A manually operated quick release mooring device

Abstract

A kind of artificial operation quick release mooring device, there is fixed ground base, the inclined angle type baffle and frame support are fixed on the base, the inclined angle type baffle is located in the center of support, support is supported with bolt stopper, bolt stopper is located above the inclined angle type baffle.Bolt stopper includes stud and nut, nut is sleeved on stud, stud top is inserted and welded with hammering rod, the shackle top bolt of shackle has chain link, chain link is sleeved on first baffle, stud bottom is resisted to chain link, the other end of shackle is connected with mooring cable.The application is manually operated, does not depend on any control equipment, is not affected by high temperature environment, has sufficient stability when fire occurs, can ensure that cable is released successfully at one time.Through inclined angle type baffle, stud brake and hammering rod three places labor-saving structure form, the force of quick release mooring cable is gradually reduced to the level that can be reached manually.

Description

Technical Field

[0001] This invention belongs to the field of shipbuilding and design, and specifically relates to a manually operated quick-release mooring device. Background Technology

[0002] Since the beginning of the 21st century, with economic development and increased environmental awareness, clean energy has become increasingly popular in various countries. Natural gas, as a hydrocarbon, has advantages such as high calorific value, clean and pollution-free operation, and wide applicability, and its development momentum has been exceptionally rapid in recent years.

[0003] The development of offshore LNG mainly follows the FLNG model, which is a floating platform that integrates offshore natural gas extraction, liquefaction, storage, and export. my country's Ministry of Industry and Information Technology's technology roadmap for ten key areas also explicitly lists FLNG and other new types of offshore oil and gas resource development equipment as key products.

[0004] Currently, all FLNGs that are in production or under construction use a side-by-side delivery method for LNG transportation. This means that the LNG carrier is moored alongside the FLNG carrier, with the two vessels in close proximity, and the FLNG delivers the LNG to the LNG carrier.

[0005] Because LNG is a flammable and explosive liquid, and its vapor is natural gas, which is also a flammable and explosive gas, both FLNG and LNG carriers pose a risk of fire and explosion. In the event of a fire between the FLNG and the LNG carrier, the LNG carrier needs to be quickly towed away from the FLNG to ensure the safety of the other vessel. However, the LNG carrier is securely moored to the FLNG side by mooring lines. Therefore, a device that allows for the rapid release of the mooring lines is needed to facilitate the quick towing of the LNG carrier.

[0006] Currently, a hydraulically driven quick-release device for mooring lines is widely used. This device is easy to operate, allowing for one-button release of mooring lines. However, its drawbacks are also significant. Because its operation relies on a hydraulic power unit, and hydraulic oil is highly sensitive to temperature, hydraulic pipelines, hydraulic pumps, and related control cables are all susceptible to damage from flames, high temperatures, and explosions. Natural gas fires spread extremely rapidly; if this device malfunctions, there is virtually no time for repairs, making it impossible to quickly release FLNG and LNG carriers, thus allowing the fire to spread between ships and causing even more severe economic losses and casualties. Even if the hydraulic drive is replaced with an electric one, it still cannot meet the requirements for safe use in emergency fire, high-temperature, and explosive situations. Summary of the Invention

[0007] To address the aforementioned problems, this invention provides a manually operated rapid release mooring device, aiming to ensure that in emergency situations, the stability of the manually operated device is not affected by fire, high temperature, or explosion. The technical solution adopted is as follows:

[0008] A manually operated quick-release mooring device has a base fixed to the ground, on which an angled baffle and a frame bracket are fixed. The angled baffle is located at the center of the bracket, and the bracket supports a bolt stopper located above the angled baffle.

[0009] The angled baffle has a groove at the top, which is formed by two baffles, namely a first baffle and a second baffle. The first baffle is set closer to the sea surface, and the second baffle is set away from the sea surface. The height of the first baffle is higher than that of the second baffle, and the top of the first baffle is arc-shaped.

[0010] The bolt stopper includes a stud and a nut. The nut is fitted onto the stud. Elbow plates are symmetrically fixed on both sides of the nut. The elbow plates are welded to the top of the bracket. A hammer rod is inserted into the top of the stud and is welded and fixed to the stud.

[0011] The shackle has a chain link attached to its top, which is fitted onto the first baffle. The bottom of the stud abuts against the chain link, and the other end of the shackle is connected to the mooring cable.

[0012] Furthermore, in the aforementioned manually operated rapid release mooring device, the groove is V-shaped, the angle between the inclined surface of the first baffle and the horizontal plane is 60°, and the height H of the first baffle is not greater than S and not less than 2R.

[0013] Where S is the stroke of the stud in the nut.

[0014] R is the radius of the groove.

[0015] Furthermore, in the aforementioned manually operated quick-release mooring device, the stud length satisfies the minimum stud stroke: S≥2R×tan60°-R=2.464R.

[0016] Where S is the stroke of the stud in the nut.

[0017] R is the radius of the groove.

[0018] Furthermore, in the aforementioned manually operated rapid release mooring device, the hammer rod is a steel rod made of high-strength steel with a yield strength of 690 MPa, and has a diameter of 50 mm and a length of 1000 mm.

[0019] Furthermore, in the aforementioned manually operated quick-release mooring device, the bottom of the angled baffle passes through the bracket and is embedded in the base.

[0020] Furthermore, in the aforementioned manually operated rapid release mooring device, the internal clear width of the support is not less than 400mm, and the internal clear height is not less than 400mm.

[0021] Furthermore, in the aforementioned manually operated quick-release mooring device, the base is fixed to the dock or ship deck.

[0022] Furthermore, in the aforementioned manually operated quick-release mooring device, the hammer rod is placed horizontally.

[0023] The present invention provides a manually operated rapid mooring release device, the advantages of which are:

[0024] 1. This invention is manually operated, does not rely on any control equipment, is not affected by high-temperature environments, and has sufficient stability in the event of a fire, ensuring successful release of the cable in one go.

[0025] 2. This invention uses three force-saving structural features—an angled baffle, a stud brake, and a hammer rod—to gradually reduce the force required for the mooring cable to be quickly released to a level that can be achieved manually. The design is reasonable, compact, and ingenious.

[0026] 3. The cost of this invention is far lower than that of currently widely used hydraulic or electric mooring cable quick release devices, thus possessing excellent economic advantages. Attached Figure Description

[0027] Figure 1 This is a schematic diagram (mid-longitudinal section) of the mooring device of the present invention;

[0028] Figure 2 This is a schematic diagram (middle cross section) of the mooring device of the present invention;

[0029] Figure 3 This is a schematic diagram of an angled baffle (side view and front view);

[0030] Figure 4 This is a schematic diagram of a stud brake (side view is the same as the front view);

[0031] Figure 5 This is a schematic diagram (side view) of the rapid release process of the mooring device of the present invention;

[0032] Figure 6 This is a force analysis diagram (side view) with the chain links as the research object;

[0033] Figure 7 This is a force analysis diagram (partial unfolded diagram) of the threads of studs and nuts.

[0034] Wherein: 1-base, 2-bracket, 3-angled baffle, 4-stud brake, 4-1-stud, 4-2-nut, 4-3-elbow plate, 5-hammering rod, 6-chain link, 7-shackle, A-mooring line, B-dock or deck, L1-internal clear height of the bracket, L2-internal clear width of the bracket, H-distance from the top to the bottom of the slope, R-radius of the groove of the angled baffle = radius of the cross-section of the chain link, S-stroke of the stud in the stud brake, Fl-tension of the mooring line, Fz-axial force of the stud in the stud brake, Fc-support force provided by the angled baffle, Fu-friction force, Fq-driving force, Fc1-support force provided by the nut thread, Fr-manual hammering force, α is the tooth profile half angle. Detailed Implementation

[0035] The invention will be further described with reference to the accompanying drawings.

[0036] A manually operated, rapid mooring release device first utilizes a unique combination of an angled baffle and a stud brake to convert the locking force of the mooring cable into an axial force in the stud brake. This axial force is the component of the mooring cable tension in the stud direction. A threaded structure further reduces the axial force of the stud brake to a radial force, and the lever principle at the handle further reduces the radial force, achieving a level of manual operation that makes the device safer and more reliable.

[0037] like Figure 1 , 2 As shown, there is a base fixed to the deck, and an angled baffle and a frame bracket are fixed on the base. The angled baffle is located in the center of the bracket, and the bracket supports a bolt stopper, which is located above the angled baffle.

[0038] The angled baffle has a groove at the top, which is formed by two baffles, namely the first baffle and the second baffle. The first baffle is set closer to the sea surface, and the second baffle is set away from the sea surface. The height of the first baffle is higher than that of the second baffle, and the top of the first baffle is arc-shaped.

[0039] The bolt stopper includes a stud and a nut. The nut is fitted onto the stud, and elbow plates are symmetrically fixed on both sides of the nut. The elbow plates are welded to the top of the bracket. A hammer rod is inserted into the top of the stud and is welded to the stud for fixation.

[0040] The shackle has a chain link attached to its top, which is fitted onto the first baffle. The bottom of the stud abuts against the chain link, and the other end of the shackle is connected to the mooring cable.

[0041] The base is strong enough to support the entire mooring device. The lower end is installed on the dock or ship deck, and the upper end is welded to the bracket and the angled baffle.

[0042] The bracket is a box-type frame structure, welded to the base at the bottom, with an angled baffle installed inside and a stud brake installed at the top. The internal clear width of the box-type structure shall not be less than 400mm, and the internal clear height shall not be less than 400mm. Figure 2 If L1≥400mm, L2≥400mm, etc. Figure 2 As shown. This is to meet the space requirements for maintenance and repair, while ensuring that the chain links do not jam. The external structure of the box-type structure should have sufficient reinforcement to give it adequate strength.

[0043] The angled baffle is embedded at the bottom of the bracket and welded to both the bracket bottom and the base to increase the welding area and improve strength. The top of the angled baffle has a groove for placing the chain link; the groove's indentation radius R is the same as the chain link's cross-sectional radius R. The front end of the groove is an inclined plane with an angle of 60°. The distance H from the top to the bottom of the inclined plane is no greater than S and no less than 2R. The end of the inclined plane is rounded to facilitate chain release. The angled baffle is as follows... Figure 3 As shown.

[0044] A stud brake consists of three parts: a stud, a nut, and a toggle plate, such as... Figure 4 As shown. The stud of the stud brake abuts against the chain link, providing chain braking; the nut is embedded in the top of the bracket; the elbow plate is welded to the top of the bracket, fixing the stud brake to the bracket, as shown. Figure 1 and Figure 2 As shown. The stud is grade 8.8, M100, and can withstand an axial force of not less than 260t, meeting the mooring force requirements of most mooring cables. Four elbow plates are welded to the outside of the nut, and these elbow plates are then welded to the bracket. The nut is matched with the stud, also grade 8.8, and the thread length meets the stud's stroke requirements. The stud's stroke should not be less than the result calculated by the following formula:

[0045] The stud stroke S≥2R×tan60°-R=2.464R.

[0046] The hammer rod is a steel rod made of high-strength steel with a yield strength of 690MPa. It passes through the top of the stud of the stud brake and is welded in place. The hammer rod has a cross-section of a circle with a diameter of 50mm and a length of 1000mm. Its end can withstand a strike of 1 ton, far exceeding the range of force required to strike a hammer manually. Therefore, striking the end of the hammer rod manually will not damage it.

[0047] The safe operating load of the chain link is matched with the stud brake and is not less than 260t. One end of the chain link is clamped by an angled baffle and a stud brake, and the other end is connected to a shackle.

[0048] The safe operating load of the shackle is matched with the stud brake and is not less than 260t. One end of the shackle is connected to the chain link, and the other end is connected to the mooring cable.

[0049] When the mooring device of the present invention is in normal mooring operation, the shackle is opened, the mooring cable is placed into the shackle, and then the shackle is closed to realize the mooring operation.

[0050] When rapid release is required by this invention, a person strikes the end of the hammer rod with a hammer, causing the stud of the stud brake to move upward. This pulls the shackle on the mooring cable, which in turn pulls the chain link. The chain link slides off the mooring device along the ramp of the angled baffle, achieving rapid release of the mooring cable. In the rapid release mode, the shackle and chain link, along with the mooring cable, are released together. The rapid release process is as follows: Figure 5 As shown.

[0051] This invention incorporates a three-stage structure to reduce mooring force, enabling personnel to open the stud brake by striking a hammer rod. The structure consists of an angled baffle, a stud brake, and a hammer rod. The calculations and verifications are as follows: (Mooring force is based on the minimum breaking strength of the mooring cable for a current international mainstream 170,000 cubic meter LNG carrier, which is 130 tons; i.e., mooring cable tension Fl = 130t.)

[0052] The angled baffle decomposes the mooring force into the axial force of the stud brake, such as Figure 6 As shown. Since the inclination angle of the inclined plane of the angled baffle is 60°, Fz=Fl×tan30°=130×0.58=75.4t.

[0053] From the above, we know that the axial force Fz of the stud in the stud brake is 75.4t. Taking the stud as the research object, we straighten the thread locally, such as... Figure 7 As shown in the figure, Fq + Fz × sinα = Fu. The friction coefficient of high-strength steel is taken as 0.142, α = 8°, Fu = 0.15Fz × cosα, thus obtaining Fq = 0.1t.

[0054] The force applied at the hammer rod acts as a lever, with the stud axis as the fulcrum. The end of the hammer rod is 500mm from the fulcrum, and the point of force application on the stud is 50mm from the fulcrum. Therefore, the manual hammering force is approximately Fr = 0.1Fq = 10kg, which is sufficient to move the stud upwards. Since a manual hammering force of 10kg is easily achieved, the mooring device of this invention allows for the rapid release of the mooring cable through manual operation.

Claims

1. A manually operated rapid mooring release device, characterized in that, It has a base fixed to the ground, on which an angled baffle and a frame bracket are fixed. The angled baffle is located at the center of the bracket, and the bracket supports a bolt stopper located above the angled baffle. The angled baffle has a groove at the top, which is formed by two baffles, namely a first baffle and a second baffle. The first baffle is set close to the sea surface, and the second baffle is set away from the sea surface. The height of the first baffle is higher than that of the second baffle, and the top of the first baffle is arc-shaped. The bolt stopper includes a stud and a nut. The nut is fitted onto the stud. Elbow plates are symmetrically fixed on both sides of the nut. The elbow plates are welded to the top of the bracket. A hammer rod is inserted into the top of the stud and is welded to the stud. The shackle has a chain link attached to its top, which is fitted onto the first baffle. The bottom of the stud abuts against the chain link, and the other end of the shackle is connected to the mooring cable. The groove is V-shaped, the angle between the inclined surface of the first baffle and the horizontal plane is 60°, and the height H of the first baffle is not greater than S and not less than 2R; Where S is the stroke of the stud in the nut; R is the radius of the groove.

2. The manually operated rapid mooring release device according to claim 1, characterized in that, The hammer rod is a steel rod made of high-strength steel with a yield strength of 690MPa. The hammer rod has a diameter of 50mm and a length of 1000mm.

3. The manually operated rapid mooring release device according to claim 1, characterized in that, The bottom of the angled baffle passes through the bracket and is embedded in the base.

4. The manually operated rapid mooring release device according to claim 1, characterized in that, The internal clear width of the bracket shall not be less than 400mm, and the internal clear height shall not be less than 400mm.

5. The manually operated rapid mooring release device according to claim 1, characterized in that, The base is fixed to the dock or ship deck.

6. The manually operated rapid mooring release device according to claim 1, characterized in that, The hammer rod is placed horizontally.

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