US3638437A

US3638437A - Floatable casting for working on hull structures below water level

Info

Publication number: US3638437A
Application number: US884757A
Authority: US
Inventors: Shozo Fukuda
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Ltd
Priority date: 1968-12-13
Filing date: 1969-12-12
Publication date: 1972-02-01
Anticipated expiration: 1989-02-01
Also published as: DE1962198A1; YU312469A; YU31592B; GB1236715A; JPS491430B1; NO128260B; NL6918729A; FR2026077A1; SE346746B

Abstract

A floatable casing which is adapted to be positioned around two hull sections of a vessel to be joined while they are in the water includes two sections or portions which are hinged together centrally and each of which includes a plurality of tanks which are adapted to be filled or emptied of sea water for the purposes of floating them, or positioning them in place around the bottom and sides of a hull section to be welded to another section. Each section includes a vertically elongated tank at each side which is adapted to extend upwardly on each side of the vessel to be joined together. Each section defines a continuous beltlike working space preferably at least as high as a man which is adapted to be enclosed in a watertight manner when the device is applied around the hull sections to be joined in a manner such that the separation plane of the hull sections lies in the working space. The device is first floated to the area of the two hull sections and then is submerged by filling the tanks at each end to cause the sections to pivot to an opened form and permit them to be inserted below the bottom of the vessel sections. The sections are moved together and the tanks of the casing structure are then ballasted to give sufficient buoyancy to the device to cause it to bear with resilient water proof portions thereof tightly against the two hull portions which are to be joined together. Thereafter the working space which is aligned with the dividing plane of the two hull sections is freed of sea water by pumping the water out of the space. The side sections are sufficiently high to permit entry of workmen from either side of the vessel and complete movement of the workmen in the passage space defined by the device, to effect the joining of the vessel parts together.

Description

United States Patent Fukuda 1 Feb. 1, 1972 [54] F LOATABLE CASTING FOR WORKING ON HULL STRUCTURES BELOW WATER LEVEL [72] Inventor:

{ 73] Assignee:

Shozo Fukuda, Nagasaki, Japan Mitsubishi Jukogyo Kabushiki Kaisha, Tokyo, Japan 22 Filed: Dec. 12, 1969 21 Appl.No.: 884,757

Primary Examiner-J. Karl Bell AttorneyMcGlew and Toren [57] ABSTRACT A floatable casing which is adapted to be positioned around two hull sections of a vessel to be joined while they are in the water includes two sections or portions which are hinged together centrally and each of which includes a plurality of tanks which are adapted to be filled or emptied of sea water for the purposes of floating them, or positioning them in place around the bottom and sides of a hull section to be welded to another section. Each section includes a vertically elongated tank at each side which is adapted to extend upwardly on each side of the vessel to be joined together. Each section defines a continuous beltlike working space preferably at least as high as a man which is adapted to be enclosed in a watertight manner when the device is applied around the hull sections to be joined in a manner such that the separation plane of the hull sections lies in the working space. The device is first floated to the area of the two hull sections and then is submerged by filling the tanks at each end to cause the sections to pivot to an opened form and permit them to be inserted below the bottom of the vessel sections. The sections are moved together and the tanks of the casing structure are then ballasted to give sufficient buoyancy to the device to cause it to bear with resilient water proof portions thereof tightly against the two hull portions which are to be joined together. Thereafter the working space which is aligned with the dividing plane of the two hull sections is freed of sea water by pumping the water out of the space. The side sections are sufficiently high to permit entry of workmen from either side of the vessel and complete movement of the workmen in the passage space defined by the device, to effect the joining of the vessel parts together.

6 Claims, 12 Drawing Figures PATENTED rm 1 m2 ATTORNEYS PATENTEDFEB H972 3;'e3s;437

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ATTORNEYS FLOATABLE CASTING FOR WORKING ON HULL STRUCTURES BELOW WATER LEVEL SUMMARY OF THE INVENTION This invention relates in general to the construction of devices for facilitating the joining together of ship parts, or hull structures, while they are floating; and in particular, to a new and useful device forming an enclosure around the two vessel parts to be joined to permit work men to move in a watertight space defined by the device to join the parts together.

The present invention is an improvement over the prior art in respect to the provision of a watertight casing body which may be floated out to a position adjacent two aligned hull section portions which are to be joined together and then positioned around each section to define a watertight working space around the separation plane. The device may be used also for repairing or for inspecting the under part of a hull structure if desired. The present/invention is particularly applicable to the present day in which ships are inclined to be very large sized because of the requirements for running economy and also because of the great progress in the art of ship building. In the case of tanker construction, it has become desirable to build ships as large as 300,000 to 500,000 dead weight tons. Consequently, building berths or duct space for building such large ships is not readily available and in most operating ship yards, it is difficult to schedule the berths for the necessary construction and repair work.

In modern times, the so-called on the sea connecting process for interconnecting various hull sections has already been started in which smaller berths are used to build relatively small size elements of the larger size ship. The smaller size units are then floated and joined together in their floating arrangement. One most important problem of effecting such construction, however, is the creation of means for connecting parts which are floating in the water in a safe and reliable manner with respect to mechanical strength. One method proposed in the past for resolving such difiiculties is to cover the hull sections to be joined adjacent the areas of their interconnection by watertight casings such as U-shaped casings or the like which are made wide enough to accommodate the width of the ships hull. Such a casing includes members which extend along the ships bottom and along each side up above the surface of the water in which the vessel is floating and water is pumped out of the inside of the casing body to form a dry working space along the connecting part. Then work is done within the space to carry out the connecting of the hull parts and also to carry out the inspection of the hull after the connection is effected. Such a proposed water proof casing body, however, does not permit the forming of room between the body and the side of the hull upon equipping the device to the hull or upon removing it from the hull because it has been primarily been constructed so that its width may coincide with the width of the hull and so the equipping or removing work is accomplished with difficulties. In addition since the width of the casing body is fixed even though it may be used for ships of equal length it cannot be utilized any more for ships of different widths. Therefore, it is necessary to reconstruct or to completely manufacture each casing body to fit each ship width which is to be joined.

The present invention provides a new and useful water proof casing structure which overcomes the disadvantages of the prior art by providing a casing body which can be utilized for various ships having different widths. The device of the invention provides a waterproof casing body which may be easily floated to the section to be operated upon and submerged beneath the vessel and secured therearound. The structure includes a plurality of tank elements defining a bottom member extending horizontally along the bottom surface of the structure and side members extending vertically on each end, the tanks being arranged to define a central work space above portions of the tanks at the bottom section and inboard of the tanks on the side sections. The structure includes means for ejecting water from the inside to form the dry working space after the device is oriented to engage against the bottom and sides of a vessel. The casing body is made of two pivotal main sections and because it can be bent at any desired location at the central part of its bottom portion the placement of the device in respect to a vessel if facilitated. At least one of the side members is displaceable in the direction of the width of the structure to open the casing to receive the vessel.

Accordingly, it is an object of the invention to provide an improved water tight casing which may easily be positioned to surround the bottom and sides of the hull parts of a vessel which are to be joined together and which also defines a central work space which may be pumped free of water after the device is sealed against the vessel by a regulation of the buoyancy of the device, the device being such to define a working space at least as high as the individual work man and which includes pivotal half sections which are pivoted together at a joint defined centrally between the bottom sections.

A further object of the invention is to provide a floatable caisson device which may be opened to position it around a ships hull and closed to define a watertight work space therewithin which may be entered from at least one side by a workman.

A further object of the invention is to provide a floatable casing which may be fitted to a vessel hull which is simple in design, rugged in construction and economical to manufacture.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a side elevation of a ship constructed of two hull parts having a casing affixed thereto constructed in accordance with the invention;

FIG. 2 is an enlarged sectional view taken along the lines IIIIofFIG. 1;

FIG. 3 is a top plan view of the casing;

FIG. 4 is a side elevational view of the casing;

FIG. 5 is an end elevational view of one of the sections of the casing taken along the line V-V of FIG. 4;

FIG. 6 is a side elevational view of the device floating in the water;

FIG. 7 indicates the partially submerged position of the device being positioned below the hull of the vessel;

FIG. 8 is a view similar to FIG. 7 with a device being positioned to tightly engage the vessel in the watertightened manner;

FIG. 9 is a view similar to FIG. 7 but of another embodiment of the invention;

FIG. 10 is a view of the device of FIG. 9 in a position to that shown in FIG. 8 of the other embodiment;

FIG. 1 l is a top plan view of still another embodiment of the invention; and

FIG. 12 is a front view of the device indicated in FIG. 11.

GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings in particular, the invention embodied therein in FIGS. 1 to 8 comprises a new and useful working casing generally designated 50 for forming a watertight sealed dry working space at the construction part of a ship or vessel, generally designated 52, which may for example be made of two or

more hull sections

1 and 2 which are joined together only after they are floated in the water 54. The waterproof casing 50 is useable not only for joining two hull sections together as shown in the drawings but also for the repairing of a single hull section or for any other inspection or repair purpose. In the case of a manufacture of a vessel 52 the

individual sections

1 and 2 comprising front and rear sections of a hull are separately built in existing relatively small'size building berths or docks and after being launched individually, are con nected together while floating on the water 54 to form a hull S.

In accordance with the invention the watertight casing 50 comprises individual L-shaped body sections 3 and 3' which are hingedly connected together by a hinged joint 8 at a central longitudinal location along the bottom surface of the casing. The hinged assembly of the two casing portions 3 and 3' forms a U-shaped caisson which may be fitted around the sides and bottom of the hull or vessel S at a location such that a working space 9 defined within the parts 3 and 3' is located at the juncture between the

vessel parts

1 and 2.

Each casing part 3 and 3' includes a plurality of horizontally elongated side tanks 4 and 4', cross tanks 4", central vertical end tanks 44, 44 end and at least one vertically elongated tank 40, 40' at each outside cover which is adapted to extend upwardly along the side of the vessel. The

tanks

4, 4", 44 and 40 are joined together to define a bottom surface 5, an inner vessel engaging top wall 10, and left and right

outer side surfaces

6 and 7. When the casing 50 is hinged closed as indicated in FIGS. 3 and 4, it defines a continuous working space 9 extending across the bottom and also a vertical access 9a to the space at each side. The casing structure is bendable at the pivot joint 8 which extends along the bottom for the purpose of manipulating the structure to an opened position,

to encompass a vessel. Continuous waterproof packings 10' and 11' extend along the top wall 10 and the interior end walls of each section 3 and 3' and when the casing 50 is floated to a location beneath the hull of the ship S and part of its buoyancy is restored by pumping water out of its associated tanks, the

waterproof packings

14 and 15 at the end of each section and the packings 10 and 11' which extend across the top wall 10 tightly engage against the bottom of the vessel and provide a water tight seal therewith. The packings l0 and 11 and 14 and 15 may by made of various configurations, for instance, as simple rubber plate elements or of rubber tubular shape which can be expanded by injecting a pressurized fluid for example. Any packing which can provide a satisfactory sealing of the casing with the vessel S would be satisfactory.

Water is drained from the space between the packings 10 and 11' through conduits 12 which connect to water concentrating grooves 13 which are provided within the working space 9. When a device is not to be used, the water is emptied from the

ballast tanks

4, 4", and 44 and it may be moored at a location with a substantial portion projecting upwardly from the surface of the water as shown in FIG. 6. With the easing floating as indicated in FIG. 6, it is towed by a tug boat on the sea until it is positioned along side the vessel S at a location centered in respect to the two

hull parts

1 and 2, which are separated. At this location the water is emptied from the ballast tanks 4 and 4' in order to reduce the buoyancy of the casing body and during this time the draft of the body is adjusted so that the upper surface of the bottom memberS of the casing body may be come somewhat deeper than the draft of the front and rear sections of the ships hull S. At this state the ballast tanks 40 and 40' and 44 and 44' adjacent each end are filled with additional water to cause the casing 50 to assume the position indicated in FIG. 7 at which end portion is lower than the central portion so that the two

parts

3 and 3 pivot relatively to each other about the pivot hinge 8 to open the casing. The buoyancy at the center of such a condition is greater than at each end and in this condition the casing 50 is floated between the

sections

1 and 2 of the hull S and then the sections are brought together and centered over the work space 9.

After the two hull sections are positioned, relative to each other, as desired, the casing 50 is manipulated to a precise position and its buoyancy increased by emptying some of the

end tanks

40 and 40 and 44 and 44 to cause the casing 50 to abut against the ships bottom. As the ballasting is continued the ends of the casing also float up until the whole casing makes a tight abutment with the outer plate of the hull through the packings l0 and 11 as indicated in FIG. 8. This condition causes the abutment of the waterproof packings l4 and 15 on the side edges of each

section

3 and 3 and a complete sealing of the working space 9 within the

casing bodies

3 and 3. Any sea water which remains in the working space 9 is pumped out by means of suitable pump elements to provide a waterproof dry working space which extends in the form of a belt along one side, bottom and other side of the vessel. A worker can enter the inside of the working space from either side and may freely carry out the joining operation of the two

ship sections

1 and 2 and stand upright during such operations. After the complete joining is effected the whole area may be inspected conveniently and without difficulty.

In some instances, it is desirable to further ensure complete water tight engagement of the packings l0'and 11' on the casing 50 with the ships hull S by applying a securing cable or rope 16 and 16' to the respective tops of the side edges 6 and 7 and tensioning them by means of a tensioning capstan or motor 56. This causes a tight drawing up of the

individual sections

3 and 3 and ensures that there is no possibility of an inadvertent disengagement of the casing 50 from the bull's. This tensioning by cables may be accomplished prior to the injection of the water from the inside'of the working space 9.

After the connecting operation is carried out and the two

hull parts

1 and 2 are joined together, to form a single hull S, the tensioning

rope

16 and 16 are disengaged and water is admitted to the working space 9. In addition, water is also admitted gradually to the

end tanks

40 and 40 and 44 and 44' to bend the casing parts 3 and 3' to open them as indicated in FIG. 7. In addition some water is poured into the ballast tanks near the center to cause a reduction of buoyancy and the removal of the casing sections 3 and 3' from the hull. After the casing 50 becomes completely separated from the hull S, the hull S and the casing are moved relatively by means of tug boats or similar pulling apparatus to cause the casing to move clear of the hull S. The casing 50 is then refloated by pumping the tanks dry and thereafter the water in the working space 9 is also ejected. The casing 50 may then be moored at an appropriate place until it is used at the next operation. The forming of the casing 50 with the two

sections

3 and 3 which are hinged together at 8 facilitates its positioning in respect to the hull S and also permits its easy removal without damage to any portion of the hull. In some instances, the bending of the two parts relative to each other is accomplished by means of a separating device which is power driven (not shown). The location of the joint 8 is advantageously at the center but it may be to one side or the other in order to have more than two individual parts 3 and 3' for example.

In the embodiment of the invention indicated in FIGS. 9 and 10, there is provided a water tight casing generally designated 60 which is capable of being applied to a ship's hull S as in the other embodiment and which once applied does define a central beltlike working space extending from the bottom around each side of the vessel. In this embodiment, the casing includes a central or bottom portion 30 and an intermediate side portion 32 and a top or outer side portion 34, all of which are hingedly connected together. The intermediate portion 32 is hinged to the central portion 30 at a hinge point 19 adjacent the top 36 of the central portion 30. The outer end portion 34 is hinged to the intermediate portion 32 at a hinge 20 which is located at the upper edges of these portions. Sealing elements or packings 10'' are provided to provide a water tight sealing engagement with the hull S as in the other embodiment. While locating the hinged

joints

19 and 20 near the inner or top surface of the casing 60, the packing elements 10" may be made in a continuous form.

In the embodiment of FIGS. 9 and 10 the casing 60 includes joints at 17 and 18 which are bridged by expandable bellows or

similar elements

22 and 23 which may be expanded to form a

triangular separation

21 and 22 at the respective locations. Means (not shown) are provided to fully expand the bellows elements22 and 23 to cause the intermediate section 32 and the end section 34 to tightly engage against the hull S. By providing expansion joints at 17 and, 18 water tight engagement of the packing with the hull can be effected and in addition, it ensures that no forces will act against the packing to disturb the water tight sea]. In this embodiment, tensioning cables 16" are advantageously secured to the top sidewall 38 of the casing 60 and tensioned by means of a capstan or other deck machine carried on the hull S.

In the embodiment of the invention indicated in FIGS. 11 and 12, there is provided a casing generally designated 70 which again is formed of two parts or sections 73 and 73'. In this construction, at least one of the sections, for example, the section 73' includes

bottom side tanks

70, 70 and a central transverse tank 72 of a lesser height which will nonnally define the bottom of the working space 79. A feature of this construction however, is that end tanks 74 are mounted in respect to the

tanks

70 and 72 such that they may be shifted laterally in order to provide for variations in the various sizes of the ships with which the device will be used. In the construction illustrated in FIGS. 11 and 12 the tank 74 is shifted inwardly from the end position and the tanks between it and the plane 75 of the juncture between the

parts

73 and 73 is provided with a number of tanks sufficient to fill this intermediate space. When the tank 74' is positioned in accordance with the width of the ship which is to be operated upon, it is advantageously welded in place and the packing elements 10" are applied over the top surface 76.

What is claimed is:

1. A floatable casing for use in joining floating ships hull sections together and in repairing submerged areas of a ships hull, comprising ballastable tank means defining at least one side portion and a bottom with an intermediate beltlike passage extending downwardly from one of said side portions along said bottom packing means along the interior of said side portion and the top of said bottom portion on each side of said beltlike passage for forming a watertight seal with a ships hull when said casing is engaged therewith to seal the beltlike passage from water, said tank means forming at least two pivotally connected sections which may be pivoted apart for separating the positions of said side portion relative to said bottom for facilitating engagement of said casing around a ships hull and which may be moved together to tightly engage said packing with said ships hull, said tank means defining a bottom portion and at least one side portion having an intermediate portion hinged to said bottom and an outer end portion hinged to said intermediate portion, and first and second expandable bellows members connected between said intermediate portion and said bottom portion and between said intermediate portion and said outer end portion respectively, said intermediate portion being pivoted to said bottom adjacent the top of said bottom portion, said end portion being pivoted to said intermediate portion adjacent the interior of said intermediate portion, said first and second bellows members being expandable to act to cause a closing movement of said intermediate portion and said end portion against the hull of a ship and being compressible to open the casing and move said end portion and said intermediate portion away from the hull of the ship.

2. A floatable casing, according to claim 1, wherein said packing means comprising a packing seal located along the top surface of each of said side portions and said bottom at least two laterally spaced locations.

3. A floatable casing, according to claim 1, including tensioning means connectable to said side portions, said casing being formed of two pivotal sections, said tensioning means being engageable with said side portions for urging said sections in a direction to engage tightly against a ship s hull.

4. A floatable casing, according to claim 1, wherein said tank means forms two pivotally connected sections each including a plurality of ballasting tanks to permit separate bal- 6. A floatable casing, according to claim 5, including ten-- sioning means engageable with said outer end portion for pivotal movement of said outer end portion in a direction to tightly engage it with said hull of a ship.

Claims

1. A floatable casing for use in joining floating ship''s hull sections together and in repairing submerged areas of a ship''s hull, comprising ballastable tank means defining at least one side portion and a bottom with an intermediate beltlike passage extending downwardly from one of said side portions along said bottom packing means along the interior of said side portion and the top of said bottom portion on each side of said beltlike passage for forming a watertight seal with a ship''s hull when said casing is engaged therewith to seal the beltlike passage from water, said tank means forming at least two pivotally connected sections which may be pivoted apart for separating the positions of said side portion relative to said bottom for facilitating engagement of said casing around a ship''s hull and which may be moved together to tightly engage said packing with said ship''s hull, said tank means defining a bottom portion and at least one side portion having an intermediate portion hinged to said bottom and an outer end portion hinged to said intermediate portion, and first and second expandable bellows members connected between said intermediate portion and said bottom portion and between said intermediate portion and said outer end portion respectively, said intermediate portion being pivoted to said bottom adjacent the top of said bottom portion, said end portion being pivoted to said intermediate portion adjacent the interior of said intermediate portion, said first and second bellows members being expandable to act to cause a closing movement of said intermediate portion and said end portion against the hull of a ship and being compressible to open the casing and move said end portion and said intermediate portion away from the hull of the ship.

3. A floatable casing, according to claim 1, including tensioning means connectable to said side portions, said casing being formed of two pivotal sections, said tensioning means being engageable with said side portions for urging said sections in a direction to engage tightly against a ship''s hull.

4. A floatable casing, according to claim 1, wherein said tank means forms two pivotally connected sections each including a plurality of ballasting tanks to permit separate ballasting of both the bottom and side portions of said casing, and including means for draining water out of the central beltlike passage.

5. A floatable casing, according to claim 1, wherein said ballastable tank means includes a side portion which may be shifted laterally for accommodating various widths of vessels.

6. A floatable casing, according to claim 5, including tensioniNg means engageable with said outer end portion for pivotal movement of said outer end portion in a direction to tightly engage it with said hull of a ship.