CA1127014A - Underwater lifting balloon - Google Patents
Underwater lifting balloonInfo
- Publication number
- CA1127014A CA1127014A CA351,171A CA351171A CA1127014A CA 1127014 A CA1127014 A CA 1127014A CA 351171 A CA351171 A CA 351171A CA 1127014 A CA1127014 A CA 1127014A
- Authority
- CA
- Canada
- Prior art keywords
- conduit
- balloon
- envelope
- winch
- opening
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63C—LAUNCHING, HAULING-OUT, OR DRY-DOCKING OF VESSELS; LIFE-SAVING IN WATER; EQUIPMENT FOR DWELLING OR WORKING UNDER WATER; MEANS FOR SALVAGING OR SEARCHING FOR UNDERWATER OBJECTS
- B63C7/00—Salvaging of disabled, stranded, or sunken vessels; Salvaging of vessel parts or furnishings, e.g. of safes; Salvaging of other underwater objects
- B63C7/06—Salvaging of disabled, stranded, or sunken vessels; Salvaging of vessel parts or furnishings, e.g. of safes; Salvaging of other underwater objects in which lifting action is generated in or adjacent to vessels or objects
- B63C7/10—Salvaging of disabled, stranded, or sunken vessels; Salvaging of vessel parts or furnishings, e.g. of safes; Salvaging of other underwater objects in which lifting action is generated in or adjacent to vessels or objects using inflatable floats external to vessels or objects
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Ocean & Marine Engineering (AREA)
- Toys (AREA)
Abstract
A + R 1 c/w UNDERWATER LIFTING BALLOON
ABSTRACT OF THE DISCLOSURE
Underwater lifting apparatus which is inflatable underwater and has a flexible balloon envelope containing gas and having upper and lower openings. A flexible conduit extending from the upper opening communicates with balloon interior, and has an open lower end. The conduit has a length sufficient to extend downwardly to a position approximately level with the lower opening of the balloon envelope. A
harness cooperates with the envelope to provide attachments for lifting, and a positioner cooperat-ing with the conduit to permit the lower end of the conduit to be positioned where desired relative to the lower opening of the balloon envelope so as to control lift of the balloon.
ABSTRACT OF THE DISCLOSURE
Underwater lifting apparatus which is inflatable underwater and has a flexible balloon envelope containing gas and having upper and lower openings. A flexible conduit extending from the upper opening communicates with balloon interior, and has an open lower end. The conduit has a length sufficient to extend downwardly to a position approximately level with the lower opening of the balloon envelope. A
harness cooperates with the envelope to provide attachments for lifting, and a positioner cooperat-ing with the conduit to permit the lower end of the conduit to be positioned where desired relative to the lower opening of the balloon envelope so as to control lift of the balloon.
Description
(1) BACKGROUND OF THE INVENTION
Field of the Invention The invention relates to a underwater lifting balloon, in particular to a buoyancy control apparatus for use with balloons as used in unde~water salvaging operations.
10 Prior Art Objects submerged in water have been lif~ed by dif~erent devices, for example sur~ace derricks, rigid hollow metal containers from which 15- wateE can be evacuated and, more recently, flexible, in~latable balloons. Surface derricks and rigid hollow containers can be used for relatively small lifting operations, but for larger lifting opera-tions, such as the salvaging o~ a sunken ship a 20 inflatable balloons have many advantages. For example, inflatable balloons occupy a small space when deflated, and are relatively lightweight and so can be positioned relatively easily around a sunken shipo Commonly, the balloons have open 2S neck configurations, that is have an open lower end~ 7? f so as to autom~tically vent gas or air so tbat the .
.
.
Field of the Invention The invention relates to a underwater lifting balloon, in particular to a buoyancy control apparatus for use with balloons as used in unde~water salvaging operations.
10 Prior Art Objects submerged in water have been lif~ed by dif~erent devices, for example sur~ace derricks, rigid hollow metal containers from which 15- wateE can be evacuated and, more recently, flexible, in~latable balloons. Surface derricks and rigid hollow containers can be used for relatively small lifting operations, but for larger lifting opera-tions, such as the salvaging o~ a sunken ship a 20 inflatable balloons have many advantages. For example, inflatable balloons occupy a small space when deflated, and are relatively lightweight and so can be positioned relatively easily around a sunken shipo Commonly, the balloons have open 2S neck configurations, that is have an open lower end~ 7? f so as to autom~tically vent gas or air so tbat the .
.
.
(2) balloon cannot be overfillecl~ thus reducing risks of bursting~
With some prior art balloons, the buoyancy can be difficult to control accurately, Usually, a balloon is equipped with a con~rollable val~e through which air is vented to control volume and thus buoyancy of the balloon. However, in some applications a considerable volume of air is re quired to be vented, and this would require a correspondingly large valve which is difficult to construct and operate in an underwater environment when fixed to a flexible balloon envelopeO To avoid excessive acceleration of balloons and the object being xaised, it is most important that the lift of the balloon can be accurately controlled.
This is particularLy important in the initial stage of raising a sunken vessel when suficient force is required to overcome not only the deadweight of the vessel but also the adhesion of the ship's hull to the seabed, Usually a far greater amount of buoyancy is required to break the ship free from the seabed than is required to raise the vessel at a controllable speed. Thus, once the ship is broken free, there is an excessive amount of lift which would produce a rapid acceleration of the
With some prior art balloons, the buoyancy can be difficult to control accurately, Usually, a balloon is equipped with a con~rollable val~e through which air is vented to control volume and thus buoyancy of the balloon. However, in some applications a considerable volume of air is re quired to be vented, and this would require a correspondingly large valve which is difficult to construct and operate in an underwater environment when fixed to a flexible balloon envelopeO To avoid excessive acceleration of balloons and the object being xaised, it is most important that the lift of the balloon can be accurately controlled.
This is particularLy important in the initial stage of raising a sunken vessel when suficient force is required to overcome not only the deadweight of the vessel but also the adhesion of the ship's hull to the seabed, Usually a far greater amount of buoyancy is required to break the ship free from the seabed than is required to raise the vessel at a controllable speed. Thus, once the ship is broken free, there is an excessive amount of lift which would produce a rapid acceleration of the
(3) balloon and ship ~owards the surface. The excessive speed can distor~ the balloon envelope which can flatten or drift at a~ angle. This distortion or drift can produce excessive accidental venting o air from the envelope with a corresponding sudden loss of lift which can result in loss of the ship3 as it will once again fall to the seabed.
Attempts at accurate control of venting of gas from the balloon in such circumstances have, to the inventor's knowledge, been relatively unsuc-cessful. In some circumstances, valves on the balloon have been manually adjustable by divers adjacent the balloon but this tends to limit depth at which the balloons can be used due to depth limitations imposed on divers. ~lternatively7 valves to vent the envelope are remotely operated from the surfaceg but these have been prone to mechanical failure. Furthermore, it is difficult to monitor the buoyancy availabIe by remote opera-~ion of such valves.
SUMMARY OF THE INVENTION
The invention reduces difficulties and disadvantag~s of the prior ar~ by providing a - , ' -.~ ,
Attempts at accurate control of venting of gas from the balloon in such circumstances have, to the inventor's knowledge, been relatively unsuc-cessful. In some circumstances, valves on the balloon have been manually adjustable by divers adjacent the balloon but this tends to limit depth at which the balloons can be used due to depth limitations imposed on divers. ~lternatively7 valves to vent the envelope are remotely operated from the surfaceg but these have been prone to mechanical failure. Furthermore, it is difficult to monitor the buoyancy availabIe by remote opera-~ion of such valves.
SUMMARY OF THE INVENTION
The invention reduces difficulties and disadvantag~s of the prior ar~ by providing a - , ' -.~ ,
(4) simple valve structure which can be used with a flexible balloon envelope so as to control accurately and remotely buoyancy of a balloon with very simple mechanical means. Fur~hermore, simple indicating means are availa~le to provide an accurate indica-tion of buoyancy of the balloon from a position adjacent the balloon, or at the surface. Further-more, the apparatus is adaptable to fit the many types of ~lexible balloons and requires little, if any, maintenance as there are essentially no major moving parts that would be subject to exces-sive wear with heavy usage~ The apparatus ca~ be adapted to be fitted on the largest underwater salvage balloons presently in use, and there ap-pears to be no particular size limit of balloonto which this valve cannot be fitted.
An underwater lifting apparatus according to the invention includes a flexible balloon enve-lope, a conduit~ a harness means and a positionermeans. When inflated in water and containing gas, the balloon envelope has upper and lower openings~
and the conduit is flexible and extends from the upper opening to communicate with the interior of the envelope. The conduit has an open lower end and a length su~ficient to exkend downwardly to a ~12~J0
An underwater lifting apparatus according to the invention includes a flexible balloon enve-lope, a conduit~ a harness means and a positionermeans. When inflated in water and containing gas, the balloon envelope has upper and lower openings~
and the conduit is flexible and extends from the upper opening to communicate with the interior of the envelope. The conduit has an open lower end and a length su~ficient to exkend downwardly to a ~12~J0
5) position approximately level with the lower opening of the balloon envelope. The harness means coope~ates wi~h the envelope to provlde attachment means ~or lifting. The positioner means cooperates with the conduit to position the lower end of the conduit where desired relative to the lower opening o the balloon envelope so as to control the buoyancy of the lifting apparatus by venting gas from the interior.
A detailed disclosure following, related to drawings, describes a preferred embodiment of the invention which is capable of expression in structure other than that particularly described and illustrated.
DESCRIPTION OF THE DRAWINGS
0 Figo 1 is a simplified side elevation of a balloon according to the invention shown inflated and in a position for lifting, the balloon being fitted with an external conduit, Fig~ 2 is a simplified top plan o the balloon ~: ,
A detailed disclosure following, related to drawings, describes a preferred embodiment of the invention which is capable of expression in structure other than that particularly described and illustrated.
DESCRIPTION OF THE DRAWINGS
0 Figo 1 is a simplified side elevation of a balloon according to the invention shown inflated and in a position for lifting, the balloon being fitted with an external conduit, Fig~ 2 is a simplified top plan o the balloon ~: ,
(6) of Flg. 1, FLg~ 3 is a diagram showing the buoyancy control of the balloon in a low lift configura~
tion J
Fig4 4 is a simplified diagram of the balloon of Fig. 3 but with the buoyancy control shown in a higher lift position, Figo 5 is a diagram showing raising of a sunken ship using two balloons~ and Fîg. 6 is a s~mplified fragmented section in a dlametrical plane of an alternative balloon with an internal conduit.
DETAILED DISCLOSURE
Figso 1 and 2 An underwater lifting apparatus 10 has a generally pear-shaped flexible balloon nvelope 12 formed of suitable air impermeable fabric such as urethane or vinyl coated nylon or polyester ~76~
tion J
Fig4 4 is a simplified diagram of the balloon of Fig. 3 but with the buoyancy control shown in a higher lift position, Figo 5 is a diagram showing raising of a sunken ship using two balloons~ and Fîg. 6 is a s~mplified fragmented section in a dlametrical plane of an alternative balloon with an internal conduit.
DETAILED DISCLOSURE
Figso 1 and 2 An underwater lifting apparatus 10 has a generally pear-shaped flexible balloon nvelope 12 formed of suitable air impermeable fabric such as urethane or vinyl coated nylon or polyester ~76~
(7) scrim. The envelope 12 has upper and lo~er openings 14 and 15 respectively acljacent upper and lower portions 16 and 17 thereof. The lower portion of the balloon is open, that is the balloon has an open neck 18 suitably reinforced and positioned so as to receive an aLr delivery conduit 20, shown in broken outline~ which extends to provide air to inflate the balloon and is supplied with com-pressed air from a compressor usually at the sur~ace, not shown. The open neck configuration is preferred as it prevents the balloon from being overfilled because excess gas can easily spill or vent from the neck. The air delivery conduit 20 supplies air through the open neck 18 until a desired buoyancy is attained, at which time the conduit 20 can be either removed or left in place to supply additional air if required.
A harness 22 includes an upper ring-like connector 24 adjacent the upper portion 16 of the balloon, and a plurality of lifting straps 26 extending from the upper connector towards the lower portion. The straps are suitably broad and flexible to transfer lifting forces from the bal-loon envelope ~o the straps and to avoid exeessivestress on the balloon envelope. Cables 28 extend :
, ~27~
(~) from lower ends of the lifting straps to a platform 3~ carrying accessories, as will be described, and a cargo hook 31 for attachment to an item to be lifted, such as a sunken vessel. It can be seen that the harness means cooperates with the enve lope and the platform to provide attachment means cooperating with the balloon envelope for lifting.
Also the cables 28 serve as connecting means cooperating with the straps to extend to the plat-form and cLearly, other connecting means andattachment me~s can be substituted. The above structure is generally common to some prior art underwater lifting bal~oons.
- 15 A flexible conduit 33 according to the invention communicates with the upper opening 14 of the envelope and has an open lower end 35~
The conduit extends outwardly from the envelope, ie. is an external conduit, and has a length 36 suficient to extend downwardly to a position 38 which is approximately level with the lower opening 15 of the balloon envelope. As drawn in Figs. 1 and 2, the lower end 35 is outside the envelope and is shown somewhat above the position 38 which represents a configuration approaching maximum lift, as will be described with reference .
' :`
' ,.
(9~
to Figs. 3 and 4. The conduit can be made of a similar flexible air impermeable fabric and is permanently secured to the portion 16 surroundlng the opening 14 so as to communicate with the interior o the envelope offering little restric-tion to air 10w from the envelope. The conduit can bend along its length and yet has sufficient wall stiffness to resist deformation or flatten-ing when curved, which would otherwise tend to restrict or prevent air flow in the conduit.
This can be achieved by using a spiral wound stiffener within the conduit~ suitably a metal or plastic coil spring, or by selection of the tube material itselfO
The lower end 35 of the conduit is pro-vided with a reinforcing ring 39 which prevents collapse of the lower end and easy attachment for a length of cable or line 40 which extends from the lo-~er end 35 to the platform 30. A
winch ~1 is carried on the platform and the cable 40 is wound on the winch so that actuation of the winch reels in or lets out a sufficient length of line to position the lower end of the conduit where desiredO The winch can be fitted with a revolution counter or the like, which would provide (10) an indication of the amount of line extending bet-ween the lower end of the condui~ and the winch.
As the winch is fixed relative to the lower open-ing of the balloon envelope, the counter would serve as an indicating means cooperating wi~h ~he winch and cable to indicate position of the lower end of the conduit relative to the lower opening of the balloon envelope~ The indicating means could be read by a diver, not shown, adjacent the winch, or if necessary, through cables or other transmission means extending to the surface to provide a remote read-out means cooperating with the indicating means to provide a remote indication of the buoyancy. A major advantage would be in pre-set~ing a desired buoyancy based on a pre-set length o line let out from the winch. The line 40 and winch 41 serve as posi-tioner means cooperating with the conduit to permit the open lower end thereof to be positioned where desired.
If desired~ a trip cord device 42 can be used, the device having a trip cord 43 extending from an on/off switch means (not shown~ on ~he winch to a small weight 44 adapted to be suppor~ed on a stationary datum, usually the seabed which . : . .
(11) is undesignated The trip cord 43 has a length such that a~ter the balloon starts to raise the objeet a small amount, which indicates that the object has "unstuck" from the seabed, the ~rip cord tautens. At this stage, to avoid excessi~e acceleration due to excessive lift, usually some air must be spilled from the balloonO When the trip cord tautens, the winch switch is triggered which in turn actuates the winch to permit the L0 end 35 of the conduit to rise to spill a controlled amount of air. This is termed a lift responsive means which cooperates with a datum and the switch means to actuate the switch means when the object to be lifted starts ~o move.
Fi~s~ 3 and 4 In Fig. 3 9 the lower end 35 of the con-duit 33 is positioned relatively closely to ~he upper opening 14 of the balloon and i5 spaced from the lower opening lS of the balloon by a vertical spacing 45. Air pressure within the conduit and the envelope is equal, and water level within the balloon would be as shown by broken line 46, and ~5 a length 47 of cable 40 would extend between the winch and open lower end 35. Clearly, in this .
2~
(1~) condition, the balloon displaces li~tle air and relatively low buo~ancy is generated.
Referring to Fig. 4, the lower end 35 is positioned as shown at a vertical spacing ~9 from the lower opening 15 and a length 51 of cable 40 extends between the lower end and the winch. Water level within the balloon is now designated by a broken line 52 and thus, consider-ably more lift is generated than in the Fig. 3 con-figuration. If the winch is actuated to wind in the cable 40 fu~ther, the lower end 35 could be positioned in broken outline position 35.1 so as to be level with the lower opening 15. This re-presents maximNm lift condition for that volumeof air because~ assuming sufficient length of conduit 33, further lowering oE the end 35 woulcl merely result in water passing up the conduit to attain a level of the lower opening 150 OPER~TION
In operation, one or more balloons are carried down to the ship usually by divers~ the balloons being in a partially inflated sta~e so ` ., (13) as to compensate for their deadweight in the water Harnesses of the balloons are aktached at appro-priate locations on the ship, and air from a com-pressor at the surface is fed to inflate tlle balloons as requiredO Sufficient air is added to break the ship free from the seabed and then air can be bled from the balloon by adjusting the con-duit position to attain a desired rate or rise.
Fi~. 5 One example of use of two balloons accord-ing to the invention is now to be described in greater detail. A sunken ship 56 has generally similar bow and stern balloons 58 and 59 connected to the bow and stern respectively thereof, The balloon at the lowexmost end of the ship, namely the bow balloon 58, is fitted with first and second trip cord devices 61 and 62, as previously des-cribed. The trip cord device 62 has a length ofcord considerably longer than the device 61 and is sufficient to indicate when the bow is gene-rally level with the stern, ie. to be just clear of the ocean floor with the ship level.
The bow balloon has a flexible conduit ~7 (14) 64 in a high lift configuration whilst the stern balloon has a conduit 65 in a low li;Et con~igurcl-tion, It is anticipated that considerable ~orce would be required to break the bow of the ship free from the seabed, whereas relatively little would be required for the stern. The buoyancy o the bow balloon is increased by adding more air, and if necessary the winch can retract the asso-ciated cable or line drawing the cond~it 64 down-wardly until sufficient buoyancy is generated tobreak the bow of the ship free. When this occurs, the first trip cord device 61 generates a signal which is relayed to the surface to stop the supply of air to the bow balloon. Also, the lower end of the conduit 64 of the bow balloon can be raised slightly to spill air from the bow balloon to slow the rate of ascent of the bow, As the bow gradually rises and the ship becomes level, the second trip cord 62 becomes taut and this indicates to operators at the surface that the vessel is now generally level. If necessary, the conduit 65 of the stern balloon is lowered to increase lift, to permit additional air to be added to the stern balloon. The lift of both balloons is adjusted as required by repositioning the open lower ends of the conduits of the respective balloons so that -7~.f~
(15) the ship is raised in a generally level manner to the surface. As the balloons approach the surface~
air is bled -Erom the conduits to attain a deslred rate of ascent and deceleration towards the sur~
face.
ALTERNATIVES A~D EQUIVALENTS
The apparatus 10 is shown with the harness 22 of lifting straps extending from the ring which extends around the flexible conduit adjacent the upper portion o~ the balloon. This is a simple structure and is adequate ~or relatively low buoyancy balloons, for example 10 ton balloons.
For larger balloons up to 200 tons, the strap harness can be eliminated and a simple mesh net can be substituted to enclose the balloon envelope and provide attachment means for the li~ting hook.
Alternatively~ for larger balloons, orbital straps (not shown) could be added to the harness to work in conjunction with the lifting straps, thereby reinforcing the maximum diameter portion of the balloon where the greatest strain is exerted on 25 the balloon envelope~ -3L:lL~7 (16) The upper opening 14 is shown at the uppermost position of the balloon disposed centrally of the envelope, In some applications~ this may be impractical and if desired the openlng can be moved downwardly somewhat which would correspond~
ingly lower the upper end of the conduit. I~
desired, the winch can be eliminated and a simple pulley substituted~ In this alternative, the cable 40 would pass from the lower end of the conduit, around a pulley to a diver who can adjust position of the lower end of the conduit as re-quired. The winch and cable which is controlled remotely from the surface, or the alternative pulley and cable controlled by a diver, bokh serve lS as control link means ex-tending between the harn-ess means and the conduit to permit the lo~er end o~ the conduit to be positioned where desired relative to the lower opening o the balloon enve-lope. A length of flexible tension link other than line or cable can be used to extend between the conduit and the winch. A further alternative would eliminate the cable and winch altogether and position `the lower end 35 by other means ?
thus servlng as a positioner means cooperating with the conduit to position the lower end 35 where desired. ~elative position of the open ~7 ~17) lower encl 35 controls buoyancy of the lifting appar~~
t~lS by venting gas from the interior oE the balloon envelope at a rate proportional to pressure dlfe~
ence across the conduit. ~lternative positionex means can be substituted for particular applicatlons, and alternative indicating means which cooperate directly with the conduit can be substi~uted.
Fi~. 6 ~ n alternative lifting apparatus 70 has a balloon envelope 71 having upper and lower open-ings 72 and 73 respectively, the opening 73 defin-ing an open neck 75. A harness 78, a portion only o~ which is shown, a platform 79 carrying a winch and a lifting hook 80 are fitted as previously described. A flexible conduit 82 extends from the upper opening 72 and communicates with the interior of the envelope by extending inwardly into the balloon as shown, and thus is an internal conduit.
The conduit 82 has a length sufficient to extend downwardly to a position appro~imately level with the lower opening 73 of the balloon envelope, and for simplicity is preferable of convoLuted or bellows-type const~uction that tends to retract au~omatically upwardly when not extendedO The (18) conduik has an open lower end 84 inside the enve-lope and is provided with a ring~ not shown, to prevent collapseO A length o cable or llne 85 extend~ to a winch on the platform 79~ and the winch actuates to position the conduit lower end where required. If required3 cable means or al-ternatives can be used to raise the lower encl-84 to attain the desired position relative to the lower opening 73.
The alternative lifting apparatus 70 can be seen to function in a manner similar to the apparatus 10 o Fig. 1. When bleeding air from the interior of the envelope, the alternative internal location of the conduit 82 produces a flow of air in the conduit which is in an opposite position to that which occurs on ~he conduit 33 of Fig. 1. Also, whilst there is little tendency for the conduit 82 to flatten due to bending as in the Fig. 1 embodiment, in this embodiment it is preerable that there is sufficient elasticity in the conduit 82 to retract the conduit autom~ti-cally towards the opening 72. This is to cause the open end 84 to be positioned as high as possible in the envelope 71 to permit purging of most of the gas from the interior of the balloon, It can be 7~
(19) appreciated that the conduit 82 may not complekely purge the upper portion o.E the balloon beca~l~e in all likelihood, the open lo~er end would not it adjacent an uppermost portion of the balLoon to remove air thererom.
The alternative structure can be seen to be basically similar to the apparatus 10 of Fig. 1, except that the conduit 33 of Fig. 1 has effectively been drawn inwardly through the upper opening 14, and is thus inside-out, to extend as the conduit 82 within the balloon envelope 71. One particular advantage o~ having the condui-t 82 within the envelope is that the conduit is no longer subject to currents flowing past the balloon, and further-more, is less prone to fouling against the struc-ture being raised, or with surrounding rocks, weeds, etc. It can be seen that the same basic concept applies to both lifting apparatus.
A harness 22 includes an upper ring-like connector 24 adjacent the upper portion 16 of the balloon, and a plurality of lifting straps 26 extending from the upper connector towards the lower portion. The straps are suitably broad and flexible to transfer lifting forces from the bal-loon envelope ~o the straps and to avoid exeessivestress on the balloon envelope. Cables 28 extend :
, ~27~
(~) from lower ends of the lifting straps to a platform 3~ carrying accessories, as will be described, and a cargo hook 31 for attachment to an item to be lifted, such as a sunken vessel. It can be seen that the harness means cooperates with the enve lope and the platform to provide attachment means cooperating with the balloon envelope for lifting.
Also the cables 28 serve as connecting means cooperating with the straps to extend to the plat-form and cLearly, other connecting means andattachment me~s can be substituted. The above structure is generally common to some prior art underwater lifting bal~oons.
- 15 A flexible conduit 33 according to the invention communicates with the upper opening 14 of the envelope and has an open lower end 35~
The conduit extends outwardly from the envelope, ie. is an external conduit, and has a length 36 suficient to extend downwardly to a position 38 which is approximately level with the lower opening 15 of the balloon envelope. As drawn in Figs. 1 and 2, the lower end 35 is outside the envelope and is shown somewhat above the position 38 which represents a configuration approaching maximum lift, as will be described with reference .
' :`
' ,.
(9~
to Figs. 3 and 4. The conduit can be made of a similar flexible air impermeable fabric and is permanently secured to the portion 16 surroundlng the opening 14 so as to communicate with the interior o the envelope offering little restric-tion to air 10w from the envelope. The conduit can bend along its length and yet has sufficient wall stiffness to resist deformation or flatten-ing when curved, which would otherwise tend to restrict or prevent air flow in the conduit.
This can be achieved by using a spiral wound stiffener within the conduit~ suitably a metal or plastic coil spring, or by selection of the tube material itselfO
The lower end 35 of the conduit is pro-vided with a reinforcing ring 39 which prevents collapse of the lower end and easy attachment for a length of cable or line 40 which extends from the lo-~er end 35 to the platform 30. A
winch ~1 is carried on the platform and the cable 40 is wound on the winch so that actuation of the winch reels in or lets out a sufficient length of line to position the lower end of the conduit where desiredO The winch can be fitted with a revolution counter or the like, which would provide (10) an indication of the amount of line extending bet-ween the lower end of the condui~ and the winch.
As the winch is fixed relative to the lower open-ing of the balloon envelope, the counter would serve as an indicating means cooperating wi~h ~he winch and cable to indicate position of the lower end of the conduit relative to the lower opening of the balloon envelope~ The indicating means could be read by a diver, not shown, adjacent the winch, or if necessary, through cables or other transmission means extending to the surface to provide a remote read-out means cooperating with the indicating means to provide a remote indication of the buoyancy. A major advantage would be in pre-set~ing a desired buoyancy based on a pre-set length o line let out from the winch. The line 40 and winch 41 serve as posi-tioner means cooperating with the conduit to permit the open lower end thereof to be positioned where desired.
If desired~ a trip cord device 42 can be used, the device having a trip cord 43 extending from an on/off switch means (not shown~ on ~he winch to a small weight 44 adapted to be suppor~ed on a stationary datum, usually the seabed which . : . .
(11) is undesignated The trip cord 43 has a length such that a~ter the balloon starts to raise the objeet a small amount, which indicates that the object has "unstuck" from the seabed, the ~rip cord tautens. At this stage, to avoid excessi~e acceleration due to excessive lift, usually some air must be spilled from the balloonO When the trip cord tautens, the winch switch is triggered which in turn actuates the winch to permit the L0 end 35 of the conduit to rise to spill a controlled amount of air. This is termed a lift responsive means which cooperates with a datum and the switch means to actuate the switch means when the object to be lifted starts ~o move.
Fi~s~ 3 and 4 In Fig. 3 9 the lower end 35 of the con-duit 33 is positioned relatively closely to ~he upper opening 14 of the balloon and i5 spaced from the lower opening lS of the balloon by a vertical spacing 45. Air pressure within the conduit and the envelope is equal, and water level within the balloon would be as shown by broken line 46, and ~5 a length 47 of cable 40 would extend between the winch and open lower end 35. Clearly, in this .
2~
(1~) condition, the balloon displaces li~tle air and relatively low buo~ancy is generated.
Referring to Fig. 4, the lower end 35 is positioned as shown at a vertical spacing ~9 from the lower opening 15 and a length 51 of cable 40 extends between the lower end and the winch. Water level within the balloon is now designated by a broken line 52 and thus, consider-ably more lift is generated than in the Fig. 3 con-figuration. If the winch is actuated to wind in the cable 40 fu~ther, the lower end 35 could be positioned in broken outline position 35.1 so as to be level with the lower opening 15. This re-presents maximNm lift condition for that volumeof air because~ assuming sufficient length of conduit 33, further lowering oE the end 35 woulcl merely result in water passing up the conduit to attain a level of the lower opening 150 OPER~TION
In operation, one or more balloons are carried down to the ship usually by divers~ the balloons being in a partially inflated sta~e so ` ., (13) as to compensate for their deadweight in the water Harnesses of the balloons are aktached at appro-priate locations on the ship, and air from a com-pressor at the surface is fed to inflate tlle balloons as requiredO Sufficient air is added to break the ship free from the seabed and then air can be bled from the balloon by adjusting the con-duit position to attain a desired rate or rise.
Fi~. 5 One example of use of two balloons accord-ing to the invention is now to be described in greater detail. A sunken ship 56 has generally similar bow and stern balloons 58 and 59 connected to the bow and stern respectively thereof, The balloon at the lowexmost end of the ship, namely the bow balloon 58, is fitted with first and second trip cord devices 61 and 62, as previously des-cribed. The trip cord device 62 has a length ofcord considerably longer than the device 61 and is sufficient to indicate when the bow is gene-rally level with the stern, ie. to be just clear of the ocean floor with the ship level.
The bow balloon has a flexible conduit ~7 (14) 64 in a high lift configuration whilst the stern balloon has a conduit 65 in a low li;Et con~igurcl-tion, It is anticipated that considerable ~orce would be required to break the bow of the ship free from the seabed, whereas relatively little would be required for the stern. The buoyancy o the bow balloon is increased by adding more air, and if necessary the winch can retract the asso-ciated cable or line drawing the cond~it 64 down-wardly until sufficient buoyancy is generated tobreak the bow of the ship free. When this occurs, the first trip cord device 61 generates a signal which is relayed to the surface to stop the supply of air to the bow balloon. Also, the lower end of the conduit 64 of the bow balloon can be raised slightly to spill air from the bow balloon to slow the rate of ascent of the bow, As the bow gradually rises and the ship becomes level, the second trip cord 62 becomes taut and this indicates to operators at the surface that the vessel is now generally level. If necessary, the conduit 65 of the stern balloon is lowered to increase lift, to permit additional air to be added to the stern balloon. The lift of both balloons is adjusted as required by repositioning the open lower ends of the conduits of the respective balloons so that -7~.f~
(15) the ship is raised in a generally level manner to the surface. As the balloons approach the surface~
air is bled -Erom the conduits to attain a deslred rate of ascent and deceleration towards the sur~
face.
ALTERNATIVES A~D EQUIVALENTS
The apparatus 10 is shown with the harness 22 of lifting straps extending from the ring which extends around the flexible conduit adjacent the upper portion o~ the balloon. This is a simple structure and is adequate ~or relatively low buoyancy balloons, for example 10 ton balloons.
For larger balloons up to 200 tons, the strap harness can be eliminated and a simple mesh net can be substituted to enclose the balloon envelope and provide attachment means for the li~ting hook.
Alternatively~ for larger balloons, orbital straps (not shown) could be added to the harness to work in conjunction with the lifting straps, thereby reinforcing the maximum diameter portion of the balloon where the greatest strain is exerted on 25 the balloon envelope~ -3L:lL~7 (16) The upper opening 14 is shown at the uppermost position of the balloon disposed centrally of the envelope, In some applications~ this may be impractical and if desired the openlng can be moved downwardly somewhat which would correspond~
ingly lower the upper end of the conduit. I~
desired, the winch can be eliminated and a simple pulley substituted~ In this alternative, the cable 40 would pass from the lower end of the conduit, around a pulley to a diver who can adjust position of the lower end of the conduit as re-quired. The winch and cable which is controlled remotely from the surface, or the alternative pulley and cable controlled by a diver, bokh serve lS as control link means ex-tending between the harn-ess means and the conduit to permit the lo~er end o~ the conduit to be positioned where desired relative to the lower opening o the balloon enve-lope. A length of flexible tension link other than line or cable can be used to extend between the conduit and the winch. A further alternative would eliminate the cable and winch altogether and position `the lower end 35 by other means ?
thus servlng as a positioner means cooperating with the conduit to position the lower end 35 where desired. ~elative position of the open ~7 ~17) lower encl 35 controls buoyancy of the lifting appar~~
t~lS by venting gas from the interior oE the balloon envelope at a rate proportional to pressure dlfe~
ence across the conduit. ~lternative positionex means can be substituted for particular applicatlons, and alternative indicating means which cooperate directly with the conduit can be substi~uted.
Fi~. 6 ~ n alternative lifting apparatus 70 has a balloon envelope 71 having upper and lower open-ings 72 and 73 respectively, the opening 73 defin-ing an open neck 75. A harness 78, a portion only o~ which is shown, a platform 79 carrying a winch and a lifting hook 80 are fitted as previously described. A flexible conduit 82 extends from the upper opening 72 and communicates with the interior of the envelope by extending inwardly into the balloon as shown, and thus is an internal conduit.
The conduit 82 has a length sufficient to extend downwardly to a position appro~imately level with the lower opening 73 of the balloon envelope, and for simplicity is preferable of convoLuted or bellows-type const~uction that tends to retract au~omatically upwardly when not extendedO The (18) conduik has an open lower end 84 inside the enve-lope and is provided with a ring~ not shown, to prevent collapseO A length o cable or llne 85 extend~ to a winch on the platform 79~ and the winch actuates to position the conduit lower end where required. If required3 cable means or al-ternatives can be used to raise the lower encl-84 to attain the desired position relative to the lower opening 73.
The alternative lifting apparatus 70 can be seen to function in a manner similar to the apparatus 10 o Fig. 1. When bleeding air from the interior of the envelope, the alternative internal location of the conduit 82 produces a flow of air in the conduit which is in an opposite position to that which occurs on ~he conduit 33 of Fig. 1. Also, whilst there is little tendency for the conduit 82 to flatten due to bending as in the Fig. 1 embodiment, in this embodiment it is preerable that there is sufficient elasticity in the conduit 82 to retract the conduit autom~ti-cally towards the opening 72. This is to cause the open end 84 to be positioned as high as possible in the envelope 71 to permit purging of most of the gas from the interior of the balloon, It can be 7~
(19) appreciated that the conduit 82 may not complekely purge the upper portion o.E the balloon beca~l~e in all likelihood, the open lo~er end would not it adjacent an uppermost portion of the balLoon to remove air thererom.
The alternative structure can be seen to be basically similar to the apparatus 10 of Fig. 1, except that the conduit 33 of Fig. 1 has effectively been drawn inwardly through the upper opening 14, and is thus inside-out, to extend as the conduit 82 within the balloon envelope 71. One particular advantage o~ having the condui-t 82 within the envelope is that the conduit is no longer subject to currents flowing past the balloon, and further-more, is less prone to fouling against the struc-ture being raised, or with surrounding rocks, weeds, etc. It can be seen that the same basic concept applies to both lifting apparatus.
Claims (10)
EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE
DEFINED AS FOLLOWS:
1. An underwater lifting apparatus which, when inflated in water, is characterized by:
(a) a flexible impermeable balloon envelope adapted to contain gas and having upper and lower openings, (b) a flexible conduit extending from the upper opening and communicating with the interior of the envelope, the conduit having an open lower end and a length sufficient to extend downwardly to a position approximately level with the lower opening of the balloon envelope, (c) harness means cooperating with the enve-lope to provide attachment means for lifting, (d) positioner means cooperating with the conduit to position the lower end of the (21) conduit where desired relative to the lower opening of the balloon envelope, so as to control buoyancy of the lifting apparatus by venting gas from the inter-ior,
(a) a flexible impermeable balloon envelope adapted to contain gas and having upper and lower openings, (b) a flexible conduit extending from the upper opening and communicating with the interior of the envelope, the conduit having an open lower end and a length sufficient to extend downwardly to a position approximately level with the lower opening of the balloon envelope, (c) harness means cooperating with the enve-lope to provide attachment means for lifting, (d) positioner means cooperating with the conduit to position the lower end of the (21) conduit where desired relative to the lower opening of the balloon envelope, so as to control buoyancy of the lifting apparatus by venting gas from the inter-ior,
2. An apparatus as claimed in Claim 1 further characterized by:
(a) winch means cooperating with the attach-ment means, (b) the positioner means including a length of flexible tension link extending between the lower end of the conduit and the winch means, so that actuation of the winch reels in or lets out flexible tension link to adjust position of the lower end of the conduit.
(a) winch means cooperating with the attach-ment means, (b) the positioner means including a length of flexible tension link extending between the lower end of the conduit and the winch means, so that actuation of the winch reels in or lets out flexible tension link to adjust position of the lower end of the conduit.
3. An apparatus as claimed in Claim 1 further characterized by:
(a) indicating means cooperating with the conduit to indicate position of the lower end of the conduit relative to the lower (22) opening of the balloon envelope.
(a) indicating means cooperating with the conduit to indicate position of the lower end of the conduit relative to the lower (22) opening of the balloon envelope.
4. An apparatus as claimed in Claim 2 further characterized by:
(a) indicating means cooperating with the winch to indicate position of the lower end of the conduit relative to the lower opening of the balloon envelope.
(a) indicating means cooperating with the winch to indicate position of the lower end of the conduit relative to the lower opening of the balloon envelope.
5. an apparatus as claimed in Claim 1 further characterized by:
(a) the upper opening of the balloon enve-lope is at an uppermost position of the balloon and disposed centrally of the envelope.
(a) the upper opening of the balloon enve-lope is at an uppermost position of the balloon and disposed centrally of the envelope.
6. An apparatus as claimed in Claim 1 in which the harness means is characterized by:
(a) an upper ring-like connector extending around the flexible conduit adjacent the upper portion of the balloon, (b) a plurality of lifting straps extending (23) from the upper connector towards the lower portion of the envelope, (c) connecting means cooperating with the straps to extend to the attachment means.
(a) an upper ring-like connector extending around the flexible conduit adjacent the upper portion of the balloon, (b) a plurality of lifting straps extending (23) from the upper connector towards the lower portion of the envelope, (c) connecting means cooperating with the straps to extend to the attachment means.
7. An apparatus as claimed in Claim 3 or 4 further characterized by:
(a) remote read-out means cooperating with the indicating means to provide a remote indication of buoyancy of the balloon.
(a) remote read-out means cooperating with the indicating means to provide a remote indication of buoyancy of the balloon.
8. An apparatus as claimed in Claim 1 further characterized by:
(a) switch means cooperating with the control link means, (b) lift responsive means cooperating with a datum and the switch means to actuate the switch means when an object to be lifted starts to rise.
(a) switch means cooperating with the control link means, (b) lift responsive means cooperating with a datum and the switch means to actuate the switch means when an object to be lifted starts to rise.
9. An apparatus as claimed in Claim 1 further (24) characterized by:
(a) the conduit extending externally from the upper opening to provide an external conduit with the lower end thereof out-side the envelope.
(a) the conduit extending externally from the upper opening to provide an external conduit with the lower end thereof out-side the envelope.
10. An apparatus as claimed in Claim 1 further characterized by:
(a) the conduit extending internally from the upper opening to provide an internal conduit with the lower end thereof in-side the envelope.
(a) the conduit extending internally from the upper opening to provide an internal conduit with the lower end thereof in-side the envelope.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA351,171A CA1127014A (en) | 1980-05-02 | 1980-05-02 | Underwater lifting balloon |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA351,171A CA1127014A (en) | 1980-05-02 | 1980-05-02 | Underwater lifting balloon |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1127014A true CA1127014A (en) | 1982-07-06 |
Family
ID=4116854
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA351,171A Expired CA1127014A (en) | 1980-05-02 | 1980-05-02 | Underwater lifting balloon |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1127014A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6789587B2 (en) | 2001-07-13 | 2004-09-14 | Triton Logging Company Inc. | Method and apparatus for underwater tree cutting and retrieval |
| NO20151184A1 (en) * | 2015-09-14 | 2016-11-14 | Lift Up As | Collector for fish cage, and method for positioning a collector in a fish cage |
| CN110329453A (en) * | 2019-08-08 | 2019-10-15 | 张西达 | Underwater lift control system, method and the quick lifting force generator of portable underwater |
-
1980
- 1980-05-02 CA CA351,171A patent/CA1127014A/en not_active Expired
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6789587B2 (en) | 2001-07-13 | 2004-09-14 | Triton Logging Company Inc. | Method and apparatus for underwater tree cutting and retrieval |
| NO20151184A1 (en) * | 2015-09-14 | 2016-11-14 | Lift Up As | Collector for fish cage, and method for positioning a collector in a fish cage |
| NO339199B1 (en) * | 2015-09-14 | 2016-11-14 | Lift Up As | Fish cage collector and method for positioning a collector in a fish cage |
| CN110329453A (en) * | 2019-08-08 | 2019-10-15 | 张西达 | Underwater lift control system, method and the quick lifting force generator of portable underwater |
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| MKEX | Expiry |