GB2120177A - Emergency buoyancy system for semi-submersible vessel - Google Patents
Emergency buoyancy system for semi-submersible vessel Download PDFInfo
- Publication number
- GB2120177A GB2120177A GB08308774A GB8308774A GB2120177A GB 2120177 A GB2120177 A GB 2120177A GB 08308774 A GB08308774 A GB 08308774A GB 8308774 A GB8308774 A GB 8308774A GB 2120177 A GB2120177 A GB 2120177A
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- GB
- United Kingdom
- Prior art keywords
- vessel
- buoyancy
- members
- column
- deck structure
- 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.)
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Links
- 230000000153 supplemental effect Effects 0.000 claims abstract description 12
- 230000008093 supporting effect Effects 0.000 claims description 16
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 9
- 239000012530 fluid Substances 0.000 claims description 8
- 239000000463 material Substances 0.000 claims description 7
- 239000006261 foam material Substances 0.000 claims description 4
- 230000004044 response Effects 0.000 claims description 4
- 230000008859 change Effects 0.000 claims description 2
- 238000007654 immersion Methods 0.000 claims description 2
- 239000008259 solid foam Substances 0.000 claims description 2
- 230000003319 supportive effect Effects 0.000 claims description 2
- VOXZDWNPVJITMN-ZBRFXRBCSA-N 17β-estradiol Chemical compound OC1=CC=C2[C@H]3CC[C@](C)([C@H](CC4)O)[C@@H]4[C@@H]3CCC2=C1 VOXZDWNPVJITMN-ZBRFXRBCSA-N 0.000 claims 1
- 230000002093 peripheral effect Effects 0.000 claims 1
- 238000012544 monitoring process Methods 0.000 abstract description 8
- 230000033001 locomotion Effects 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- 230000001687 destabilization Effects 0.000 description 4
- 238000005553 drilling Methods 0.000 description 3
- 238000011161 development Methods 0.000 description 2
- 229930195733 hydrocarbon Natural products 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 208000031501 Emergencies Diseases 0.000 description 1
- 238000006424 Flood reaction Methods 0.000 description 1
- HCBIBCJNVBAKAB-UHFFFAOYSA-N Procaine hydrochloride Chemical compound Cl.CCN(CC)CCOC(=O)C1=CC=C(N)C=C1 HCBIBCJNVBAKAB-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000003466 anti-cipated effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012354 overpressurization Methods 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 230000008439 repair process Effects 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING
- B63B39/00—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude
- B63B39/02—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude to decrease vessel movements by displacement of masses
- B63B39/03—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude to decrease vessel movements by displacement of masses by transferring liquids
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING
- B63B1/00—Hydrodynamic or hydrostatic features of hulls or of hydrofoils
- B63B1/02—Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving lift mainly from water displacement
- B63B1/10—Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving lift mainly from water displacement with multiple hulls
- B63B1/107—Semi-submersibles; Small waterline area multiple hull vessels and the like, e.g. SWATH
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING
- B63B1/00—Hydrodynamic or hydrostatic features of hulls or of hydrofoils
- B63B1/02—Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving lift mainly from water displacement
- B63B1/10—Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving lift mainly from water displacement with multiple hulls
- B63B1/12—Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving lift mainly from water displacement with multiple hulls the hulls being interconnected rigidly
- B63B1/121—Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving lift mainly from water displacement with multiple hulls the hulls being interconnected rigidly comprising two hulls
- B63B2001/123—Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving lift mainly from water displacement with multiple hulls the hulls being interconnected rigidly comprising two hulls interconnected by a plurality of beams, or the like members only
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- Ocean & Marine Engineering (AREA)
- Cultivation Receptacles Or Flower-Pots, Or Pots For Seedlings (AREA)
- Processing Of Solid Wastes (AREA)
- Filling Or Discharging Of Gas Storage Vessels (AREA)
Abstract
A supplemental buoyancy system for a column stabilized semisubmersible vessel comprises an arrangement of inflatable buoyancy members 24,26 disposed adjacent to and/or within each of the column members interconnecting the vessel deck structure 16 with twin submersible hulls. The inflatable members may be supported beneath the deck structure 16 in a collapsed or partially inflated condition by a flexible containment net. Interior chambers of each of the column members can be provided with inflatable buoyancy members. The buoyancy system includes a control circuit for sensing unwanted column flooding or inclination of the deck to release pressure air for inflation of a particular set of members from a pressure source comprising a set of high pressure air storage bottles. The inflatable members are maintained in at least a partially collapsed condition by a pressure monitoring and alarm system adapted to indicate leakage in any one of the inflatable members. The buoyancy members may be foamed members alternatively. <IMAGE>
Description
SPECIFICATION
Emergency buoyancy system for semi-sub
mersible vessel
The present invention pertains to an emer
gency buoyancy system for a semi-submersi
ble vessel such as of the type used in offshore
drilling and production of hydrocarbons and,
in particular, a column stabilized type vessel.
The development of offshore submarine pe
troleum deposits and other activities as re
sulted in the concept of a floating vessel
having small motions in varying sea condi
tions. The so-called column stabilized type
vessel has been particularly attractive for use
as a drilling and production platform and for
servicing vessels in the petroleum production
art. Such vessels are typically characterized by two spaced apart longitudinal hulls which
have disposed adjacent their opposite ends, vertically extending column members for sup
porting a platform or deck structure. The hulls
and column members are interconnected by a truss structure and by the platform itself to form a multi-legged floating vessel which has considerably less motion in heavy seas than a
monohull vessel.These vessels may be oper
ated at varying drafts by flooding ballast com
partments in the submersible hulls. Although such vessels are quite stable when the ballast chambers are flooded and pumped out under controlled conditions, the stability of column stabilized semi-submersible vessels can be adversely affected by uncontrolled flooding of the hulls or the column members.
Accordingly, it has become an important consideration to provide an emergency or supplemental system which is adapted to prevent the capsizing or sinking of a vessel subjected to unwanted destabilization due to flooding or other catastrophe. Such a system should at least minimize the rate of sinking sufficiently to permit evacuation of personnel. Moreover, such an emergency system should be arranged such that it is unlikely to be damaged during normal use of the vessel or as a result of damage to one of the hulls or column members which causes the destablization. It is also highly desirable to provide an emergency system adaptable to be retrofitted to existing column stabilized semi-submersible vessels and the like. An emergency system meeting the desiderata indicated herein has been provided by the present invention.
The present invention provides an emergency buoyancy system for use with a column stabilized semi-submersible vessel having a deck structure normally disposed above the water surface and a hull structure connected to said deck structure and including a plurality of spaced apart column members supporting said deck structure, and wherein at least portions of the interior of said hull structure form buoyancy chambers of said vessel, said sys
tem including means disposed, in use, in
proximity to respective ones of said column
members and providing supplemental'buoy
ancy for said vessel. Typically, a vessel for
which the buoyancy system of the present
invention is adapted, includes a pair of elon
gated lower hulls disposed spaced apart in
side-by-side relationship and supporting at
least a pair of columns adjacent the opposite
ends of the hulls.The vessel may be ballasted
to change its draft from a shallow draft, in
transit, condition to a deep draft working or in
transit condition with the hulls and lower
portions of the columns submerged. The pre
sent invention provides a buoyancy system
which tends to minimize the possibility of
capsizing or sinking of the vessel in the event
that uncontrolled flooding of all or a portion of
one of the hulls and/or column members
occurs.
In a preferred form of the present invention,
the system includes buoyant members dis
posed, in use, in proximity to each of the
main or corner column members and adapted to displace a sufficient amount of water to
maintain the vessel in an attitude which will
prevent sinking or minimize the rate of sinking
to permit evacuation of personnel from the
vessel.
The emergency buoyancy system may in
clude a plurality of inflatable members formed
of flexible material which can be stored in a
deflated or only partially inflated condition
and are secured, in use, within the column
members or to the underside of the deck
structure adjacent each of the column mem
bers. In a preferred form of the invention, the
inflatable buoyancy members are stored in a
collapsed or generally deflated condition and
are secured by a flexible net or webbing
which partially releases the buoyancy mem
bers in response to inflation thereof while
maintaining the buoyancy members con
nected to the vessel.
Advantageously, in one embodiment of the
invention, an emergency buoyancy system
comprises a plurality of inflatable members
disposed, in use, at least adjacent each of the
main corner column members and includes an
inflation system including a source of high
pressure gas and a control system for inflating
selected ones of the buoyancy members in
accordance with the direction of destabiliza
tion of the vessel. The control system for
inflating the buoyancy members may include
means for sensing flooding of the column
members and means for sensing the inclina
tion of the vessel from a normal or predeter
mined attitude by measuring the roll and pitch
characteristics of the vessel.Inflation of the
buoyancy members at one or more columns
may be effected when the vessel inclination or
combined roll and pitch motion exceeds a
predetermined limit, or when one or more of
the column members floods to a predeter mined level.
The present invention extends to an emergency buoyancy system suitable for use with a column stabilized semi-submersible vessel having a deck structure normally disposed above the water surface and a hull structure connected to said deck structure and including a plurality of spaced apart column members supporting said deck structure, and wherein at least portions of the interior of said hull structure form buoyancy chambers of said vessel, said system including selectively inflatable members disposed, in use, in proximity to respective ones of said column members, control means comprising sensor means for sensing a predetermined degree of inclination of said vessel and/or flooding of at least part of the vessel, said control means being capable of selectively inflating at least one of the selectively inflatable members in response to a signal from said sensor means.
The present invention also extends to an emergency buoyancy system suitable for use with a column stabilized semi-submersible vessel having a deck structure normally disposed above the water surface and a hull structure connected to said deck structure and including a plurality of spaced apart column members supporting said deck structure, and wherein at least portions of the interior of said hull structure form buoyancy chambers of said vessel, said system including a solid foam material disposed, in use, in proximity to respective ones of said column members and capable of providing supplemental buoyancy for said vessel.
Also encompassed by the present invention is a column stabilized semi-submersible vessel having a deck structure normally disposed above the water surface and a hull structure connected to said deck structure and including a plurality of spaced apart column members supporting said deck structure, and wherein at least portions of the interior of said hull structure form buoyancy chambers of said vessel, said vessel comprising an emergency buoyancy system including means disposed, in use of the system, in promixity to respective ones of said column members and capable of providing supplemental buoyancy for said vessel.
Figure 5 is a schematic diagram of a control and monitoring circuit for the buoyancy system of the present invention;
Figure 6 is a detail section view of one of the column members showing an alternate arrangement of one of the inflatable buoyancy members;
Figure 7 is a detail section view of one of the column members illustrating a second alternate embodiment of buoyancy means in accordance with the present invention; and
Figure 8 is a schematic diagram of an alternate embodiment of a control and monitoring circuit for the buoyancy system of the present invention
In the description which follows, like parts are marked throughout the specification and drawings with the same reference numerals, respectively.The drawings are not necessarily to scale and the scale of cetain components may be exaggerated as well as nonessential features omitted in order to illistrate better the features of the invention.
Referring to Fig. 1, there is illustrated a semi-submersible vessel of the so-called column stabilized type and which is generally designated by the numeral 10. The vessel 10 is characterized as having a pair of spaced apart generally elongated hulls 12, each of which are typically provided with a plurality of buoyancy chambers comprising separate ballast compartments certain ones of which are illustrated in somewhat schematic form in Fig.
1 and designated by the numeral 1 3. The ballast compartments 1 3 are adapted to be selectively flooded to vary the operating draft of the vessel. The vessel 10 is further characterized by four spaced apart vertically extending column members 1 4 which are disposed at opposite longitudinal ends of the hulls 12, respectively. The column members 14 are of a typical hollow shell or tubular type construction and provide some of the buoyancy of the vessel 10. The vessel 10 also includes a horizontal platform or deck structure, generally designated by the numeral 1 6 mounted on the upper ends of the columns 14.The deck structure 1 6 is adapted to include deck houses 1 8 and 1 9 for housing machinery and personnel as well as controls for operating the vessel 10. The vessel 10 is also typically provided with a plurality of intermediate column members 20 and a truss structure interconnecting the column members 20 and the column members 14 to form a substantially rigid vessel structure. The vessel 10 may be adapted to perform various functions in connection with, for example, offshore exploration, drilling and production of hydrocarbons.
Various pieces of equipment may be mounted on the deck structure such as the exemplary crane 22, illustrated.
The vessel 10 is of a type which is particularly adaptable for operating in varying sea conditions while being relatively unaffected by winds or wave action of the sea. The vessel 10, which may be of the general type disclosed in U.S. Patent 4,281,615 assigned to the assignee of the present invention, is typically self-propelled by propulsion means disposed in each of the hulls 12, although this characteristic is not critical to the present invention. The vessel 10 is particularly adapted for operating at varying draft conditions by controlled flooding of selected ones of the compartments 13. For example, if the vessel is in transit or operating in particularly shallow seas, it may operate with the hulls 1 2 only partially submerged.On the other hand, if the vessel 10 is hove to or is operating at a particular work site it might be ballasted down to a draft condition wherein the waterline would be that indicated by the reference line 23 in Fig. 1, for example. Obviously, the vessel may be operated at draft conditions in between the aforementioned limits. Although the vessel 10 is particularly suitable for operating in heavy seas, the general arrangement of the spaced apart hulls which support the platform or deck structure 1 6 on plural column members, provides a certain degree of vulnerability to destabilization and capsizing if one or more of the compartments 1 3 should be subject to uncontrolled flooding which would result in a substantial list of the deck structure.In this regard, it has been considered desirable to provide for emergency supplemental buoyancy means to prevent capsizing and/or sinking of the vessel or at least to retard sinking sufficiently to permit evacuation of personnel and/or equipment from the vessel.
Referring to Fig. 2, the present invention contemplates the provision of emergency buoyancy means which is not normally submerged even at the maximum operating draft of the vessel, and which is disposed in proximity to the main column members 14. Although the buoyancy system disclosed herein is adapted for use in conjunction with a column stabilized vessel having four spaced apart columns arranged in a generally rectangular pattern, it will be understood that the buoyancy system may be used with other types of column stabilized vessels having a different column configuration. Fig. 2 illustrates an arrangement of supplemental buoyancy means adapted to be supported on the underside of the deck structure 1 6 in proximity to each of the column members 14.Accordingly, if the vessel 10 should tend to capsize or sink, the buoyancy means at each of the corners would become selectively operable to provide additional buoyancy to prevent sinking or slow the rate of sinking to permit evacuation of personnel from the vessel. Fig.
2 illustrates an arrangement of buoyancy members, generally designated by the numerals 24 and 26, arranged adjacent to each of the column members 1 4. The arrangement of buoyancy members 24 and 26 are adapted to be supported beneath and by the deck structure 1 6 so that upon immersion of the deck structure, the vessel 10 will remain in a floating condition with at least a portion of the deck structure above the waterline. Moreover, by providing the arrangement of the buoyancy system on the underside of the deck structure 1 6 the system is protected from damage by movement of objects or equipment on or about the top of the deck structure itself and the buoyancy system does not occupy usable space on the deck.
In accordance with one embodiment of the present invention, the buoyancy system is characterized by a plurality of inflatable members made of a flexible rubberlike material which may be stored in a collapsed and deflated or only partially inflated condition and, when needed to provide buoyancy for the vessel 10, inflated to an expanded shape which will provide sufficient displacement to at least retard sinking of the vessel. Referring to Figs. 3 and 4, the arrangement of buoyancy members 24 is illustrated in some detail.
The arrangement illustrated in Figs. 3 and 4 is typical of the arrangements 24 and 26 disposed at each corner of the deck structure 16, as shown in Fig. 2, and the difference between the arrangements 24 and 26 is only in regard to the number of separate inflatable members in each arrangement.
Referring to Fig. 3 in particular, the deck structure 1 6 is typically characterized by elongated spaced apart main girders 28 which normally extend the full length of the deck structure and are in supportive relationship to transverse beams 30. Suitable deck plating 32 is typically disposed on top of the beams 30. In accordance with the present invention, it is contemplated that the arrangements of buoyancy members 24 and 26 each comprise one or more flexible inflatable tanks 34. Each of the tanks 34 may comprise a collapsible bag of flexible material which is adapted to hold a gas such as compressed air under moderate pressure. The tanks 34, when provided in sufficient numbers, should be capable of being immersed to depths of at least 40 to 50 feet without collapsing. Alternatively, the tanks 34 could be formed to be semirigid.The tanks 34 are contemplated as being generally elongated cylindrical bags with oval or hemispherical ends and, in the inflated condition, the longitudinal axis of the bag would lay perpendicular to the length of the girders 28. This arrangement is considered to be attractive in that the maximum pressure differential to which the bags would be exposed when submerged would be minimized, even with a deck inclination angle of up to 40 from the horizontal. Typically, the tanks 34 may be fabricated in accordance with the type of material and fabrication techniques such as is provided for tanks adapted to contain various types of liquids. The tanks or bags 34 may each comprise a modified socalled pillow tank used for storing fuel or other liquids at remote or temporary work sites or military installations.One source of a tank of the type contemplated by the present invention is Goodyear Aerospace Corportion,
Engineered Fabrics Division, Akron, Ohio,
U.S.A.
As shown in Fig. 4, it is contemplated that, in the inflated condition, a plurality of tanks 34 will extend generally downwardly to form elongated containers which are maintained secured to the deck structure 1 6 by a flexible webbing or net, generally designated by the numeral 36. The net 36 is adapted to be suitably secured around its upper periphery to a support frame 38 which is suitably attached to the underside of the floor beams 30 and between the main deck girders 28.
As shown in Fig. 3, it is preferable to store the buoyancy tanks 34 in at least a partially collapsed or folded condition. This may be advantageously accomplished utilizing a tank of flexible material which may be stored folded in a somewhat accordian fashion to form a plurality of pleats 37, as illustrated, and suitably secured by the net 36. The net 36 is preferably gathered at spaced apart points and secured to the frame 38 to form pleats 39. It is contemplated in accordance with the present invention, that the net 36 may be secured at points intermediate the periphery of the net by frangible fasteners 40 which typically can be tension bolts interconnecting the net with the frame 38.The fasteners 40 are adapted to break under a predetermined load, upon inflation of the tanks 34, to permit the net to be deployed or dropped, thereby allowing the tanks 34 to expand to their fully inflated shape, while still maintaining the tanks connected to the deck structure 1 6. By storing the tanks 34 in a folded or only partially inflated condition, the tanks are not subject to deterioration by exposure to the environment and are not as likely to be damaged by being struck by an object if, for example, the vessel 10 was involved in a collision. Moreover, in the arrangement illustrated in Figs. 3 and 4, the tanks 34 are also not submerged under any normal operating condition of the vessel 10.The buoyancy arrangement 26 is similar to the arrangement 24; however, the number of tanks 34 may be varied in accordance with the buoyancy requirements of a particular vessel.
Referring now to Fig. 5, the buoyancy members comprising the tanks 34 are adapted to be monitored and inflated by a control system illustrated in schematic form.
In the schematic diagrams of Figs. 5 and 8, only a representative number of tanks 34 are shown and it will be understood that a greater or lesser number of tanks may be provided, as needed, in accordance with the buoyancy requirements of a particular vessel. The tanks 34 are each provided with an inlet conduit 35 and a maximum pressure limiting valve 33 whereby the tanks may be inflated to a suitable pressure to prevent collapse at the anticipated operating depth and to prevent rupture of the tanks from overpressurization.In accordance with this invention, it is contemplated that the tanks may be inflated to a working pressure of from 5 to 20 psig by a source of high pressure gas -such as compressed air which is available from a source capable of providing rapid inflation of each tank A separate control system for the buoyancy member arrangements 24 and 26 for each column would typically be provided and the control circuitry including the monitoring equipment might be maintained at a central control panel in the deck house 1 8 or 1 9 for constant monitoring of the condition of the buoyancy system.
In order to provide for the desired rapid inflation of the tanks 34, the source of pressure air is preferably a plurality of high pressure fluid storage vessels or air bottles illustrated schematically in Fig. 5 and designated by the numeral 41. The air bottles 41 might, for example, each have a volumetric capacity of 25 cubic feet and be capable of storing pressure air at a pressure of 3500 psig. The air bottles 41 are arranged to be connected to the inlet conduits 35 for the buoyancy tanks 34 by way of suitable manifolds and conduits which are connected to a normally closed power operated valve 42. The separate conduits leading to each of the tanks 34 are preferably provided with one way or check valves 44 to prevent backflow of pressure air out of any one of the tanks 34 in the event of failure of another one of the tanks.Each of the tanks 34 may also be provided with a manually operable valve 46 which could be closed in the event that any one of the tanks was required to be removed from the system for replacement or repair. Manual valves 48 also are preferably provided for each of the high pressure air bottles 41 to enable removal of any one of these components from the system, as needed.
The valve 42 is arranged to be controlled by a condition sensing system which may include a suitable controller, generally designated by the numeral 50, which is adapted to sense the inclination of the deck structure 16.
The controller 50 may include means for sensing the roll and pitch motion of the vessel and, upon sensing a predetermined limit roll and/or pitch condition, operate to open the valve 42 to inflate the tanks 34 associated with a particular one of the arrangements of buoyancy members 24 or 26. For example, if the roll and pitch motion of the vessel 10 indicated that the vessel was likely to founder by sinking toward any one or a combination of two of the column members 14, the arrangements 24 and 26 of buoyancy members associated with that particular column member or members would be inflated to anticipate a tendency to capsize or sink in the indicated direction. Moreover, the control system illustrated in Fig. 5 also includes sensing means 52 for sensing the flooding of one of the column members 16. The sensing means 52 might comprise a float switch, for example, disposed in the interior of each of the column members as illustrated in the schematic diagram and in Figs. 1 and 6. The switch 52 is shown in parallel circuit arrangement with the controller 50 although the switch 52 could also be arranged in series with the controller so that the buoyancy members would be deployed only on sensing a limit roll and/or pitch condition coupled with a flooding signal. The control circuit illustrated also includes a manual override switch 54 which could be operated by personnel on board the vessel 10 in the event it was desired to deploy the buoyancy members in any one of the arrangements 24 or 26, at will.
As mentioned previously, it is considered desirable to store the buoyancy tanks 34 in a substantially collapsed or folded condition and to monitor the condition of the tanks so that possible leaks can be detected and repaired as needed. As illustrated in Fig. 3, the tanks 34 are adapted to be stored in a partially inflated or pressurized condition which may, for example, provide for pressurizing the tanks to a pressure of about .5 to 1.0 psig. A monitoring and alarm control system is illustrated in
Fig. 5 including a source of low pressure air 60 which is connected to each of the tanks 34 through suitable conduit means connected to the tanks between the inlet conduits 35 and the check valves 44.The conduits interconnecting the source 60 and each of the tanks 34 also include one way valves 62 arranged between each of the tanks and the connection of each of the tanks to the source 60 so that leakage of a particular tank 34 may be detected. The control system illustrated in Fig. 5 also includes a condition monitoring and alarm unit, generally designated by the numeral 64, which is arranged to have pressure indicators 66, for example, and suitable alarm indicators 68 which would signal a reduced pressure condition in any one of the tanks 34 indicating the development of a leak in a particular tank. The unit 64 is also adapted to monitor the pressure in the manifold connected to the high pressure air bottles 41.
Referring briefly to Fig. 8, an arrangement is illustrated similar to the arrangement of Fig.
5, but including means for evacuating each of the tanks 34, which means comprises a vacuum pump 70. In the arrangement of Fig. 8, the one way valves 62 are reversed in their direction so that leakage of air into any one of the tanks 34 due to a puncture of the tank wall, for example, may be detected as to the specific tank that is leaking. A pilot operated valve 71 is also arranged to be closed upon opening of the valve 42 to prevent evacuation of the tanks 34 if the buoyancy system is activated. Accordingly, a positive or negative pressure monitoring and alarm system may be provided for the flexible buoyancy members comprising the tanks 34 so that the integrity of the emergency buoyancy system may be observed and controlled at all times.It will be understood that the control circuits illustrated in Figs. 5 and 8 are exemplary in the respect
that additional tanks 34 may be added to the
circuitry. A separate set of air bottles 41 may
be provided for each buoyancy arrangement
24 or 26 or a single set of high pressure air
tanks may be provided with a suitable conduit
arrangement and a valve 42 for each buoy
ancy member arrangement 24 and 26. More
over, the schematic diagrams of Figs. 5 and 8
are typical for one of the arrangements of
buoyancy members 24 or 26 and the control
ler 50 could be adapted to actuate any one of
a plurality of valves 42 in accordance with the
indicated direction of excessive inclination of
the vessel.
Destabilization and sinking of the vessel 10
may be caused by unwanted flooding of one
or more of the column members 14 and 20
and, depending on vessel design character
istics, regardless of whether or not all or some
of the ballast compartments 1 3 are flooded.
In particular, if the vessel 10 was operating at
a deep draft condition with a substantial num
ber of the ballast compartments 1 3 flooded or
at least partially flooded, unwanted flooding
of or structural damage to any one of the
column members 1 4 might cause the vessel
10 to be threatened with capsizing or sinking.
Accordingly, it is contemplated that buoyancy
means may be provided within the interior
space formed in each of the column members
14 in the form of inflatable members similar
to the inflatable buoyancy tanks 34. Referring
to Fig. 6, there is illustrated one of the
column members 1 4 in vertical longitudinal section in somewhat schematic form and in
cluding buoyancy means in the form of a
flexible inflatable tank, generally designated
by the numeral 80. The tank 80 is illustrated
stored in a deflated or collapsed condition in an an upper portion of the column 1 4 which is not normally submerged.Accordingly, if the
column 14 is holed or otherwise subject to
unwanted flooding, or severely damaged by
collision with another vessel, the tank 80 may be be inflated to prevent complete flooding of the column and add buoyancy to the vessel 10.
The tank 80 is similar to the tanks 34 and is
configured to inflate to substantially occupy
the interior space 81 of the column 14.
Depending on the particular internal structural
configuration of the column members 14, one
or more tanks 80 might be provided for
inflation to occupy the interior space of one or
more specific chambers within the column
members. For example, the column members
14 typically include anchor chain lockers or
other work or storage spaces separated by
vertically spaced bulkheads. Accordingly, each
of the compartments or chambers could be
provided with a tank 80 stored in either a
collapsed or partially inflated condition and
supported by means such as a net or straps,
designated by the numeral 82. The net 82 is
adapted to be connected to suitable structure
within the column member 14 by frangible fastening means, similar to the fasteners 40, such that upon pressurization of the tank 80, the fasteners would break to release the tank 80 for complete inflation.Each of the tanks 80 is adapted to be arranged in a control circuit such as the circuit illustrated in Figs. 5 and 8 for inflation upon receiving a suitable signal responsive to flooding of a particular column member.
Although two specific locations of inflatable tanks 34 and 80 are disclosed and which provide protection for the tanks, other arrangements are possible within the scope of the present invention such as, for example, inflatable collars disposed around the exterior of the column members 1 4 and 20 just below the deck structure 1 6.
One advantage of the buoyancy system of the present invention is that a minimum amount of additional weight is added to the vessel 10 and the space occupied by the buoyancy system is also minimized. However, the present invention also contemplates the provision of fixed buoyancy means disposed within the interior of each of the column members 14. Referring to Fig. 7, the interior of one of the column members 14 is shown provided with supplemental buoyancy means comprising space occupying closed cell foam material generally designated by the numeral 90.The foam material 90 could be deployed in one or more separate compartments within each of the column members 14 and 20 to prevent flooding of such compartments and to add buoyancy to the vessel 10 in the event of unwanted flooding of the ballast compartments in the hulls 1 2 or in the event of holing or collapse of one of the column members 14.
The foam material 90 might also be provided in large blocks or the like and secured between the girders 28 in place of or in addition to the arrangements of buoyancy members 24 and 26.
It will be appreciated from the foregoing description that an emergency or supplemental buoyancy system is provided for a column stabilized vessel which is adapted to prevent sinking or minimize the rate of sinking in the event of unwanted flooding of one or more of the submersible hulls as well as one or more of the column members. Such a buoyancy system could minimize the risk of loss of the vessel and/or personnel in the event of encountering extremely severe sea conditions, malfunction of the control system for the ballast compartments, striking a pinnacle of doom, or other unwanted holing of the hulls 1 2 or the stabilization columns. Moreover, various substitutions and modifications of the arrangement disclosed herein may be made without departing from the scope and spirit of the invention as recited in the appended
Claims (27)
1. An emergency buoyancy system for use with a column stabilized semi-submersible vessel having a deck structure normally disposed above the water surface and a hull structure connected to said deck structure and including a plurality of spaced apart column members supporting said deck structure, and wherein at least portions of the interior of said hull structure form buoyancy chambers of said vessel, said system including means disposed, in use, in proximity to respective ones of said column members and providing supplemental buoyancy for said vessel.
2. A system according to Claim 1 wherein said buoyancy means is not submerged when said vessel is floating in an operating draft condition
3. A system according to Claim 1 or 2, wherein said buoyancy means includes at least one inflatable member disposed in proximity to respective ones of said column members.
4. A system according to Claim 3, wherein said inflatable member is stored in at least a partially collapsed condition and is operably connected to a source of pressure fluid for substantially fully inflating said inflatable member.
5. A system according to Claim 4, the system comprising conduit means interconnecting said source of pressure fluid and said inflatable member, valve means interposed in said conduit means, and control means for operating said valve means to conduit pressure fluid to said inflatable member.
6. A system according to Claim 5, wherein said control means includes a sensor for sensing the flooding of said chamber.
7. A system according to Claim 6, wherein said sensor is disposed in a chamber formed at the base of respective ones of said column members.
8. A system according to Claim 5, wherein said control means includes sensing means for sensing a predetermined inclination of said vessel.
9. A system according to any one of
Claims 5 to 8, wherein said control means includes a control circuit for sensing the fluid pressure in said inflatable member in said stored condition, said control circuit being operable to signal a change in said fluid pressure indicating leakage of fluid with respect to said inflatable member.
10. A system according to Claim 9, wherein said inflatable member is stored in a partially inflated condition, and said control circuit includes a source of pressure air for partially inflating said inflatable member.
11. A system according to Claim 9 wherein said control circuit includes means for maintaining the pressure within the interior of said inflatable member at less than atmospheric pressure in said stored condition of said inflatable member.
1 2. A system according to any one of
Claims 4 to 11, wherein said source of pressure fluid includes at least one pressure vessel containing compressed air at relatively high pressure.
1 3. A system according to any one of
Claims 3 to 1 2 wherein said inflatable member comprises a flexible bag adapted to be collapsed to reduce the space occupied by said inflatable member in a stored condition.
1 4. A system according to Claim 1 3 wherein said inflatable member is disposed within a chamber formed in said column member.
1 5. A system according to Claim 1 3 wherein said system includes a plurality of said flexible bags supported on the underside of said deck structure adjacent respective ones of said column members.
1 6. A system according to Claim 15, the system comprising bag supporting means for supporting said flexible bags in said stored condition, said bag supporting means being adapted to at least partially release said flexibly bags to expand and space occupied by said flexible bags when said flexible bags are inflated.
1 7. A system according to Claim 16, wherein said bag supporting means includes a net, said net being secured to said deck structure at a peripheral portion of said net and including means for supporting gathered portions of said net to provide for said net to support said flexible bags in said stored condition, said means for supporting said gathered portions being operable to release said gathered portions upon inflation of said flexible bags to allow said net to permit said flexible bags to expand while remaining in supportive relationship to said flexible bags.
1 8. A system according to any one of
Claims 1 to 17, wherein said vessel includes two spaced apart submersible hulls, each of said hulls being connected to the lower end of spaced apart pairs of said column members.
19. A system according to any one of
Claims 1 to 18, wherein said buoyancy means comprises a substantially rigid foam material disposed in a chamber in said column member to reduce the floodable volume of said chamber.
20. A system according to Claim 1 comprising buoyancy members disposed, in use, at least in proximity to each of said column members and not submerged at a normal working draft of said vessel, said buoyancy members being adapted to be stored in a condition occupying a predetermined space on said vessel and being operable to be deployed to occupy sufficient space to retard the sinking of said vessel upon immersion of said buoyancy members, and control means for selectively deploying said buoyancy members in proximity to at least one of said column members in response to an event which tends to cause said vessel to founder.
21. A system according to Claim 20, wherein said buoyancy members comprise a plurality of flexible inflatable members supported on the underside of said deck structure adjacent respective ones of said column members.
22. A system according to Claim 20, wherein said buoyancy members comprise inflatable members disposed within a chamber formed in each of said column members.
23. An emergency buoyancy system suitable for use with a column stabilized semisubmersible vessel having a deck structure normally disposed above the water surface and a hull structure connected to said deck structure and including a plurality of spaced apart column members supporting said deck structure, and wherein at least portions of the interior of said hull structure form buoyancy chambers of said vessel, said system including selectively inflatable members disposed, in use, in proximity to respective ones of said column members, control means comprising sensor means for sensing a predetermined degree of inclination of said vessel and/or flooding of at least part of the vessel, said control means being capable of selectively inflating at least one of the selectively inflatable members in response to a signal from said sensor means.
24. An emergency buoyancy system suitable for use with a column stabilized semisubmersible vessel having a deck structure normally disposed above the water surface and a hull structure connected to said deck structure and including a plurality of spaced apart column members supporting said deck structure, and wherein at least portions of the interior of said hull structure form buoyancy chambers of said vessel, said system including a solid foam material disposed, in use, in proximity to respective ones of said column members and capable to providing supplemental buoyancy of said vessel.
25. A column stabilized semi-submersible vessel having a deck structure normally disposed above the water surface and a hull structure connected to said deck structure and including a plurality of spaced apart column members supporting said deck structure, and wherein at least portions of the interior of said hull structure form buoyancy chambers of said vessel, said vessel comprising an emergency buoyancy system including means disposed, in use of the systen, in proximity to respective ones of said column members and capable of providing supplemental buoyancy for said vessel.
26. An emergency buoyancy system for a column stabilized semi-submersible vessel substantially as hereinbefore described with reference and as illustrated in the accompanying drawings.
27. A column stabilized semi-submersible vessel fitted with an emergency buoyancy system according to any of the preceding claims.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US37991182A | 1982-05-20 | 1982-05-20 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB2120177A true GB2120177A (en) | 1983-11-30 |
Family
ID=23499198
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08308774A Withdrawn GB2120177A (en) | 1982-05-20 | 1983-03-30 | Emergency buoyancy system for semi-submersible vessel |
Country Status (2)
| Country | Link |
|---|---|
| GB (1) | GB2120177A (en) |
| NO (1) | NO831778L (en) |
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2199290A (en) * | 1986-11-27 | 1988-07-06 | Earl & Wright Ltd | Auxiliary buoyancy for off-shore operations |
| GB2239308A (en) * | 1989-12-23 | 1991-06-26 | Marconi Gec Ltd | Supporting device for heat exchanger |
| GR900100123A (en) * | 1990-02-19 | 1992-06-30 | Emmanouil Mparmpopoulos | Safety baloon preventing boats from sinking |
| GR1001464B (en) * | 1993-01-29 | 1994-01-31 | Konstantinos Nikiforos | Restoring buoyancy mechanism for salvage of a passenger ship in emergency condition. |
| WO1995015279A1 (en) * | 1993-12-02 | 1995-06-08 | Julian Edwin Cook | Control of pneumatic devices |
| EP0753455A1 (en) * | 1995-07-12 | 1997-01-15 | Georgios Teleionis | Construction of vessels with industrially prefabricated tubular floats |
| GB2314814A (en) * | 1996-02-01 | 1998-01-14 | Francis Norman Potter | Vessel Flotation and Anti-capsize System |
| EP0919461A1 (en) * | 1997-11-27 | 1999-06-02 | Diehl Stiftung & Co. | System for the salvaging of ships |
| WO1999048751A3 (en) * | 1998-03-21 | 1999-12-09 | Rainer Seidel | Ship with a protection system making it unsinkable |
| NL1009611C2 (en) * | 1998-07-10 | 2000-01-11 | Peter Vermeulen | Emergency buoyancy devices are bags which are deployed in ship which is about to sink and filled with rapidly expanding material which has specific gravity less than water |
| WO2000029284A1 (en) * | 1998-11-14 | 2000-05-25 | Lopez Perea Lloveres Vicente | System for keeping afloat any type of boat in case of a leak |
| WO2003043881A1 (en) * | 2001-11-23 | 2003-05-30 | Giuseppe Cappelluti | Buoyant divisor |
| US6612256B1 (en) * | 2002-02-15 | 2003-09-02 | Calford S. Martin | Combination boat and distressed boat flotation apparatus and related methods |
| WO2006066490A1 (en) * | 2004-12-21 | 2006-06-29 | Deli Fu | A load-carrying type floating structure with double-floor stabilizing board |
| WO2007048358A3 (en) * | 2005-10-26 | 2007-07-19 | Karel Jan Stolc | The matter for safety purposes and its utilization |
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| GB288677A (en) * | 1927-01-03 | 1928-04-03 | Neil Mcdonald | Improved means of increasing the buoyancy of boats |
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| US4287624A (en) * | 1979-02-14 | 1981-09-08 | Lowther Lou Y | Auxiliary flotation gear for fishing boats |
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| GB288677A (en) * | 1927-01-03 | 1928-04-03 | Neil Mcdonald | Improved means of increasing the buoyancy of boats |
| GB285774A (en) * | 1927-11-22 | 1928-02-23 | Carl Gustaf Fridholm | Arrangement on ships for preventing sinking |
| GB579644A (en) * | 1940-08-16 | 1946-08-12 | British Power Boat Company Ltd | Improvements in or relating to hulls for motor-boats |
| GB853693A (en) * | 1957-06-26 | 1960-11-09 | M E P Company Ltd | Improvements in or relating to ship's lifeboats |
| GB1397280A (en) * | 1971-10-20 | 1975-06-11 | Bridgestone Tire Co Ltd | Safety device for ships |
| GB1450135A (en) * | 1972-12-26 | 1976-09-22 | Bridgestone Tire Co Ltd | Protective device for gas bag of ship safety device |
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| US3952350A (en) * | 1974-10-04 | 1976-04-27 | Emil Moucka | Gravity weight trigger for a life raft |
| GB2034252A (en) * | 1978-10-23 | 1980-06-04 | Tuffier R | Safety device for rendering a boat unsinkable |
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Cited By (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2199290A (en) * | 1986-11-27 | 1988-07-06 | Earl & Wright Ltd | Auxiliary buoyancy for off-shore operations |
| GB2239308A (en) * | 1989-12-23 | 1991-06-26 | Marconi Gec Ltd | Supporting device for heat exchanger |
| GB2239308B (en) * | 1989-12-23 | 1993-09-01 | Marconi Gec Ltd | Heat exchanger |
| GR900100123A (en) * | 1990-02-19 | 1992-06-30 | Emmanouil Mparmpopoulos | Safety baloon preventing boats from sinking |
| GR1001464B (en) * | 1993-01-29 | 1994-01-31 | Konstantinos Nikiforos | Restoring buoyancy mechanism for salvage of a passenger ship in emergency condition. |
| WO1995015279A1 (en) * | 1993-12-02 | 1995-06-08 | Julian Edwin Cook | Control of pneumatic devices |
| EP0753455A1 (en) * | 1995-07-12 | 1997-01-15 | Georgios Teleionis | Construction of vessels with industrially prefabricated tubular floats |
| GB2314814B (en) * | 1996-02-01 | 2000-07-26 | Francis Norman Potter | Instantaneous and automatic vessel safety floatation and anti capsize system |
| GB2314814A (en) * | 1996-02-01 | 1998-01-14 | Francis Norman Potter | Vessel Flotation and Anti-capsize System |
| EP0919461A1 (en) * | 1997-11-27 | 1999-06-02 | Diehl Stiftung & Co. | System for the salvaging of ships |
| WO1999048751A3 (en) * | 1998-03-21 | 1999-12-09 | Rainer Seidel | Ship with a protection system making it unsinkable |
| US6327988B1 (en) | 1998-03-21 | 2001-12-11 | Rainer Seidel | Ship with a protection system making it unsinkable |
| NL1009611C2 (en) * | 1998-07-10 | 2000-01-11 | Peter Vermeulen | Emergency buoyancy devices are bags which are deployed in ship which is about to sink and filled with rapidly expanding material which has specific gravity less than water |
| WO2000029284A1 (en) * | 1998-11-14 | 2000-05-25 | Lopez Perea Lloveres Vicente | System for keeping afloat any type of boat in case of a leak |
| ES2163958A1 (en) * | 1998-11-14 | 2002-02-01 | Lloveres Vicente Lopez-Perea | System for keeping afloat any type of boat in case of a leak |
| US6431108B1 (en) | 1998-11-14 | 2002-08-13 | Vicente Lopez-Perea Lloveres | System for keeping afloat any type of boat in case of a leak |
| WO2003043881A1 (en) * | 2001-11-23 | 2003-05-30 | Giuseppe Cappelluti | Buoyant divisor |
| US6612256B1 (en) * | 2002-02-15 | 2003-09-02 | Calford S. Martin | Combination boat and distressed boat flotation apparatus and related methods |
| WO2006066490A1 (en) * | 2004-12-21 | 2006-06-29 | Deli Fu | A load-carrying type floating structure with double-floor stabilizing board |
| WO2007048358A3 (en) * | 2005-10-26 | 2007-07-19 | Karel Jan Stolc | The matter for safety purposes and its utilization |
Also Published As
| Publication number | Publication date |
|---|---|
| NO831778L (en) | 1983-11-21 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |