Segmentation, block and carrying stage construction method for ship draft sign

Abstract

The invention relates to a segmentation, block and carrying stage construction method for a ship draft sign, which comprises the following steps of: manufacturing a segment where the bottom of a middle water gauge sign is located, and drawing and mounting the bottom of the middle water gauge sign; a block where the top of the middle water gauge and the freeboard mark are located is manufactured, and the top of the middle water gauge mark and the freeboard mark are worked out and installed; manufacturing a section where the bottom of the head water gauge mark is located, and performing drawing and mounting on the bottom of the head water gauge mark; a block where the head water gauge mark is located is manufactured, and the top of the head water gauge mark is worked out and installed; building a dock and slipway three-dimensional measurement and control network, and carrying out rapid and refined large-closure carrying work of each subsection and block; according to the base line of the segmented block where the middle water gauge mark and the freeboard mark are located, the whole ship body base line is determined, and finally water gauge mark positioning scribing is conducted on the tail area according to the whole ship body base line. According to the method, the draft water gauge mark and the freeboard mark are marked and installed in the segment or block stage, the production procedure is effectively moved forwards, cross construction of the segments and the blocks in the large closure carrying stage is reduced, the later production construction difficulty is lowered, and the overall integrity is improved.

Description

Technical Field

[0001] The invention relates to the technical field of ship construction, and in particular to a construction method for a ship draft mark in sections, blocks and loading stages. Background Art

[0002] Conventional ship draft marks mainly include draft gauge and freeboard marks. After the entire hull is formed at the dock or slipway during the large assembly and loading stage, the deformation of the keel baseline at the bottom of the hull is measured, and the average value is calculated according to the ship construction standard. After the hull reference baseline is determined, the draft gauge and freeboard marks are marked and installed based on this baseline. Because according to the ship construction quality standard, the standard range of the disturbance deformation of the center line of the keel at the bottom of the hull, that is, the baseline, is ±25mm (limit range ±50mm), and the allowable construction error range is large; but the draft gauge mark deviation standard range is ±1mm (limit range ±2mm), and the freeboard mark deviation standard range is ±0.5mm (limit range ±1mm), and the allowable construction error range is very small. The hull construction standard is far lower than the mark marking requirements, so in the actual ship construction process, it is impossible to implement the draft gauge and freeboard marks in advance at the block or total block stage. It can only be implemented after the average baseline of the hull bottom is measured after all the hull blocks and total blocks are completed and loaded at the dock or slipway.

[0003] The construction of draft gauge and freeboard marks during the large assembly and loading stage will cause damage to the paint of multiple cabins, loss of overall integrity, increase a large amount of repeated sanding and painting work, increase a large amount of repeated additional scaffolding erection work, reduce the dock and slipway loading efficiency, and increase the risk of safety hazards for personnel working at height.

[0004] If the hull construction standard is raised from ±25mm to ±1mm or ±0.5mm, so that the draft and freeboard marks are marked and installed at the block or block stage, it will cause huge waste to the low-profit shipbuilding industry, the production equipment and supporting facilities will not be able to meet the construction requirements, and the shipyard will not be able to bear the time and labor costs; if the draft and freeboard marks are marked and installed at the block stage according to conventional construction standards, it can be implemented for very few small ships that form a ring-shaped block, but it is only limited to a part of small ships, and it is difficult to implement for larger ships whose blocks exceed the lifting capacity of the shipyard; and it is also very easy to cause multiple draft and freeboard marks to fail to meet the construction standards, resulting in repeated rework, causing damage to the paint of multiple cabins, adding a large amount of repeated grinding and painting work, adding a large amount of repeated additional scaffolding work, increasing the risk of safety hazards of personnel working at high altitudes, and reducing the dock and slipway loading efficiency. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide a method for constructing ship draft marks in sections, blocks and loading stages to solve the problem that the existing draft scale marks and freeboard marks cannot be marked and installed in sections and blocks.

[0006] The object of the present invention is achieved in that: A method for constructing a ship's draft mark in sections, sections and loading stages, comprising the following steps: Step 1: Make the section where the bottom of the middle water gauge mark is located, and mark and install the bottom of the middle water gauge mark on the outer plate of the section; Step 2: Make a section where the top of the middle water gauge mark and the freeboard mark are located, and combine this section with the section where the bottom of the middle water gauge mark is located to form a total section where the middle water gauge mark and the freeboard mark are located. On the outer plate of this total section, the top of the middle water gauge mark and the freeboard mark are marked and installed based on the marked bottom of the middle water gauge mark; Step 3: Make the section where the bottom of the bow water gauge mark is located, and mark and install the bottom of the bow water gauge mark on the outer plate of the section; Step 4: Make a section where the top of the bow water gauge mark is located, and combine this section with the section where the bottom of the bow water gauge mark is located to form a total section where the bow water gauge mark is located. The outer plate of the total section is based on the marked bottom of the bow water gauge mark as the basis and reference, and the top of the bow water gauge mark is marked and installed; Step 5: Set up multiple digital targets at the rear and both ends of the dock and slipway to establish a three-dimensional measurement and control network for the dock and slipway; Step 6: Use the three-dimensional measurement and control network to carry out the rapid assembly and mounting of the bow, stern, engine room and cargo hold sections according to the conventional assembly and mounting process; Step 7: After the main hull is assembled and the main body is welded and pyrotechnics are completed, the remaining marks of the bow water gauge at the large closure port of the outer plate are marked and installed according to the requirements of the construction drawings using a calibrated ruler and laser theodolite or total station based on the total section mark of the bow water gauge and the requirements of the construction drawings, and the work is reported and qualified; Step 8. Determine the overall baseline of the ship's hull based on the keel baseline at the bottom of the block where the middle water gauge and freeboard marks are located, and locate and mark the water gauge marks in the stern area based on the overall baseline of the hull.

[0007] Preferably, in step 1, the specific operation of marking the bottom of the middle water gauge mark is as follows: According to the draft gauge and freeboard mark construction drawings of the entire ship, determine the specific rib number, i.e. the longitudinal position, of the middle gauge mark on the block outer plating; Based on the theoretical line of the inner bottom plate at the location of the section, the baseline reference point of the outer plate of the hull bottom of the section is determined, which is the hull baseline of the ship; Use the total station to position and mark the bottom area of ​​the middle water gauge mark in sequence from the determined hull baseline position upwards according to the requirements of the drawings; Spot welding is carried out according to the determined water level marks as per the requirements of the drawings. After the inspection is passed, welding work is carried out to complete the marking and installation of the water level marks of this section.

[0008] Preferably, the overall segment and overall group operation in step 2 is as follows: Rotate the section where the bottom mark of the middle water gauge in step 1 is located by 90 degrees and place it on the base surface of the outer plate; complete the overall construction of the total section according to conventional construction technology, and assemble the section where the middle water gauge mark and freeboard mark are located with the adjacent sections to form the total section where the middle water gauge mark and freeboard mark are located; take the bottom mark of the middle water gauge as the basis and benchmark, use a calibrated ruler and laser theodolite or total station to mark and install the top mark of the middle water gauge and freeboard mark of the outer plate of the total section according to the requirements of the construction drawings, and report them for acceptance.

[0009] Preferably, in step 3, the specific operation of marking the bottom of the head water gauge mark is as follows: According to the draft gauge and freeboard mark construction drawings of the entire ship, determine the specific rib number, i.e. the longitudinal position, of the bow gauge mark on the block outer plating; Based on the theoretical line of the inner bottom plate at the location of the section where the bow water gauge mark is located, determine the baseline reference point of the outer plate of the hull bottom of the section, which is the hull baseline of this section; Use the total station to position and mark the bottom area of ​​the bow water gauge mark in sequence from the determined baseline position of the segmented hull upwards according to the requirements of the drawings; Spot welding is carried out according to the determined water level marks as per the requirements of the drawings. After the inspection is passed, welding work is carried out to complete the marking and installation of the water level marks of this section.

[0010] Preferably, in step five, a total station is used to establish a spatial coordinate system with the center line of the dock bottom, data is collected for the No. 0 rib position line, the reference height line, and the reference target points on both sides of the dock slipway, and the measured data is converted in the precision analysis software, the No. 0 rib position line is used to determine the X value of the established coordinate system, the center line determines the Y value of the established coordinate system, and the base height line determines the Z value of the established coordinate system, thereby establishing a three-dimensional measurement and control network coordinate system.

[0011] Preferably, in step six, the section where the middle water gauge and freeboard marks are located is turned over and normalized before participating in the large assembly and loading work; during the large assembly and loading process, when the bow section of the cargo hold is undergoing large assembly and loading construction, the positions of the inner bottom plate theoretical line of the section where the bow water gauge mark is located and the keel line of the outer bottom of the hull are simulated and determined in the three-dimensional measurement and control network coordinate system to ensure that the baseline deviation of the section where the middle and bow water gauge marks are located is within ±2mm, and other sections are gradually transitioned within the range of ±25mm to within ±2mm of the section where the bow water gauge mark is located.

[0012] Preferably, after the loading and positioning of the bottom section where the bow water gauge mark is located is completed and during the welding construction, a laser instrument is installed on the bow peak bulkhead at 1 meter away from the inner bottom centerline of the bottom section where the draft water gauge mark is located, and a centering target plate is arranged at a distance of more than 10 meters from the bow peak bulkhead at the centerline of the inner bottom of the bow section of the cargo hold to check the horizontal change of its water gauge mark and control the deviation accuracy of the section mark where the bow water gauge mark is located to be within the range of ±2mm.

[0013] Preferably, in step eight, the specific operation of marking the bottom of the stern water gauge mark is as follows: according to the construction drawings of the draft water gauge and freeboard marks of the entire ship, determine the specific rib position number, i.e., the longitudinal position, of the stern water gauge mark on the outer plate of the area; according to the determined overall baseline of the hull, use a total station to position and mark the water gauge marks of the stern area in sequence from the determined hull baseline position upwards as required by the drawings; spot welding is performed according to the requirements of the drawings based on the determined water gauge marks, and welding work is carried out after passing the inspection to complete the marking and installation of the water gauge marks in the stern area.

[0014] Preferably, in step eight, there are many conventional outfitting works in this area during the large assembly and embarkation stage, so the work can be carried out together with the draft mark, and the stern draft mark can be marked and installed during the large assembly and embarkation stage.

[0015] The beneficial effects of the present invention are: 1. Break the traditional model, adopt reverse thinking to innovate, and determine the overall baseline of the hull based on the bottom keel baseline of the block and block where the middle draft gauge mark and freeboard mark are located. Except for the block and block mark position where the bow draft gauge is located, the disturbance deformation of the bottom keel of other blocks and blocks only needs to be within the range of ±25mm according to the conventional requirements of ship construction standards, which effectively avoids the restrictions of the draft gauge mark deviation standard ±1mm and the freeboard mark deviation standard ±0.5mm, greatly reduces the difficulty of construction, and makes it possible to implement the draft gauge and freeboard mark planning and installation at the block or block stage according to conventional ship construction technology. It has been approved by relevant shipowners and classification societies and actually implemented by the shipyard, and no adverse feedback has been received after the delivery of the ship and put into normal operation.

[0016] 2. Establish a three-dimensional measurement and control network for the dock and slipway, implement the timely measurement data carried by the dock and slipway, and use the digital means of precision analysis software to form a precision digital information space for the dock and slipway based on the actual site and equipment of each target equipment, to ensure the unification of the coordinate system of the ship's hull section and the total section, ensure the spatial relative position relationship of each benchmark, avoid cumulative errors, improve positioning accuracy and improve the measurement environment.

[0017] 3. The use of laser instrument and centering target plate at the center line of the segmented total section facilitates the control of deformation of the bottom segmented total section during the welding process of the large closing construction, ensuring that the horizontal change at the water level mark position is within the standard control range.

[0018] 4. The draft and freeboard marks are marked and installed at the block or total block stage, which effectively realizes the advancement of production process, reduces the cross-construction of blocks and total blocks during the large assembly and loading stage, reduces the difficulty of subsequent production and construction, and improves the overall integrity.

[0019] 5. The draft gauge marks and freeboard marks are marked and installed in the block or block stage, which can avoid repeated rework of assembly, welding, grinding, painting and other types of work, reduce damage to cabin paint, reduce repeated grinding and painting work, reduce repeated additional scaffolding work, reduce the risk of safety hazards of personnel working at height, improve dock loading efficiency, and shorten the ship construction cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the section where the bottom of the middle water level mark of the present invention is located.

[0021] Figure 2 It is a schematic diagram of the draft scale and freeboard mark of the whole ship of the present invention.

[0022] Figure 3 It is a schematic diagram of the installation of the segment marking where the bottom of the middle water level mark of the present invention is located.

[0023] Figure 4 It is a schematic diagram of the section where the top of the middle water gauge mark and the freeboard mark of the present invention are located.

[0024] Figure 5 This is a schematic diagram of the top of the middle water mark and the section where the freeboard mark is located flipped 90 degrees.

[0025] Figure 6 This is a schematic diagram of the overall section where the middle water gauge and freeboard marks are located.

[0026] Figure 7 It is a schematic diagram of the installation of the total section where the top of the middle water gauge mark and the freeboard mark are located according to the present invention.

[0027] Figure 8 It is a schematic diagram of the section where the bottom of the head water level mark of the present invention is located.

[0028] Fig. 9 It is a schematic diagram of the installation of the segment marking where the bottom of the head water gauge mark is located in the present invention.

[0029] Fig.10 It is a schematic diagram of the general section where the head water gauge mark of the present invention is located.

[0030] Fig.11It is a schematic diagram of the installation of the general section where the head water gauge mark of the present invention is located.

[0031] Fig.12 It is a schematic diagram of the three-dimensional measurement and control network of the dock of the present invention.

[0032] Fig.13 It is a schematic diagram of the total section where the middle water gauge and freeboard mark of the present invention are located, turned over 90 degrees.

[0033] Fig.14 It is a schematic diagram of the horizontal control of the total section where the bow water gauge mark is located during the large-scale closure loading process of the present invention.

[0034] Fig.15 It is a schematic diagram of the installation of the remaining markings at the closing mouth of the fore water gauge of the present invention.

[0035] Fig.16 It is a schematic diagram of marking and installing the area where the tail water gauge mark is located in the present invention.

[0036] Among them: the middle water gauge mark 1; the freeboard mark 2; the bow water gauge mark 3; the stern water gauge mark 4; the inner bottom plate theoretical line 5; the hull outer plate 6; the hull baseline 7; the total station 8; the bottom ballast water tank 9; the top ballast water tank 10; the No. 0 rib position line 11; the dock centerline 12; the reference height line 13; the bow water gauge section 14; the cargo hold bow section 15; the forepeak bulkhead 16; the laser instrument 17; the centering target plate 18. DETAILED DESCRIPTION

[0037] See also Figure 1-16 Taking a conventional medium-sized bulk carrier as an example, the present invention relates to a construction method for the segmentation, overall segmentation and loading stages of a ship's draft mark, comprising the following steps: Step 1: Make the section where the bottom of the middle water gauge mark is located, and mark and install the bottom of the middle water gauge mark on the outer plate of the section.

[0038] The structure of the section where the bottom of the middle water gauge mark is located is completed according to the conventional construction process. After the tire is removed, the section is transported to the outfitting site by a flatbed truck to complete the remaining structural welding and outfitting parts installation. After all the electric welding and pyrotechnics of the section are completed, the level is adjusted, and the water gauge mark of the outer plate is marked and installed.

[0039] The section where the bottom of the middle water gauge mark is located is the bilge section (such as Figure 1 ), involving the outer bottom structure and bilge structure in the turning circle area and a part of the side outer plate, wherein the bottom and bilge areas are both bottom ballast tanks, and the bilge inclined plate is the boundary between the ballast tank and the cargo hold.

[0040] The specific operation of marking the bottom of the middle water gauge mark is as follows: According to the ship's draft and freeboard marking construction drawings (such as Figure 2), determine the specific rib position number, i.e. the longitudinal position, of the middle water gauge mark on the block shell; like Figure 3 , based on the theoretical line of the inner bottom plate at the location of the section where the middle water gauge mark is located, determine the baseline reference point of the outer plate of the bottom of the hull of the section, which is the hull baseline of the ship; Use the total station to position and mark the bottom area of ​​the middle water gauge mark in sequence from the determined hull baseline position upwards according to the requirements of the drawings; Spot welding is carried out according to the determined water level marks as per the requirements of the drawings. After the inspection is passed, welding work is carried out to complete the marking and installation of the water level marks of this section.

[0041] Step 2: Make the section where the top of the middle water gauge mark and the freeboard mark are located, and combine this section with the section where the bottom of the middle water gauge mark is located to form the total section where the middle water gauge mark and the freeboard mark are located. On the outer plate of this total section, the marked bottom of the middle water gauge mark is used as the basis and benchmark to mark and install the top of the middle water gauge mark and the freeboard mark.

[0042] The structure of the section where the top of the middle water gauge mark and the freeboard mark are located is completed according to the conventional construction process. The section where the top of the middle water gauge mark and the freeboard mark are located is the topside tank deck section (such as Figure 4 ), involving the side shell, deck and top sloping plating, which together constitute the top side ballast tanks. The top sloping plating is the boundary between the ballast tanks and the cargo holds.

[0043] The total segment and total group operation in step 2 is as follows: like Figure 5 , rotate the section where the bottom mark of the middle water gauge in step 1 is located by 90 degrees, and place it on the outer plate as the base surface; complete the assembly construction of the total section according to the conventional construction process, and assemble the section where the middle water gauge mark and freeboard mark are located with the adjacent sections to form the total section where the middle water gauge mark and freeboard mark are located (such as Figure 6 After all welding and pyrotechnics are completed, the level of the section shall be adjusted, and the bottom mark of the middle water gauge shall be used as the basis and benchmark, and a calibrated ruler and laser theodolite or total station shall be used according to the construction drawings (such as Figure 7 ) requires the marking and installation of the middle water gauge top mark and freeboard mark on the outer plate of the overall section and report them for approval.

[0044] Step 3: Make the section where the bottom of the bow water gauge mark is located, and mark and install the bottom of the bow water gauge mark on the outer plate of the section.

[0045] The section where the bottom of the bow water gauge mark is located is the forepeak tank bottom section (such as Figure 8), the structural construction of the section is completed according to the conventional construction process, and after the tire is removed, it is turned over and transported to the outfitting site by a flatbed truck to complete the remaining structural welding and outfitting parts installation work. After all the electric welding and pyrotechnics of the section are completed, the level is adjusted, and the water gauge marking and installation of the outer plate are carried out.

[0046] The specific operation of marking the bottom of the head water gauge mark is as follows: According to the ship's draft and freeboard marking construction drawings (such as Figure 2 ), determine the specific rib number, i.e. the longitudinal position, of the bow water gauge mark on the block outer plating; like Fig. 9 , based on the theoretical line of the inner bottom plate at the location of the section where the bow water gauge mark is located, determine the baseline reference point of the outer plate of the bottom of the hull of this section, which is the hull baseline of this section; Use the total station to position and mark the bottom area of ​​the bow water gauge mark in sequence from the determined baseline position of the segmented hull upwards according to the requirements of the drawings; Spot welding is carried out according to the determined water level marks as per the requirements of the drawings. After the inspection is passed, welding work is carried out to complete the marking and installation of the water level marks of this section.

[0047] Step 4: Create a section where the top of the header water gauge mark is located, and group this section with the section where the bottom of the header water gauge mark is located to form the total section where the header water gauge mark is located (such as Fig.10 ), the outer plate of the total section is based on the bottom of the bow water gauge mark as the basis and benchmark, and the top of the bow water gauge mark is marked and installed.

[0048] The section where the top mark of the bow water gauge mark is located shall complete the conventional construction work of the section according to the conventional construction process. The section where the top mark of the bow water gauge mark is located is the forepeak tank and void tank section, of which the lower half is the forepeak tank. When dividing the bow section into sections, the bow water gauge mark shall be controlled within one section as much as possible. The upper mark of the bow water gauge can be at the closing mouth of the section, and the remaining few marks can be completed in the large closing and loading stage, which will not affect the overall construction integrity.

[0049] The main section where the head water gauge mark is located shall be constructed according to the conventional construction process. After all the welding and pyrotechnics of the main section are completed, the level shall be adjusted. The bottom mark of the head water gauge shall be used as the basis and benchmark, and a calibrated ruler and laser theodolite or total station shall be used according to the construction drawings ( Fig.11 ) It is required to carry out the marking and installation of the top mark of the bow water gauge of the outer plate and report it for acceptance.

[0050] Step 5: Set up multiple digital targets at the rear and both ends of the dock to establish a three-dimensional measurement and control network for the dock (such as Fig.12), using precision analysis software to form a precision digital information space for the dock and slipway, ensuring the unification of the coordinate system of the ship's total section, avoiding cumulative errors, improving positioning accuracy and improving the measurement environment.

[0051] A total station is used to establish a spatial coordinate system with the center line of the dock bottom, and data is collected for the No. 0 rib position line, the benchmark height line, and the benchmark target points on both sides of the dock slipway. The measured data is converted in the precision analysis software, and the No. 0 rib position line is used to determine the X value of the constructed coordinate system, the center line determines the Y value of the constructed coordinate system, and the base height line determines the Z value of the constructed coordinate system, thereby establishing a three-dimensional measurement and control network coordinate system.

[0052] Step six: According to the conventional large-scale assembly and loading process, use the three-dimensional measurement and control network to carry out the rapid large-scale assembly and loading of the bow, stern, engine room and cargo hold area sections. During loading, multiple total stations are coordinated for positioning, and the positioning and loading software displays the measurement data of multiple total stations in real time. The loading section model moves in real time with the movement of the measurement data, monitors the on-site loading conditions, and controls and completes the on-site loading in real time to ensure that the theoretical line of the inner bottom plate of each section and the outer bottom keel of the hull are within the range of ±25mm as required by the conventional construction standards.

[0053] like Fig.13 , the section where the middle water gauge and freeboard marks are located is turned over and normalized before participating in the large assembly and loading work; during the large assembly and loading process, when the bow section of the cargo hold is undergoing large assembly and loading construction, the positions of the theoretical line of the inner bottom plate of the section where the bow water gauge mark is located and the keel line of the outer bottom of the hull are simulated and determined in the three-dimensional measurement and control network coordinate system to ensure that the baseline deviation of the section where the middle and bow water gauge marks are located is within ±2mm, and other sections are gradually transitioned within the range of ±25mm to the section where the bow water gauge mark is located within ±2mm.

[0054] like Fig.14 After the loading and positioning of the bottom section where the bow water gauge mark is located is completed and during the welding construction, a laser instrument is installed on the bow peak bulkhead at 1 meter away from the inner bottom centerline of the bottom section where the draft water gauge mark is located, and a centering target plate is arranged at a distance of more than 10 meters from the bow peak bulkhead at the centerline of the inner bottom of the bow section of the cargo hold to check the horizontal change of the water gauge mark and control the deviation accuracy of the section total mark where the bow water gauge mark is located within the range of ±2mm.

[0055] Step 7: Fig.15 , after the main hull is assembled and the sections are completed, and the main body welding and pyrotechnics are completed, the remaining marks of the bow water gauge at the outer plate's large assembly opening are marked and installed based on the section mark of the bow water gauge and a calibrated ruler and laser theodolite or total station according to the requirements of the construction drawings and reported for acceptance.

[0056] Step 8. Determine the overall baseline of the ship's hull based on the keel baseline at the bottom of the block where the middle water gauge and freeboard marks are located, and locate and mark the water gauge marks in the stern area based on the overall baseline of the hull.

[0057] The baseline deviation of the bow water gauge is within the standard ±1mm, and the limit range is ±2mm. The disturbance deformation of the bottom keel of other sections is only within the range of ±25mm according to the conventional requirements of ship construction standards, and the limit range is ±50mm. The baseline deviation of the section where the bow water gauge is located and the section in other areas gradually transitions.

[0058] Specifically: According to the draft and freeboard marking construction drawings of the whole ship (such as Figure 2 ), determine the specific rib number of the stern water gauge mark on the outer plate of the area, that is, the longitudinal position; according to the determined overall baseline of the hull, use the total station to move upward from the determined hull baseline position according to the drawings (such as Fig.16 ) It is required to locate and mark the water gauge marks in the tail area in turn; spot welding is carried out according to the requirements of the drawings based on the determined water gauge marks, and welding work is carried out after passing the inspection to complete the marking and installation of the water gauge marks in the tail area.

[0059] The lower part of the draft gauge mark at the rear of a conventional ship is in the rudder blade area, and the upper part of the draft gauge mark is in the rear area of ​​the engine room. There are many conventional outfitting works in this area during the large assembly and loading stage, so it can be constructed together with the draft gauge mark. The rear draft mark will be marked and installed during the large assembly and loading stage. If necessary, it can be marked and installed step by step in the block, block and loading stages in accordance with the construction method of the bow draft gauge mark.

[0060] If the draught gauge marks and freeboard marks in the middle and bow and stern of a small ship are within a circular section, they can all be surveyed and installed at the section stage.

[0061] In addition to the above embodiments, the present invention also includes other implementation modes. Any technical solutions formed by equivalent transformation or equivalent replacement should fall within the protection scope of the claims of the present invention.

Claims

1. A method for constructing ship draft marks in sections, blocks and loading stages, characterized by: The following steps are involved: Step 1: Make the section where the bottom of the middle water gauge mark is located, and mark and install the bottom of the middle water gauge mark on the outer plate of the section; Step 2: Make a section where the top of the middle water gauge mark and the freeboard mark are located, and combine this section with the section where the bottom of the middle water gauge mark is located to form a total section where the middle water gauge mark and the freeboard mark are located. On the outer plate of this total section, the top of the middle water gauge mark and the freeboard mark are marked and installed based on the marked bottom of the middle water gauge mark; Step 3: Make the section where the bottom of the bow water gauge mark is located, and mark and install the bottom of the bow water gauge mark on the outer plate of the section; Step 4: Make a section where the top of the bow water gauge mark is located, and combine this section with the section where the bottom of the bow water gauge mark is located to form a total section where the bow water gauge mark is located. The outer plate of the total section is based on the marked bottom of the bow water gauge mark as the basis and reference, and the top of the bow water gauge mark is marked and installed; Step 5: Set up multiple digital targets at the rear and both ends of the dock to establish a three-dimensional measurement and control network for the dock; Step 6: Use the three-dimensional measurement and control network to carry out the rapid assembly and mounting of the bow, stern, engine room and cargo hold sections according to the conventional assembly and mounting process; Step 7: After the main hull is assembled and the main body is welded and pyrotechnics are completed, the remaining marks of the bow water gauge at the large closure port of the outer plate are marked and installed according to the requirements of the construction drawings using a calibrated ruler and laser theodolite or total station based on the total section mark of the bow water gauge and the requirements of the construction drawings, and the work is reported and qualified; Step 8. Determine the overall baseline of the ship's hull based on the keel baseline at the bottom of the block where the middle water gauge and freeboard marks are located, and locate and mark the water gauge marks in the stern area based on the overall baseline of the hull.

2. The method for constructing a ship draft mark in sections, sections and loading stages according to claim 1, characterized in that: In step 1, the specific operation of marking the bottom of the middle water gauge mark is as follows: According to the draft gauge and freeboard mark construction drawings of the entire ship, determine the specific rib number, i.e. the longitudinal position, of the middle gauge mark on the block outer plating; Based on the theoretical line of the inner bottom plate at the location of the section, the baseline reference point of the outer plate of the hull bottom of the section is determined, which is the hull baseline of the ship; Use the total station to position and mark the bottom area of ​​the middle water gauge mark in sequence from the determined hull baseline position upwards according to the requirements of the drawings; Spot welding is carried out according to the determined water level marks as per the requirements of the drawings. After the inspection is passed, welding work is carried out to complete the marking and installation of the water level marks of this section.

3. The method for constructing a ship draft mark in sections, sections and loading stages according to claim 1, characterized in that: The total segment and total group operation in step 2 is as follows: Rotate the section where the bottom mark of the middle water gauge in step 1 is located by 90 degrees and place it on the base surface of the outer plate; complete the overall construction of the total section according to conventional construction technology, and assemble the section where the middle water gauge mark and freeboard mark are located with the adjacent sections to form the total section where the middle water gauge mark and freeboard mark are located; take the bottom mark of the middle water gauge as the basis and benchmark, use a calibrated ruler and laser theodolite or total station to mark and install the top mark of the middle water gauge and freeboard mark of the outer plate of the total section according to the requirements of the construction drawings, and report them for acceptance.

4. The method for constructing a ship draft mark in sections, blocks and loading stages according to claim 1, characterized in that: In step 3, the specific operation of marking the bottom of the head water gauge mark is as follows: According to the draft gauge and freeboard mark construction drawings of the entire ship, determine the specific rib number, i.e. the longitudinal position, of the bow gauge mark on the block outer plating; Based on the theoretical line of the inner bottom plate at the location of the section where the bow water gauge mark is located, determine the baseline reference point of the outer plate of the bottom hull of the section, which is the hull baseline of this section; Use the total station to position and mark the bottom area of ​​the bow water gauge mark in sequence from the determined baseline position of the segmented hull upwards according to the requirements of the drawings; Spot welding is carried out according to the determined water level marks as per the requirements of the drawings. After the inspection is passed, welding work is carried out to complete the marking and installation of the water level marks of this section.

5. The method for constructing a ship draft mark in sections, blocks and loading stages according to claim 1, characterized in that: In the step five, a total station is used to establish a spatial coordinate system with the center line of the dock bottom, and data is collected for the No. 0 rib position line, the reference height line, and the reference target points on both sides of the dock slipway. The measured data is converted in the precision analysis software, and the No. 0 rib position line is used to determine the X value of the established coordinate system, the center line determines the Y value of the established coordinate system, and the base height line determines the Z value of the established coordinate system, thereby establishing a three-dimensional measurement and control network coordinate system.

6. The method for constructing a ship draft mark in sections, blocks and loading stages according to claim 1, characterized in that: In the step six, the section where the middle water gauge and freeboard marks are located is turned over and normalized before participating in the large assembly and loading work; during the large assembly and loading process, when the bow section of the cargo hold is undergoing large assembly and loading construction, the positions of the theoretical line of the inner bottom plate of the section where the bow water gauge mark is located and the keel line of the outer bottom of the hull are simulated and determined in the three-dimensional measurement and control network coordinate system to ensure that the baseline deviation of the section where the middle and bow water gauge marks are located is within ±2mm, and other sections are gradually transitioned within the range of ±25mm to within ±2mm of the section where the bow water gauge mark is located.

7. A method for constructing a ship draft mark in sections, blocks and loading stages according to claim 6, characterized in that: After the loading and positioning of the bottom section where the bow water gauge mark is located is completed and during the welding construction, a laser instrument is installed on the forepeak bulkhead at 1 meter away from the inner bottom centerline of the bottom section where the draft water gauge mark is located, and a centering target plate is arranged at a distance of more than 10 meters from the forepeak bulkhead at the centerline of the inner bottom of the bow section of the cargo hold to check the horizontal change of the water gauge mark and control the deviation accuracy of the section mark where the bow water gauge mark is located within the range of ±2mm.

8. The method for constructing a ship draft mark in sections, blocks and loading stages according to claim 1, characterized in that: In the step eight, the specific operation of marking the bottom of the stern water gauge mark is as follows: according to the draft water gauge and freeboard mark construction drawings of the whole ship, determine the specific rib position number, i.e. the longitudinal position, of the stern water gauge mark on the outer plate of the area; according to the determined overall baseline of the hull, use a total station to position and mark the water gauge marks of the stern area from the determined hull baseline position upwards in sequence according to the requirements of the drawings; spot welding is performed according to the requirements of the drawings based on the determined water gauge marks, and welding work is carried out after passing the inspection to complete the marking and installation of the water gauge marks in the stern area.

9. A method for constructing a ship draft mark in sections, blocks and loading stages according to claim 1 or 8, characterized in that: In the step eight, there are many conventional outfitting works in this area during the large assembly and loading stage, so it can be constructed together with the draft mark, and the rear draft mark can be marked and installed during the large assembly and loading stage.

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