form and operation to habitation bulkhead 80. For example, like habitation bulkhead 80, fumigation bulkhead 110 includes a body 82, a generally rectangular seal 84 on an outer surface 86 of body 82 that extends generally around the periphery of body 82, a plurality of brackets 88, associated T-shaped tubular rods 96, a plurality of generally circular apertures 98 through body 82 of bulkhead 110 configured to receive the distal ends of tubular rods 96, and respective nuts 100 disposed around each of the distal ends of rods 96 on the inner surface of body 82 for securing rods 96 to body 82. Additionally, fumigation bulkhead 110 is sealed against habitation ladder landing watertight door 36 in much the same manner as habitation bulkhead 80 is sealed against opening 64 into habitation area 20. However, the fumigation bulkhead 110 is fitted externally to the accommodation ladder landing watertight door 36 and the accommodation bulkhead 80 is fitted internally to the opening 64 into the accommodation area 20 .

[0128] The fumigation bulkhead 110 also includes a plurality of generally circular openings or plugs 112 generally disposed within the upper half of the body 82 for delivering gaseous fumigation agent across the bulkhead 110, the plurality of generally circular openings or plugs 112 configured to be fluidly and sealingly connected to respective first conduits 52 of the fumigation system 50. Specifically, the fumigation bulkhead 110 includes 36 openings or plugs 112 arranged in three adjacent vertically extending groups, with each group including six rows of two side-by-side openings 112. Thus, the fumigation bulkhead 110 can accommodate 36 first conduits 52 from the mobile fumigation agent-containing vehicles 56 and can distribute the 36 first conduits 52 throughout the cargo area 13. For example, as shown in FIG. 14 , openings or plugs 112 penetrate the bulkhead 110 connecting to respective first conduits 52 on either side of the bulkhead 110. It will be understood that the fumigation bulkhead 110 may include any number of openings or plugs 122 as needed according to the particular vessel being fumigated. Generally, the fumigation bulkhead 110 will include a sufficient number of openings or plugs 112 to allow two to four conduits 52 to be routed to each cargo deck 16.

[0129] The fumigation bulkhead 110 also includes a series of ports 119 disposed within the lower half of the body 82, the series of ports 119 configured to receive and transmit power and / or data across the bulkhead 110. In the embodiment shown, the fumigation bulkhead 110 includes eight ports 119 arranged in two rows on top of each other. As noted above, it will be understood that the fumigation bulkhead 110 may include any number of ports 119 as needed according to the particular vessel being fumigated. Generally, the fumigation bulkhead 110 will include a sufficient number of ports 119 to allow at least one three-phase power cable to be routed to each cargo deck 16. Each port 119 is preferably configured to supply between 15 and 50 Amps of current.

[0130] Ports 119 may provide power to the recirculation fans 33 in each cargo area of ​​cargo area 14. Ports 119 may also provide data connections between the sensors 35 of the high range monitoring system and controller 41. Specifically, one or more power cables may be connected between the first and / or second mobile generators 45 and ports 119 on the outside of the fumigation bulkhead 110, and may be connected between ports 119 on the inside of the fumigation bulkhead 110 and the recirculation fans 33 located in each of the cargo areas 14. The sensors 35 of the high range monitoring system may be connected to controller 41 in a similar manner.

[0131] As mentioned above, FIGS. 15 and 16 respectively show door bulkheads 111 disposed within each door of each stairway within the elevator escape trunk and hatch bulkheads 115 disposed within each hatch 19 within the elevator escape trunk. The door bulkheads 111 are generally similar in format to the accommodation bulkheads 20 and the fumigation bulkheads 110. The door bulkheads 111 are sealed around each door of each stairway within the elevator escape trunk in generally the same manner as the accommodation bulkheads 80 and the fumigation bulkheads 110 are sealed to their respective openings 64 and 36. Specifically, each of the door bulkheads 111 includes a plurality of circular apertures 98 configured to accommodate tubular rods 9 or the like. The hatch bulkheads 115 include a generally rectangular plate-like body 115a that is larger in each dimension compared to the generally rectangular hatch opening 19a. In this manner, when positioned opposite the hatch opening 19a, the plate-like body acts to seal the opening 19a. Each hatch opening 19a is approximately 900mm x 900mm or 1000mm x 1000mm.

[0132] fumigants As noted above, different fumigant chemicals may be used which may require variations on the fumigation agent delivery methods described. As will be appreciated by those skilled in the art, fumigation chemicals such as ethyl formate, ethanedinitrile and hydrogen cyanide may be flammable under some conditions and concentrations that may be encountered if the methods described above are used.

[0133] In the above method, this most likely occurs during vaporization of the chemical from a liquid to a gas as a concentration of fumigant passes through the flammable area. This change in concentration occurs when the fumigant is introduced into the recirculation fans 33 in the cargo area 14 of the RoRo vessel 10. To avoid the risk of fire starting in the cargo area 14, alternative methods of fumigant delivery may be used for fumigant gases that present this risk.

[0134] Fumigation with potentially flammable fumigants may be safely accomplished using the sulfuryl fluoride method described above. For example, liquid ethyl formate may be delivered to the cargo area 14 via a plurality of first conduits 52 connected to the fumigant-containing cylinder 54 of a mobile fumigant-containing vehicle 56 and one or more temporary bulkheads 110. The ethyl formate is supplied to a pump in the cargo area 14 near the recirculation fan 33. The pump increases the pressure of the ethyl formate to a range of 7 bar to 300 bar (preferably around 200 bar). The liquid ethyl formate may be forced out of the pump through a nozzle or restriction and into the airflow path of the recirculation fan 33. Due to the high pressure of the liquid ethyl formate, it leaves the nozzle at high velocity and is atomized into a fine spray, mist, or fog. The atomized liquid ethyl formate is subjected to a drop in pressure, which causes the liquid ethyl formate to change to a gaseous state and disperse into the air. The amount of air supplied by the recirculation fan 33 is such that the concentration of ethyl formate is rapidly reduced below the flammable range. By using this method, the risk of fire due to combustion of the fumigant may be low as only a small portion of the atomized stream exiting conduit 52 may be within the flammable range for short periods of time.

[0135] In an alternative fumigation delivery method, the potentially flammable fumigation agent is directed to the cargo area 14 under fumigation in liquid form through a plurality of conduits 52 in a manner similar to that described above. However, the liquid fumigation agent is not directed to the recirculation fan 33, but instead to a mixer comprised of a vaporizer or heat exchanger and a high-volume mixer located near the recirculation fan. The vaporizer or heat exchanger typically consists of a coil of copper tubing in a hot water or hot oil bath, although many other suitable types of heat exchangers exist. As it passes through the copper coil, the liquid fumigation agent warms and transitions from a liquid to a gas. The vaporizer typically has a power rating of 1 kW to 15 kW, preferably 10 kW. The gaseous fumigation agent is then directed into the high-volume mixer, which draws in air and fumigation agent in the ratio needed to produce the desired fumigation agent concentration. The rate at which mixing occurs is such that flammable concentrations of the fumigation agent are rapidly avoided. The air / fumigation agent mixture exits the mixer near the recirculation fan 33 to be evenly distributed around the cargo area 14 under fumigation. Alternatively, the vaporized fumigation agent may be delivered directly to the recirculation fan 33 to be mixed rather than entering a high volume mixer.

[0136] In another alternative fumigation delivery method, a mixer is located on the wharf rather than within the cargo area 14 of the RORO vessel 10 to be fumigated. The fumigation agent is vaporized in a vaporizer or heat exchanger and mixed with air in a high-volume mixer. The gaseous air / fumigation agent mixture is then delivered to the cargo area 14 under fumigation via a flexible duct and a temporary bulkhead configured to accommodate the flexible duct in a manner similar to the pneumatic system 60 described in detail above.

[0137] It is possible that the liquid fumigant does not require vaporization using a vaporizer located within the cargo area 14 or on the wharf. In this case, the liquid fumigant may be vaporized within a high volume mixing device located either within the cargo area 14 or on the wharf side. Alternatively, the liquid fumigant may be pressurized by a pump and then removed from a nozzle to produce a spray, mist or fog that may be mixed with air on the wharf side. The fumigant may be delivered to the cargo area 14 either as a liquid as described above or as a gaseous air / fumigant mixture via flexible ducting as described above.

[0138] In another embodiment, the gaseous air / fumigation mixture may be delivered to the cargo area 14 to be fumigated via ducts 25, 27 connecting the cargo area 14 to the supply mechanical ventilator 24 or exhaust mechanical ventilator 26 on the open deck 18 of the RoRo vessel 10. The gaseous air / fumigation mixture may be prepared in any of the manners previously described, or may be delivered to the ducts 25, 27 or mechanical ventilators 24, 26 as a liquid and vaporized within the mechanical ventilators 24, 26 or ducts 25, 27.

[0139] In another alternative, the fumigant may be mixed at the wharf with a non-flammable gas other than air, such as carbon dioxide or nitrogen, to the desired concentration and then delivered to the cargo area 14 for fumigation via flexible ducts in a manner similar to the pneumatic system 60 or mechanical ventilation fans 24, 26 as described above.

[0140] It may also be desirable to mix the fumigant with liquid carbon dioxide to a desired concentration and deliver the fumigant mixture to the cargo area 14 as a cryogenic liquid which may then be safely vaporized by using a vaporizer, heat exchanger or atomization as described above.

[0141] It will be understood by those skilled in the art that combinations of the above fumigation methods may be utilized based on the configuration of the vessel and the fumigation being performed.

[0142] Temporary Flexible Vent The remaining figures provide details regarding the flexible temporary exhaust vents configured to assist in removing gaseous fumigation agent from the cargo area 14 during ventilation operations.

[0143] Type I Temporary Flexible Vent 17-20, there is shown a flexible temporary exhaust vent 58 (Type I) disposed about the periphery of the exhaust mechanical ventilation fan 26. As noted above, the flexible temporary exhaust vent 58 is configured to assist in removing gaseous fumigation agent from the cargo area 14 during a ventilation operation (after a fumigation operation is completed).

[0144] Referring initially to Figure 17, the temporary flexible vent 58 includes an inflatable conduit 120 that inflates in a generally vertical direction during use to provide an upright vent. The temporary flexible vent 58 is configured to be inflated by exhaust air (including gaseous fumigation agent) from the cargo area 14. The inflatable conduit 120 includes a first opening 122 at its lower end and a second opening 124 at its upper end. As shown in Figure 17, for example, the second opening or upper opening 124 may have a smaller cross-sectional area during use than the first opening or lower opening 122.

[0145] The first opening 122 is fitted over the exhaust mechanical ventilation fan 26 (or a similar conduit could be fitted over the ventilated housing as described below) and is mechanically secured to the exhaust mechanical ventilation fan 26 via an adjustable length flexible strap 126. When the first or lower opening 122 is secured to the mechanical ventilation fan 26 via the strap 126, the flexible exhaust outlet 58 is in fluid communication with the mechanical ventilation fan 26 and is thus configured to exhaust air exhausted from the mechanical ventilation fan 26 located downstream of the lower opening 122 through the upper opening 124 (as shown by the direction of the arrow in FIG. 20 ).

[0146] As shown in these figures, flexible exhaust 58 is generally conical and inflated when in use. Flexible exhaust 58 includes a lower generally cylindrical portion 128 (which appears somewhat rectangular in FIGS. 17 and 18 due to flexible conduit 120 conforming to the rectangular cross-sectional shape of mechanical exhaust fan 26). Flexible exhaust 58 further includes an upper generally frusto-conical portion 130.

[0147] 17, the first opening 122 of the inflatable conduit 120 fits around the base of the mechanical vent 26 below the vent of the mechanical vent 26. In use, this positioning of the flexible vent 58 creates a plenum chamber below the vent, thereby assisting in the inflation of the flexible vent 58.

[0148] As shown in Figures 17-18, the inflatable conduit 120 is sized to accommodate the mechanical exhaust fan 26, and is preferably sized in such a way that a gap is created between the housing of the exhaust fan 26 and the inflatable conduit 120 during use (as specifically shown in Figures 19 and 20). The gap between the inner wall of the inflatable conduit 120 and the exhaust fan housing 26 is preferably about 300 mm (on each side of the exhaust fan housing 26). The inflatable conduit 120 is sized to have a height that exceeds the height of the occupant area 20. Thus, during use, the inflatable conduit 120 has a height of about 8 to 10 meters. As mentioned above, the relatively high positioning of the upper downstream opening 124 of the flexible exhaust vent 58 ensures, as much as possible, that the exhaust air (including the gaseous fumigation agent) is directed away from the occupant area 20.

[0149] The particular ventilation arrangement (e.g., the number of mechanical ventilators 26 employed) may depend on various factors, such as the design of the RORO vessel; the cargo, fumigation agent, and ventilation requirements and safe levels of dilution for the particular type of cargo and fumigation agent as determined by relevant regulations; the flow rate of each mechanical ventilator 26; and the compartmentalization of the cargo deck 16. Other prevailing wind conditions may also have a bearing on ventilation requirements. These factors may be taken into consideration when designing a suitable ventilation plan for that particular vessel.

[0150] In one embodiment of the ventilation arrangement shown in Figures 2 and 17-20, respective flexible temporary exhaust vents 58 are disposed around each exhaust mechanical vent 26 to assist in exhausting air containing the gaseous fumigation agent from the cargo area 14. As noted above, during ventilation operation, the supply mechanical vents 24 and their associated fans 24a are operated to draw fresh air into the cargo area 14, and the exhaust mechanical vents 26 and their associated fans 26a are operated to remove air containing the gaseous fumigation agent from the cargo area 14 via the flexible temporary exhaust vents 58. As shown in Figure 1, during fumigation operation, the flexible temporary exhaust vents 58 are attached to each exhaust mechanical vent 26 but are tied together at their downstream openings to prevent escape of the gaseous fumigation agent into the atmosphere above the open deck 18 during fumigation.

[0151] Type II Temporary Flexible Outlet The flexible temporary vent 58 described above may encounter the limitation that an airtight seal cannot be formed at the bow or rise duct of the mechanical vent vent 26 due to piping or other obstructions. Figure 21 shows a RORO vessel 10 in which the flexible vent 58 described above cannot be attached to the mechanical vent 26.

[0152] The fumigation operation of Figure 21 is similar to that described above, with an alternative flexible exhaust vent 240 (Type II) installed within the exhaust mechanical vent 26. When ventilating the cargo area 14 of the fumigant, fresh air is drawn into the cargo area 14 by using the supply mechanical vent 24 and / or drawn from the cargo area 14 by using the exhaust mechanical vent 26.

[0153] 22, the mechanical ventilation fans 26 on the open deck 18 are typically housed in ventilation fan enclosures 242 to protect the mechanical ventilation fans 26 / exhaust fans 26a from weather and other interference. The enclosures 242 have maintenance access doors 244 on one side that open to allow access to the exhaust ducts 27 and / or the top of the axial fans 26a (not shown). These doors are opened to install the alternative flexible exhaust vents 240.

[0154] 23-25 ​​show an alternative flexible exhaust vent 240 (Type II) configured for attachment to the top of exhaust duct 27 to direct exhaust fumigant away from weather deck 18 during ventilation operation. Alternative flexible exhaust vent 240 is constructed from gas-resistant ripstop nylon and is generally "L" shaped to allow flexible exhaust vent 140 to mate with the top of exhaust duct 27 and to allow cleaning of enclosure 242. As shown in FIG. 24, alternative flexible exhaust vent 240 includes a generally horizontal portion 246 and a generally vertical portion 248.

[0155] The generally horizontal section 246 is an inflatable plenum 247, which is generally elongated and cubical, but may also be cylindrical. The generally horizontal section 246 has a circular connector 250, approximately 1 m in diameter, slightly larger than the axial fan 26a, to accommodate and surround the top of the exhaust duct 27. The circular connector 250 is secured using tension / ratchet straps 252, which create a gas-tight seal. The exhaust duct 27 provides a clean surface to which the plenum 247 can be attached without obstruction. When inflated, the plenum extends from the maintenance door 244 and beyond the exhaust fan housing 242, such that the generally vertical section 248 is unobstructed by the housing 242.

[0156] Generally vertical portion 248 connects to plenum 247 distal to circular connection 250. Generally vertical portion 248 tapers to a frustoconical velocity cone 252 having upper downstream opening 124 and drawstring 134 for varying the diameter of upper downstream opening 124 to modify the velocity of the discharged fumigation agent. Velocity cone 252 may be adjustable.

[0157] Velocity cone 252 / substantially vertical portion 248 is inclined at an angle of approximately 12° relative to the horizontal towards exhaust fan housing 242 to allow the force of the emitting fumigation agent to act on the interior surface of inflatable plenum 247 and / or substantially vertical portion 248. As can be seen in Figure 25, this inclination causes velocity cone 252 to be more vertical as it discharges the fumigation agent. Velocity cone 252 / substantially vertical portion 248 penetrates vertically through exhaust fan housing 242 to safely direct the emitting fumigation agent away from open deck 18 and crew accommodations.

[0158] To further support the alternative flexible vent 240, a support assembly including at least one bracket 254 including a cross member, as shown in FIG. 23, depends from the maintenance access door 244 to provide support to the bottom of the alternative flexible vent 240 to hold the door in an open position during ventilation operation. The support assembly may be adjustable to allow the cross member to be set at a range of heights to support the plenum from below. An additional cross member may be threaded through a loop on the chimney to hold the chimney toward the exhaust fan housing. Alternatively, another method of providing support to the inflatable structure would be to extend the lower portion of the inflatable plenum down to the vessel deck to support the inflatable structure from below.

[0159] Pneumatic system compensation As mentioned above, the pneumatic system 60 is operated throughout the fumigation run, preferably throughout the ventilation run, until all or nearly all of the gaseous fumigation agent has been removed from the cargo area 14 and cargo 30. The gaseous fumigation agent is considered to have been removed or nearly removed from the cargo area 14 and cargo 30 when the high range monitoring system sensor 35 detects a concentration of gaseous fumigation agent in the form of sulfuryl fluoride at a concentration of 5 ppm or less.

[0160] As will be appreciated, during ventilation operations, the pressure within the cargo area 13 may increase by virtue of the supply of fresh air provided by the intake mechanical ventilation fan 24. Thus, the pneumatic system 60 operates to maintain a desired pressure differential between the cargo area 13 and the accommodation area 20 in light of any increase in pressure within the cargo area 13. It has been discovered that "the pneumatic system 60 can deliver air to the accommodation area 20 such that the accommodation area 20 is at a pressure of up to 300 Pa to 1 kPa above mean sea level atmospheric pressure (while maintaining a desired pressure differential of at least 50 Pa above the pressure within the cargo area 13) without significantly affecting the habitability or usability of the accommodation area 20." However, the preferred maximum pressure within the accommodation area 20 is approximately 300 Pa above mean sea level atmospheric pressure.

[0161] If the pressure in the accommodation area 20 approaches or exceeds 300 Pa above mean sea level atmospheric pressure, an alarm may be triggered to notify the operator to reduce the pressure in the cargo area 13. This may be achieved by adjusting the operation of the supply air mechanical ventilation fans 24 and / or by opening one or more hatches 29 in the open deck 18.

[0162] Alternative ventilation arrangements The above-described RORO vessel with supply, exhaust, and reversible mechanical ventilation fans is the most common configuration (especially for newer RORO vessels), but other configurations that present additional ventilation challenges may also be found within RORO vessels.

[0163] Passive ventilation through a vented enclosure In the first case, the RORO vessel may not have any exhaust mechanical ventilation fans and may instead rely on passive ventilation of the cargo area by means of ventilated enclosures located on the open deck. Ventilated enclosures are typically found on Pure Car and Truck Carrier (PCTC) type vessels. Such a RORO vessel is shown in Figures 3 and 4.

[0164] As can be seen in Figure 3, the vessel 10' includes supply air mechanical ventilators 24 with associated fans 24a that draw air into each of the cargo areas 14, and a series of ventilation enclosures 39 located on the open deck 18. Each cargo area 14 includes a dedicated ventilation enclosure 39 and ductwork that allows passive ventilation of the respective cargo area 14. The directions of the arrows in Figure 4 indicate the direction of air movement into the cargo areas 14 via the supply air mechanical ventilators 24 and the direction of air movement out of the cargo areas 14 via the ventilation enclosures 39.

[0165] Figure 3 shows a RORO vessel 10' undergoing fumigation. The fumigation system 50 and pneumatic system 60 shown in Figure 3 are the same as those described herein in relation to Figures 1 and 2, and the fumigation operation is carried out in substantially the same manner as that described herein in relation to the RORO vessel 10 shown in Figures 1-2. As shown in Figure 3, each of the ventilated enclosures 39 is equipped with a temporary flexible exhaust vent 262 (Type III), which will be described in further detail below.

[0166] Alternatively, temporary flexible exhaust vents (not shown) of a type similar to temporary flexible exhaust vent 58 may be attached around the periphery of vented housing 39 in much the same manner as described above in connection with exhaust mechanical ventilation fan 26 (see, e.g., Figures 17-20).

[0167] During fumigation operations (as shown in FIG. 3), the temporary flexible vents 58 / 262 may be tied together at their downstream openings to prevent escape of gaseous fumigation agent into the atmosphere above the open deck 18.

[0168] Figure 4 illustrates ventilation operation. As can be seen in this figure, the downstream openings of the temporary flexible exhaust vents 58 / 262 are not tied together to allow air containing gaseous fumigant to be exhausted from the cargo area 14 through the ventilation enclosure 39. During ventilation operation, the supply air mechanical ventilators 24 and their associated fans 24a are operated to draw fresh air into the cargo area 14. The drawing of fresh air into the cargo area 14 assists the passive exhaust ventilation through the ventilation enclosure 39.

[0169] Type III Temporary Flexible Vent An alternative temporary flexible exhaust vent 262 is now presented in relation to Figures 26-28. Such a vessel is shown in Figure 26, where the passive exhaust duct 27 from the cargo area 14 is housed inside a ventilated enclosure 39 (typically at the aft end 34 of the open deck 18). Fumigation operation is the same as previously described. However, ventilation of the fumigation agent relies on a mechanical supply air fan 24 to draw and increase the pressure of air through the passive exhaust duct 27 into the cargo area 14 being fumigated to drive out the fumigation agent.

[0170] 27 shows a typical ventilation enclosure 39 installed on the open deck 18 of a RORO vessel 10. The ventilation enclosure 39 has an access doorway 258 connecting the inside of the ventilation enclosure 39 to the open deck 18, which is normally closed unless maintenance or access is required. A shuttered vent 260 in the wall of the ventilation enclosure 39 is normally provided to vent exhaust gases or fumigants from inside the ventilation enclosure 39 to the atmosphere of the open deck 18. An exhaust duct 27 from the cargo area 14 terminates on the floor inside the ventilation enclosure 39.

[0171] 27 is a second alternative flexible exhaust vent 262 (Type III) installed over the access door 258 of the ventilation enclosure 26. A shuttered vent 260 in the wall of the ventilation enclosure 39 is covered to prevent airflow by any conventional means, such as a plastic sheet 264 secured with adhesive tape. In this arrangement, exhaust gases or fumigation agents are prevented from exiting the ventilation enclosure 39 through the shuttered vent 260 and are instead forced to exhaust through the access door 258. The second alternative flexible exhaust vent 262 is secured to the access doorway 258 to cover the doorway and direct airflow into the second alternative flexible exhaust vent 262, as shown in FIG. 29.

[0172] Referring to Figure 28, a second alternative flexible vent 262 expands during ventilation operation. The vent is made from gas-resistant ripstop nylon. The connection point 266 of the second alternative vent 262 is an aluminum profile shaped similar to the access door 258 (usually oval, typically one access door 258 per vent housing) so that the connection point 266 can be secured to the access door 258 using a clamp. Alternatively, the second alternative vent 262 can be attached to the access door 258 using adhesive tape instead of having an aluminum profile.

[0173] The second alternative exhaust vent 262 includes a plenum 268 that extends away from the access doorway 258 when inflated, a lower portion of the plenum 268 that extends downwardly toward the outdoor deck 18 to provide support for the second alternative exhaust vent 262, and an adjustable velocity cone 270 that extends upwardly from the plenum 268 to direct the exhaust fumigation agent away from the outdoor deck 18. The plenum may be an elongated cube or generally cylindrical. The velocity cone 268 is frusto-conical in shape and has an upper downstream opening 224 at its uppermost point and a drawstring 234 for changing the diameter of the opening to modify the velocity of the exhausted fumigation agent.

[0174] To install the second alternative exhaust vent 262 in the vented housing 39: 1. All supply air fans are switched off. 2. The duct leading to the ventilation housing is closed via its lid. 3. The maintenance door to the vented enclosure can be opened. 4. Plastic sheeting / plastic cardboard / other sheeting is fitted or taped over the ventilation shutters from the inside of the ventilation enclosure. 5. The exhaust vent 262 fits into the access door 258. 6. The supply air fan is turned on. 7. The ventilation housing duct is opened to allow expansion of the second alternate exhaust vent 262.

[0175] Additionally, the vent 262 may include a strap for securing it to the vent housing 256 .

[0176] Ventilation via escape trunk In a second example, the preferred method may not be possible due to the incompatibility of the flexible exhaust vents discussed above, due to the placement of mechanical exhaust fans or vented enclosures, or due to other circumstances.

[0177] In this case, ventilation may be achieved through the use of an escape trunk. As mentioned above, the escape trunk may be in the form of a hatch 29 (FIG. 1) that extends downward and includes a ladder into the top cargo area 14. Alternatively, the escape trunk may be in the form of a staircase 31 (FIG. 5) that leads into the top cargo area 14. Temporary vents 58 may be used with an intake fan, such as an axial or mixed flow fan, within the escape trunk. However, such temporary vents need not fit over structures such as mechanical ventilation fans. Therefore, the temporary vents need not be flexible. Additionally, the temporary vents need not be shaped, as velocity cones and cylindrical ducts or other straight pipes may be employed.

[0178] As will be appreciated by those skilled in the art, this alternative method of ventilation may be used by the RORO vessel 10 shown in FIG. 1 and the RORO vessel 10' shown in FIG.

[0179] Referring initially to FIG. 5, it can be seen that the RORO vessel 10″ includes, by way of example, an intake mechanical ventilation fan 24 and an exhaust mechanical ventilation fan 26. It will be understood that the RORO vessel of FIG. 5 need not have an intake mechanical ventilation fan 24 or an exhaust mechanical ventilation fan 26 for the second case approach to be adopted. The RORO vessel 10″ also includes an escape trunk in the form of a staircase or hatch 29 and an escape trunk in the form of a staircase 31.

[0180] FIG. 5 shows a RORO vessel 10" undergoing fumigation. The fumigation operation is carried out in much the same manner as described above. As can be seen in FIG. 5, prior to commencing the fumigation operation, temporary flexible exhaust vents 58 are attached to each hatch 29 and staircase 31 and tied together at their downstream openings. Although only a single hatch 29 and a single staircase 31 are shown in FIG. 5 with an attached temporary flexible exhaust vent 58, it will be understood that multiple hatches 29 and staircases 31 will be attached with temporary flexible exhaust vents 58. FIG. 5 also shows the temporary bulkheads 154 within the axial or mixed flow fans 164 and the respective flexible ducts 159 leading to the top cargo area 14. 5 shows two hatches 29 including an axial or mixed flow fan 164 and a staircase 31 including an axial or mixed flow fan 164. As will be explained below, during ventilation operations, the hatch 29 including the axial or mixed flow fan 164 is operated as a supply air fan to draw fresh air into the cargo area 13. However, during fumigation operations, the temporary bulkhead 154 and the hatch 29 including the axial or mixed flow fan 164 are covered by a removable cover 188 to prevent the escape of air containing the gaseous fumigant into the atmosphere above the open deck 18. Although FIG. 5 only shows the hatch 29 including the axial or mixed flow fan 164 used as a supply air fan during ventilation operations, it will be understood that the staircase 31 including the axial or mixed flow fan 164 may also be used as a supply air fan.

[0181] In one arrangement, approximately one-half of the total number of escape trunks (either hatches 29 or staircases 31) are attached to flexible temporary vents 58, and the remaining one-half of the total number of escape trunks (either hatches 29 or staircases 31) are attached to respective temporary bulkheads and axial or mixed flow fans 164 for use as supply air fans during ventilation operation.

[0182] FIG. 6 illustrates ventilation operation. Specifically, first, the downstream openings of the flexible temporary exhaust vents 58 are disconnected, and the cover 188 covering the hatch 29 is removed. The top cargo area 14 is ventilated prior to the ventilation of the other cargo areas 14. As described above, the hatch 29 containing the axial or mixed flow fan 164 is operated as a supply air fan to supply fresh air into the top cargo area 14. As shown in FIG. 6, the leftmost hatch 29 containing the axial or mixed flow fan 164 also includes a flexible duct 159. The flexible duct 159 includes a downstream opening located within the top cargo area 14, thereby supplying fresh air into the top cargo area 14. The supply of fresh air into the top cargo area 14 causes the air in the top cargo area 14 to be exhausted through the hatch 29 attached to the flexible temporary exhaust vent 58 and the staircase 31.

[0183] When the concentration of the gaseous fumigant (a gaseous fumigant containing sulfuryl fluoride) in the top cargo area 14 falls below 5 ppm, specially trained fumigation personnel enter the top cargo area via hatch 29 or staircase 31. The specially trained fumigation personnel then opens hatch 19 leading from the top cargo area 14 to the second cargo area 14. Next, the specially trained fumigation personnel route flexible duct 159 of air supply hatch 29 into the second cargo area 14 from the top so that the downstream opening of flexible duct 159 is located within the second cargo area 14 from the top. In this way, fresh air can be supplied into the second cargo area 14 from the top. It will be understood that "Figure 6 only shows that the right-most hatch 29, which includes an axial or mixed flow fan 164, includes a flexible duct 159 with its downstream opening located above the penultimate cargo area 14."

[0184] After the flexible duct 159 is routed to the second-to-top cargo area 14, the specially trained fumigation personnel then exit the cargo area 13. Once cargo area 13 is finished, ventilation operations are resumed to ventilate the second-to-top cargo area 14. Specifically, fresh air is drawn into the second-to-top cargo area 14 through the open hatch 19 and the hatch 29 containing the axial or mixed flow fan 164. The supply of fresh air to the second-to-top cargo area 14 causes the air containing the gaseous fumigant to be exhausted from the second-to-top cargo area 14 through the open hatch 19, the hatch 29 containing the flexible temporary exhaust vent, and the staircase 31. When the concentration of gaseous fumigant (gaseous fumigant containing sulfuryl fluoride) in the second-to-top cargo area 14 falls below 5 ppm, specially trained fumigation personnel enter the second-to-top cargo area via hatch 29 or staircase 31 and internal hatch 19.

[0185] The specially trained fumigation personnel then open the hatches 19 to the second-lowest cargo area 14 and route the flexible ducts 159 so that their downstream openings are located within the second-lowest cargo area 14. The specially trained fumigation personnel then exit the cargo area 13. Once cargo area 13 is finished, the ventilation operation is started again and the second-lowest cargo area 14 is ventilated. This process is repeated until all of the cargo areas 14 have been ventilated.

[0186] Thus, as explained above, in this alternative method of ventilation, the cargo area 13 is ventilated by fresh air that is actively drawn through the hatches 29 and / or staircases 31 by the axial or mixed flow fans 164. In essence, the hatches 29 and / or staircases 31 containing the axial or mixed flow fans 164 act as supply air ventilators, performing a similar function to the mechanical supply air ventilators 24.

[0187] Any of the above arrangements that result in passive exhaust of air from the cargo area are less desirable in view of the potential pressure buildup within the cargo area that could possibly exceed the positive pressure applied to the living area and other passenger areas.

[0188] As will be appreciated by those skilled in the art, a combination of the above methods may be used to achieve fumigation of the RORO vessel 10. For example, it is possible to combine another method for drawing fresh air into the cargo area 13 through the mechanical air supply duct 25 during ventilation and discharging the fumigation agent through the hatch 29 in the escape trunk or the staircase 31.

[0189] An assessment of the appropriate arrangement may include an inspection of the ship. For example, a ship in poor condition due to fatigue causing hairline cracks in the metal sheets between the various compartments would be unsuitable for such an arrangement. However, if the ship is in good condition, such an arrangement may be sufficient.

[0190] insect collecting net As shown in FIG. 18 , the flexible exhaust vent 58 includes an insect net 132 disposed within the inflatable conduit 120 and configured to trap any live insects and prevent them from being expelled into the atmosphere during ventilation operation. The insect net 132 is positioned approximately above the exhaust mechanical exhaust fan 26, generally closer to the upstream upper opening 122 than the downstream upper opening 124. The insect net 132 may be positioned approximately 30 cm above the mechanical exhaust fan. This maintains a low center of mass and provides better aerodynamic characteristics for the flexible exhaust vent 58. The insect net 132 has an approximate grid side size ranging from 0.5 mm to 10 mm. The insect net 132 may be removable, i.e., velcroed in place, but is ideally sewn / secured in place.

[0191] Alternative methods of protection include: a) first covering the exhaust mechanical ventilator with insect netting and fastening it to the base of the exhaust mechanical ventilator, and then covering the netted exhaust mechanical ventilator with the flexible exhaust vent 58; or b) fastening an insect net over the intake (exhaust duct) in the cargo area to prevent insects from being sucked into the exhaust duct and expelled into the atmosphere (in this example, the insect netting is not present in the flexible exhaust vent 58).

[0192] The Type II and Type III flexible vents 240, 262 may also be fitted with insect screens as described above.

[0193] Adjustable upper opening The use of a velocity cone is intended to narrow the shape of the conduit 58 from the first opening. The first opening is intended to be large and fit over the structure of the exhaust mechanical ventilation fan 26 to the upper second opening, which is intended to be sized to maintain the flexible conduit 58 in an expanded configuration. Additionally, because the outflow from the exhaust mechanical ventilation fan 26 is downward, the flexible conduit 58 must be shaped to create a plenum chamber below the exhaust mechanical ventilation fan 26. Additionally, adequate clearance around the exhaust mechanical ventilation fan 26 is required for the upward passage of exhaust air. These factors dictate the large base of the flexible conduit 58, thereby necessitating a frustoconical taper to the smaller upper second opening 124.

[0194] As shown in FIGS. 17-20 , the flexible exhaust 58 further includes a drawstring 134 disposed around the upper opening 124 to adjust the cross-sectional area of ​​the upper opening 124. Adjustment of the downstream upper opening 124 can be achieved by first pulling the opening 124 via the drawstring 134 and allowing the pressure of the exhaust air to automatically adjust the opening 124. FIG. 18 illustrates the adjustability of the cross-sectional area of ​​the upper opening 124 through the use of the drawstring 134. As shown in this figure, the opening 124 is adjustable between a first, relatively unrestricted, open configuration in which the upper portion 130 of the flexible exhaust 58 is generally cylindrical in shape and a second, relatively constrained configuration in which the upper portion 130 is generally frusto-conical in shape. Typically, the opening 124 is initially positioned in the second, relatively constrained configuration, with the force of the vented air allowing the opening 124 to conform to the appropriate open configuration. Typically, the cross-sectional area of ​​the open configuration can correspond to the cross-sectional area of ​​the output fan. The adjustable aperture allows automatic adjustment of the exhaust port 58 to produce an appropriately sized velocity cone proportional to the ventilated air output.

[0195] It will be understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features apparent from the text or the accompanying drawings, all of which various combinations constitute various alternative aspects of the invention.

Claims

1. 1. A control system associated with a roll-on / roll-off vessel (roro vessel), the associated control system including a controller, the controller comprising: receiving pressure or pressure differential measurements from selected areas and / or cargo areas of the vessel during fumigation, and in response to such measurements, controlling air delivery to the selected areas suitable for human occupancy to maintain a selected minimum pressure differential between the selected areas suitable for human occupancy and the cargo areas such that the pressure in the selected areas suitable for human occupancy is greater than in the cargo areas; and a control system configured to maintain said selected minimum pressure differential throughout fumigation and subsequent evacuation of fumigation agent from said cargo area.

2. The control system of claim 1 , wherein the selected minimum pressure differential is at least 50 Pa or between 50 Pa and 100 Pa.

3. The control system of claim 1 or claim 2, wherein the selected minimum pressure differential is preselected.

4. 4. The control system of claim 1, wherein the associated control system is responsive to one or more pressure sensors and / or differential pressure sensors, and wherein the associated control system is further configured to control one or more supply air fans to supply air to the selected areas suitable for human occupancy to maintain the selected minimum pressure differential.

5. The control system of claim 4 , wherein the associated control system is configured to control at least the speed of the one or more fans via a variable speed drive.

6. 6. The control system of any one of claims 1 to 5, wherein the associated control system is further configured to perform low range monitoring to detect one or more of gaseous fumigants; carbon dioxide; carbon monoxide; and other volatile organic compounds (VOCs) within the selected area suitable for human occupancy and / or at air intakes for the delivered air.

7. 1. A method of pre-configuring a control system associated with a roll-on / roll-off vessel (roro vessel), the method comprising: a controller of the associated control system, operable to receive pressure measurements or pressure differential measurements from selected areas and / or cargo areas of the vessel during fumigation and, in response to such measurements, control air delivery to the selected areas suitable for human occupancy on the vessel to maintain a selected minimum pressure differential between the selected areas suitable for human occupancy and the cargo areas, such that the pressure in the selected areas suitable for human occupancy is greater than in the cargo areas; and pre-configuring the controller of the associated control system to be operable to maintain the selected minimum pressure differential throughout fumigation and subsequent evacuation of fumigation agent from the cargo area.

8. The method of claim 7, further comprising preconfiguring the associated control system to maintain the selected minimum pressure differential of at least 50 Pa or between 50 Pa and 100 Pa.

9. 9. The method of claim 7 or claim 8, further comprising preconfiguring the associated control system to maintain at least one preselected minimum pressure differential.

10. A method as described in any one of claims 7 to 9, further comprising pre-configuring the associated control system to control one or more supply air fans to deliver air to the selected area suitable for human occupancy.

11. A method as claimed in any one of claims 7 to 10, further comprising pre-configuring the associated control system or an additional associated control system to perform low range monitoring to detect one or more of gaseous fumigants; carbon dioxide; carbon monoxide; and other volatile organic compounds (VOCs) within the selected area suitable for human occupancy and / or at the air intake of the delivered air, wherein the controller controls the air delivery in response to an output of the low range monitoring.

12. 1. A method of configuring a system for fumigating a vessel, the system being incidental to said vessel, said method comprising:

1. A method comprising: configuring an air intake for a pneumatic system operable to maintain a minimum selected pressure difference between a selected area suitable for human occupancy and a cargo area of ​​the vessel such that the pressure in the selected area suitable for human occupancy is greater than the pressure in a cargo area of ​​the vessel, the air intake configured to draw air from a wharf or at a location outwardly beyond the hull of the vessel.

13. 13. The method of claim 12, wherein the pneumatic system includes one or more intake fans, and further comprising configuring the fans at a wharf.

14. 14. The method of claim 13, wherein the pneumatic system includes a variable speed drive via which a controller controls the speed of the one or more intake fans, and further comprising configuring the variable speed drive at a wharf.

15. 15. The method of any one of claims 12 to 14, further comprising providing a source of fumigation agent for fumigating the vessel, wherein the source of fumigation agent is located at a wharf.

16. A method according to any one of claims 12 to 15, further comprising providing a movable occupant escape boom on the wharf.

17. 1. A system for fumigating a vessel, said system being associated with said vessel, said system comprising: a fumigant delivery system for delivering a fumigant to a cargo area of ​​the vessel; and a pneumatic system for maintaining a selected minimum pressure differential between the selected area suitable for human occupancy above the cargo area of ​​the vessel and the cargo area such that the pressure in the selected area suitable for human occupancy is greater than the pressure in the cargo area.

18. 20. The system of claim 17, wherein the vessel is a roll-on / roll-off vessel.

19. 19. The system of claim 17 or 18, wherein the pneumatic system includes a controller for maintaining the selected minimum pressure differential throughout fumigation and exhaust of the fumigation agent.

20. 1. A system for fumigating a vessel, said system being incidental to said vessel, said system comprising: a fumigant delivery system for delivering fumigation to a cargo area of ​​said vessel at one or more delivery sites; and a pneumatic system for maintaining a pressure in a selected area of ​​said vessel suitable for human occupancy that is greater than the pressure in a cargo area of ​​said vessel; A system wherein an air intake of the pneumatic system is remote from the one or more fumigation agent delivery locations and the one or more exhaust sites.

21. 21. The system of claim 20, wherein the air intake is more than 30 meters from the one or more fumigation agent delivery locations and one or more exhaust sites for the emitted fumigation agent.

22. 22. A system according to claim 20 or claim 21, wherein the air intake is located on a quay outside the hull of the vessel or at the forward end of the vessel.

23. A system according to any one of claims 20 to 22, wherein the vessel is a roll-on / roll-off vessel.

24. 24. The system of any one of claims 20 to 23, wherein the pneumatic system includes a controller for maintaining the pressure throughout fumigation and exhaust.

25. 1. A method of fumigating a vessel, comprising: delivering a fumigant to a cargo area of ​​said vessel at one or more delivery sites; exhausting the fumigation agent from the cargo area following fumigation from one or more exhaust sites; and delivering air to the selected area suitable for human occupancy to maintain a selected minimum pressure differential between the selected area suitable for human occupancy and the cargo area of ​​the vessel such that the pressure in the selected area suitable for human occupancy is greater than the cargo area, wherein an air intake for said air delivery is remote from the one or more fumigation agent delivery locations and the one or more exhaust sites, said air intake being located at a pier outside the hull of the vessel or at the forward end of the vessel; The method wherein the vessel is a roll-on / roll-off vessel.

26. The method of claim 25, further comprising delivering air to the selected area suitable for human occupancy above the cargo area to maintain the selected minimum pressure difference between the selected area suitable for human occupancy and the cargo area so that the pressure in the selected area suitable for human occupancy is greater than the pressure in the cargo area.

27. 26. The method of claim 25, wherein the air intake is more than 30 meters from the one or more fumigation agent delivery locations and the one or more exhaust site.

28. The method of claim 25, wherein the air delivery is maintained throughout the fumigation and exhaust.

29. A system for fumigating a vessel according to any one of claims 20 to 24, comprising: a temporary bulkhead configured to fluidly seal an inlet passage of the vessel, a body configured to be positioned within an inlet passage of the vessel; a seal disposed about the body and configured to contact the inlet passage to fluidly seal the inlet passage; and a temporary septum including one or more openings in the body adapted to connect with a fluid conduit; system.

30. 30. The system of claim 29, wherein at least some of the one or more openings include a respective valve.

31. 31. The system of claim 29 or 30, wherein the one or more openings are configured to deliver power and / or data across the bulkhead.

32. 30. The system of claim 29, wherein the septum is configured to be sealingly connected to one or more air conduits.

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