JPH057596U - Wide-bottom semi-submersible - Google Patents

Abstract

(57) [Summary] [Objective] To provide a wide-bottom semi-submersible vessel with improved stability. A long elongated deck 10, means including a plurality of stable columns 20 extending from the deck, and a pontoon 30 connected to the lower end of each stable column to provide a wide floating base in the longitudinal direction thereof. In a wide-bottom semi-submersible vessel consisting of equal cross-sections and stable columns and ballast loading and unloading means 64, 66 in the pontoon, each stabilizing column faces downward from the respective port starboard and starboard bottoms. And it is characterized by extending outward.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

  The present invention is a buoyant pontoon or footing, stable column. y-column) and deck have a new assembly and improved stability characteristics It concerns a semi-submersible ship that provides a ship. A ship constructed in accordance with the invention also It is especially suitable for use in areas of ice swarms.

[0002]

[Prior art]

  Conventional semi-submersibles are the product of design progress. Initial offshore exploration and production of hydrocarbons During that time, the drilling technique was based on experience near the coast. Offshore support platform The dome may be a fixed structure or tower constructed on top of the pile work, or may be floating offshore. Either a barge or caisson that was brought out and then submerged to rest on the seabed Met. Increased water depth when exploration goes farther from the coast to dig wells Needed improved construction. Barge or caisson attempts to float in water Pontoons or footings, stable columns extending upwards through the water, and safety Evolved into a floating structure with a non-buoyant deck on top of the constant column. The deck is dug The rig and other exploration equipment were given. Minimize vertical movement of drilling rig In order to achieve this, the cross-sectional area of the stable column was minimized at the waterline. Ship you get Are collectively called semi-submersible ships.

[0003]   Although the morphology of offshore support structures was evolving to accommodate deeper waters, , The location of the well has also expanded to a more severe environment. The first underwater well is the coast Excavated in a protected body of water near. Danger goes away when you're stormed The worker was evacuated. But nowadays, the underwater drilling front is far from the coast. Existing. The distance from the coast makes quick evacuation impossible in stormy weather, Homes are becoming more and more important as the waters are no longer protected by the land itself Exposed to a violent storm.

[0004]   The customary design of semi-submersible ships has become a reality at remote and often poor environmental points. The offshore platform as it is a product of progress through conditions different from the one being tested. Home stability is a condition imposed on ships by work in such remote environments Does not fit well.

[0005]   Conventional semi-submersibles are subject to adverse weather conditions to provide sufficient air between the large waves and the bottom of the deck structure. A gap and increase in work platform height, Ballast is pulled out. However, such deballasting is more against wind and waves. Exposes the surface of, while actually raising the center of gravity and lowering the metacenter height Let

[0006]   There are three aspects to the stability phenomenon: initial, large angle (la Rage angle) and damaged. Initial stability of the ship Gender is a familiar concept of metacenter height (GM). From 5 ° to 10 ° Represents the ship's resistance to tilt over a range of, and is essentially a characteristic of the ship's water surface. Is. The technique of quantifying large angle stability differs from the measurement of GM. Measure this stability To determine, the ship's restoring arm is calculated over a range of tilt angles. Under the curve obtained Represents the energy that can be absorbed. Lastly, damage stability (damaged) stability) is a measure of a ship's ability to withstand flooding of tanks and compartments. It Although more subordinate than other aspects of stability, thorough analysis is within design criteria. Represents the ship's ability to survive.

[0007]   Conventional semi-submersibles lose initial stability during deballasting. Ballast water is pontou The vertical center of gravity (VGG) of the ship is pumping water when it is pumping water. It goes up and GM goes down. The rationale behind such measures in bad weather is Large-angle stability provides more reserve buoyancy to withstand large-angle tilts while at the same time The angle at which the ship can be tilted before the downflooding occurs It means that it will be improved by increasing. In addition, the worker moves the semi-submersible When you want to, the draft is reduced until the pontoon is exposed. The water surface is pon The intermediate state before the dramatic increase due to the appearance of the toon often remains stable at last. To present.

[0008]   An extremely simplistic answer to this problem is the ship's bees until a minimum GM is acceptable. It is to increase the time. Unfortunately, too much initial stability is also harmful. It Accelerations resulting from extreme GM in working draft ) Is the entire structure for degrading crew and handling inertial loads Requires additional steel over. In addition, the entire deck structure itself is stable. Increase due to the wider span that occurs between spaces.

[0009]   Another problem is the flock of offshore ice that ice groups constantly form over a period of the year. Occurs when exploring a closed area. These groups of ice are up to 8 feet (2.4 m) Or thicker plates of ice, which is substantially thicker. May have a "pressure ridge" . These ice populations are not stationary and can be exposed to surface winds and currents several times per day. May move a hundred feet. Clearly, these moving ice populations are substantive Power, which may be destructive to objects in the passage of the ice mass. unknown.

[0010]

[Means for Solving the Problems]

  According to the present invention, the deck, a plurality of stable columns extending downward from the deck, A means for connecting to the lower end of the stabilizing column to provide a wide buoyant base, and a ship A wide bottom consisting of ballast access means for raising and lowering the draft of ed) semi-underwater vessels are provided.

[0011]   The present invention angled the stable column out of the deck structure to a wider support base, The deck structure itself is watertight and effective at large angles or when damaged By doing so, the stability problem is solved. Wide at shallow draft The effective beam provides a larger GM, while the angularity of the column allows for deep drafts. Limits stability and does not require additional deck steel. Floating deck structure is underwater And contributes to large-angle stability at Provides extra buoyancy.

[0012]   The resulting wide-bottom semi-submersible is superior to the conventional design of semi-submersibles. In draft range The GM across can be optimized further so that the stability never deteriorates below the minimum value. Similarly, the angularity of the column prevents the GM from becoming overly aggressive. In all cases The large-angle stability of this wide-bottom semi-submersible exceeds that of the conventional vertical leg configuration. loss In the event of a scratch, this wide-bottom semi-submersible will better withstand submersion and provide better residual recovery energy. Larger to reduce the risk of downflooding. Of columns against vertical It is thought that the angularity can be in the range greater than 0 ° and less than 90 °. Has been.

[0013]   Semi-submersibles are particularly suitable for use in ice swarms of water. Ice pack at compression The intensity of is substantially higher than that at the time of the tune. According to one aspect of the invention, when desired Drain and incorporate ballast to bring the stable column into contact with the ice mass. The ship When climbing, the outboard surface of the column, which extends downwards and outwards, is located outside the ship. It exerts an upward or bending force on the ice block to be placed to destroy this type of block. Reverse In addition, lowering the ship is done by bending the inner surface of the column downwards against the ice located below deck. Exert a force. Ballast should be continuously ingested and ejected under ice conditions The ship may be cycled up and down when it is severe.

[0014]   Referring to FIGS. 1-3, a waterproof float supported on three stabilizing columns 20. A wide-bottom semi-submersible with a deck 10 is shown, this column being on each side of deck 10. Continuously extends downward and outward from the bottom of the. Three stabilizers on each side of the ship The rams 20 are connected to each elongated pontoon 30 to provide the boat 30 with a wide floating base. Give a su. An example of a structural trust assembly 40 faces each other, as shown in FIG. It is provided between each of the three pairs of stabilizing columns 20 and the bottom of the deck 10 to provide the structural integrity of the ship. Guarantee the sex. Each of the three structural truss assemblies 40 faces the stable column 20. A lateral member 42 that connects the respective sets to each other, and The vertical member 44 extending to the bottom 46 of the plate 10 and the center of the lateral member 42 from the deck 1 It has a pair of diagonal members 48, 50 extending to the bottom 46 of the zero. This structure The lath assembly may take any form or shape as long as the integrity of the ship is maintained. Yes.

[0015]   The deck 10 extends downward from both sides of the central portion 52 of the lateral direction and the central portion 52 of the deck 10. It has sponson parts 54 and 56. Within each of sponsons 54 and 56 The side surfaces 58, 60 extend downwardly and outwardly from the central portion 52 of the deck 10 to each side of the ship. It extends at an angle corresponding to the stability column extending downwards and outwards on top.

[0016]   The bottom 46 of deck 10 is structurally sufficient to withstand "wavy" loads from the sea. The whole deck is structurally structured to the level of the main deck or the open deck 62. It has been enhanced to be waterproof.

[0017]   Seawater ballast, fuel oil, and drilling water are located in each of the floating pontoons. Suitable for use in a tank 64 located in each of the tank 64 and the stabilizing column 20 Is located in. Space for propulsion motors and shafts, thrusters, floating pontoons It is located in the lower part of the window 30. Dry bulk storage for drilling mud and cement May be placed in the upper tank 68 and deck 10 of the stabilizing column 20. Machine room, storage Warehouses, workshops and living facilities are also located within deck 10. Main deck or open deck Plates 62 may also be used for additional storage space, pipe racks, drilling rigs and other drilling Like equipment and machinery, additional facilities, service or specialized shops and fire fighting Good equipment, may be used for.

[0018]   Stabilization column 20 is from a vertical at an angle selected specifically to enhance the stability characteristics of the ship. Inclined, it can be in the range greater than 0 ° and less than 90 ° . At the normal working water line 80, the effective beam of the ship is am) and therefore the stability of the ship is increased and increased without increasing the span and weight of the deck structure. A large effective beam increases the stability of the ship. If you need more ballast, The low position of the ballast water in the ballast tank 64 of the toon 30 lowers the ship's gravity. , Even if the effective beam of the ship is reduced, the stability of the ship is not impaired.

[0019]   As shown in FIG. 3, the sponsons 54 and 56 forming the pair are arranged on the deck 10 Together with the bottom 46 of the, form an inverted V-shape between the sponsons 54, 56. Deck 10 Such a form of the bottom 46 of the ship can cause the "whacking" impact when the ballast is increased. The ship's ability to minimize the harmful interference of deck 10 during work drafts. Improve. Moreover, since the deck 10 is entirely waterproof, the buoyancy of the deck 10 is Prevent inundation or other accidents during catastrophic damage.

[0020]   The following are the results of a study conducted to show the advantages of the present invention.

Constraints The hull form of the semi-submersible vessel used to study the effect of the proposed form is based on the MSV "IOLAIR". "IOLAIR" consists of a pair of pontoons supporting six stable columns below the floating deck. The pontoons are "vessel-shaped" in that they have a bow tailored to the design and a hull-shaped tail that supports the propellers that are transmitted by ducts. The stable column has a rectangular cross section with rounded corners.

[0022]   In order to bring out the effect of the wide bottom semi-submersible structure, some simplifications are It was applied to the "IOLAIR" type as shown in FIG. First, all elements, po The pontoon 92 and the stability column 94 are considered to be rectangular with a rounded cross section. The six stable columns 94 were of the same size. Furthermore, the bow tip of the pontoon 92 And the stern end was a plinth without any shaping. The column of the bow is on the bow It is thought to be cut off vertically, and the column of the stern is also the same as for the stern. It was located. The dimensions of both the pontoon 92 and the stability column 94 are 36 feet x It was chosen to be 24 feet (10.8m x 7.2m). Column 94 is a ship The long dimensions are arranged vertically at the neck and stern, and the pontoon 92 has a short dimension. The method was arranged vertically. The centerline of column 94 is the center of each pontoon It was a line. Ignore buoyancy of truss (not shown) between columns 94 did. Around the top of the stabilizing column 94 is the same width as the column and has an "IOLAIR" shell A perfectly fitted pox beam 90 with the same depth as the board structure is running A force ring was formed. This minimum, though not sufficient to support the full weight of the ship The surplus buoyancy of the understated effect of the floating deck without compromising the contribution of the angle column. It was purposely selected to be forgotten. In the final design, the entire deck is waterproof Should be.

[0023]   The main features of the baseline vessels of Figures 4 to 6 are also adapted from the "IOLAIR" Let Both the pontoon 92 and the main deck 90 (they are flat at each end) The length of the beam on the main deck 90 is 99.97m (328 feet). It reached 475 feet (47.55 meters). The depth of the ship is 30.48m (100 feet) The floating deck 90 occupies the top of 4.88m (16 feet). Eyes had.

[0024]   From the vertical-legged baseline vessels of Figures 4-6, in this study, on the baseline Turn the stability column from the bottom of the floating deck at 14.63 m (84 ft) toward the outside of the ship. The angle of the column was changed by rolling over a range of 0 ° to 30 °. This Thus, the deck dimensions and all other major dimensions were kept constant.

[0025]   The stability column is angled outward, so adjust the offset to A constant cross section was maintained perpendicular to the axis of the ram. This angling increases the effective width of the column So, while keeping the outboard offset constant, we reduced the outboard offset. Pontoon Does not rotate with stable column, but maintains alignment with outboard rim of column Positioned further away to do so.

[0026]   A design displacement of 20,000 mt was selected for a vertical-legged baseline ship and nominal 1 Provides a design draft of 5.24 (50 feet). However, the column is angled outward The amount of drainage increased a little because it had a certain degree. Designed for wide-angle morphology to match The amount of water was increased to maintain the design draft.

[0027]   VCG of ships at design displacement is baseline for all considered configurations Hold to be 13.71 m (45 ft) above. Other drafts are possible In some cases, the difference in drainage was adjusted by adding or removing salt water ballast. You In all cases, the ballast will be 3.66m (12 feet) from the volume in the pontoon. Eaten) VCG. Therefore considered The VCG of the ship at each draft was calculated and incorporated into the assessment. VC The deviation obtained in G is large over the range considered and is therefore significant .

[0028]   The effect of consumption of stockpile and supplies reduces the top weight and thus increases stability. So Therefore, another loading condition was not considered. Fuel consumption is ballast in the pontoon Compensation by adding, which does not change stability or Compensated by raising the ship from the water, this is the calculated deballasting situation Is the same as.

Wide bottom semi-submersible configurations with hull form 10 °, 15 °, 20 ° and 30 ° angle stabilizing columns are shown in FIGS. 7-9 and 10, respectively.

[0030]   The exact angle of the stable column matches the nominal number for a 30 ° wide bottom semi-submersible However, in the case of configurations with intermediate angles, the actual angle is not nominal. Somewhat different. Characteristics of ships with columns closer to the expected optimum value are important , The compensation chosen is more realistic, i.e. Is selected. The angle of the resulting column was rounded to the nominal angle. Either Also in the case of, the difference is quite small and less than 1 °.

[0031]   Hydrostatics for ships with stable columns at angles of 0 °, 20 °, and 30 ° is given in Appendix I. Shown in.

Initial Stability FIG. 11 shows the initial stability of a wide-bottom semi-underwater vessel. This figure shows the GM along the horizontal axis, corresponding to the draft along the vertical axis. The various curves represent the characteristics of ships with various stable column angles, ranging from 0 ° to 30 °.

[0033]   Stability is column angle, as can be seen at the 50-foot design draft. 30 ° from 1.37 m (4.5 ft) GM at 0 ° with increasing degrees In the case of, it will increase rapidly to 9.45 m (31 ft).

[0034]   At lighter drafts, the stability varies over a larger range. column For ships with angles less than about 10 °, stability actually decreases, while greater Ships with a steeper angle are more stable. For extremely light conditions in front of the pontoon surface At, the vertical-legged baseline ship experiences negative GM, but at 30 ° wide bottom semi-water The ship has a GM that exceeds 30.48 m (100 ft).

[0035]   These characteristics are more likely to occur in drafts deeper than 50 feet (15.24 m). Does not diverge. All ships have stable columns around the same point, the bottom of the floating deck. Since they were rotated by, their water surface is more similar to that of the ship's ballast down. Will be When the bottom of the floating deck is about to be submerged, the The difference is due to the slight variation in the loaded ballast, giving slightly different VCG. Get In these drafts, GM is about 4.57 for all the forms studied. It is 5.18 m (15 to 17 ft).

[0036]   GM is 7.32m using hydrostatics shown in 4th to 10th drawings and Appendix I (24 ft) and 25.60 m (84 ft), or pontoon Calculated at the waterline just before the surface breaks and the waterline just before the floating deck is submerged. It was At the other calculated water lines, GM is 0 °, 20 ° and 30 °. Obtained from the restoring arm curve described in the next section for ships with column angles of It was For angles between 10 ° and 15 °, GM is 7.62 m and 1 with drawing. With hydrostatics at the 5.24 m (24 and 50 ft) water line And the rest of the curve is well calculated. Obtained by earrings.

[0037]   Figure 11 shows the pontoon exposed condition or the floating deck is immersed. The GM for the conditions is not shown. Stability in these situations makes comparison insignificant The more it tastes, the far above the suggested waterline range . However, Appendix II gives a calculation of the restoring arm in which GM can be ascertained in these ranges. Presenting.

[0038]   The conclusion drawn from Fig. 11 is that the rational choice of stable column angling is the draft. The idea is to create a wide-bottom semi-submersible with improved GM across the entire working range. And. From this initial consideration, angles of about 10 ° to about 20 ° are preferred.

A large angle stability restoring arm (GZ) versus tilt angle curve was calculated for a vertical leg baseline ship and a wide bottom semi-submersible ship configuration with 20 ° and 30 ° angle stability columns. Details of the calculations are given in Appendix II. The results are shown in Figures 12-17. To aid in comparing the various configurations considered, each of Figures 12-17 shows the results for three ships at a particular draft. The draft used varies from 24.1 feet, the mostly flooded pontoon, to 48 feet, the floating deck being mostly washed with water. Each of FIGS. 12 to 17 shows the GZ along the vertical axis, which corresponds to the tilt angle of the ship along the horizontal axis.

[0040]   In each case examined, large angle stability was associated with increased stable column angulation. It has increased. Furthermore, the maximum restoring arm and the area under the curve, that is, the restoring energy Fluctuates contrary to the draft. All forms are shallower than deep ballast It possessed a greater restoring energy in water.

[0041]   From this part of the discussion, angling stable columns is both advantageous and large It should be concluded that the benefits are enormous.

[0042]   Another important observation to be gathered from this part of the study is wind-induced tilt It is about. Egon P. D. Bjerregareed and Sv Enn Blschov's "Unwinding Effect on Semi-Underwater Vessels" OTC Paper 30 63, (10th Annual Offshore Technology) (Conference, Houston, Texas, May 8-11, 1978). Is the tilt moment due to the wind MSV "IOLAIR" calculated by the ABS method It presents the lever about. The information provided is the form of this review It was used to clarify the slope curve due to the wind. Got The tilting arm is plotted in Figures 12-17. . These figures show a wind speed of 51.44 m / sec (100 knots) for a vertical-legged baseline ship. 17 ° or so when design draft is 15.24 m (50 ft) under It shows that there is a large inclination. However, the wide-bottom semi-submersible structures considered were the same. The inclination is less than 3 ° under the environment. This big difference is due to the small difference between GM and form. It shows the sensitivity performance of the ship to the ship and can be attributed to the relationship between the angles of the restoring arm and the tilting arm. It

Damage Stability This study includes a brief description of the damage stability of a vertical leg baseline ship and a wide bottom semi-submersible ship with a 30 ° angle stabilizing column. Two conditions were considered. The first is the flooding of one forward stabilizing column between the top of the pontoon and the bottom of the floating deck; the second is the column combined with the first 23.16 m (76 ft) of the pontoon in the same column, Is. These cases were chosen to represent catastrophic disasters, ignoring the vast majority of subdivisions actually expected in the final design.

[0044]   The results of the analysis show that the wide-bottom semi-submersibles have a greater restoration for any degree of damage. It retains energy and is less flooded than baseline vessels.

[0045]   For the purposes of this discussion, the relative performance of the two forms considered is important. Therefore, the absolute number is not important. The selected simplified hull form is not a floating structure Since it only has a waterproof ring around the main deck, the final measurement of tilt and trim The definition is exaggerated. The final design has an overall floating deck structure. Then there for comparison The table below shows the results of the two conditions examined.

[0046]   Details of the damage stability calculations are given in Appendix III.

[0047] CONCLUSION The proposed concept of wide-bottom semi-submersibles creates vessels with excellent properties in all areas of stability.

[0048]   For the size and proportion of the ship chosen as the baseline, please refer to the stability column. The preferred angle is between 10 ° and 20 °, but the excellent characteristic is 0 ° Greater than stable column angles up to 30 ° are shown next. The exact form is the desired work Depends on business characteristics. The floating deck structure has a large tilt angle and damage conditions (dam aged condition), and preferably in the design Can be included.

[0049]   The above description and discussion are based on a slender deck and a stable column as shown in Figure 18. A particular semi-submersible with parallel pontoons connected to the deck of a ship However, the present invention contemplates any number of stable columns, and Outside of the ship from one of the many semi-submersible ship structures shown in Figure 28 I am thinking about angling the stable column.

[0050]   FIG. 19 shows a pentagonal array of stable columns 96 and footings 97. 18 and 19 each also show drilling rigs 100, 101 and their respective ships. The means 102, 103 for propelling the vehicle are shown. The present invention is a stable column 96 and basic Radially angled at 97 to improve stability of the pentagon ship shown.

[0051]   Similarly, FIG. 20 shows a triangular arrangement of the stabilizing column 104 and the foundation 105, The stable column and foundation, such as, are angled outward in the radial direction as shown by the wavy lines. Be done. The semi-submersible ships shown in Figs. Mold, Y-shape in FIG. 23, V-shape in FIG. 24, raft-shape in FIG. 25, a-shape in FIG. Shown as an angled raft, the tri-camera raft of Figure 27, and the grid type of Figure 28. .

[0052]   The semi-submersible vessel constructed according to the present invention is particularly suitable for operation in an area of ice swarm. It For example, referring to FIG. 3, the ship may be on a deck via a conduit or moonpool 55. It is shown where a submarine drilling hole is being drilled with a drilling rig through 10. When it is desirable to break an outboard ice block as shown at 61, ballast The seawater ballast in the tank 66 is pumped out by the pumps 57 and 59 to the outside of the ship. Then, the column 20 exerts an upward bending force on the ice block 61 to break the ice.   Conversely, cracking an ice mass below deck 10 such as that shown at 63 When desired, ballast is pumped from surrounding waters by pumps 57, 59. When the ballast is pumped into the tank 56 to deepen the ballast and the ship is submerged, the stability column 20 is A downward bending force is applied to the ice block 63 to break it.

[0053]   A semi-submersible vessel as contemplated by the present invention has a drilling odor as shown in FIG. Not only to find applications, but also for production at subsea points and offshore like rescue vessels. It also finds use in general utility in equipment. In this way, half used for service purposes It is believed that underwater vessels can act as icebreakers to protect offshore facilities.

Appendix I Hydrostatic Dynamics i Baseline Form ii WBSS 20 ° Form iii WBSS 30 ° Form Hydrostatic Dynamics Baseline 0 ° Date Unit and Definition Drainage Discharge (Long ton) Draft Baseline in central part of ship Height above (feet) Height of buoyancy center above KB baseline (feet) LCB Center of longitudinal buoyancy from the center of the ship (feet) (+ FWD) LCF Center of longitudinal buoyancy from the center of the ship (feet) ( + FWD) LONG KM Vertical metacenter height above the baseline (feet) MT ₁ Moment to change draft by 1 inch (ft-ton, GML = BML) TPI tons per inch TRANS KM Above baseline Horizontal metacenter height (feet) Volume displacement Volume Water surface area Water surface Product (square feet) Ship length = 328.00 feet Maximum beam = 168.00 feet Ship offset file name MSV-A1 Ship offset file Production date 10/22/82 Draft difference 0.00 feet, water density 35. 0 cubic feet / ton Hydrostatics 20 ° Date unit and definition Drainage Drainage (long ton) Draft Height above baseline in the center of the ship (feet) KB Height of buoyancy center above the baseline (feet) LCB From center of the ship Vertical buoyancy center (feet) (+ FWD) LCF Vertical buoyancy center from the center of the ship (feet) (+ FWD) LONG KM Vertical metacenter height above the baseline (feet) MT ₁ Moment that changes draft by 1 inch (Ft-ton, GML = BML) TPI Tonnage per inch of sinking TRANS KM Transverse metacenter height above baseline (feet) Volume drainage volume (cubic feet) Water surface area Water surface area ( Square foot) Ship length = 328.00 feet Maximum beam = 212.00 feet Ship offset File name MSV-A7 ship offset file production date draft difference 0.00 feet, density 35.0 ft3 / ton of water Hydrostatic 30 ° Date unit and definition Discharge amount Discharge amount (long ton) Draft Height above baseline in the center of the ship (feet) KB Height of buoyancy center above the baseline (feet) LCB From center of the ship Vertical buoyancy center (feet) (+ FWD) LCF Vertical buoyancy center from the center of the ship (feet) (+ FWD) LONG KM Vertical metacenter height above the baseline (feet) MT ₁ Moment that changes draft by 1 inch (Ft-ton, GML = BML) TPI tons per inch of immersion TRANS KM Transverse metacenter height above baseline (feet) Volume drainage volume (cubic feet) Water surface area Water surface area ( Square foot) Ship length = 328.00 feet Maximum beam = 237.28 feet Ship offset Airu name MSV-A5 ship offset file production date 10/15/82 draft difference 0.00 feet, density 35.0 ft3 / ton of water Appendix II Restoration Arm Curve line i Baseline form ii WBSS 20 ° form iii WBSS 30 ° form iv VCG Baseline form v VCG 20 ° form vi VCG 30 ° Form i Baseline form Dynamic stability Vessel name Baseline Date 11 / 9/82 Unit and definition Discharge amount Discharge amount (long ton) Draft Height above the baseline at the center line in the center of the ship (feet) KG Height above the baseline center of gravity (feet) LCB From the center of the ship Vertical buoyancy center (feet) (+ = FWD) LCG Vertical gravity center from the center of the ship (feet) (+ = FWD) TR ₁ M Successive draft (feet) (+ = AFT) RA Restoring arm (feet) Offset file name MSV-A1 Date of production 10/22/82 Ship length = 328.00 feet Water density 35.00 ft3 / ton ii WBSS 20 ° form Dynamic stability Vessel name 20 °, wide date 11/10/82 Defined as unit Discharge amount Discharge amount (long ton) Draft Height above the center line in the center of the ship (feet) KG base Height of gravity center above line (feet) LCB Center of vertical buoyancy from ship center (feet) (+ = FWD) LCG Center of vertical gravity from ship center (feet) (+ = FWD) Trim Suffering Difference (feet) (+ = AFT) RA Restoration arm (feet) Offset File name MSV-A7 Date of manufacture Ship length = 328.00 feet Water density = 35.00 cubic feet / ton iii WBSS 30 ° form Dynamic stability Vessel name 30 ° + 39.28B Wide date 11/10/82 Unit and definition Displacement Discharge (Long ton) Draft Height above the baseline at the center line in the center of the ship (feet) ) Height of the center of gravity above the KG baseline (feet) LCB Center of vertical buoyancy from the center of the ship (feet) (+ = FWD) LCG Vertical position of the center of gravity from the center of the ship (feet) (+ = FWD) TR ₁ M Successive draft difference (+ = AFT) RA Restoration arm (feet) Offset file name MSV-A5 Production date 10/15/82 Ship length = 328.00 feet Water density = 35.00 cubic feet / Ton Appendix III Damaged stability i Baseline form ii WBSS 30 ° Form Ship name Baseline Date Damaged conditions 2 Draft 50,000 feet Drainage 20,000,000 tons VCG 45.00 feet (base) Above the line) LCG 0.00 ft (+ = FWD Amidships) Damaged compartment Permeability tank Outflow Data ID No. Compartment Filling Depth Density Free Surface (feet) Cubic Feet (feet / ton-ton) 1 Column 1-S 1.00 24.00 35.00 0.0 3 Pontoon 1-S 1.00 0.00 35.00 0.0 Damaged Ship Properties after Outflow Discharge = 19.999 .90 tons LCG = -0.00 feet VCG = 45.00 feet TCG = -0.00 feet Lateral metacenter (0 °) = 78.55 feet Metacenter high restoration (0 °) = 33.55 feet Stability at Damage Vessel Name Baseline Date Vessel Offset File Name MSV-A1 Damaged Compartment File MSV-D1 Damage Condition 1 Draft 50.00 ft Drainage 20,000.000 ton VCG 45.00 ft (above baseline) LCG 0 .00 ft (+ = FWD Amidships) Damaged Compartment Permeability Tank Outflow Data ID No. Compartment Filling Depth Density Free surface (feet) Cubic feet (feet / ton-ton) 1 Column 1-S 1.00 24.00 35.00 0.0 Damaged vessel properties after outflow Discharged water = 19.999.97 tons LCG = -0.00 Feet VCG = 45.00 feet TCG = −0.00 feet Transverse metacenter (0 °) = 45.05 feet Metacenter high restoration (0 °) = 0.05 feet Stability at damage Ship name 30 ° wide date Ship offset file name MSV-A5 Damage compartment file MSV-D5 Damage condition 1 Draft 50.00 feet Drainage 20,600.00 tons VCG 45.00 feet (above baseline) LCG 0.00 ft (+ = FWD Amidships) Damaged Compartment ID No. Compartment Permeability Tank Outflow Data Filling Depth Density Free Surface (feet) Cubic Feet (feet / ton-ton) 1 Column 1-S 1.00 25.00 35.00 0.0 Damaged Ship Properties after Outflow Discharge = 20,599.97 ton LCG = -0.00 ft VCG = 45.00 ft TCG = -0.00 ft Transverse Metacenter (0 °) = 64.93 ft Metacenter Height Restoration (0 °) = 19.93 ft Vessel name 30 ° Wide Date Damage condition 2 Draft 50.00 feet Drainage 20,600.00 tons VCG 45.00 feet (above the baseline) LCG 0.00 feet (+ = FWD Amidships) Damaged compartment Permeability tank outflow Data ID No. Compartment Filling Depth Density Free surface (feet) Cubic feet (feet / ton-ton) 1 Column 1-S 1.00 24.00 35.00 0.0 3 Pontoon 1-S 1.00 0.00 35.00 0.0 Damaged ship properties after outflow Drainage = 20,599 .89 tons LCG = -0.00 feet VCG = 45.00 feet TCG = -0.00 feet Lateral metacenter (0 °) = 95.75 feet Metacenter height restoration (0 °) = 50.75 feet

[Brief description of drawings]

FIG. 1 is a side elevational view of a semi-submersible ship constructed in accordance with the present invention.

FIG. 2 shows a top plan view of the ship of FIG.

3 is an end elevational view of the ship of FIG. 1 with a drilling rig.

FIG. 4 is a schematic side view of a baseline ship with vertical stabilizing columns.

FIG. 5 is an end elevational view of the ship of FIG.

FIG. 6 is a top plan view of the ship of FIG.

FIG. 7 is an end elevational view of an embodiment of the present invention in which the angle of the stabilizing column is 10 °.

FIG. 8 is an end elevational view of an embodiment of the present invention in which the angle of the stabilizing column is 15 °.

FIG. 9 is an end elevational view of an embodiment of the present invention in which the angle of the stabilizing column is 20 °.

FIG. 10 is an end elevation view of an embodiment of the present invention in which the angle of the stabilizing column is 30 °.

FIG. 11 is a curve representing the characteristics of a ship with various stable column angles.

FIG. 12 is a diagram showing a curve of a restoring arm versus a tilt angle for a vertical leg baseline ship and a wide bottom semi-underwater ship according to the present invention.

FIG. 13 is a diagram showing a curve of a restoring arm versus a tilt angle for a vertical leg baseline ship and a wide-bottom semi-underwater ship according to the present invention.

FIG. 14 is a diagram showing a curve of a restoring arm versus a tilt angle for a vertical leg baseline ship and a wide-bottom semi-underwater ship according to the present invention.

FIG. 15 is a diagram showing a curve of a restoring arm versus a tilt angle for a vertical leg baseline ship and a wide bottom semi-underwater ship according to the present invention.

FIG. 16 is a diagram showing a curve of a restoring arm versus a tilt angle for a vertical leg baseline ship and a wide bottom semi-underwater ship according to the present invention.

FIG. 17 is a diagram showing a curve of a restoring arm versus a tilt angle for a vertical leg baseline ship and a wide bottom semi-underwater ship according to the present invention.

FIG. 18 is an illustration of an exemplary semi-submersible ship configuration modified in accordance with the present invention to provide a wide floating base, thereby improving the stability of this type of ship.

FIG. 19 shows an example of a typical semi-submersible ship configuration modified in accordance with the present invention to provide a wide floating base, thereby improving the stability of this type of ship.

FIG. 20 is an illustration of an exemplary semi-submersible ship configuration modified in accordance with the present invention to provide a wide floating base, thereby improving the stability of this type of ship.

FIG. 21 shows an example of a typical semi-submersible ship configuration modified in accordance with the present invention to provide a wide floating base and thereby improve the stability of this type of ship.

FIG. 22 shows an example of a typical semi-submersible ship configuration modified in accordance with the present invention to provide a wide floating base, thereby improving the stability of this type of ship.

FIG. 23 is an illustration of an exemplary semi-submersible vessel configuration modified in accordance with the present invention to provide a wide floating base, thereby improving the stability of this type of vessel.

FIG. 24 is an illustration of an exemplary semi-submersible ship configuration modified in accordance with the present invention to provide a wide floating base, thereby improving the stability of this type of ship.

FIG. 25 shows an example of a typical semi-submersible ship configuration modified in accordance with the present invention to provide a wide floating base and thereby improve the stability of this type of ship.

FIG. 26 is an illustration of an exemplary semi-submersible ship configuration modified in accordance with the present invention to provide a wide floating base, thereby improving the stability of this type of ship.

FIG. 27 is an illustration of an exemplary semi-submersible vessel configuration modified in accordance with the present invention to provide a wide floating base, thereby improving the stability of this type of vessel.

FIG. 28 is an illustration of an exemplary semi-submersible ship configuration modified in accordance with the present invention to provide a wide floating base, thereby improving the stability of this type of ship.

[Explanation of symbols]

10 deck 20 stable columns 30 pontoons 40 truss assembly 54, 56 Sponson 64, 66 Ballast loading / unloading means 68 Upper tank

Claims (5)

[Scope of utility model registration request] 1. A means comprising an elongated deck (10) and a plurality of stable columns (20) extending from the deck, and an elongated stretch connected to the lower end of each stable column to provide a wide floating base. A pontoon (30) having an equal cross-sectional area along its length.
In a wide-bottom semi-submersible vessel consisting of a stable column and ballast access means (64, 66) in the pontoon, each stable column has a deck port and a port to change the effective beam of the vessel as a function of draft. A wide-bottom semi-submersible, characterized by extending downward and outward from each starboard bottom. 2. A wide-bottom semi-submersible vessel according to claim 1, wherein the base application means comprises a pair of long extended pontoons connected to the lower ends of the stabilizing columns on each side of the vessel. 3. The wide-bottom semi-submersible ship according to claim 1 or 2, wherein the deck is waterproof. 4. Sponsons (54, 56), each consisting of a horizontally elongated hollow body, are provided on the stability column along the bottom of each deck of the deck. A wide-bottom semi-submersible ship according to any one of item 3. 5. The method according to any one of claims 1 to 4, wherein the inner surface (58, 60) of each sponson extends downwardly and outwardly from the central portion (52) of the deck at the same angle as the stabilizing column. A wide-bottom semi-underwater ship described in the crab