Marine Anchor Swivels & Swivel Shackles for Anchor Chain Systems
OLIPORTS is a leading global provider of port engineering and marine solutions, with many years of specialized experience in mooring and anchoring systems. We manufacture high-quality marine anchor chain swivels and swivel shackles—core safety components specifically designed to eliminate dangerous torsional stresses in ship anchor chain systems.
OLIPORTS comprehensive product range includes Type A swivel shackles for light to medium-duty applications, heavy-duty Type B swivel shackles engineered for ocean-going vessels, and durable lead swivel shackles (also known as tracking swivel shackles) optimized for trawlers. As part of our comprehensive mooring and anchoring product line, all swivel shackles are precision-manufactured from premium Grade 2, Grade 3, and ORQ marine-grade steel, fully comply with IACS standards, and undergo rigorous verification load testing and impact testing.
We can provide third-party inspection reports and certifications from ABS, DNV, BV, and CCS upon request, ensuring reliability consistent with our full range of anchor chains, end shackles, and Kent chain links.
Each swivel ring undergoes precision heat treatment and surface corrosion protection processes to ensure structural integrity and rotational reliability under high salt spray exposure, severe impact, and long-term cyclic loading. Its internal ball-bearing or roller-bearing design significantly reduces rotational resistance, ensuring smooth untwisting of the anchor chain during deployment and retrieval, and effectively preventing the risk of breakage caused by tangling.
OLIPORTS Complete Range of Marine Swivel Products
Swivel Shackle Type A (Single Axis Design)
OLIPORTS Type A swivel shackles feature a robust single-axis rotating design, offering reliable performance at an excellent value. Designed specifically for light to medium-duty applications, they effectively prevent anchor chain tangling during routine anchoring and mooring operations.
Key Advantages: Simple design, easy installation and maintenance, low total cost of ownership
Standard Specifications: Compatible with anchor chain diameters of 12.5mm–82mm; Grade 2 / Grade 3 / ORQ steel; hot-dip galvanized finish
Applications: Inland cargo ships, coastal fishing vessels, small to medium-sized yachts, auxiliary mooring systems
Type B Swivel Shackle (Universal Dual-Axis Design)
OLIPORTS’ premium Type B swivel shackles feature an industry-leading universal dual-axis design that enables 360° free rotation in all directions, completely eliminating torsional stress in challenging sea conditions. Engineered for extreme heavy-duty applications, they offer unmatched strength and impact resistance.
Key Advantages: 360° omnidirectional rotation, exceptional torsional resistance, high breaking load, long service life
Standard Specifications: Compatible with anchor chain diameters of 12.5mm–132mm, Grade 3 / ORQ steel, reinforced safety pin design
Applications: Ocean-going cargo ships, large oil tankers, bulk carriers, offshore platforms, heavy-duty towing operations
Swivel Forerunners
OLIPORTS’ specialized swivel forerunners (commonly known as a chaser swivel) is custom-engineered for the harsh conditions of commercial fishing operations. Featuring a surface-hardened finish, it offers exceptional wear resistance against silt erosion and frequent dragging.
Key Benefits: Superior wear resistance, excellent corrosion resistance, smooth rotation under heavy loads, compatible with all chaser systems
Standard Specifications: Compatible with anchor chain diameters of 16mm–102mm; Grade 3 / ORQ steel; extra-thick galvanized coating
Applications: Trawlers, purse seiners, longliners, and fishing net connection systems
[View Front Swivel Details]
Anchor Chain System Installation & Swivel Shackle Position
A properly installed anchor chain system is critical to a vessel’s safety. The swivel shackle is the central component connecting the anchor to the first section of the anchor chain; it is specifically designed to eliminate torsional stress during anchoring and weighing operations and to prevent the anchor chain from becoming entangled. Below is a standard installation diagram for a marine anchor chain system.
Anchor: The primary holding device that secures a vessel by embedding itself into the seabed. OLIPORTS supplies a full range of Danfoss anchors, Delta anchors, and high-holding-power anchors.
Swivel Shackle: The core rotating component connecting the anchor to the first section of the anchor chain. It allows for 360° rotation, eliminating torsional stress and preventing the anchor chain from tangling. This is the product series featured on this page.
First Anchor Chain Section : The initial section of the anchor chain directly connected to the swivel. OLIPORTS offers both notched and non-notched designs.
Kent Shackles: Detachable connectors used to link different sections of anchor chain. OLIPORTS manufactures high-strength Kent shackles compatible with all standard chain diameters.
Subsequent Anchor Chain: The sections that make up the main length of the anchor chain, providing the sufficient chain length required for safe anchoring.
End Links: The terminal links at both ends of each anchor chain section, used to connect to shackles or other accessories.
Key Points for Installing Swivel Shackles
- Always use a swivel shackle with a diameter rating that exactly matches that of your anchor chain.
- Ensure the swivel shackle rotates freely before installation.
- Inspect the swivel shackle every 6 months for wear, cracks, or corrosion.
- Replace the swivel shackle immediately if wear exceeds 10% of the original diameter.
- Never use a damaged or worn swivel shackle for anchoring operations.
One-Stop Guide to Purchasing Complementary Products
OLIPORTS offers a complete, one-stop solution for all your anchor chain system needs. In addition to marine anchor swivels, we also supply:
- Marine Anchor Chains: stud-link, studless, short-link, and long-link types)
- End Shackles for anchor chain ends
- Kent Shackles for connecting anchor chain sections [Kent Shackles]
- Marine Anchors: Danforth, Delta, and High-Grip types
All our products are manufactured to the same high standards and are fully compatible with one another.
How to Choose the Right Marine Anchor Swivel
| Key Question | Considerations | Recommendation |
|---|---|---|
| Connection Points | Components to Connect: • Anchor bolt • Chain end link • End shackle • Other transition links | For direct anchor bolt → Choose A-Type For versatile connections → Choose B-Type For mid-chain transition → Choose Forerunner |
| Chain Specs | Key Parameter Matching: ① Diameter: 12.5-132mm, must match exactly ② Grade: Grade 2/3/ORQ, swivel grade ≥ chain grade ③ Load: Calculate WLL based on vessel tonnage, apply 1.5-2.0 safety factor | Ø12.5-26mm → SF-12/ASA-16/BSA-16 Ø28-42mm → SF-28/ASA-28/BSA-28 Ø48-132mm → SF-48+/ASA-48+/BSA-48+ |
| Operating Conditions | Seawater corrosion:Prioritize hot-dip galvanizing, Dacromet, or stainless steel; • Low-temperature environments: Verify impact toughness at -20°C to prevent brittle fracture; • High-frequency dynamic loads: Select designs with precision bearings or self-lubricating structures; • Ease of maintenance: For ocean-going vessels, maintenance-free or easily inspectable designs are recommended; Corrosion protection upgrade: Hot-dip galvanizing can extend service life by 30% or more. | Standard corrosion protection solution Stainless steel: Highly corrosive marine environments Structures with bearings: High-frequency operation scenarios |
| Certification Needs | Class Society Options: ABS DNV BV CCS; LR RINA KR NK | No certification needed: We still manufacture per IACS standards and provide Mill Test Certificates (MTC) |
| Final Decision | Direct anchor connection + fast install → A-Type Uncertain connections / flexibility → B-Type Mid-chain transition / modular system → Forerunner High corrosion / long life → All types + galvanized/stainless Mandatory class certification → All types + specified certs | Not sure which model to choose? Contact an engineer for free technical support Drawing reviews responded to within 24 hours Load calculations and product selection recommendations provided |
FAQ
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OLIPORTS offer: Technical Datasheet PDF、Material Certificates、DWG or STEP files for design integration、On-request layout support. Our lashing experts typically reply within 24 hours. 💡 Based on your port design, berthing energy, and vessel data, we’ll provide:
⚙️ Recommended drawings & specifications
💬 A tailored quotation with best lead time
📎 Support for class approval documents
We’re here to assist you with any inquiries. One of our product specialists will get back to you within 24 hours with the information you need.
