CA1157669A - Containment boom - Google Patents

Abstract

ABSTRACT

A method of manufacturing a floating containment barrier with an air and water impervious bulkhead located therein and an apparatus produced by the said method. A
rectangular piece of air impervious flexible bulkhead material made from unsupported vinyl is folded along one of its bisecting axes and is bonded along one of the edges transverse to the bisecting axis. The opposed edge of the bulkhead material is then opened and appropriately positioned on the fabric of the buoyancy chamber with the unbonded edge being transverse to the longitudinal axis of the boom when in deployed position and is bonded to the buoyancy chamber fabric. The buoyancy chamber and bulkhead material are then folded and the unbonded edge opposed to the bisecting axis assumes a position between the interface of the buoyancy chamber walls where they meet beneath the buoyancy chamber.
The interface, together with the unbonded edges of the bulkhead, is then bonded.

Description

1157f~9 INTRODUCTION

This application relates to floating containment barriers and, more particularly, to containment booms which are collapsible and self-inflating.

BACXGROUND OF THE INVENTION

In recent years, there has developed an expertise in designing floating containment barriers, due in large measure to environmental concerns when oil or other foreign substances unnecessarily contaminate the natural state of water. Whereas booms were previously made from substantially solid material such as cork, foam, and the like, and were used to delineate areas of water and for containment purposes other than contamination, booms may now be used to contain oil and other contamination and must have the capability to be deployed on short notice in the event of an oil spill or other mishap to prevent the spread of undesirable contamination. Hence, an objective in the state of floating containment barriers is to have a containment boom located in a readily accessible storage location, occupying a minimum amount of storage space and being capable of quick deployment when needed.

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- 2 - llS76~9 The objective of minimum storage space being occupied is met by having the boom adapted to be air inflatable. Such a boom also incorporates a desirable weight reduction relative to substantially solid booms.

Present air containable floating containment booms may be either of two types. The first type is the inflatable boom.
In this boom, air is supplied under pressure to the buoyancy chamber causing the boom to be inflated throughout its length.
This type of boom has the advantage of being deployed from a single Iocation which may be desirable in situations where quick deployment and minimum manpower is required. The boom is fed into the water from one deployment point, air under pressure is provided to the buoyancy chamber and the boom inflates throughout its length under the influence of the air.

The second type of air containable floating containment boom is the self-inflating type. This boom is deployed using two locations because the buoyancy chamber needs to be stretched in order to cause a suction in the boom which creates an ingress of air through appropriately designed one-way check valves. In this type of boom, hoops or other methods of support are necessary to provide support for the buoyancy chamber walls wXich cannot be allowed to totally collapse in which case there would be no suction created.

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, 7~ 9 Inflatable containment booms, however, have inherent problems. It is desirable, in such booms, to have a single valve for inflating the boom both because of material cost and for efficiency of inflation procedure. Providing a single valve, however, obviously dictates a buoyancy chamber with no air impervious bulkheads located therein. With no such bulkheads, a single leak anywhere in the walls of the buoyancy chamber may result in the boom eventually sinking because of the egress of air and the ingress of water. To deal with this problem to some extent, air may be continuously supplied to the boom but this unsatisfactory solution is clearly of limited value.

Self-inflating containment booms, on the other hand, overcome these leakage and inflation problems by utilising a series of compartments in the buoyancy chamber separated by water impervious bulkheads. Each compartment is appropriately designed to incorporate a one-way check valve which allows for the ingress of air upon the expansion of the buoyancy chamber when the boom is deployed. Nevertheless, two locations are necessary in order to provide the appropriate expansion.

The manufacture of present self-inflating floating containment booms which utilize water impervious bulkheads and restraining means within the buoyancy chamber to prevent the ..~

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~L~S7~;~9 collapse of the buoyancy chamber walls has, in the past, been inefficient. In relation to the manufacture of the water impervious bulkheads, a first approach was by providing a diamond-shaped piece of flexible bulkhead material (the "diamond"). The diamond was positioned such that the short-axis between the opposed apexes of the diamond-shape was substantially aligned with a longitudinal axis of the buoyancy chamber. The two adjacent sides on one side of the diamond were then bonded to the buoyancy chamber which was subsequently folded over and the unbonded sides of the diamond were folded over the bonded strips. The open sides of the buoyancy chamber were then bonded together while, at the same time, the unbonded sides of the diamond were bonded with the edge strip of the buoyancy chamber at the interface.

This technique, however, was subsequently found to be disadvantageous. Two separate heat seal or bonding operations were needed when the bulkhead material was originally bonded to the buoyancy chamber material. Further, when the diamond was folded back on itself, there were six layers of fabric appearing at the forwardmost portion of the bulkhead opening along the interface. When this material was bonded, an uneven bonding was created because the thickness of material at the interface would suddenly change and a situation was created .

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~i ~l576~9 where leaks could and did appear. Finally, the inherent diamond-shape of the bulkhead created point loading conditions where the fabric was subject to excessive loads under certain environmental conditions resulting in tears occurring in the bulkhead.

SUMMARY OF THE INVENTION

According to the present invention, there is disclosed a method of producing a tubular containment boom comprising folding each of a plurality of substantially identically shaped rectangular pieces of bulkhead material, each along one of its bisecting axes; bonding an edge portion transverse to the bisecting axis; opening the opposed unbonded edge portion while allowing the bonded edge portion to fold inwardly; positioning said bonded and opened bulkhead material on material used for the buoyancy chamber of said containment boom with said unbonded edge portion being transverse to the longitudinal axis of said buoyancy chamber; bonding said unbonded edge of said bulkhead material to said buoyancy chamber material;
positioning and bonding hoop envelopes on said buoyancy chamber material; encasing a plurality of plastic hoops, each within a flexible sleeve; inserting each of said hoop and sleeve within ,, . ~

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' ~L~57~9 each of said hoop envelopes; closing the circumference of said hoop by inserting the respectively opposed ends in a ferrule adapted to receive said ends; crimping said ferrule on each respective end of said hoop; encasing said ferrule within said flexible sleeve; folding said buoyancy chamber and bulkhead material along said bisecting axis whereby said bonded edge portion opens outwardly and assumes a position transverse to said bisecting axis and the unbonded edge opposed to said bisecting axis assumes a position between the interface of the walls of said buoyancy chamber where said walls meet beneath thP longitudinal axis of said containment boom; and bonding said interface of the walls of said buoyancy chamber and said unbonded edge.

BRIEF DESCRIPTION OF THE SEVERA~ VIEWS OF THE DRAWINGS
-An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a view of the containment barrier or boom of the present invention in assembled and deployed condition with the buoyancy chamber hoops and water tight bulkheads shown in cutaway;

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_ 7 ~ 7~9 Figures 2A-2C depict three steps involved in producing the watertight bulkhead before it is positioned on the walls of the buoyancy chamber material;

Figures 3A and 3B depict two steps involved in bonding the watertight bulkhead within the buoyancy chamber;

Figure 3C is a sectional view taken along the plane III C -III C of Figure 5A.

Figures 4A and 4B show the hoop pocket and enclosed hoop and envelope in the buoyancy chamber, both in the initial unassembled condition of the boom and in the partially assembled condition of the boom; :

Figures 5A and 5B are detail views of various hardware attached to the boom; and Figures 6A-6C depict an end~connector of the boom in bottom view with various connections to the boom parts.

DESCRIPTION OF SPECIFIC EMBODIMENT

A floating containment barrier or boom is shown generally .~ . ~ . . .. .-, -,, , - . . . - :; , . ' ., ' ~ .` ' ... :
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- ~lS76~9 at 10 in Figure l. It comprises a buoyancy chamber 11, a flexible skirt 12 extending downwardly-from the buoyancy chamber 11, a control passageway 23 and a chain envelope 16 all manufactured from a single piece of polyester reinforced polyvinyl chloride (nP.V.C."). Boom-end connectors 13,14 are positioned on respectively opposite ends of the boom 10. They are designed to allow for connection between individual sections of boom and, since the end connectors form no part of the present invention, they will not be further described.

A chain tension member 15 extends between end connectors 13,14. The chain tension member 15 acts to maintain the end connectors 13,14 in aligned position and to provide ballast for the boom 10. The chain tension member 15 is mounted within the chain envelope 16 formed in the lowermost portion of the flexible skirt 12 and is connected to the end connectors 13,14 by bolted connections 27,28. The left hand end connector 13 with its bolted connection 27 is shown in more detail in Figure 6C which is representative of both end connectors 13, 14.

Check valve assemblies 17 are located in the uppermost portion of the buoyancy chamber 11. They are manually inserted in check valve retainers 40 when the boom 10 is deployed and act to allow the ingress of air while preventing the ingress of '~"~
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i ~L1576~9 g water and egress of air, thereby keeping the boom inflated and without water in the buoyancy chamber. When the boom 10 is removed from the water, the check valve assemblies 17 are manually removed to allow the air within the buoyancy chamber 11 to escape and to allow compaction of the boom 10. The check valves 17 will not be described in specific terms since their construction forms no part of the present invention.

A restraining means or hoop 18 (Figure 4) is inserted in a sleeve 19 made from neoprene foam and acts to keep the walls of the buoyancy chamber 11 from collapsing. The hoop 18 and sleeve 19 are retained on a circumference of the inner wall of the buoyancy chamber 11 by an unsupported P.V.C. envelope 20 bonded by heat sealing to the wall of the buoyancy chamber 11.
The hoop 18 terminates in an aluminum ferrule 21 which, upon insertion of the opposite end of the hoop, is crimped over that end and forms a permanent connection for the two hoop ends.
The hoop 18 enclosed within sleeve 19 is encased by envelope 20 which is bonded to the buoyancy chanber 11.

Water and air impervious bulkheads 22 (Fig. ll)are mounted to the inner walls of the buoyancy chamber 11 at regular intervals along the boom length and are adapted to form a barrier to water and air between adjacent compartments of the .
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11576b9 boom 10. Each bulkhead 22 is manufactured from a rectangularly shaped piece of unsupported P.V.C. and is connected to the walls of the buoyancy chamber utilizing the manufacturing techniques disclosed hereafter.

The control passageway 23 is positioned directly below the buoyancy chamber 11. Unlike the buoyancy chamber 11, the control passageway 23 is not divided into sections or compartments. Rather, there is one section only~ A valve 24 is mounted on the end of the control passageway 23 furthest removed from the initially deployed end, which it has been assumed, is the right hand end of the boom 10 as seen in Figure 1 and provides ingress for air under pressure to inflate the control passageway 23 when the boom 10 is deployed. The construction of valve 24 forms no part of the present invention and since its construction is known, it will not be specifically further described.

In addition to these specified portions of the containment barrier, there are also miscellaneous pieces of hardware utilized for various purposes.

An anchoring shackle 31, best seen in Figure SA, is attached through chain 15 and a cutout 47 is provided in the : : ...
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~S76~9 chain envelope 16 at the point where the shackle 31 is attached. The anchoring shackle 31 is used to anchor the boom-10 or it may be used as a means to attach additional ballast.

A tagline bracket 32, best seen in Figure 5B, is mounted on the interface 25 of the heat bonded area between the buoyancy chamber 11 and the control passageway 23. The tagline bracket 32 consists of two anchor brackets 33,34 which are interconnected by rivets 35,36 and which sandwich the fabric material at the interface 25. Anchor lines 37,38 are attached to the anchor brackets 33,34. The tagline bracket 32 is typically used when a pair of booms 10 are being towed through contamination to funnel it towards a contamination remover such as a skimmer or the like and the booms are maintained in the form of a "V" shaped funnel while operating. In such event, lines are attached to respectively opposed tagline brackets 32 on each boom to maintain the "V" shape.

The end connectors 13,14, one of which is representatively shown in Figure 6, hold the sealed end portion 44 of each end of the boom by the use of first and second aIuminum tubes 42,43, respectively, as will be hereinafter explained.
AIuminum tube 43 is held in place within end connector 13 by bolted connection 27 on the bottom and end connector handle 45 on the top (Figure 1).

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~S7~9 OPERATION

The method of making the boom 10~commences by selecting an appropriately dimensioned boom membrane material of the aforementioned polyester supported P.V.C. and thereupon marking the positions for the installation of the hoop envelopes 20 (Figure 4), the bulkheads 22, the check valve retainers 40 and the control passageway valve 24. The bulkheads 22 are partially assembled prior to their installation in the boom 10. With reference to Figures 2 and 3, a rectangular piece of unsupported P.V.C. bulkhead material 46 is folded as indicated along the short axis B-E bisecting the material. Corners C,D then fall on corners A,F as seen in Figure 2B. The edge portion E-DF is then bonded along the area 39 by heat sealing. Corner C (Figure 2C) is then opened outwardly as indicated and corner DF and bonded edge area 39 are allowed to move inwardly. The bulkhead material 46 is subsequently positioned on the inner walls of the buoyancy chamber 11 (Figure 3A) with the axis B-E falling along the line X-X running longitudinally along the top of the buoyancy chamber 11. The edge portion C-B-A of the bulkhead is then bonded to the material of the buoyancy chamber 11 by heat sealing.

Proceeding simultaneously with the installation of the ~bulkhead material 46, the unsupported P.V.C. hoop envelopes 20 ~:3 , '"' ' '' ',, ' ' . ~;
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, _ ~157~9 are also installed in the buoyancy chamber 11. With reference to Figure 4A the hoop sleeve 19 of neoprene foam material is appropriately positioned on the buoyancy chamber material 48 under the hoop envelope 20 and the edges of the envelope 20 are bonded by heat sealing to the boom membrane material after inserting the hoop 18 with a ferrule 21 crimped on one end.

In addition to the heat sealing operations described above for bonding the bulkheads 22 and the hoop envelopes 20 to the buoyancy chamber 11, check valve retainers 40 and any retainer necessary for the control passageway valve 24 are also installed by heat sealing in their appropriate positions.

As seen in Figure 48, the hoop 18 has a ferrule 21 previously assembled on one end by crimping. Following the installation of the check valve and control passageway valve retainers, the opposite end of the hoop 18 is inserted into the open end of ferrule 21 and the ferrule 21 is crimped on this end. The buoyancy chamber material then encircles the hoop 18.

After the assembly of the hoops 18 and again with reference to Figures 3A, 3B and 3C, the corner DF is pulled~o~twardly and downwardly such that the edge portion CA-DF lies along and is sandwiched between the interface 25 where the buoyancy chamber .,.:. . ~ .

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~1576~9 material meets after the buoyancy chamber material encircles the hoops 18 as particularly well shown in Figure 3C. There is, therefore, a four layer depth of material running along the interface 25 where the edge portion CA-DF of the bulkhead 22 is sandwiched. The interface 25 together with edge portion CA-DF
of the bulkhead 22 is then bonded together by heat sealing.
Thus, a watertight seal along both the buoyancy chamber interface 25 and bulkhead edge portion CA-DF is achieved which causes a water and air impervious seal between the compartments of the buoyancy chamber 11 located on opposite sides of the bulkhead 22 when the boom is in its final assembled condition.

Following the assembly of the buoyancy chamber 11, the bulkheads 22 and the hoops 19, the control passageway 23 is formed. The control passageway 23 will have previously been appropriately dimensioned and any necessary retainer for the control passageway valve 24 has been installed. Bonding is made along the control passageway seal 26 (Figure 3C) by heat sealing.

The chain envelope 16 is subsequently formed by folding the lower end of the flexible skirt 12 upwardly the required distance and bonding the chain envelope seal 41 again by heat sealing. Cutouts 47 are made in the chain envelope 16 to .
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~L~S76~)9 provide space for the anchoring shackle 31. It may be necessary to form a double thickness of fabric material in the chain envelope area and, if so, the skirt 12 is appropriately dimensioned so that it may be folded into the double thickness configuration.

The completion of the chain envelope seal 41 ter~inates the longitudinal boom bonding operations.

With reference to Figure 6A, the left hand end connector 13 is shown in plan view adjacent the left hand end portion of the buoyancy chamber material 48. An aluminum tube 42 extends substantially the width of the end of the boom 10 and the boom material 48 is bonded about the tube 42 at 44 by heat sealing.
The walls of the buoyancy chamber 11, the ends of the control passageway 23 and the ends of the chain envelope 16 are all bonded along the transverse edges of the boom 10 extending from aluminum tube 42 to form transverse edge seal 44. The transverse edge seal 44 is then partially wrapped about a second aluminum tube 43 and the tube 43 with the sealed material wrapped thereabout is slidably mounted from the bottom upwardly in end connector 13 and its position is seen in Figure 6B. An identical procedure both for sealing and for mounting to the end connector 14 is used at the opposite transverse end .. ~.,..
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~lS7~i,9 of the boom 1~. The aluminum tubes 43 inserted in end connectors 13,14 are prevented from sliding out of the end connectors by end connector handles 45 (Figure 1) inserted in the top of the end connectors 13,14 and by bolted connections 27,28 in the bottom of the end connectors 13,14, which are installed after the installation of the aluminum tubes 43. The bolted connections 27,28 are inserted through the end connectors 13,14 while attaching the chain 15, one end connector 13 being representatively shown in Figure 6C.

~ he tagline bracket 32 (Figure 5B) and the anchoring shackle 31 (Figure 5A) are installed as is self-evident from the illustrations. The boom is now in its manufactured condition.

There are two deployment possibilities. In the first instance, the boom 10 may be deployed by attaching one end of the boom 10 to a sea or bottom anchor (not shown) and moving the deployment vessel away from the anchor or, alternatively, two vessels may be used, one for feeding the boom into the water and the other for creating tension on the boom and expanding that portion of the buoyancy chamber 11 between the bulkheads 22. In any event, control passageway 23 is not utilized with this technique of boom deployment. As the boom .~, .
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10 is fed into the water from its position of deployment, the check valves 17 are manually inserted in their retainers 40.
As the tension on the boom 10 expands the buoyancy chamber 11 b-etween the bulkheads 22, a suction within the buoyancy chamber is created and the check valve assemblies 17 allow ingress of air into the various compartments of the buoyancy chamber 11 between the bulkheads 22 thus inflating the boom 10. Since egress of air from the check valves 17 is not permitted by the check valves 17, the boom 10 remains in its inflated condition.

In the second instance, the boom 10 may be deployed without the use of an anchor or a second vessel. -In this case, the check valves 17 are again manually inserted into their receptacles 40 as the boom 10 is deployed into the water. When the boom 10 is entirely deployed, an air pressure line is connected to control passageway valve 24 and the control passageway 23 is inflated. As the control passageway 23 is inflated, it causes the buoyancy chamber 11 to expand between the bulkheads 22 and the resulting suction causes the ingress of air through the check valves 17 into the buoyancy chamber 11 thus causing inflation of the boom 10. Following inflation, the air pressure line may be removed from the control passageway 40 and, since the check valves prevent the egress of air from the buoyancy chamber 11, the boom remains in its inflated position.

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~S7~,9 Certain changes may be made to the boom design. If, for example, the boom 10 is to be a length such that the control passageway 23 will not inflate the entire length of the boom, the control passageway may be divided into chambers with a control passageway valve 24 inserted in one end of each chamber. In this event, only a portion of the length of the boom is deployed until the end of each control passageway chamber is encountered whereupon the particular control passageway is inflated through each valve 24 and causes only that portion of the boom corresponding to the length of the particular control passage to expand and permit self-inflation.

While the materials specified throughout the disclosure have been found to be satisfactory in use, many other materials are also available. For example, although the boom membrane material is specified as being supported vinyl, it is clear that other supported materials would include nylon, Kevlar T-M or polyester, each coated with vinyl, P.V.C., urethane, neoprene, Shelterite T-M- XR5 or Hypalon T-M-Similarly, while the bulkhead and hoop envelopes are specified as being unsupported P.V.C., they may also be made from a supported material. Accordingly, they may be made from the coatings and fabrics specified above, as well as the materials specified in the disclosure and any other appropriate material .

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l~S76~9 which is flexible and air impervious. Further, while the material specified for the ferrule 21 is aluminum and the material specified for the sleeve 19 is neoprene foam, it should be clear that many other appropriate materials are available for the former and any appropriate closed cell foam would be suitable for the latter.

While the boom 10 is specified as being stored without the check valves 17 in their retainers 40, it is, however, usually preferable to store the boom 10 with the check values 17 installed in order to allow for easier and faster boom deployment.

Under certain conditions, it may be desirable to insert strips between the bulkheads in the interface 25 prior to bonding the strips being made of material appropriate to the material used in the manufacture of the boom. This will alleviate the problems of discontinuous heat sealing when a "four layer"
thickness of material in the interface is encountered as the bulkhead is sealed with the interface.

Other changes and modifications to the invention may be readily apparent in addition to those specified to those skilled in the art without departing from the scope of the invention which should, therefore, be limited only by the accompanying claims.

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Claims (5)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A method of producing a tubular containment boom comprising folding each of a plurality of substantially identically shaped rectangular pieces of bulkhead material, each along one of its bisecting axes; bonding an edge portion transverse to the bisecting axis; opening the opposed unbonded edge portion while allowing the bonded edge portion to fold inwardly; positioning said bonded and opened bulkhead material on material used for the buoyancy chamber of said containment boom with said unbonded edge portion being transverse to the longitudinal axis of said buoyancy chamber; bonding said unbonded edge of said bulkhead material to said buoyancy chamber material;
positioning and bonding hoop envelopes on said buoyancy chamber material; encasing a plurality of plastic hoops, each within a flexible sleeve; inserting each of said hoop and sleeve within each of said hoop envelopes; closing the circumference of said hoop by inserting the respectively opposed ends in a ferrule adapted to receive said ends;
crimping said ferrule on each respective end of said hoop;
encasing said ferrule within said flexible sleeve; folding said buoyancy chamber and bulkhead material along said bisecting axis whereby said bonded edge portion opens outwardly and assumes a position transverse to said bisecting axis and the unbonded edge opposed to said bisecting axis assumes a position between the interface of the walls of said buoyancy chamber where said walls meet beneath the longitudinal axis of said containment boom; and bonding said interface of the walls of said buoyancy chamber and said unbonded edge.

2. A method as in claim 1 wherein said material of said buoyancy chamber is supported vinyl.

3. A method as in claim 2 wherein said bonding is accomplished by heat sealing.

4. A method as in claim 3 wherein said bulkhead material is unsupported P.V.C. and said supported vinyl is polyester reinforced with P.V.C..

5. A method of as in claim 1 and comprising the further step of positioning longitudinal vinyl strips of equal thickness to said bulkhead material at positions in said interface where said bulkhead material is not present prior to bonding and subsequently bonding them with said interface.