Joining Shackle for Ship Anchor Chain: Types, Standards, and Selection Guide
Joining Shackle is an indispensable key component in the anchor chain system, responsible for safely connecting all links of the anchor chain to ensure the reliability and durability of the anchor chain in extreme marine environments. This article combines international standards, production specifications and industry application scenarios to analyze the technical parameters, selection strategies and maintenance points of the connecting shackle, which will help shipowners, marine engineers and purchasers to make efficient decisions.
I. Core functions and types of connecting shackles
1. Definition and role
Kenter Joining Shackle is a kind of detachable connector designed for anchor chain, used to connect the link of the anchor chain or the anchor chain with the anchor body, its core functions include:
High strength connection: withstands tensile, torsional and impact loads on the anchor chain, ensuring the stability of the mooring system.
Quick maintenance: detachable design facilitates the replacement of damaged links and reduces maintenance cost.
2. Main types
| Type | Features | Applicable scenarios |
| Kenter shackle | Bolted to standard anchor chains, the breaking load is up to 100% of the chain strength. | Ocean freighters, oil rigs |
| End Shackle | Connecting the end of the anchor chain with the anchor body, the surface is galvanized, and it is resistant to salt spray corrosion. | Port ships, offshore operations |
| Detachable Shackle | Quick tool-free installation, suitable for temporary mooring or emergency repairs. | Temporary anchorage and emergency maintenance scenarios |
II. Material and production standard
1. Material Selection
Alloy steel: such as Grade 2, Grade 3 steel, tensile strength up to 490-690 MPa, suitable for regular marine environment.
Stainless steel 316L: Resistant to chloride ion corrosion, life expectancy 3 times higher than normal steel, suitable for deep sea or high salinity areas.
Surface treatment: hot dip galvanized (zinc layer ≥85μm) or epoxy coating to extend service life.
2. International certifications and standards
Classification society certifications: including ABS (USA), CCS (China), DNV (Norway), LR (UK), etc., to ensure that the product meets maritime safety specifications.
Industry Standard:
ISO 1704: Manufacturing and testing requirements for anchor chains and shackles.
EN 13889: Mechanical properties and safety coefficient of shackle (≥4:1).
III. Application Scenarios and Technical Parameters
1. Typical application scenarios
Ocean Cargo Ship: Kenter shackle is used to connect high strength anchor chain (diameter 22-162mm) to withstand the dynamic load of trans-oceanic voyage.
Offshore platforms: stainless steel shackles are suitable for high pressure, high corrosion deep sea environment, such as oil rig mooring system.
Port and river vessels: galvanized end shackles are economical and practical, suitable for short-term mooring and low-frequency operations.
2. Key parameters and selection guide
As a Kenter Shackle supplier, we provide you with the following selection reference:
Breaking Load (BLL): ≥4×Working Load (WLL), e.g. 10 tons WLL needs BLL≥40 tons.High-risk scenarios choose the safety factor 6:1
Size fit: the inner diameter of the shackle is 10%-15% larger than the diameter of the anchor chain (e.g. 30mm anchor chain fits 34-35mm shackle).Avoid stress concentration caused by size mismatch.
Temperature range: -40 ℃ ~ 120 ℃, polar operations require special low-temperature steel, to verify the low-temperature impact toughness of the material.
IV. Maintenance and Inspection Specifications
1. Daily maintenance
Monthly inspection: check the surface cracks, corrosion and loose bolts, and use magnetic particle flaw detection (MT) to detect internal defects.
Lubrication and maintenance: Apply silicone-based lubricant quarterly to prevent thread jamming.
2. Professional testing
Annual load test: Commission a third-party organization to conduct a breaking load test to ensure that the performance is up to standard.
Replacement standard: The following conditions require immediate replacement:
Crack depth ≥ 0.5mm.
Deformation exceeds 5% of the original size.
V. Frequently Asked Questions (FAQ)
Q: What is the difference between connecting shackle and common shackle?
A: The connecting shackle is specially designed for anchor chain, with higher breaking load (≥4:1 safety factor) and certified by Classification Society.
Q: How can I tell if a shackle needs to be replaced?
A: If there are visible cracks, thread wear or deformation exceeding 5%, it should be replaced immediately.
Q: Are stainless steel shackles suitable for all marine environments?
A: Yes, but it is not recommended for extreme corrosive environments containing hydrogen sulfide (special coatings are required).
