JIS F2017-BC Standard Bulwark Chock - 316 stainless steel material / High strength corrosion-resistant / Deck and ship side mooring hardware / Surface polished or brushed treatment

Material and Manufacturing:

Material Advantages:

JIS F2017 - BC The mainstream material for bulwark guide holes is cast steel. Steel plates or stainless steel composite plates can also be selected according to customer needs. These materials are well-suited to the harsh conditions of ship mooring, and their specific advantages are as follows:

Cast Steel (e.g., ZG200-400, ZG230-450)
* **Superior Load-Bearing Capacity and Impact Resistance:** This material possesses excellent strength and toughness. The guide hole weighs between 276-472 kg, capable of withstanding the enormous loads generated during ship mooring. It is suitable for mooring operations on various vessels such as tugboats, bulk carriers, and tankers, and can withstand the instantaneous tensile impact of the cable, preventing breakage or deformation under high-intensity stress.

* **Adaptability to Complex Forming and Subsequent Protection:** Cast steel has good casting fluidity, allowing for precise casting of complex curved surfaces where the guide hole contacts the cable. After forming, it can be sandblasted to remove rust, and then coated with epoxy polymer paint or asphalt black paint, significantly improving its corrosion resistance in marine salt spray environments and extending its service life. Meanwhile, its contact surfaces are finely polished, reducing wear on the cables.

Steel Plate (compliant with JIS G3106 standard)
Flexible processing and robust structure: Steel plates can be processed into various shapes through bending and welding, adapting to the structural requirements of the guide hole base and bulwark. For special sizes or installation scenarios, steel plate processing offers greater adaptability.

High performance controllability: This type of steel plate has stable mechanical properties. After standardized welding and heat treatment, the overall structural strength of the guide hole can be guaranteed. Furthermore, a standardized surface coating process can achieve the same corrosion resistance as cast steel, while facilitating mass production.

Stainless Steel Composite Plate (e.g., 1Cr18Ni9Ti)
Extreme corrosion resistance: The 1Cr18Ni9Ti stainless steel layer in the stainless steel composite plate forms a dense protective oxide film in high-salt, high-humidity marine environments, effectively resisting seawater erosion and salt spray corrosion. Compared to ordinary cast steel, it maintains its good condition without frequent maintenance, making it particularly suitable for vessels operating in harsh marine environments for extended periods.

Balancing strength and cost-effectiveness: The base layer of the composite plate ensures the structural strength of the cable guide hole and meets the load-bearing requirements, while the surface stainless steel is only used for corrosion protection. Compared with the use of stainless steel material throughout, this greatly reduces production costs and achieves a cost-effective balance between high strength and high corrosion resistance.

Manufacturing Process:

1. **Raw Material Preparation and Inspection**
- First, select raw materials that meet the standards. For cast steel materials, such as ZG200 - 400, ZG230 - 450, etc., it is necessary to conduct sampling inspection on the chemical composition and mechanical properties of the cast steel ingots to ensure that the content of elements such as carbon and manganese meets the requirements, so as to avoid performance defects caused by impure materials. For steel plate materials conforming to JIS G3106, check the flatness and thickness uniformity of the plates to ensure that there are no cracks or inclusions on the surface.
- Then, the raw materials are cut into blanks of appropriate size according to the design drawings of the guide cable hole. The cast steel ingots are cut into blocks matching the mold volume, and the steel plates are cut into rectangular plates that can be processed into the base and surrounding structures by numerical control cutting to ensure the accuracy of the blank size.
2. **Molding Processing**
- **Cast steel molding**: Since the JIS F2017 - BC bulwark chock has a curved contact surface with the cable, a sand mold or precision investment mold is usually made according to its shape. The mold cavity is polished smoothly to avoid surface defects of the casting. Then the molten cast steel is poured into the mold. After natural cooling and solidification, the mold is removed to obtain the rough casting of the chock. The key of this step is to control the pouring temperature and cooling rate to prevent the casting from generating internal stress, cracks or shrinkage cavities.
- **Steel plate bending and forming**: For the parts such as the base of the chock made of steel plate, the cut steel plate is bent into the required arc or angular shape by a cold bending machine. For special structures such as double - shell bulwarks, the steel plate can also be processed into components such as outer sealing plates and intermediate cylindrical sealing plates according to the structure, and the dimensional accuracy of the bent parts is corrected by a calibrator to ensure that it matches the assembly requirements.
3. **Welding and Reinforcement**
- For cast steel chocks, if the casting has local defects or needs to be connected with the reinforcing bracket, welding reinforcement is required. The welding rod matching the cast steel material is selected, and the welding parts are preheated to reduce the welding stress. After welding, the weld seam is polished to make it smooth and flat.
- For the chock structure assembled by multiple components, such as the combination of the chock body and the reinforcing bracket, the connection between the chock and the bulwark's elbow plate, etc., full welding is adopted. Especially for the double - shell bulwark chock, radial connecting elbow plates need to be welded around the cylindrical part of the chock. Generally, no less than 8 elbow plates are arranged at equal angles to enhance the overall bearing capacity. After welding, non - destructive testing such as ultrasonic testing is carried out on the weld seam to ensure no hidden dangers such as false welding and incomplete penetration.
4. **Precision Machining and Polishing**
- The surface of the formed chock is subjected to rough machining by a milling machine to remove the casting riser, flash and excess welding meat, so that the overall size meets the requirements of JIS F2017 standard.
- Focus on finishing the inner contact surface of the chock. Use a grinder to polish it repeatedly to make the surface roughness meet the standard. The purpose is to increase the contact area with the cable, reduce the wear of the cable, and ensure that the cable can pass smoothly. Finally, the overall size and shape of the chock are measured with a three - coordinate measuring instrument to ensure that the deviation is within the allowable range.
5. **Anti - corrosion Treatment**
- First, the chock is subjected to sandblasting or shot blasting. This step can completely remove the rust, oxide scale and oil stains on the surface of the workpiece, and increase the adhesion of the subsequent coating.
- Then, apply anti - corrosion coatings such as epoxy polymer paint or asphalt black paint. For the chocks used in harsh marine environments, a double - layer coating process can be adopted. After the first layer of primer is dried, apply the topcoat. For stainless steel composite plates, the stainless steel surface can also be passivated to form a dense oxide film to further improve the corrosion resistance and prolong the service life of the product.
6. **Final Inspection and Assembly Calibration**
- Conduct a comprehensive performance test on the processed chock. The load - bearing test is carried out to verify whether it can withstand the tension impact of the cable during mooring; check the corrosion resistance of the coating through the salt spray test. At the same time, review the dimensional parameters such as the inner diameter and thickness of the chock to confirm that it complies with the JIS F2017 - BC specification.
- Before formal shipment, simulate the assembly with the bulwark sample. Mark the installation position on the bulwark, check the fitting degree of the chock and the bulwark opening, and adjust the installation holes and connecting parts to ensure that it can be quickly and accurately installed during the ship section pre - outfitting stage.

Features:

1. **Strong Load - Bearing Capacity for Stable Mooring**
- It is specially designed to adapt to the mooring working conditions of large ships. With nominal sizes ranging from 310mm to 500mm and weights from 276kg to 422kg, it can bear extremely heavy loads during the ship mooring process. This enables it to stably guide mooring cables for various large vessels such as bulk carriers, oil tankers, and LNG tankers, and maintain excellent structural stability even when facing the instantaneous tension impact of cables.
2. **Closed Structure for High Operational Safety**
- Unlike some open - type cable - guiding devices, it adopts a closed - hole structure. This design can effectively limit the position of the mooring cable and avoid the cable jumping out of the chock due to turbulent water flow or sudden changes in ship posture during mooring. Meanwhile, its inner contact surface is polished smoothly. This not only reduces the friction and wear between the device and the cable, prolonging the service life of the cable, but also prevents potential safety hazards caused by cable damage.
3. **Fixed Installation Design for Firm Combination with Hulls**
- As a bulwark - mounted type, it is specially designed for installation on the ship's bulwark. It can be directly installed on or in the hull, and can also be equipped with a base plate to be fixed on the plinth with bolts. This installation method makes it closely combined with the ship's structure. When bearing the huge tension of the mooring cable, it can evenly disperse the force to the hull, avoiding local structural damage due to concentrated stress, and ensuring the firmness and stability during long - term use.
4. **Standardized Production with Reliable Quality Certification**
- It is produced in strict accordance with the JIS F2017 - 1982 standard. For example, its cast steel material complies with the requirements of JIS G5101, and the optional steel plate material meets the JIS G3106 standard. In addition, the product has obtained many authoritative ship classification society certifications such as CCS, ABS, DNV - GL, and BV. These certifications fully verify its quality and performance, making it recognizable and applicable in the global maritime field.
5. **Flexible Customization and Strong Adaptability**
- It supports personalized customization according to customer needs. On the one hand, there are multiple material options. In addition to the mainstream cast steel, it can also be made of steel plates according to special requirements. On the other hand, it can be customized in terms of specifications to match different ship types and bulwark structures. Moreover, it is one of the commonly used Panama chocks for ships passing through the Panama Canal, which can meet the special mooring equipment requirements of ships navigating in key waterways around the world.
6. **Professional Anti - Corrosion Treatment for Long Service Life**
- The surface of the product will go through sandblasting treatment first, and then be coated with workshop primer or anti - corrosion protective coatings. This kind of double anti - corrosion treatment can effectively resist the corrosion of salt spray, seawater and humid air in the marine environment, slow down the oxidation and rust of the chock, and ensure that it can maintain stable performance during long - term marine service without frequent maintenance.

Technical Parameters:

Application Scenarios:

1. **Various Commercial Ships**
This device is capable of withstanding heavy loads during mooring, making it applicable to a wide range of large and medium - sized commercial ships with high mooring load requirements. For example, bulk carriers that transport bulk goods like coal and grain, oil tankers and LNG tankers that carry flammable and explosive dangerous goods, and container ships that need stable berthing to ensure the safety of container stacking. It can steadily guide the mooring cables, preventing cable deviation or detachment due to factors such as sea breeze and waves, thus guaranteeing the safety of the ship during loading, unloading and berthing. In addition, it is also suitable for small and medium - sized ships such as tugboats, barges and yachts, meeting their daily mooring needs in ports or anchorages.
2. **Ships Navigating the Panama Canal**
It is one of the commonly used Panama chocks for ships passing through the Panama Canal. The Panama Canal authorities have strict requirements on the mooring equipment of ships passing through the canal. This product complies with the JIS F2017 - 1982 standard and meets the specified working load requirements. Meanwhile, it has obtained certifications from many authoritative classification societies such as CCS, DNV - GL and ABS. These advantages enable it to meet the equipment specifications required by the Panama Canal, ensuring that ships can smoothly complete mooring - related operations during their passage and anchorage in the canal area.
3. **Special Marine Working Scenarios**
It can also be applied to some special marine working occasions that require temporary mooring. For instance, during offshore oil exploration and development, supply ships need to stably berth near offshore platforms to transport materials and personnel. This chock can provide reliable mooring guidance for supply ships, ensuring the safety of material transfer and personnel transportation. Besides, in marine rescue operations, when rescue ships need to berth alongside damaged ships for rescue work, this device can help the rescue ships maintain a stable posture, creating favorable conditions for the smooth progress of rescue operations. Moreover, it can also be used in the mooring of port service ships, which is helpful for these ships to carry out daily port management, maintenance and other work.

Support and Services:

Standardized Warranty System: Most industrial and machinery products on the platform follow a standard 1-year warranty, with some high-value equipment offering warranties up to 3 years. For critical equipment like marine mooring systems, free repair or parts replacement services are available for non-human-caused quality issues such as material cracking or structural deformation within the warranty period.

Multilingual Dedicated Service Support: A multilingual buyer service team of over 200 people covers multiple languages ​​including English, Arabic, and Russian, suitable for after-sales communication in cross-border procurement. It also assists both suppliers and buyers in conducting video conferences to resolve after-sales issues such as equipment installation and troubleshooting face-to-face.

 
In addition, we offer a range of services to complement our mooring bollards products. These include custom design and engineering, installation and commissioning, and repairs and upgrades. Our goal is to provide a comprehensive solution to meet your mooring needs, from product selection to ongoing support.
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