CA2086439A1 - Floating contaminant containment systems - Google Patents

Abstract

Leaking oil and other contaminants (10) floating on water (12) are contained by providing sheet material (14) at the site (15) of the contaminant for fabrication of a containment boom structure.
Such containment boom structure (13) is continually fabricated from that sheet material at the site and upon the occurence of the contaminant floating on water and is continually deployed into the water (12) against the spread of the contaminant on that water.
By way of example, oceans and other bodies of water (12), as well as coastal environments (54), may thus be protected against the spread of leaking oil after accidents involving oil tankers (39) or offshore drilling operations, or against other floating contaminants (10).

Description

WO 92/09751 n o ~ ~ ~ 3 9 PCI/US91/07328 Description Floatin~ Contarninant Containment Svstems Technical Field The subject invention relates to systems for effectively impeding, 5 if not in many cases preventing, the spread of leaking oil on seas and for containing other contaminants floating on water, and to systems for protecting coastal environments against such floating contaminants. It specifically addresses issues of speed of deployment, capacity and effectiveness of containment, and economy of manufacture and o deployment.
Recent catastrophic contaminations from oil spills in Alaska, the Gulf of Mexico, and many other environmentally sensitive regions ; around the globe testi~y to the irnportance of such systems and the need to improve their effectiveness.

15 Background Art -Various systems, apparatus and devices for containing floating , contaminants have been proposed over the years, including a number of varied designs for containrnent boom structures. Several of these systems have been put to use to contain actual spills, and most can deal 20 adequately with small volumes of contaminant. However, well-publicized spill incidents of recent years have demonstrated that current containment technologies are not adequate to deal with the huge volumes of petroleum and other contarninants which can be released by - a foundering supertanker or darnaged drilling platform.
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WO 92/0'~7~1 PCI/US9t~)7328 208u~3~) - 2 -A clear shortcoming of existing containment systems is their inability to deploy sufficient lengths of floating containment boom around a leaking t~er or plaffo~n during the first few hours of a spill episode. While most industry experts concede that no containrnent 5 technology is likely to be e~fective in heavy sea conditions or near rocky coastlines, the most damaging of recent spills have occurred m relatively calm conditions, and in locations where rapid deployment of containment booms would have greatly reduced the consequent environmental damage. Instead, vessels equipped for large-scale 10 deployment of containment booms often took hours or days to reach the sites of spills, by which time the oil had spread over areas too large for the vessels' equipment to handle.
A number of measures have been taken or proposed to shorten these response times. Studies have been made into the feasibility of creating a chain of oil-spill response bases along the entire length of the U.S. coastline, each with one or more specially-designed cleanup vessels on call. Such vessels, which may typically carry about one kilometer of containment boom, recently began accompanying every outbound tanker during its passage through Prince William Sound in Alaska. But though 20 they are regarded as the most effective spill fighting tool currently available, even if such a cleanup vessel were to accompany every tanker throughout its entire voyage, its containment capacity would be overwhelmed in the event of a major spill.
Rather than assigning a separate vessel to deploy containment 25 booms, it is reasonable to question why large quantities of boom, along with a motorized launch to aid in deployment, car~not instead be carried by the tankers themselves, ready i or immediate use. Certainly there is no shortage of potential storage space on the deck OI a modern supertanker. In fact, most tankers and p}atforms do have lengths of 30 fabricated containment boom stowed aboard. In practice, however, the amount of boom which may be deployed directly from a tanker is ,;, .. . , -.. ` ~ .
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~vo s2/os7sl 2 0 ~ ~ ~ 3 9 P~r/us9l/073t8 limited to a few hundred meters in most cases; this is enough to deal wi~h tens or hundreds of barrels of floating oil, but not wi?~h major spills.
The basis of this limitation, apart from cost, is principally operational. In the early hours of a spill episode, it would typical?ly be - 5 necessary to deploy ~he containment boom in a generally encircling or even multiply encircling patte~n around the tamker. If an analysis is made of the operation of paying out a stored boom from the deck of a t~nker while a separate motorized launch drags the initial end of the boom out and around a zone of floating oil, it is seen to be di~lcult if not impossible to deploy the boom so as to attain the desired encirclement.
- The physical laws which govern ?~he movement of a flexible linear structure as it is towed through a viscous fluid tend at all times to force ~he containrnent boom into a more or less linear arrangement upon the water. Through skillful maneuvering of the launch, it is possible to coax a limited length of boom into an awkwardly polygonal pattern. But as the length of the boom increases, these maneuvers become more and more difficult since the entire length of the boom must be pulled out from the tanker before the launch begins to travel around the contaminant zone. In addition, the drag exerted on the launch by the boom under tow, and the tensile stresses experienced by the boom itself, rapidly become unmanageable. Sequential deployment of several separate leng~s of boom does not offer much practical advantage since the boom segments must be brought together and joined end-to-end during deployment; such an undertaking requires highly trained personnel on the launch to perform difficult, time-consuming, and potentially hazardous tasks at sea.
These facts demonstrate that any practical system for deploying very long lengths of containment boom at sea must effect that deployment from a moving structure, e.g. a launch or another, - 30 independent vessel, rather than from the tanker itself. Thus, in determining ~e amount of containment boom available for deployment, it is the storage capacity of the launch or other vessel which is re~evant, ~' .

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~VO 92/0~)751 PCI/VS9~/07328 ~.a~439 4 rather than that of the tanker. It is not surprising, there~ore, that the problem of designing containment booms which are more compactly storable has received much attention in recent years. While there is a large body of pnor art ~n the design of floating contaimnent booms, only 5 a small fraction of prior designs are capable of being stored in a volume significantly smaller than their deployed volume; for the puIposes of the ` present discussion, those designs which are not capable of significant compaction for storage are not deemed relevant.
Several prior art coneainment systems achieve compact storage volumes by utilizing collapsible and/or inflatable boom structures, wrapping the compacted boom on a reel or stuffing it into a container for storage. Early versions of these systems borrowed technology from life raft designs, inflating the boom with cylinders of compressed gas or with combinations of gas producing chemicals, as seen for example in U.S.
Patent 3 S63 036, by Smith et al, issued February 16, 1971, for Inflatable Floating Booms, and in U.S. Patent 3 701 2597 by Heartness, issued October 31~ 1972, for an Oil Pollution Barrier. Later designs have used various other means of inflation or self-inflation of flotation tubes on collapsible containment booms; among these are the inclusion of coil springs in the collapsed flotation tube, as disclosed in U.S. Patent 4 295 755, by Meyers, issued October 20, 1981, for a Reel Mountable Boom AlTangement, or coil springs in "outngger" floats, as illustrated in U.S Patent 3 807 617, by Tanksley, issued April 30, 1974, or the inclusion of plastic foam formers in the collapsed flotation tube, as disclosed in U.S. Patent 4 652 173, by Kallestad, issued March 24, 1987 to Acme Containment Systems, for a Self-Inflating Oil Spill Boom.
However, all of these methods greatly increase the stored volume and the cost of the containment boom s~ructure.
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The importance of achieving maximum storage compactness may be illustrated as follows. One kilometer of open-sea containment boom of typical dimensions may have a deployed volume on the order of 300 cubic meters. Certain commercial implementations of the above-, . . .
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WO 92/09751 ~ ~ ~ ~ 3 ~ PC-r/US91/07328 mentioned self-inflating boom technologies offer compaction ratios (i.e.
the ratio of deployed volume to collapsed volume) of approximately 20 to l; one kilometer of boom would thus require 15 cubic meters for storage. Consequently, a vessel capable of carTying several kilomeeers i of such boom, plus the support structures needed to store and deploy the boom, would obviously need to be of substantial size and e~pense. The cleanup vessels mentioned above are typically over 40 meters in length and cost over a million dollars for the basic vessel, plus another half million dollars or more for on-board equipment. A vessel of such size and expense would not reasonably be referred to as a "launch" or be considered an "accessory" of a tanker.
A different approach to inflatable boom design is disclosed in U.S.
Patent 4123 911, by Finigan et al, issued November 7, 1978 to The British Petroleum Company, for an Oil Control System. Finigan e~ al provide a relatively simple collapsible boom structure without internal springs or formers. This and other similar inflatable boom designs may achieve a compaction ratio on the order of 50 to 1. However, Finigan et al require machinery at both ends of their boom so that air may be pumped into one end of the preformed flotation tube while the odler end iS deployed from a reel. Such designs are subiect to potential difficulties during deployment of very long lengths of boom, difficulties which may be visualized by considering the analogy of attempting to draw water through a tangled and kinked garden hose. From a -topological perspective, it is practically impossible to unreel, unfold, or 2~ otherwise deploy an empty flattened continuous tube and simultaneously inflate that tube from the deploying side of the tube without breaching the continuity of the tube; inflation must be accomplished by pumping the inflating medium through the entire length of the tube from the initially deployed end.
An alternate way of dealing with this topological problem is to incorporate an air hose or hoses into the boom structure, such as disclosed in U.S. Patent 4 403 888, by Teasdale, issued September 13, , ,,; , . ~ . .~ ~ - . .

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1983, for Oil Containment Booms. Teasdale's method of pumping air through Ihe hoses to the initially deployed end of the boom eliminates the need for machinery at that end of the boom, but does not totally solve the problem of lcinkin~, and fouling of long booms during deployment.
5 In addition, designs such as thèse which require an unobstructed path through the flotation ~ube are subject to total boom failure in the event of a rupture at any point along that tube~
Another method which has been suggested for containment is to manufacture containrnent booms on-site f~om foam plastics. Discussion of ~is approach rnay be seen in U.S. Patent 4 237 237, by Jarre et al, issued December 2, 1980, for Hydrophobic Polyurethane Foams, Their Manufacture and Use; in an article by K. Lanfe~naml et al, entitled "Schaumstoffe zur Bekamp~ung von Olunf~llen" ~subentitled "Foam Plastics for Control of an Accidental Oil Spi}l"), in Proc. of Tnt'l Marine ~cience/ Ocean Engineenng Conf. (l 9~s0), Hamburg, 9/24-25/80, Paper No. IMT 80-320, pp. 666-670; and in Gerrnan Patent Publication 29 10 975, published 9 October 1980, by Dr.rer.nat. Karl Dietzel. In his Patent Publication, Dr. Dietzel proposed extrusion of a boom from closed-cellular or partially closed-cellular soft synthetic foam mateAal, 20 in combination with a partially embedded dependent barrier composed of synthetic foil or fleece; the stated extrusion was to occur on, and subsequent deployment of the resulting boom structure to be accomplished from, a boat which could encircle an oil slick floating on water. In his subsequent article entitled " Ol-Barriere aus 25 Superlastichem Polyurethanweichschaum" (subentitled "Polyurethane Flexible Foarn Boom Against Oil Pollution"), in Proc. of Int'l. Marine Science/ Ocean En~ineerin~Conf. (1982), Harnburg, 9/29-30/82, Paper No. IMT 82-313, pp. 558-562, Dr. Dietzel describes the manufacture of a polyurethane flexible foam boom extruded on and deployed from a 30 floating vessel right at ~he site of a spill, though this boom structure was not stated to include a dependent curtain or web. A. ratio of 60 to 1 between the volume of the deployed boom and the volume of the stored ,: - ' . ~ ' - ' : . -, .. . .. . . ..
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WO 92/0~751 ~ g ~ 3 9 Pcr/usg1/07328 constituent chemicals is cited in the Diet~el article as a significant advantage over existing prefabricated oil booms. However, the foam boom systems dsscribed in these references are favored principally for their oil-absorbent properties, and do not readily lend themselves to the 5 fabrication of conventional boom shapes, which incorporate wide, impenetrable dependent curtains below the flotation chambers tO prevent oil from passing under the bcom. The added complexity of the machinery required to integrate dissimilar forms of plastic material into a single functional boom structure tends to weigh against the on-site o fabrication of such structures. Shortly after the publication of the cited articles, Dr. Dietzel ab~ndoned his patent application.
indeed, the question of the size of the impervious dependent cur~ain below an oil boom is an issue of some debate in judging the effectiveness of containment boom systems. The curtain must be 15 su~fi~iently deep to span the thickness of the oil or other floating pollutant, auld to prevent underflow of the pollutant due to localized wa~e-induced pitching of the boom. However, if a contaimnent boom is secured at a fixed location, any currents which may exist in the body of water will cause floating oil to be calTied along and to accumulate in 20 front of the boom. This transport of oil is due to drag at ~e interface between the layer of oil and the water below it. At low current velocities, ~e thickness of the oil layer in front of the boom reaches an equilibrium value; containrnent is then possible provided the boom incorporates a dependent curtain at least as wide as the equilibrium 25 ` thickness of the oil layer. At higher current velocities, however, the accumulation of oil occurs faster than the oil can spread bacl; away from its accumulation front; oil droplets can also become entrapped in ~he flowing water at the boundary layer between the oil and the water, and the undersurface of the floating oil can experience unstable wave 30 phenomena. In such currents, as a result of these failure mechanisms, effective containment is not possibIe regardless of the width of the dependent curtain.

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: , : , ;, ~ : - ., ~ . . . , . : ~ ' ' - " ' ~` , : - ~ . . -.: : . :. ,: , WO 92/0~751 2 ~ 3 9 PCI/US~1/07328 Extensive research has been undertaken to determine the factors which affect this "zero containment culTent"; such research is discussed in "The Cleanup of Oil Spills from Unprotected Waters", by J.
Milgram, in Oceanus, Vol. 20, No. 4, Fall 1977, pp. 86-94; in "Loss 5 rates and operational limits for booms used as oil barriers", by T.
Fannelop, in App~ied Ocean Research, Vol. 5, No. 2, 1983, pp. 80-92;
and in "Barrier Failure by Critical Accumulation of Viscous Oil", by G. Delvigne, in Proc. of American Petroleum Institute 20th Anniv. Oil Spill Conference (1989), pp. 143-148. The results of this research 10 indicate that oil may begin to escape a floating bar~ier, regardless of its draft, at currents below 0.25 meters/second (approximately one-half knot) of relative velocity between the boom and the underlying body of water. At relative velocities in excess of 0.5 meter/second (approximately one knot), these losses become so great that the boom's 15 containment capacity is seriously compromised. Existing containment systems and strategies, insofar as they employ single bar~iers secured in more or less fixed positions, do not adequately account for these current-induced failure modes.
In addition~ many existing containment boom designs are 20 optimized to work in concert with skimmer ships and other systems for recovering the floating pollutant from the water. To fulfill this role, such containment booms are often of robust construction, capable of surviving days or weeks of deployment at sea, and even capable of being recovered and reused. Such design criteria have weighed against boom 25 designs which are economically manufacturable, compactly storable, and rapidly deployable.

Disc]osure of Invention It is an object of tne subject invention to provide methods and apparatus which will allow several kiiometers of lightweight floating 30 containment boom to be economically deployed within tne first few ;. : . . - . .
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W O 92/0`~751 2 0 ~ ~ 4 3 9 P~r/US9`1/~7328 hours following a oil or other contaminant spill. By acting as "first aid"
during a pollution episode, embodiments of the subject invention overcome the speed, cost, and effectiveness limi~ations of existing containment technologies. When employed in conjunction with existing cleanup technolo"ies, the invention will greatly enhance the oil indus~ry's ability to prevent the ecological disasters which have too often accompanied the mishaps of ocean drilling and transport.
The invention resides in a method of containing a contaminant floating on water, comprising in combination the steps of providing sheet material at the site of that contaminant for fabrication of an inflatable structure, continually closing that sheet material into an inflatable stmcture at that site and upon the occurrence of the contaminant floating on water, continually inflating that structure, continually working the sheet material including the inflated structure into a containment boom structure, and continually deploying that containment boom structure into the water against the spread of the contarninant on that water. , The invention from a related aspect thereof resides in apparatus for containing a contaminant floating on water, comprising, in 20 combination, means for continually closing sheet material into an inflatable structure at the site and UpOII the occurrence of the contaminant floating on water, means for continually working the sheet material into a containment boom structure, including means for continually inflating said inflatable structure, and means for continually 2~ deploying that containment boom structure into the water against the spread of the contaminant on that water.
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Brief Descliption of the Drawin~
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The subject in~en~,ion and its various aspects and objects will become more readily apparent from the following detailed description of , .

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WO 92/0~751 P(~/US91/07328 2~3~39 - 10-preferred embodiments thereof, illustrated by way of example in the accompanying drawings, in which like reference numerals designate like or equivalent parts, and in which:
Figures 1, 5 and 6 show vari~us containment boom deployment s methods according to embodiments of the invention;
Figure 2 shows containment boom manufacture according to an embodiment of the invention;
Figure 3 shows a phase of fabrication of an inflatable structure according to an embodiment of the invention that may, for instance, be 10 used in the system of Figure 2;
Figure 4 shows the fabrication of a containment boom stru~ture on a vessel, and the deployment of that structure from that vesse~;
Figures 7 and 8 show containment boom fabrication according to a further embodiment of the invention that may, for instance, be used in the system of Figures 4 or 6; and Figures 9 and 10 show containment boom fabrication according to two additional embodiments of the invention that may, for instance, by used in the system of Figures 4 or 6.

Preferred Embodiments of the ~vention According to the invention, a contaminant 10 floating on water 12 is contained by continually fabricating a containment boom structure 13 from sheet material 14 upon occurrence and at the site 15 of that contaminant, such as shown in F;igures 2 and 3, and by continually deploying onto the water 12 tha~ containment boom structure 13 as 2~ continually fabricated from sheet material 14 at the site 15 of dlat contaminant, such as shown in Figure 4.
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In particular, according to a preferred embodiment sf the invention, the containment boom structure 13 is fabricated from sheet matenal 14 using machinery 16, and both that sheet material and that machinery are stored on a moveable structure prior to use. Such 5 moveable structure may typically be a launch or similar watercraft, such as shown at 40 in Figure 4. Upon the occurrence of a contaminant spill, such launch is deployed to or at the site 15 of t'ne contaminant, and fabrication of the containment boom structure 13 is then initiated. The containment boom structure is thereupon continually fabricated on the 10 launch 40 at the site of the contaminant and is continually deployed from that launch against the spread of the contaminant. Within the scope of the invention, a transportable structure may be provided for transporting the machinery 16 to the site 15 of, or to a location 54 potentially threatened by, the contaminant 10, and the containment boom structure 13 is continually fabricated from sheet material 14 with the machinery 16 and is continually deployed from the transportable structure as herein disclosed.
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The method of fabricating a containment boom structure from sheet material right at ~e site of the contamination when it occurs, and 20 of perforrning this fabrication and deployment from a moveable structure such as a launch, as provided in a preferred embodiment of the subject invention, offers several significant advantages over the use of prefabricated containment booms. These advantages include: the ability to begin deploying extremely long continuous lengths of containment 25 boorn at the site of the contaminant within minutes following the onset of a spill; the ability to deploy these continuous lengths of containment boom out of storage volumes which are much smaller relative to the volume of the deployed boom tha;n heretofore realized; the ability to maneuver the containment boom during deployment so that it forms 30 single or multiple spiral or independent loops or arcs on ~e surface of the water, in whatever position or combination of positions are deemed most efficacious in containing the floating contaminant; and the ability ... . : .
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wo 92/0~751 2 ~ 8 ~ ~3 9 PCr/US91/~7328 to provide long lengths of contain~nent boom at the site of the contarninant much more economically than heretofore realized. While some existing containment boom technologies have the ability theoretically to provide some of the above stated advantages, the subject 5 invention is able to provide all of [hese advantages in combination. The need for a contair~nen~ method which provides these benefits is evident in view of the oil industry's inability to deploy suffilciently large amounts of prefabricated containment boom in the critical hours immediately following recent oil spill incidents.
By way of quantitative example, a roll of sheet material 0.25 millimeters thick~ 1 meter in diameter, wound on a 200 millimeter diameter core, can theoretically provide the material for a containment boom over 3 kilometers in length. This is a much longer length of continuous containment boom ~an is currently availab}e for immediate deployment from oil tankers or platforms. Further, accarding to an embodiment of the invention, the volume of the containrnent boom structure 13 fabricated from the sheet material at the site lS of the contaminant lO is at least two orders of magnitude larger than the combined volume of that sheet material 14 and any machinery 16 20 employed in that fabrication. This ratio of deployed containment boom volume to "standby volume", i.e. the volume required to store the materials and machiner,v prior to use, is better than the 50:1 ratio which is quoted for certain commercially available collapsible boom structures, which ratio does not even include the volume of reels or o~er apparatus 25 required to store and deploy said structures. It is also better ~an the 60~
ratio given in the above mentioned Dietzel article relative to the volume of the polyurethane foarn raw materials, which ratio does not even take into account the volume of the rmachinery required to mix, cure, and deploy the foam boom. For direct comparison, an analysis of the cross-30 sectional area of several proven containment booms shapes and thecross-sectional area of the thin sheet material from which they could be fabricated according to the subject invention shows that volume ratios in . . . . . .
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' ~. ' ` '' , ' ` ' WO 92/09751 2 0 ~ ~ ~ 3 9 P~T/US91/07328 excess of 250:1 can be realized between the deployed volume of the boom and the stored volume of the sheet material only. The machinery required to continually fabricate the contaimnent boorn structure from the sheet material at the site of the contaminant, as will beidescribed hereinafter, is not significantly more voluminous than the machinery required to store and deploy many prior art collapsible boom structures.
Nor is it significantly more voluminous than the machinery required to mix, cure, and deploy the polyurethane foam boom as described in ~e Dietzel article, which machinery is described therein as occupying ~e 0 volume of one 20-foot long ocean cargo container, with the raw materials for the production of 1 Icilometer of boom being stored in a second such container.
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An embodiment of ~e subject invention fabricates a containment boom structure from sheet material 14 at the site 15 of the contarninant ~s 10 by providing machinery 16 including a ~orming shoulder assembly 20 ; such as shown in Figure 3. The sheet material 14 is passed through the forming shoulder assembly 20 to form the sheet material into a tubular structure 21, and the containment boom structure 13 is made or completed from such tubular structure. The forming shoulder assembly may be of the type shown at 20 in Figure 3, or of any o~er type which performs ~e equivalent function of forming sheet material into a tubular structure. Piping 23 may be provided in conjunction with ~e forming shoulder assembly 20 for loading the tubular structure as disclosed hereinafter.
For rapid implementation of the invention, technology may be transferred from the material packaging field where sheet material formers have been used ~r a Iong time to form tubular structures that are made into bags to enclose granular or other solid materials or even liquids. By way of example, reference may be made to U.S. Patent 4 288 965, for Form-Fill-Seal Packaging Method and Apparatus, by Robert C. James, issued September 151 1981 to Hayssen Manufacturing : Company, and U.S. Patent 4 578 931, for Apparatus for Producing . ,~, . .

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WO92/~)9751 ~ 36~39 PCI/US91/07328 Pouch Packages, by Gijsbertus Roovers, issued April 1, 1986 to RobeIt Bosch GmbH. Both of these patents with their disclosures are herewith incorporated by reference herein for any and all sheet forming equipment, tube sealing means and methods, and for sheet and tube 5 advancing means shown only symbolically at 2~, and for pouch sealing or forming means shown only symbolically at 122 in Figure 3.
According to a preferred embodiment of the subject invention, Figure 2 diagrammatically shows a ~lrst sheet forming assembly at 25 and a second sheet forming assembly at 26. These sheet forming 10 assemblies may comprise a pair of forming shoulder assemblies for forming the sheet m~terial 14 into tubes at the site lS of the contarninant.
Each of these forrning shoulder assemblies may be of the type shown at 20 in Figure 3, or as otherwise mentioned above. The sheet material 14 is passed through the sheet forming assemblies 25 and 26 to forrn the sheet material into a tubular structure 27 having a first tube 21 for flotation and a second tube 28 for ballast. Accordingly, the containment boom structure 13 is made or completed at the site of the contaminant from the tubular structure 27.
~ In particular, a pump or fan is symbolically shown at 30 in Figure ; 20 2 and somewhat differently in Figure 4 for loading air 31 into the tube 21, such as by way of piping 23 associated with the forming shoulder assembly 20. The same piping 23 may be used to load the flotation tube with a gas other than air, or wi~h foam plastic material if desired However, the presently conceived most convenient method of providing flotation is to fill the tube 21 with air as it is being formed Correspondingly, using method~s such as described in the above mentioned U.S. Patents by James and by Roovers, heavier granular or other materials may be loaded into the second tube 28 as ballast However, ~e presently conceived most convenient method of providin ballast is to pump water 33 from the body of water 12 into the tube 28 as it is being formed. This may be accomplished by using a pump as diagrammatically shown at 34 in Figure 2, drawing water 33 from the ' .,: . - ~ . , WO 92/CJ9751 2 0 ~ 6 ~13 9 P~/US91/07328 body of water 12 through an immersed pipe 35, and pump~ng the water to the second sheet forming assembly, where it iS loaded into the tu~e 28 though piping associated with the second forming shoulder assembly~
There may be advantages to first fonning and filling the flotation tube 5 21, then forming and filling the ballast tube 28, as shown in Figure 2, but as conceived in this disclosure, these two form-and-fill operations may be perforrned in either orden According to Figures 2 and 3, the first sheet fo~ming process at 20 or 25 leaves a web 36 in parallel to the flotation tube 21. According tO
10 Figure 2, the similar second sheet forming process at 26 forms the ballast ; tube 28 from that web, leavlng a resulting web 37 between the flotation tube 21 and the ballast tube 28. By adiusting the dimensions of the sheet formers and associated mechanisrns, the width of that resulting web may be set to any desired fraction of the width of the original sheet material.
15 When the containrnent boom structure 13 is deployed onto the water 12, the web 37 and attached ballast tube 28 form a dependent curtain which is suspended in the water below the flotation tube 21, thus serving to prevent or at least impede the floating contaminant 10 from passing under the flotation tube. The same or similar fabricaeion and 20 deployment method may be used for containment boom designs which include little or no web between the flotation and ballast chambers, such as descAbed in U.S. Patent 4 140 424, for a Barrier for Oil Spilt on Water, by BretherAck et al, issued February 20, 1979 to The British Petroleum Company. In the case of these webless cont~inment boom 25 designs or any other containment boom designs comprising combinations of flexible weblike and tubular elements, the method of continual fabAcation from sheet material at the site of the contaminant, as disclosed pursuant to an embodliment of the subject invention, may be applied. That embodiment of the invention may also be used to fabricate 30 boom structures which include folds and poclcets to enhance the stability - of the containment boom in the water, such as those disclosed in U.K.

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WO 92/O`J7~1 PCI`/US91/07328 ~o8~43 16 Patent 2117 326, by Milligan, published 12 October 1983, for an Oil Containment Boorn.
In principle, material heavier than water can be used in the ballast tube. Alternatively, lead or other ballast material may be crimped, 5 riveted, or otherwise attached to the single web 36 of the tubular structure 21 produced by the first sheet forming assembly 25 as part o~
the continual fabrication process, and the resulting containment boom structure deployed directly into the water without the addition of a second ballast tube. Separately attached ballast material may also be 10 used in conjunction with the water-filled ballast tube, or a heavy rope or cable may be inserted or laminated into the continually fabricated boom ~ ~
structure. Howeveri using water from the body of water 12 in the ballast ~ ~ itube 28 is a useful expedient, since the storage and transportation of special ballast material may thus be avoided. Even if only water is used in the ballast tube, the inertiaI moment and drag of the ballast tube 28 against the vertical component of wave motion on the water 12 transmitted through the web 37 from the flotation tube 21 will tend to maintain the boom structure 13 in a fairly vertical orientation.
The type of continual on-site sheet-into-tube forrning and filling process disclosed herein overcomes the previously discussed topological difficulties associated with filling continuous preformed tubes. It also offers a simple way of preventing boom failure caused by rupture of an unobstructed flotation tube, which was mentioned above in connection ~ith the U.S. Patent by Finigan et al. The sheet fomling equipment 25 and/or 26 may be provided with conventional pouch sealing means 122, such as disclosed in the above mentioned U.S. Patents by James and by Roovers, for producing in the tubu:lar structure 27 or tubes 21 and 28 transverse seals 18 and/or 19 and elongate compartments 118 and/or 119. Accordingly, a tubular struc~ure 21 is formed from the sheet material 14 in this or any other manner pursuant to ~he currently disclosed embodiment of the invention, and such tubular structure is continually subdivided into elongate compartments 118 and such . . . . ......................... ,:
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elongate compar~nents are continually filled with gas for ~lotation, such as in Figures 2, 3 and 4, during the continual fabricating of the containment boom structure 13. Such segmentation of the flotation and ballast chambers increases the durability of the boom structure by 5 preventing a localized rupture from affecting the entire length of the ; containrnent boom.
The specific embodiments of the subject invention discussed thus far have utilized a single, essentially flat layer of sheet material for the fabrication of the containrnent boom structure, such sheet material bein"
10 rolled or folded merely for convenience and compactness in storage and transport. Further embodiments of the subject invention, by contrast, utilize sheet material which has been preformed or prefolded in one manner or another so as to facilitate the process of on-site closing and inflation. Various alternate geometries may be utilized for such preforming or prefolding of the sheet material, and for each variant a correspondingly configured apparatus may be employed for the on-site inflation or filling of the flotation and/or ballast chambers.
By way of illustrating three principal alternate configurations of sheet material, according to Figures 2 through 4 and 7 through 10, ~e 20 sheet material used in these embodiments has longitùdinal margins which are at opposite sides of that sheet material 14 when that sheet material is delivered to the current or prospective site of the contaminant for succeeding or subsequent fabrication of the containment boom structure. In the embodiment of Figures 2 through 4, previously 25 discussed, all of the sheet material 14 is between those longitudinal margins (the opposite sides or margins of the sheet material roll shown in Figures 2 through 4) when that sheet material is delivered to the site 15.
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Contrastingly, according to the embodiments of Figures 7 ~rough 10, only part of the sheet material 14, such as an inner region or part 61 or 91, is between longitudinal margins 63 and 64, while a remainder of .~.

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W O 92~0`~751 PCT/US91/07328 ~o~ 39 the sheet material is folded over, or laminated to, or otherwise fixed in relation to, that part 61 or 91 when the sheet material is delivered to the site, such as on a roll.
Specifically, in the embodiment of Figures 7 and 8, ~e sheet 5 material 14 has at least one marginal region 71 folded over part of an inner region 61 of that sheet material when that rnaterial is delivered to the site. At ~e site and upon the occurrence of a contarninant floating on water, the sheet material is continually closed at 73 by continually sealing the marginal region 71 along a marginal portion 74 thereof to an 10 adjacent longitudinal portion of the inner region 61, and the space 76 between that marginal region 71 and an adjacent area 77 of the inner region 61 is continually inflated, by the introduction of air or other gas such as indicated by the arrows 31.
In this respect, the kind of pipe 23 shown in Figure 2 may be extended into the space 76 between the folded-over marginal region 71 and its adjacent underlying part of the inner region 61 of the sheet material 14, as shown in Figures 7 and 8. Air or another gas 31 may thus be pumped into the space 76 for formation of the flota~ion tube 21 through inflation. Sealing equipment is again shown symbolically at 22.
In the embodiment shown in Figures 7 and 8, the sheet material has a second marginal region 81 folded over part of a second inner region of that sheet material, such second inner region being an extension of the inner region 61 under the second marginal region 81.
That second marginal region 81 is continually sealed, such as by 25 equipment 22, along a marginal portion ~3 of that second marginal region to an adjacent longitudinal portion of the second inner region just mentioned. Ballast may be loaded into space 84 between ~e second folded-over marginal region 81 and its underlying adjacent area of the second inner region, being an extension of the inner region 61. By way 30 of example, a ballast supply pipe 35 may be extended into that space 84 between the second marginal region 81 and its underlying part of the .. . ...... .
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W O 92/09751 P ~ /US~1/07328 irmer region of the sheet matenal 14, as shown in Figure 7; the ballast tube 28 may thus be loaded with ballast material, such as water 33 pumped through the pipe 35.
To prevent air and water from escaping from the sealed spaces 76 and 84 during the inflation and filling processes, accordinc, to an embodiment of the invention, the folded sheet material is passed between a pair of rollers 85 and 86, preferably after the sealing process at 22. The roller 85 is shown for this embodiment in Figure 7 with semi-circular grooves for accommodating the presence of pipes 23 and 3S
10 between the folded-over marginal regions 71 and 81 and the adjacent underlying region 61 between margins 63 and 64. An idler roller 89 may be provided as shown in Figure 8 to maintain the relative positions of pipes 23 and 35 and the sheet mateAal 14 as the diarneter of the roll 68 diminishes as folded sheet material is pulled therefrom. (If desired, folding machinery could, of course, be utilized to fold over portions 71 and 81 of unforrned flat sheet material at the site of the contaminant, with the folded-over material then entering directly into the inflation apparatus describedabove.) The incorporation of supply reels, rollers and similar apparatus in the systematic embodiments described herein should be distinguished from existing uses of reels and rollers in the deployment of containment booms. A number of inventors, incIuding the above mentioned Tanksley and Meyers, have secured patents for various means of storing, unreeling, and/or deploying pre-fabricated containment booms into the 25 water. By contrast, the embodiments of the subject invention do not deploy pre-fabricated containment booms, but rather fabricate their containment boom structures from sheet material at the site of the contauninarlt. Such reels, rollers, ~md similar apparatus as are utilized ~erein are functional components of the boom-fabrication apparatus, as for exampIe, the roll apparatus at 42 in Figure 4, which supplies ~e flat sheet material to the subsequent boom forming and inflation apparatus. I~
is a salient feature of the subject invention that the contaimnent boom ..... , . ~ . . .

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struc~ures are deployed directly into the water as they are formed and inflated. The simple support or transport means by which the fabricated boom structure is conveyed from the final inflation apparatus into the - water is not a cenLral issue of the sub~ect specification.
The web 37 between tubes 21 and 28 of t;he tubular s~ructure 27 may be made as wide as necessary to provide the impenetrable skirt to prevent the contaminant 10 from escaping beneath the floating barrier.
Equipment or machinery of the type shown in Figures 7 and 8 may also be used in the implementation of the embodiments of Figures 9 and 10. Accordingly, these latter embodiments are shown rather diagrammatically in a cross-sectional view.
In particular, Figure 9 shows the sheet matenal in a partially pre-sealed condition. Again, only part o~ the sheet material 14 is between the lateral margins 63 and 64. However, in this embodiment, the sheet material 14 is composed of at least two interconnected parts 91 and 92 having adjacent first and second margins 63 and 93 and an inflatable region 94 between the parts 91 and 92 and inside of these ~lrst and second margins. As indicated at 95, the two sections or parts 91 and 92 may be sealed together at the factory, through thermal welding, adhesives, stitching, or by any other means, to provide the web 37. The resulting composite sheet material 14 may be wound on a roll (not shown) and shipped to the site 15 where containment boom fabrication is to take place. There the sheet material 14 is continually closed by continually sealing its two parts 91 and 92 along their first and second margins 63 and 93 at the outer edge of the inflatable region 94. Sealing equipment 22 for this purpose is again shown symbolically. The ir~latable region 94 is continually imlated9 such as through the pipe 23, with air or other gas 31.
- In Figure 9, the marginal regions of the two parts of the yet-unsealed sheet material are shown spread apart for clarity, but in practice ,- ~ . ... . . . . .
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wo ~2/Og751 2 ~ 8 6 ~ 3 9 PCI/~JS91/07328 would be held in closer proximity to the pipes 23 and 35 during the sealing and inflation process. The entry of the pipe or pipes into the region between the sheet material parts 91 and 92 is, of course, located ahead of the sealing equipment 22, as it is in Figures 7 and 8, and rollers sirnilar to those shown in Figures 7 and 8 may also be incorporated in the machinery of Figures 9 and 10y though they are not e~plicitly shown therein.
In the embodiments of Figures 9 and 10, the sheet material has a third part 97 interconnected with at least the first part 91, these first and 10 third parts 91 and 97 having adjacent third and fourth margins 64 and 98. As shown in Figures 9 and lO respectively, the third part 97 may either be in one piece with the second part 92 or may be separate therefrom. In the case of the embodiment of Figure 9, the two parts 91 and 92 of the sheet material 14 may be pre-attached to each other, as indicated at 95, through thermal welding, adhesive bonding, or any other means, in a factory prior to delivery of the sheet material to the site of the contaminant. Alternativel~, flat sheet material from two separate rolled or folded supplies may be sealed together at the site of the contaminant as a process step precedent to the continual closing and 20 inflation process previously described. By contrast, it is likely that the multiple bonding steps required to produce the three-part sheet material stock for the embodiment of Figure 10, though they could be performed at the site of the contaminant, will be most effectively perforrned in a factory prior to delivery of the sheet material to the site.
The first and third parts 91 and 97 are sealed along their third and fourth margins 64 and 98, such as with sealing equipment 22, and are loaded with ballast inside of these sealed third and fourth margins, such as wi~ water 33 through the laterally incoming pipe 35.
By way of recapitulation, the four illustrated embodiments of 30 Figures 2 throug}i 4, 7, 8, 9 and 10, a11 provide sheet material 14 at ~e site 15 of the contaminant 10 for fabrication of an inflatable structure ... ~. - . . . . .

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2~86'139 - 22-27, such material being provided in a roll or folded, for instance. These embodiments continually close the sheet material into such inflatable structure at that site and upon the occulTence of the contaminant floating on water 12, and they con~inually inflate that structure 27. These 5 embodiments continuaIly work the sheet material includin;, the inflated structure 27 into a containrnent boom structure 13, such as in the manner described above, and continually deploy that containment boom s~ucture into the water against the spread of th~e contarninant on that water.
, In a~l four illustrated embodirnents, a closed portion of the sheet material 14 is inflated, such as at the end of pipe 23 in Figures 3, 7, 8, and 10, while a succeeding portion of that sheet material is being closed, such as at 22, for succeeding inflation thereof. `
Preferably, the sheet material 14 is incrementally closed by 15 continually sealing a marginal section of that sheet material, such as the margin of the folded-over section in Figure 3 or the margin at 73 in Figure 7, or the margins 63 and 93 in Figure 107 to a longitudinally extending inner section of that sheet material 14. Each closed increment of that sheet material is inflated, while a succeeding increment of that 20 marginal section is sealed to a corresponding portion of ~e inner section of the sheet material.
The term "increment" as used herein may be regarded as referring to a finite length of material, as would be the case in a move-and-seal, move-and-seal process, which process might, for example, utilize sealing 25 machinery in the form of "wallcing bearn" material advancing means and longitudinally extended heat-sealing bars. Alternatively, the term "increment" may also be regarded as referring to an inf~itesimal length of material, as would apply in the case of a continual, roller-driven-and-sealed process.

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WO 92/~751 2 3 ~ 6 ~ 3 9 PCl/US91/07328 According to the embodiments shown at 25 and 26 in Figure 2, and in Figure 7, and in Figure 10, the sheet material is incrementally closed by continually sealing a first marginal section of that sheet ;~ material 14 to a longitudinally extending ~lrst inner section (Figure 3;
Figure 7, 71 to 61; Figure 10, 93 to 63) of that sheet material, and by continually sealing a second marginal section of that sheet material to a longitudinally extending second inner section (Figure 2, at 26; Figure 7, 81 to 61; Figure 10, 98 to 64) of that sheet matelial 14.
- Each closed increment of the sheet material on one side of the sealed first marginal section and first inner section is inflated, such as at 23, while a succeeding increment of that first marginal section is sealed to a corresponding portion of that ~lrst inner section, and each closed increment of sheet material on one side of the sealed second marginal section and second inner section is loaded with ballast, such as at 26 in Figure 2, or at 35 in Figures 7 and 10.
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In practice, there are a number of different types of sheet material 14 which may be employed for the on-site fabrication of containment boom structùres according to the subject invention. These include, but are not limited to, polyethylene filrn, polypropylene film, polyester film, : ~ 20 polyvinyl chloride filrn, and other plastic films, as well as certain types of papers treated so as to be water resistant, fabrics, and laminated combinations of paper, fabric, plastic film and/or metal foils. Although all of the illustrations of embodiments of the invention contained in this specification depict sheet material consisting of a single layer, it is intended within the scope of the invention that the terrn "sheet material"
: incIude both single and multiple layers of material, and that individual layers of multiple-layer sheet ma.terial may be either fully or partially laminated surface-to-surface or m;~y be loosely held in proximity to each other by edge-sealing, stitching, o:r any other means, as may be deemed advantageous for the specific material and end-use applicadon.

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wo 92/~)9751 PCr/US91/073tg ~,3~39 ;~4 A preferred embodiment of the subject invention provides a launch 40 capable of being carried by an oil tanker, installs fabrication machinery 16 on that launch for continually fabricating a containment boom structure, stores unformed sheet material on that launch prior tO
5 deployment, deploys that launch at the site 15 of the contaminan~ spiLI
when it occurs, continually fabricates the containment boom structure 13 from that sheet material witn that machinery, and continually deploys that containrnent boom structure from that launch against ~e spread of the contaminant. Such sheet material is stored on said launch in an 10 unformed condition, typically on a roll, and is only fo~ned into a tubular structure as part of the continual fabrication and deployment process which commences when a contaminant spill has occurred. A reel mechanism for storing and dispensing the sheet material on that launch is broadly shown at 42 in Figure 4. Guide rollers and other e~uipment 15 for assisting the deployment of the fabricated boom from the launch are broadly shown at 41.
A possible deployment sce.nario for ~he continually fab;icated containment boom structure is shown in Figure 1, in which the central structure 39 may represent a stationary structure such as an oil platfo~n, 20 or a temporarily stationary structure such as an oil tanker or o~er vessel, being located at the site 15 of the contaminant or even being the source of an oil slick or other contarninant 10 on the body of water 12. An initial length of boom as fabricated may be attached to an anchor point 116 which may be on the stationary structure 39. According to this 25 possible deployment scenario, the launch 40 containing the sheet material 14 and the fabrication machinery 16 would proceed away from and encircle the stationary struGture, all the while fabricating and deploying contaimnent boom 13 to contain the floating contaminant 10.
Because a substantial amount of boom material can be deployed by the 30 launch as disclosed herein, it is possible to continue to encircle the source of the contaminant, laying down additional loops of containmen~
boom such as shown at 113 in Figure 1, so that any oil or other ~.

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cont~ninant which succeeds in escaping o~er or under the initial loop of containrnent boom, such as shown at l l O, will still be contained.
The fact that the containment boom structure is fabricated on and deployed from a moving structure, such as the aforementioned launch, at the site of the contaminant when it occurs is an important factor in the ef~lcacy of the preferred embodiment of the subject in~ention such as shown in Figures l, 4, and 5. Although it would be possible to mount the apparatus for storing the sheet material and fabricating the containment boom structure directly onto an oil tanker or platform, and 10 to use a launch merely to tow the end of the contaimnent boom away from the tanker or platform as the boom was fabricated, the physical forces at wor~ on a floating containment boom as it is deployed in the water, as were previously discussed, make it practically impossible to achieve multiple encirclement of the floating contaminant unless the 5 boom is deployed from a moving structure, such as in ~is case the launch.
Embodimènts of the subject invention specify that sheet material and fabrication machinery be provided on a launch capable of being carried by an oil tanker, or that continual deployment of the fabricated 20 containrnent boom be effected with such a launch, such as shown in Figure 6. However, the expression "capable of being carried by an oil tanker" is herein employed to refer to the size of the launch 40 relative to ocean-going oil tankers and does not necessarily mean that the launch need actually be carried on an oil tanker. The launch 40 may be carried 25 on an oil tanker, or may accompany the oil tanker under its own power during all or part of the tanker's ~royage, or may be deployed from a platform, from another vessel or aircraft, or from nearby land. In each such case, the preferred embodiment of the subJect invention deploys the continually fabricated contair~nent boom structure from or with that 30 launch at the site of the contarninant.
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wo92~0~75~ 8~439 PCI/US91/07328 The above mentioned quantitative advantages offered by the method of on-site fabncation of containrnent boom struchIres from sheet material, specifically the ability to deploy several kilometers of containrnent boom within four to six hours irnunediately following a 5 contaminant spill, lead to qualitative differences in the way in which such containrnent booms might be utili7ed in combatting an actual spill.
By way of example, a boom deployrnent pattern which might be used in the event of a major oil spill is sho~,vn in Figure 5. The in;tial end of ~e containment boom 13 has been anchored at point 116 on the oil tanker 10 39, and the launch 40 has deployed containment boom in a spiral pattern similar to that which was shown in Figure 1. After deploying a second spiral loop 113, the launch reaches point 216, at which poirlt the containment boom stn~cture is attached to the previous loop 13, and the launch doubles baclc and deploys arc 213, which is then terrninated by 15 attaching the boom structure to the second loop at point 316, then deploying arc 313 to point 416, then arc 413, and so on as required.
Substantial quantities of oil 10 have surfaced within the initial loops of containrnent boom and been carried by the current 43 so as to accumulate in front of and eventually flow under or over the 20 containment booms; these successive zones of escaped oil are indicated by 110, 210, 310, and 410. However, each successive line of - containment barrier serves to contain some of the oil and to delay the spread of that oil which it cannot stop. The launch 40 can continue to deploy additional arcs of containment boom as required until the 25 available sheet material is exhausted. Additional quantities of sheet material can be delivered to the launch, and additional launches can be employed, if needed and available.
The objective of such an lntensive boom deployment strategy would not be to bring the entire mass of floating contarninant to a "dead 30 stop". As was discussed above, even light currents can cause floating oil to build up in front of containment booms and eventually to flow under them. Rather, the objec~ive is to deploy as many nested loops and arcs ., ., . , ~::
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Wo 92/0`)751 2 U ~ PCI`/US91/07328 - of barrier as possible, to establish many thresholds of obstruc~on, so ~at ~he spread of the oil will be delayed at each successive line of boom and the oil will thus be confined to a significantly smaller area during the initial hours of a spill episode than would have been [he case had it been 5 allowed to be carried freely by the current and dispersed by wave action.
Wherever the oil escapes the existing network of containment booms, another arc of boom would be laid by the deployment launch. In the presence of a current, the entire network of booms would tend to drift, with initially circular deployment pattems eventually distorting into 10 elongated teardrop shapes originating at the leaking tanker or platform.
Such drift and distortion slowly reduce the containment capacity of the boom network, but this reduction can be continually counteracted by deploying additional lengths of boom.
What this containment strategy accomplishes is to "buy time" for . 15 heavier equipment such as oil skimrning vessels to reach the site, deploy their heavy-duty containment booms, and begin their cleanup operations.
; Even though the lightweight boom structures which can be fabricated on-site from sheet material may not be sufflciently robust for use in an ; oil skimming operation, their intensive deployment during the first ~ew 20 hours of a spill may keep the contaminant sufficiently confimed so as to contribute substantially to the speed and effectiveness of ~e slcimming operation once it commences.
The mobility of the launch used to deploy the containment boom also allows a different strategy to be employed in the event that a 25 contaminant spill occurs in the vicinity of a geographical area of particular environrnental sensitivity, such as coastal wetlands or estuarial waters, the inlet zone of a desalination plant, or other such area. In such a situation, it would be possible for the launch, after deploying, or instead of deploying, lengths of containment boom around the 30 contaminant spill itself, to proceed in the direction of the sensitive area and to depIoy one or more lines of containment boom around or in front of said area to yrovide it additional protection from contamination.
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WO 9~/03751 PCI`/US91/07328 2 ~ 3 9 As an extension of this shoreline protection method, according to an alternative embodiment of the invention, sheet material 14 and - machinery 16 for fabricating a containment boom structure ~rom that sheet material are installed at a location imrnediately adiacent to the 5 shore of a bay, harbor, estuary, wildlife refuge, desalination plant inlet, or other shoreline fea~re before the occurrenc:e of, or are deployed ~o that location upon the occurrence of, a potentially threatening contaminant spill. If such machinery and sheet material are to be installed in advance of a potential contaminant spill, they may be 10 enclosed in fixed structures on land, or on a pier, or in a floating structure such as a barge positioned at or near the shore of the area to be protected. If such machinery and sheet material are to be deployed upon the occurrence of a contaminant spill, they may be transported to the shoreline location in structures similar to ocean cargo containers or any :: 15 other appropriate transport containers by means of truck, helicopter, barge, or by any other available transport means, and may be placed upon prepared or unprepared sites on adjacent land, on piers, or on floating structures adjacent to the shore. Fixed or transportable structures which serve to house the sheet material and fabrication 20 machinery pursuant to the subject embodiment are broadly shown at 52 ' in Figure 6. -Once such machinery and sheet material are in place and upon ~e occurrence of a contaminant spill 10 such as from an oil tanker or oil platform or other structure shown at 39 in Figure 6, continual 25 fabrication of a containment boom structure is commenced. Because a generally linear boom structure deployment pattern is called ~r in such near-shore cases, rather than the generally encircling deployment patterns required for open-sea containment of floating contaminants discussed above, the launch 40 or a tugboat may in this method ~e used 30 to pull the boom structure 13 away from the fabrication machinery 16 located at or in the shoreside structure 52 as such boom structure is being fabricated. Protection of areas such as the shoreline 51 or bay 54 , .

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WO 92/09751 2 1~ 3 9 PCI'/US91/07328 - 29- ` -against contamination is thus achieved through continual deployment by the launch 40 of the continually fabricated containment boom structure 13. In terms of apparatus, a first structure 52 rnounts machinery 16 for continually fabricating the containrnent boom stmcture 13 at a shoreline 5 Sl, and continual deployment is effected by a mo~eable second struc~ure 40 for pulling the continually fabricated contairLment boom structure away from the first strucn~re 52.
A single shoreside boom manufacturing structure 52 and a single launch 40 for pulling the fabricated containment boom structure 13 away 10 from that structure may be employed according to the subject method. -Alternatively, as further shown in Figure 6, two boom manufactunng structures may be positioned at opposite points across a bay 54, for fabricating two boom structures 13 which are deployed by two launches 40 moving toward each other in opposite directions. The resulting pair 5 of boom structures may be tied together where the launches meet in the middle of the bay to provide a long composite boom across the bay, or a space 57 may be left between the booms to provide increased protection or to facilitate skimming or pumping of floating contaminant.
Por contair~nent boom structures fabricated pursuant to such near-20 shore embodiments of the invention as shown in Figure 6, the inelusion of reinforcing ropes or lines laminated within or attached to such boom .
structures and/or the inclusion of gravel or other ballast material heavier than water in their ballast tube 28 may be more feasible than would be the case with open-sea embodiments of the invention.
In this or any other manner within the scope of the invention, it is possible to protect a bay, harbor, estuary, beach, wildlife refuge, desalination plant, or other shoreline feature from contamination.
Alternatively, an oil spill or other contamination occurring within a harbor, bay, river, or similarly con~med body of water may be pre~ented 30 from escaping into the ocean or other body of water by one or more .. ~ ~ . . . ... .
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Wo ~L/097~1 PCl/VS91/û7328 2~&6l~39 30-containment booms continually manufactured at such location upon the occurrence of such contarnination.
Also within the scope of the subiect invention, it is anticipated that public agencies charged with the protection of the environment from :~ 5 contarninant spills, as well as owners and operators of tankers, oil plafforrns, and odler facilities, and other parties under contract to these entities, will from time to time conduct exercises and maneuvers to train crews and test systems for the on-site manufacture and deployment of containment boom structures in Lhe manner herein disclosed for the first time. In this respect, it is intended that the expression "contaminant" as herein employed be sufficiently broad to cover not only actual-contaminants, but also contaminants supposed to exist for the purpose of practice exercises and maneuvers, and that the expression "upon occurrence" be sufficiently broad to cover occurrences supposed for the purposes of such exercises and maneuvers. Similarly7 the expression "at the site of the contaminant" is intended to be su~ficiently broad to cover not only the actual site of an oil spill or other contamination, but also the site of contamination supposed to exist for the purpose of exercises and maneuvers, as well as presently unaffected bays, inlets and other environrnentally sensitive areas, such as ~e bay 54 in Fi~ure 6, which is endangered by a contarninant drifting toward it, or is supposed to be so endangered for the pulpose of exercises.
The type of boom deployment strategies described here can only be undertaken if very substantial lengths of containrnent boom ar available for imrnediate and continual deployment during the early hours of a spill episode. The method c~f on-site fabrication of containrnent boom structures from sheet material meets these requirements to a degree not heretofore at~ained.

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Claims (38)

Claims

1. A method of containing a contaminant float-ing on water, comprising in combination the steps of:
providing sheet material at the site of said contaminant for fabrication of an inflatable structure;
continually closing said sheet material into an inflatable structure at said site and upon the occurrence of said contaminant floating on water;
continually inflating said structure;
continually working the sheet material including the inflated structure into a containment boom structure; and continually deploying said containment boom structure into said water against the spread of said contaminant on said water.

2. A method as in claim 1, wherein:
a closed portion of said sheet material is inflated, while a succeeding portion of said sheet material is being closed for succeeding inflation.

3. A method as in claim 1, wherein:
said sheet material is incrementally closed by continually sealing a marginal section of said sheet material to a longitudinally extending inner section of said sheet material; and each closed increment of said sheet material is inflated, while a succeeding increment of said marginal section is sealed to a corresponding portion of said inner section of the sheet material.

4. A method as in claim 1, wherein:
said sheet material is incrementally closed by continually sealing a first marginal section of said sheet material to a longitudinally extending first inner section of said sheet material, and by continually sealing a second marginal section of said sheet material to a longitudinally extending second inner section of said sheet material;
each closed increment of said sheet material on one side of said sealed first marginal section and first inner section is inflated, while a succeeding increment of said first marginal section is sealed to a corresponding portion of said first inner section;
and each closed increment of said sheet material on one side of said sealed second marginal section and second inner section is loaded with ballast.

5. A method as in claim 1, wherein:
said sheet material has longitudinal margins which are at opposite sides of said sheet material when said sheet material is delivered to said site prior to said closing of the sheet material into an inflatable structure at said site.

6. A method as in claim 5, wherein:
all of said sheet material is between said longitudinal margins when said sheet material is delivered to said site.

7. A method as in claim 5, wherein:
only part of said sheet material is between said longitudinal margins, while a remainder of said sheet material is on said part, when said sheet material is delivered to said site.

8. A method as in claim 1, wherein:
said sheet material has a marginal region folded over part of an inner region of said sheet material;
said sheet material is continually closed by continually sealing said marginal region along a marginal portion thereof to an adjacent longitudinal portion of said inner region; and space between said marginal region and an adjacent area of said inner region is continually inflated.

9. A method as in claim 8, wherein:
said sheet material has a second marginal region folded over part of a second inner region of said sheet material;
said second marginal region is continually sealed along a marginal portion of said second marginal region to an adjacent longitudinal portion of said second inner region; and ballast is loaded in space between said second marginal region and an adjacent area of said second inner region.

10. A method as in claim 1, wherein:
said sheet material is composed of at least two interconnected parts having adjacent first and second margins and an inflatable region inside said first and second margins;
said sheet material is continually closed by continually sealing said two parts along said first and second margins; and said inflatable region is continually inflated.

11. A method as in claim 10, wherein:
said sheet material has a third part intercon-nected with at least said first part, said first and third parts having adjacent third and fourth margins;
said first and third parts are sealed along said third and fourth margins and loaded with ballast inside of said sealed third and fourth margins.

12. A method as in claim 1, 2, 3, 4, 5, 6, 7, 8, 9,10 or 11, wherein:
said inflating structure is continually subdivided into floating compartments.

13. A method as in claim 1, 2, 3, 5, 6, 7, 8 or 10, wherein:
said working of sheet material into a containment boom structure includes loading said sheet material with ballast.

14. A method as in claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11, including the steps of:
providing machinery for continually fabricating said containment boom structure from said sheet material at said site; and continually closing said sheet material into an inflatable structure, continually inflating said structure, and continually working said sheet material into a containment boom structure with said machinery at said site upon the occurrence of said contaminant floating on water.

15. A method as in claim 14, wherein:
said working of said sheet material includes using said machinery to load said sheet material with ballast.

16. A method as in claim 14, wherein:
said machinery is stationary at said site.

17. A method as in claim 14, wherein:
said machinery is transportable and is transported to said site upon occurrence of said contaminant.

18. A method as in claim 14, including the steps of:
providing a launch capable of being carried by an oil tanker;
storing said machinery on said launch for fabricating said containment boom structure;
deploying said launch to said site;
continually closing said sheet material into an inflatable structure, continually inflating said structure, and continually working said sheet material into a containment boom structure on said launch at said site upon the occurrence of said contaminant floating on water; and continually deploying said containment boom structure from said launch into said water against the spread of said contaminant while said launch is advancing on said water at said site.

19. A method as in claim 14, wherein:
the volume of said containment boom structure continually fabricated from said sheet material with said machinery at the site and upon the occurrence of said contaminant is at least two orders of magnitude larger than the combined volume of said sheet material and machinery.

20. A method as in claim 1, including the steps of:
providing a forming shoulder assembly for forming said sheet material into a tubular structure, and continually closing said sheet material by passing said sheet material through said forming shoulder assembly at the site of said contaminant to form said tubular structure with said sheet material, and continually sealing said tubular structure;
continually inflating said tubular structure;
and continually working sheet material including said continually inflated tubular structure into a containment boom structure.

21. A method as in claim 1, including the steps of:
providing a pair of forming shoulder assemblies for forming said sheet material into tubes, and continually closing said sheet material by passing said sheet material through said forming shoulder assemblies at the site of said contaminant to form said sheet material into a tubular structure having a first tube for flotation and a second tube for ballast, and continually sealing said first tube and said second tube;
continually inflating said first tube;
continually loading said second tube with ballast; and continually working sheet material including said continually inflated first tube and loaded second tube into a containment boom structure.

22. Apparatus for containing a contaminant floating on water, comprising in combination:
means for continually closing sheet material into an inflatable structure at the site and upon the occurrence of said contaminant floating on water;
means for continually working the sheet material into a containment boom structure, including means for continually inflating said inflatable structure;
and means for continually deploying said containment boom structure into said water against the spread of said contaminant on said water.

23. Apparatus as in claim 22, wherein:
said means for continually inflating said structure inflate a closed portion of said sheet material, while said means for continually closing sheet material close a succeeding portion of said sheet material for succeeding inflation.

24. Apparatus as in claim 22, wherein:
said means for continually closing sheet material incrementally seal a marginal section of said sheet material to a longitudinally extending inner section of said sheet material; and said inflating means inflate each closed increment of said sheet material, while a succeeding increment of said marginal section is sealed to a corresponding portion of said inner section of the sheet material.

25. Apparatus as in claim 22, wherein:
said means for continually closing sheet material incrementally seal a first marginal section of said sheet material to a longitudinally extending first inner section of said sheet material, and incrementally seal a second marginal section of said sheet material to a longitudinally extending second inner section of said sheet material;
said inflating means inflate each closed increment of said sheet material on one side of said sealed first marginal section and first inner section, while a succeeding increment of said first marginal section is sealed to a corresponding portion of said first inner section; and said apparatus includes means for loading each closed increment of said sheet material on one side of said sealed second marginal section and second inner section with ballast.

26. Apparatus as in claim 22, wherein:
said sheet material has a marginal region folded over part of an inner region of said sheet material;
said means for continually closing sheet material continually seal said marginal region along a marginal portion thereof to an adjacent longitudinal portion of said inner region; and said inflating means continually inflate space between said marginal region and an adjacent area of said inner region.

27. Apparatus as in claim 26, wherein:
said sheet material has a second marginal region folded over part of a second inner region of said sheet material;
said means for continually closing sheet material continually seal said second marginal region along a marginal portion of said second marginal region to an adjacent longitudinal portion of said second inner region; and said apparatus includes means for loading ballast in space between said second marginal region and an adjacent area of said second inner region.

28. Apparatus as in claim 22, wherein:
said sheet material is composed of at least two interconnected parts having adjacent first and second margins and an inflatable region inside said first and second margins;
said means for continually closing sheet material continually seal said two parts along said first and second margins; and said inflating means continually inflate said inflatable region.

29. Apparatus as in claim 28, wherein:
said sheet material has a third part intercon-nected with at least said first part, said first and third parts having adjacent third and fourth margins;
said inflating means seal said first and third parts along said third and fourth margins; and said apparatus includes means for loading said sealed third and fourth margins with ballast.

30. Apparatus as in claim 22, wherein:
said means for continually closing said sheet material include a forming shoulder assembly, and means for forming said sheet material into an inflatable tubular structure by passing said sheet material through said forming shoulder assembly at the site of said contaminant; and said means for continually working the sheet material into a containment boom structure include means for continually inflating said inflatable tubular structure and for continually working said inflating tubular structure into a containment boom structure.

31. Apparatus as in claim 22, wherein:
said means for continually closing said sheet material include a pair of forming shoulder assemblies, and means for forming said sheet material into a tubular structure having a first tube for flotation and a second tube for ballast by passing said sheet material through said forming shoulder assemblies at the site of said contaminant; and said means for continually working said sheet material into a containment boom structure include means for continually inflating said first tube and for continually loading said second tube with ballast, and for continually working the sheet material containing said inflating first tube and the loaded second tube into a containment boom structure.

32. Apparatus as in claim 22, 23, 24, 25, 26, 27, 28, 29, 30 or 31, wherein:
said apparatus includes means for continually subdividing said inflating structure into floating compartments.

33. Apparatus as in claim 22, 23, 24, 26, 27, 28 or 30, wherein:
said means for continually working said sheet material into a containment boom structure include means for loading said sheet material with ballast.

34. Apparatus as in claim 22, 23, 24, 25, 26, 27, 28, 29, 30 or 31, including:
a first structure at a shoreline for mounting said means for continually closing said sheet material, and said means for continually working said sheet material into a containment boom structure, including said means for continually inflating said structure;
said means for continually deploying said containment boom structure including a moveable second structure for pulling said containment boom structure away from said first structure.

35. Apparatus as in claim 22, 23, 24, 25, 26, 27, 28, 29, 30 or 31, including:
a transportable structure;
said means for continually closing said sheet material, and said means for continually working said sheet material into a containment boom structure, including said means for continually inflating said structure, being on said transportable structure.

36. Apparatus as in claim 22, 23, 24, 25, 26, 27, 28, 29, 30 or 31, including:
a launch capable of being carried by an oil tanker;
said means for continually closing said sheet material, and said means for continually working said sheet material into a containment boom structure, including said means for continually inflating, said structure, and said means for continually deploying said containment boom structure being on said launch.

37. Apparatus as in claim 22, 23, 24, 25, 26, 27, 28, 29, 30 or 31, wherein:
the volume of said containment boom structure fabricated from said sheet material at the site of said contaminant is at least two orders of magnitude larger than the combined volume of said sheet material and said means for continually closing said sheet material, and said means for continually working said sheet material into a containment boom structure, including said means for continually inflating said structure.

38. A containment boom structure on a body of water at the site of a contaminant, made by a method, comprising in combination the steps of:
providing sheet material at the site of said contaminant for fabrication of an inflatable structure;
continually closing said sheet material into an inflatable structure at said site and upon the occurrence of said contaminant floating on water;
continually inflating said structure;
continually working the sheet material including the inflated structure into a containment boom structure; and continually deploying said containment boom structure into said water against the spread of said contaminant on said water.