Marine metal straight ladder with low radar wave scattering cross section and installation method

Abstract

The application discloses a ship metal straight ladder with a low radar wave scattering cross section and a mounting method, which comprises a ladder frame, a step rod and a fixing base, the ladder frame is symmetrically arranged left and right, and is connected into a shape through the step rod, the step rod is uniformly and spacedly arranged along the axial direction of the ladder frame, the bottom of the ladder frame is sleeved with a ladder frame sleeve, the ladder frame sleeve is connected with the fixing base, the fixing base is arranged correspondingly to the left and right sides of the ladder frame, and is fixed on a mounting platform. The application effectively reduces the head radar wave scattering cross section area of the ship straight ladder, avoids becoming a local bright spot of ship radar wave scattering, and supports the design of a stealth ship.

Description

Technical Field

[0001] This application relates to the technical field of radar stealth design for ship outfitting, and more specifically, to a marine metal ladder with a low radar cross section and its installation method. Background Technology

[0002] The primary threats to surface ships come from early warning aircraft and anti-ship missiles. These threats are mostly at swept-in angles, affecting ships 360° circumferentially, and spanning frequency bands from the P-band to the Ka-band. With the rapid development of detection technology, the requirements for radar stealth of ships are increasingly stringent. In addition to controlling the radar scattering characteristics of the hull platform, the stealth design of the ship's outfitting facilities and accessories is particularly important.

[0003] The ship's deck is dotted with numerous metal straight ladders. None of the steel straight ladders currently in service have incorporated radar stealth design features. According to CB / T73-1999, the ladder width is typically 300-400 mm, and the length is 600-3600 mm. Most adopt... Straight ladders use round steel steps, square steel steps, and steel pipe steps, with flat steel often used for the ladder frame. The radar cross section (RCS) of a single straight ladder is not large, mainly due to its cylindrical or columnar shape. When facing incoming waves from a sweeping incidence direction, the structural characteristics of round and square steel will cause strong specular scattering in the incident direction, resulting in multiple scattering effects with the mounting surface. Furthermore, straight ladders typically use eyeplates to connect to the mounting surface, and the sidewalls of these eyeplates are all straight walls, which are also strong scattering sources. In conclusion, although straight ladders occupy a small area, they are strong scattering structures for stealth ships, compromising the stealth capabilities of the hull platform.

[0004] Considering the materials used in the straight ladder, composite materials are used to mitigate radar waves by utilizing their high-frequency transparency. However, as the frequency bands of threats expand, composite materials exhibit different electrical characteristics at different frequencies, failing to guarantee complete radar transparency. Furthermore, composite materials are susceptible to impacts, are expensive, difficult to maintain, and have a short lifespan. Therefore, a metal straight ladder with radar stealth design, through a specific configuration, can solve the problem of wide-band radar stealth while offering advantages such as low cost and easy maintenance. Meanwhile, the straight ladder is fixed to the ship's platform via an eyeplate. Existing eyeplates are designed according to CB / T 60-1999 marine eyeplates and do not consider radar stealth. Therefore, it is necessary to design the metal straight ladder itself and its installation method to achieve low radar target characteristics, providing a design scheme with a low radar cross-section. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a marine metal ladder with a low radar cross section and an installation method, which addresses the above-mentioned problems. By rationally designing the external structure of the metal ladder and optimizing its installation form, the radar cross section of the marine ladder can be effectively reduced, thus preventing it from becoming a local bright spot in the radar scattering of the ship.

[0006] The embodiments of this application are implemented as follows:

[0007] This application provides a marine metal straight ladder with a low radar cross-section, characterized in that it includes a ladder frame, step rods, and a fixing seat. The ladder frame is symmetrically arranged on the left and right sides and connected in the middle by the step rods. The step rods are evenly spaced along the axial direction of the ladder frame. A ladder frame sleeve is fitted at the bottom of the ladder frame. The ladder frame sleeve is connected to the fixing seat. The fixing seat is arranged corresponding to the left and right sides of the ladder frame and fixed to the installation platform.

[0008] In some alternative implementations, the ladder frame is an odd-numbered regular polygonal prism structure; the step bars are an even-numbered regular polygonal prism structure.

[0009] In some alternative implementations, the ladder sleeve is an odd-numbered regular polygonal prism with an odd-numbered number of regular polygonal cavities, and the inner surface of the ladder sleeve has a cylindrical plug.

[0010] In some alternative implementations, the mounting base is a multi-faceted trapezoidal structure with cylindrical insertion holes configured to match the insertion connector and fastened by connecting bolts.

[0011] In some alternative implementations, the ladder frame, step rods, fixing bases, and ladder frame sleeves are all made of structural wave-absorbing material.

[0012] A method for installing a marine metal straight ladder with a low radar cross-section, characterized by comprising the following:

[0013] The step bars are welded to the ladder frame at equal intervals. The bottom of the ladder frame is fitted with a ladder frame sleeve. The fixing seat is welded to the installation platform. The plug on the ladder frame sleeve is inserted into the plug hole of the fixing seat on the corresponding side and connected and tightened by connecting bolts.

[0014] In some alternative implementations, the convex ridges of the ladder frame are positioned facing the mounting surface of the hull.

[0015] In some alternative implementations, the step bar is positioned with its flat surface facing upwards and its convex surface facing outwards.

[0016] In some alternative embodiments, the angle between the sidewall of the mounting base and the normal is not less than 7°.

[0017] The beneficial effects of this application are: This invention provides a marine metal straight ladder with low radar wave scattering cross section and an installation method. Through the optimized design of the installation method of the marine straight ladder and the configuration and material application of the ladder frame, steps, fixing eye plate, and ladder frame sleeve, the radar wave scattering cross section of the marine straight ladder is effectively reduced, avoiding becoming a local bright spot of radar wave scattering of the ship, and supporting the design of stealth ships. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of an embodiment of this application;

[0020] Figure 2 This is a top view of an embodiment of this application;

[0021] Figure 3 This is a side view of an embodiment of this application. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0024] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0025] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0026] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0027] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0028] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0029] The features and performance of this application will be further described in detail below with reference to the embodiments.

[0030] like Figure 1As shown, the present invention proposes a marine metal straight ladder with low radar cross section, including a ladder frame 1, step rods 2 and a fixing seat 3. The ladder frame is symmetrically arranged on the left and right sides and connected in the middle by step rods. The step rods are evenly spaced along the axial direction of the ladder frame. The bottom of the ladder frame is fitted with a ladder frame sleeve 4, which is connected to the fixing seat. The fixing seat is arranged on the left and right sides of the ladder frame and fixed to the installation platform.

[0031] The ladder frame is an odd-numbered regular polygonal prism structure; the step bars are an even-numbered regular polygonal prism structure. It does not generate strong specular scattering in the incident direction, nor does it create multiple scattering effects with the mounting surface, effectively reducing the radar wave scattering cross-section of the marine ladder and preventing it from becoming a local bright spot in the ship's radar wave scattering.

[0032] The ladder sleeve is an odd-numbered regular polygonal prism with an odd number of regular polygonal cavities, and the inner side of the ladder sleeve has a cylindrical plug 5.

[0033] The mounting base has a multi-faceted trapezoidal structure and is equipped with a cylindrical insertion hole, which is matched with the insertion connector and fastened by connecting bolts.

[0034] The ladder frame, step rods, fixing base, and ladder frame sleeve are all made of structural wave-absorbing material.

[0035] The installation method for the aforementioned marine metal ladder includes the following:

[0036] The step bars are welded to the ladder frame at equal intervals. The bottom of the ladder frame is fitted with a ladder frame sleeve. The fixing seat is welded to the installation platform. The plug on the ladder frame sleeve is inserted into the plug hole of the fixing seat on the corresponding side and connected and tightened by connecting bolts.

[0037] The ladder frame is mounted with its convex ridge facing the hull, and the step bar is placed with its flat surface facing upwards and its convex ridge facing outwards.

[0038] The angle between the side wall of the mounting base and the normal direction shall not be less than 7°.

[0039] Example 1

[0040] The ladder frame is a 1000m long, 22mm side length regular pentagonal prism. The step rods are regular hexagonal prisms with 10mm side length and 280mm length. The step rods are welded to the ladder frame with a 300mm gap. To transfer the normal scattering peak caused by the probe wave, the ladder frame edges are placed outwards. The step rod edges are placed upwards and outwards. The fixing base adopts a trapezoidal structure with an angle of 83° between each side and the bottom. The fixing base trapezoid is a square with a 20mm side length and a 10mm diameter cylindrical insertion hole in the center. The ladder frame sleeve adopts a regular pentagonal prism structure with an inner side length of 22mm and an outer side length of 32mm. It is sleeved with the ladder frame. The side wall of the ladder frame sleeve has a 10mm diameter cylindrical insertion joint, which is bolted into the cylindrical insertion hole of the fixing base.

[0041] To further reduce the RCS value, structural absorbing materials can be used in the straight ladder, which have good absorption characteristics in the HF to Ku band range; thus reducing the RCS value of the straight ladder.

[0042] This straight ladder has a reasonable structure, is sturdy and durable, and can be designed according to the size of the space and the inclination angle of different ship backgrounds. It is easy to install and maintain and has significant practical value.

Claims

1. A method for installing a marine metal straight ladder with a low radar cross-section, the marine metal straight ladder comprising a ladder frame, step bars, and a fixing base, wherein the ladder frame is symmetrically arranged on the left and right sides and connected in the middle by the step bars, the step bars are evenly spaced along the axial direction of the ladder frame, a ladder frame sleeve is fitted at the bottom of the ladder frame, the ladder frame sleeve is connected to the fixing base, the fixing base is arranged corresponding to the left and right sides of the ladder frame and fixed to an installation platform; the ladder frame is an odd-numbered regular polygonal prism structure; the step bars are even-numbered regular polygonal prism structures; the ladder frame sleeve is an odd-numbered regular polygonal prism with an odd-numbered regular polygonal cavity, and the inner surface of the ladder frame sleeve has a cylindrical plug-in joint; the fixing base is a multi-faceted truncated ladder structure with a cylindrical plug-in hole, configured with the plug-in joint, and connected and fastened by connecting bolts; characterized in that... The installation of this metal ladder includes the following: Even-numbered regular polygonal prism structure step bars are welded to odd-numbered regular polygonal prism structure ladder frames at equal intervals. Ladder frame sleeves are fitted at the bottom of the ladder frames. Fixing seats are welded to the installation platform. The plugs on the ladder frame sleeves are inserted into the plug holes of the fixing seats on the corresponding sides and are connected and tightened by connecting bolts.

2. The installation method of a marine metal straight ladder with low radar cross-section according to claim 1, characterized in that, The convex surface of the ladder is oriented towards the mounting surface of the hull.

3. The installation method of a marine metal ladder with low radar cross-section according to claim 2, characterized in that, The step bar is placed with its flat surface facing upwards and its convex surface facing outwards.

4. The installation method of a marine metal straight ladder with low radar cross-section according to claim 3, characterized in that, The angle between the side wall of the fixed seat and the normal is not less than 7°.

5. The installation method of a marine metal straight ladder with low radar cross-section according to claim 3, characterized in that, The ladder frame, step rods, fixing bases, and ladder frame sleeves are all made of structural wave-absorbing material.

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