Technical Field The invention relates generally to containment, exclusion, and deflection boom systems, and more particularly, to boom systems that are designed to operate in tidal waters or waters that are subject to relatively rapid level changes and that can be used for temporary liquid storage.

Background Containment booms are used to contain floating oil or other water surface contaminants in a particular location, or to deflect or exclude the contaminants from an area.

They are commonly formed from a plurality of boom sections designed to fit together, allowing the size of the boom to be adjusted to fit the appropriate circumstances.

Booms are designed to float in use, with a portion of the boom rising above the water line and the remainder of the boom penetrating below, thus forming a barrier to prevent oil or other contaminants from escaping by spilling over the boom or flowing under it. Boom sections known in the art are generally tubes filled with air, or are solid tubes made of foam.

Air filled tubes are typically made of high strength, durable, coated fabrics, such as polyvinyl chloride (PVC) or polyurethane (PU). Other boom sections known in the art are made for solid flotation and are manufactured from foam, typically closed cell polyethylene foam. The boom section may be a solid log shaped piece of foam, or may comprise sheets rolled into

cylinders. Foam boom sections are bulkier than their air filled counterparts, and accordingly more difficult to store, but they do not require an inflation source, and are more resistant to damage.

Air filled booms do not function well in tidal water or waters that are subject to relatively rapid level variations such as beaches, mud flats, marshes or rivers with strong current. In these areas, the booms (or a portion thereof) will inevitably, at least for some period of time, be grounded on the shore, as opposed to float on the water surface. This may be because of the tidal flow or as result of the spatial requirements of the boom user.

However, when such booms are grounded, due to their light weight, they fail to conform to the shore surface, and therefore, contaminants can seep under the boom. Furthermore, the degree of buoyancy of such booms is not readily adjustable while the boom is use.

Moreover, booms known in art do not provide temporary storage means for storing liquid contaminants that may be removed from the water surface by a skimmer or similar device while the boom is deployed.

Summary of the Invention Accordingly, it is an object of the present invention to provide an improved system for containing, excluding or deflecting oil and other water surface contaminants, that may operate in shallow water, where booms may be grounded and move. It is a further object of this invention to provide booms that can also act as temporary storage of liquid contaminants that may be removed during the cleaning operation while the boom is deployed.

A boom section is provided comprising: an elongated outer tube closed at both ends, adapted to contain a fluid with a density at least that of water; and an elongated inner tube, closed at both ends, substantially commensurate in length with said outer tube and enclosed inside said outer tube, adapted to contain a fluid with a density less than that of water.

An alternative boom section is provided, comprising: an outer tube closed at both ends; an inner tube commensurate in length with said outer tube, closed at both ends, and enclosed inside said outer tube ; a first valve connected to said inner tube and passing through and fixedly attached to the surface of said outer tube such that said valve is accessible from

the exterior of said boom section for filling and emptying said inner tube; and a second valve connected to said outer tube for filling and emptying said outer tube.

A system for containing or excluding oil and other water surface contaminants is provided, comprising: a plurality of boom sections adapted to be coupled together to form a unitary structure; at least one of said boom sections comprising of an inner and an outer tube and equipped with one or more valves to permit the loading and unloading of water and air; and means for connecting said boom sections.

A alternative system for containing water surface contaminants is provided comprising: a plurality of boom sections adapted to be coupled together to form a unitary structure; at least one of said boom sections comprising of an inner tube adapted for receiving air and an outer tube adapted for receiving a liquid; and connecting means for connecting said plurality of boom sections.

Brief Description of Figures Further objects, features and advantages of the present invention will become more readily apparent to those skilled in the art from the following description of the invention when taken in conjunction with the accompanying drawings, in which: Figure 1 is a cross sectional view of a boom section according to the invention; Figure 2 is a top view of a boom comprising a plurality of boom sections deployed according to the invention; Figure 3 is a top view thereof, showing the boom used on a shore; Figure 4 is a top view of a boom showing it deployed with a skimmer; and Figure 5 is a top view of a boom according to the invention, showing it deployed in a river.

Detailed Description of Preferred Embodiments

As best seen in Figure 1, boom section 10 includes a larger elongated outer tube 20 and a smaller elongated inner tube 30 that is enclosed within outer tube 20. Inner tube 30 and outer tube 20 are approximately the same length and run along the entire length of boom section 10. Air, or another gas, may be placed in inner tube 30 to facilitate the floatation of boom section 10 on water, while water, or another liquid, may be placed in outer tube 20 to cause the boom section to displace below the water surface, and to conform to the ground surface should boom 10 be grounded. In a preferred embodiment, apart from the area around valve 35, there is no connection between the interior of inner tube 30 and the interior of outer tube 20.

Valve 35 passes through outer tube 20 and is adapted to allow air, or another gas, to flow into or out of inner tube 30. Valve 40 is adapted to allow water, liquid contaminants, or another liquid to flow into or out of outer tube 20. Outer tube 20 may have more than one valve 40 to facilitate filling and emptying, as may inner tube 30. In the embodiment shown, other than at valve 35, inner tube 30 does not share a surface with outer tube 20. Preferably, each valve or pair of valves, for air and water, would be installed in the same general position on the boom section 10 surface to promote ease of loading and unloading.

Inner tube 30, in an alternative embodiment of the invention, may be adapted to receive and contain fluids other than air. For example, inner tube 30 may be filled with a liquid with a density sufficiently less than that of water to allow boom section 1 to float.

Likewise outer tube 20 may be adapted to receive a liquid other than water or a contaminant.

In use, inner tube 30 is filled with air which pushes boom section 10 upwards, and will come to rest at the top portion of boom section 10. Therefore, the position of inner tube 30 within outer tube 20, will generally dictate the orientation of boom section 10 on the water. Inner tube 30 and outer tube 20 may share a surface either completely along the length of boom section 10, at intermediate points thereon, or only at a single point.

As seen in Figs. 2 and 3, boom 1, comprising a plurality of boom sections 10, will ground on the exposed surface 100, for example, a beach, mud flat, or river bank, if the water

level falls, and will be held there by the weight of the liquid in outer chamber 20. This weight causes each boom section 10 to flatten on and conform to the exposed surface 100 thereby preventing the oil or other contaminant from escaping the containment area 110 by seeping under boom 1. As the water level rises, boom 1 floats with the water and continues to provide a barrier against the oil or other contaminant. Sufficient air is contained in inner tube 30 to provide a barrier preventing the oil or other contaminant from flowing over the top of boom 1, while the water filled outer tube 20 allows boom 1 to have sufficient draft (i. e. depth below the water surface) to prevent a floating contaminant from flowing under boom 1.

Boom section 10 can be constructed in any size to suit the needs of the target area environment. Boom section 10 should be constructed of material impervious to hydrocarbons or other contaminants with which it may come into contact. Materials from which boom section 10 may be constructed include, but are not limited to, polyvinyl chloride (PVC), urethane, plastics, rubber or other material with similar properties. The selected material should be able to contain water and other liquids, and inner tube 30 should be able to contain gas at a pressure greater than atmospheric pressure.

Boom section 10 may have rings 45, or hooks or other holding means, secured to the outer surface of outer tube 30 through which anchors can be roped or chained to retain boom section 10 in a desired position. Rings 45 may also be used for the attachment of additional ballast or towing paraphernalia. Rings 45 can be manufactured as an integral part of the boom section or form part of an accessory that may be mounted on or connected to the boom section.

Boom section 10 can be made in almost any length or diameter to meet the needs of a prospective user. A boom section of this design is easy to handle because it is lighter by comparison to boom sections of the prior art. The boom section can be manufactured to have a sufficiently low weight to length ratio such that it could readily be transported while empty thereby increasing the potential speed with which the boom section could be delivered to a site and deployed. For example, boom section 10 may be kept on a reel with other boom

sections making up boom 1 and pulled into position by a watercraft or small helicopter and then filled with air and water.

Use of the Boom Sections as part of a Boom Boom 1 may be used to prevent the spread of contaminants from containment area 110 from a spill of such contaminants onto land, water or ice. When deploying boom 1, boom 1 is placed at a desired location to block the advance of the spill. Inner tube 30 of each boom section 10 is then inflated, typically, with air, but outer tube 20 is kept empty. If boom section 10 is on a surface 100, plastic sheets (not shown) are then placed on boom section 10, on the side of boom section 10 towards containment area 110, with the downward sloping ends of the plastic sheets extending up and over the boom. Where the boom section 10 is placed on a surface 100, the upslope edge of the plastic sheet should then be driven into the surface 100 to allow the contaminant to flow onto the surface of the sheeting. Outer tube 20 can then be used as temporary storage for the recovered contaminant, for example, by using a skimmer (as seen in Figure 4). The plastic sheets cause soil contamination to be minimized as the sheets assist in preventing the contaminant from seeping into the ground.

An alternate method of using boom 1 involves filling the outer tube 20 in boom sections 10 with liquid. In this method inner tube 30 may or may not be inflated. Inflating inner tube 30 places an obstruction in the path of the contaminant and will give form to boom section 10. Boom 1 will typically be deployed at a location in the path of, but not yet reached by an advancing contaminant spill. When outer tube 20 is filled with a liquid such as water, the weight of the water or other liquid creates pressure against the ground or water surface and slows the progress of the spill.

Boom 1 would also then be in position to be utilized as a temporary storage tank.

Outer tube 20 need only be partially filled with liquid to leave space to accommodate recovered liquid contaminants. A bell hole may be dug on the side of the boom 1 towards the containment area 110 to allow more depth for a skimmer 120, vacuum, or other recovery

system. If skimmer 120 is equipped with an internal pump there is no need for a second pump.

When boom 1 is used on a surface 100, if significant quantities of water are available and the plastic sheet is not being used, water may be spread on the side of boom 1 towards the containment area 110. This causes the contaminant to float on the water surface in and reduce the potential for soil contamination. In most jurisdictions, the water, once so contaminated, will have to be treated.

Alternatively, a boat may be used to deploy boom 1 and skim contaminants, in which case outer tube 20 of boom sections 10 can be used as a temporary liquid storage unit. Boom 1 may be deployed directly from a reel deck loaded at the stern of the vessel or from a rolled bundle.

Boom sections 10 of boom 1 may be held in place with intermediate anchors (not shown). Anchor ropes connected to the anchors hold the boom sections 10 in place. The anchor connector rings can be made of plastic, wire cable or another metal or material.

Anchor line connector rings 45 are typically installed on the top and bottom of each boom section 10. These rings 45, if required, can be used to connect lateral anchors that will aid in holding the boom 1 in the desired location. In shallow water subject to tidal or other water level variations a stake can be inserted through rings 45 and driven into the ground.

Typically, boom 1, is comprised of a series of boom sections 10 adjacent to each other. A boom section is typically connected to an adjacent boom section 10 through the use of connecting means, such as clamps positioned at the end of the sections. Such clamps are well known in the art. The clamps are placed to overlap on each adjacent boom section to provide a continual barrier to the contaminants. The clamps may have rings or other means to hold anchor lines.

Boom 1 may be placed parallel to a shore or be placed so that it extends from a point on the shore into the water, to prevent oil or other floating contaminants from contaminating

the land. In tidal waters boom sections 10 ground with the low tide and float with the high tide. The weight of the water in outer tube 20 provides a seal against sand, mud or other flat surfaces when the boom section 10 is grounded. Boom section 10 will typically not rise off the shore until the incoming water level reaches approximately half way up the side of the boom section 10. This allows boom 10 to act as a barrier to prevent the migration of a surface contaminant spill into the water.

For areas where the force of the water may move boom 1 from its desired deployment location, anchor lines may be fixed to rings 45 provided on the boom sections 10 or clamps to hold a boom section 1 in place. Boom 1 can also be used in cold weather with no damage to the fabric and may be used as a berm on an ice surface to block the advance of a spill.

Boom 1 may be used in extreme cold situations, however, liquid in outer chamber 20, in such circumstances, may begin to freeze and turn semi-solid or solid. This may occur even if a high percentage of the contents of outer chamber 20 are recovered hydrocarbons, despite a lower freezing point of the liquid. To counter this freezing process, hot air may be injected into inner chamber 30. Preferably one air valve 35 is used for injection of the hot air and a second air valve, positioned at the other side of boom section 10, is opened to allow the air to exit. This causes heat transfer through inner chamber 30 to the liquid in the outer chamber 30. This process will not disperse the gases generated by the recovered contaminant as the inner chamber 30 and outer chamber 20 are not connected.

Inner and outer chambers 30, 20 of boom section 10 can be filled prior to or following deployment. The amount of air (or other gas) in inner chamber 30 can be adjusted during use to adapt to the density of the contaminant.

All valves used with boom section 10, whether air or liquid valves, are preferably of a check/free flow type. The user may elect to engage or disengage the check valve function by a slight adjustment to such valves. Boom section 10 will preferably have valves for both air and liquid at either end of boom section 10, and boom section 10 can be loaded with air and liquid from either end of boom section 10 or from both ends of boom section 10

simultaneously. To remove the air and liquid when boom section 10 is no longer required, the valves at each end of boom section 10 are opened and the check valve function, if necessary, is disengaged, typically by pushing on the center of the knob in the valve and rotating one eighth turn in a clockwise direction. Rotating the knob counter clockwise restores the check function.

Boom 1 may be used with skimmers. Boom section 10 can be attached to a skimmer 120 or skimmer 120 can be deployed in a spill containment area 110 fenced by boom 1.

Boom 1 can be used as both a boom and a temporary liquid storage unit when deployed with skimmer 120 that includes an internal pump 130. If skimmer 120 operates in containment area 110, skimmer 120 is typically secured in position with an anchor or shore ropes and skimmer discharge hose 70 is connected to liquid valve 40 closest to the heaviest concentration of the contaminants. Boom section 10 to which hose 70 is connected should have a light load of water ballast to permit room for the recovered contaminants. Recovered contaminants may be removed through liquid valve 40 at the other end of boom section 10.

Skimmer 120 and pump 130 are supported on the water by float 125. Float is secured to boom sections 10 using clamps and other means known in the art.

Traditionally, a river-skimming configuration for boom 1 is to attach the downstream portion of boom 1 to skimmer 120 and angle the two ends of boom 1 upstream. The angle of the ends relative to the downstream point is based on the speed of water flowing past the location. Alternatively, boom 1, connected to skimmer 120, is attached to an anchor point 200 upstream on the shore side. This prevents contaminants from bypassing boom 1 on shore 100. Inner chamber 30 is fully inflated and outer chamber 20 is filled sufficiently to keep boom 1 in the desired position. The portion of boom 1 attached to the offshore side of skimmer 120 is angled upstream and retained in place with a rope to the opposite shore or to an anchor 210 set in the river, as seen in Figure 5. The angle of deployment is dictated by the river speed. Using boom sections 10 for both arms connected to the skimmer gives greater draft and freeboard than conventional river boom. This allows more of the spill to be concentrated to await recovery by the skimmer.

The contaminant, e. g. oil, is pumped directly from skimmer 120 into boom 1.

Recovered liquid contaminants that are lighter than water will float on the water ballast and gravitate to the shore end of boom 1 where they can be transferred into portable tanks, a vacuum or a tank truck. During the time inside boom 1 the recovered contaminant water mixture separates with the typical lighter contaminant gathering on the water surface at the shore end within boom 1 due to the shore end being on land and consequently higher than the water surface within outer chamber 20.

The position of inner tube 30 containing air within outer tube 20 reduces the likelihood of inner tube 30 being punctured, which improves the likelihood of 1 staying buoyant if punctured.

Boom section 10 does not require, but may be provided with, an additional barrier extending below inner tube 30 to prevent the contaminant from passing below. Without such a barrier, boom section 10 is more compact and requires less storage space.

While the principles of the invention have now been made clear in the illustrated embodiments, it will be immediately obvious to those skilled in the art that many modifications may be made of structure, arrangements, and algorithms used in the practice of the invention, and otherwise, which are particularly adapted for specific environments and operational requirements, without departing from those principles. The claims are therefore intended to cover and embrace such modifications within the limits only of the true spirit and scope of the invention.