Marine Insight: Anchor Shackles

Critical Role of Anchor Shackles in Vessel Safety and Operational Integrity

Anchor shackles are critical load-bearing components in marine anchoring systems, serving as the primary connection between the anchor and the chain. Their failure can result in catastrophic consequences, including loss of vessel control, grounding, or collision. As such, compliance with international standards and rigorous quality control are non-negotiable for maritime safety.

Safety and Regulatory Compliance Imperatives

Class societies (ABS, DNV, LR, BV) mandate strict testing protocols for anchor shackles. For example:
UR W18 requires anchor shackles for SHHP anchors to meet Grade 3 anchor chain toughness standards.
RR-C-271F specifies material and performance requirements for screw-pin shackles, with Grade A Class 2 being the industry benchmark for high-stress applications.
Failure to meet these standards can lead to vessel detention during inspections, costly delays, and reputational damage.

Operational Impact of Substandard Components

In harsh marine environments, substandard shackles may suffer from premature wear, corrosion, or fatigue failure. This compromises the entire anchoring system’s integrity, especially during storm conditions or emergency maneuvers. Properly engineered shackles with a safety factor of 5 (WLL = 20% of breaking strength) ensure reliable performance under dynamic loads, minimizing operational risks and downtime.

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Market Trends Driving Demand for High-Performance Anchor Shackles

New Shipbuilding Boom

Global shipbuilding activity, particularly in Asia, continues to rise with a focus on larger, more complex vessels. Newbuilds require anchor shackles with higher load capacities (U3 grade) and compliance with the latest class society standards. For instance:
Container ships and LNG carriers often require shackles rated for 100+ tons WLL, necessitating precision engineering and certified manufacturing processes.
The International Maritime Organization (IMO)’s focus on vessel safety has accelerated demand for certified, high-strength components in new constructions.

Replacement Market Growth

Over 40% of the global merchant fleet is over 15 years old, driving consistent demand for replacement parts. Regulatory updates (e.g., IMO’s enhanced safety requirements) often mandate upgrades to existing anchoring systems. Ship repair yards require suppliers who can provide:
Certified, ready-to-install components with minimal lead times.
Compatibility with legacy systems while meeting modern standards.

Sustainability and Regulatory Shifts

Increasing environmental regulations (e.g., IMO 2020 sulfur cap) have accelerated fleet modernization. Newer vessels incorporate advanced materials and coatings for longevity, while existing ships undergo retrofits to meet updated standards. This trend underscores the need for suppliers with adaptable, compliant product lines that balance durability, corrosion resistance, and regulatory adherence.

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Why Hangzhou Star Marine Technology is the Preferred Sourcing Partner

Technical Excellence and Standards Compliance

Hangzhou Star Marine Technology delivers anchor shackles engineered to exceed international standards. Our U2/U3 grades comply with RR-C-271F Type IVB Grade A Class 2, UR W18, and Class Society requirements (ABS, DNV, LR, BV). Each unit undergoes rigorous testing, including:
Tensile tests per Class Society protocols
Proof testing at 2.0x WLL for shackles ≥85 metric tons
Corrosion resistance validated through salt spray testing

Product Specifications

Product Grade	Working Load Limit (WLL)	Breaking Strength	Surface Treatment	Compliance Standards
U2	5–50 tons	25–250 tons	Hot-Dip Galvanized (Standard), Black Paint (Optional)	RR-C-271F Type IVB Grade A Class 2, UR W18, ABS, DNV, LR
U3	50–200 tons	250–1000 tons	Hot-Dip Galvanized (Standard), Black Paint (Optional)	ABS, DNV, LR, BV, Class Society Tensile Test Certificates

Cost-Effective Manufacturing Without Compromising Quality

Leveraging China’s advanced manufacturing ecosystem, we maintain competitive pricing while adhering to strict quality controls. Our integrated supply chain reduces lead times by 30% compared to Western suppliers, with no sacrifice in material integrity or certification rigor. All products are ISO 9001-certified and undergo 100% inspection before shipment.

End-to-End Solution Provider for New Builds & Repairs

For New Shipbuilding Projects: Custom engineering support, design validation, and compliance documentation tailored to class society requirements (e.g., ABS, DNV).
For Ship Repair Yards: Rapid-response inventory of certified components, ensuring minimal downtime during critical repairs.
Global Logistics Network: Timely delivery to major shipbuilding hubs in China, South Korea, Europe, and North America, with traceable quality records for regulatory audits.

Why Choose Star Marine?
As a trusted partner for Tier-1 shipyards and global fleet operators, we combine Chinese manufacturing efficiency with Western-grade quality control. Our commitment to technical excellence, regulatory compliance, and responsive service ensures your anchoring systems meet the highest safety and operational standards—every time.

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Technical Specs & Class Approval

Technical Specifications & Class Approval

Critical Specifications Overview

As a leading marine equipment manufacturer, Hangzhou Star Marine Technology delivers anchor shackles engineered to meet the most stringent maritime safety and performance standards. Our products are rigorously tested and certified to ensure reliability in critical anchoring applications. Below are the core technical specifications, with clear differentiation between standard offerings and customizable solutions for specialized requirements.

Key Technical Parameters

Grade: Defined by material strength and compliance with international standards (e.g., RR-C-271F, UR W18).
Weight: Optimized for structural integrity while minimizing unnecessary mass.
Working Load Limit (WLL): Calculated with a minimum safety factor of 5× (WLL = Breaking Strength / 5). For shackles exceeding 85 metric tons, proof testing is performed at 2.0× WLL per ABS Marine guidelines.
Surface Finish: Corrosion-resistant treatments tailored to operational environments.
Class Approval: Mandatory for vessel compliance and classification society surveys.

Standard vs. Custom Specifications

Specification	Standard Option	Custom Option
Grade	U2: RR-C-271F Class 2 compliant U3: UR W18 Grade 3 chain compatibility	Higher grades (e.g., U4 for extreme conditions) Tailored to specific class society standards (ABS, LR, etc.)
Weight	Standard sizes: 500kg to 50t (per ISO 1704 or equivalent)	Specialized weights up to 100t+ with structural analysis
Working Load Limit (WLL)	Safety factor of 5× (WLL = BS/5) Proof test for sizes >85t: 2.0× WLL	Enhanced WLL with additional testing protocols Custom safety factors (e.g., 6× for high-risk applications)
Surface Finish	Hot-dip galvanized (ASTM A123) Standard corrosion protection	Black epoxy paint, zinc-rich primer, or custom coatings Specialized marine coatings for harsh environments
Class Approval	CCS, DNV, BV, ABS certified Compliance with ISO 1704, UR W18	Additional certifications (KR, RINA, NK, etc.) Project-specific approvals

Class Society Certifications

All anchor shackles are manufactured under strict adherence to global classification society requirements. Our certifications include:
CCS (China Classification Society): Mandatory for Chinese-flagged vessels and shipyards.
DNV (Det Norske Veritas): Global benchmark for offshore and commercial shipping.
BV (Bureau Veritas): Widely recognized for European and international projects.
ABS (American Bureau of Shipping): Essential for U.S.-flagged vessels and Gulf of Mexico operations.

Each certificate includes a Tensile Test Report verifying breaking strength, elongation, and impact resistance per UR W18 and ISO 1704. For new-build projects, we provide full traceability of material batches and test results to simplify class society surveys.

Solution Provider for New Shipbuilding & Ship-Repair

As a trusted partner for shipyards and owners worldwide, we deliver:
New Shipbuilding: Precision-engineered shackles compliant with vessel-specific design requirements, including custom WLL, surface treatments, and class approvals. All products undergo 100% dimensional and load testing prior to shipment.
Ship-Repair: Rapid-response solutions for replacement parts, with standardized sizes matching existing fleets and custom options for legacy systems. Our technical team provides on-site support to ensure seamless integration during dry-docking.

Pro Tip: For critical applications (e.g., deep-sea anchoring or high-stress environments), specify U3-grade shackles with ABS Type Approval to ensure compliance with UR W18 and exceed Grade 3 chain requirements. Our engineering team can optimize WLL and surface treatments for your operational profile.

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Hangzhou Star Marine Technology Co., Ltd. – Delivering certified, high-performance anchoring solutions for the world’s most demanding maritime operations. Contact us for project-specific technical documentation and compliance support.

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Shipbuilding & Repair Solutions

Anchor Shackles: Technical Excellence and Comprehensive Solutions for Marine Operations

Hangzhou Star Marine Technology Co., Ltd. specializes in high-performance marine anchoring equipment, with anchor shackles engineered to meet the most stringent international standards. As a trusted supplier to shipyards, shipowners, and repair facilities worldwide, we deliver not just products but comprehensive solutions that ensure safety, reliability, and operational efficiency across all marine operations.

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Technical Specifications

Product Grades and Performance Metrics

Our anchor shackles are manufactured in Grade U2 and U3 configurations, tailored to meet specific operational requirements. Each product undergoes rigorous testing to ensure compliance with international standards.

Product Code	Grade	WLL (t)	Breaking Strength (t)	Weight (kg)	Surface Treatment	Standards Compliance
AS-U2-5	U2	5	25	8.5	Galvanized	RR-C-271F Class 2, UR W18
AS-U2-10	U2	10	50	15.2	Galvanized	RR-C-271F Class 2, UR W18
AS-U3-15	U3	15	75	28.6	Galvanized	ABS Type Approval, DNV GL
AS-U3-25	U3	25	125	52.3	Black Paint	LR Certificate, UR W18
AS-U3-50	U3	50	250	110.5	Galvanized	Class 1 Tensile Test, ISO 17025
AS-U3-85+	U3	85+	425+	220+	Galvanized	ABS Proof Test (2.0x WLL), DNV GL

Note: WLL = 20% of Breaking Strength (Safety Factor 5). Shackles ≥85 metric tons WLL undergo individual proof testing at 2.0x WLL per ABS Marine standards.

Compliance with International Standards

UR W18: All shackles for SHHP anchors meet toughness requirements for Grade 3 anchor chains.
RR-C-271F: Compliant with Type IVB Grade A Class 2 specifications for screw-pin shackles.
Class Society Certifications: Tensile test certificates issued by ABS, DNV, LR, BV, and other recognized societies.
ISO 17025: Laboratory testing procedures adhere to international quality standards.

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Shipbuilding & Repair Solutions

Integrated System Matching

At Star Marine, we understand that anchor shackles are only one component of a complete anchoring system. Our engineering team provides precise compatibility analysis to ensure seamless integration with:
Anchor Types: Matching shackle grade (U2/U3) to anchor specifications (e.g., Bruce, Danforth, Stockless).
Windlass Capacity: Ensuring shackle WLL aligns with windlass design loads to prevent overload failures.
Chain Grades: U3 shackles paired with Grade 3 chains per UR W18 requirements for optimal load distribution.
Vessel Class Requirements: Custom solutions for specialized vessels (offshore support, dredgers, tankers).

Example: For a newbuild VLCC requiring a 150t anchor system, our team cross-references windlass specifications, chain grade, and anchor type to recommend the optimal shackle configuration, preventing system failure during critical operations.

Technical Support & Customization

Pre-Sales Engineering Consultation: Our marine engineers analyze vessel specifications to recommend the correct shackle grade, surface treatment (galvanized for saltwater exposure, black paint for specific coatings), and size.
Custom Surface Treatments: Galvanized for maximum corrosion resistance or black paint for compatibility with existing vessel paint systems.
Documentation: Full technical documentation including tensile test certificates, material traceability, and installation guidelines.

Emergency Response for Ship Repairs

24/7 Technical Support: Immediate assistance for urgent repair scenarios, including on-site technical guidance.
Global Inventory Network: Same-day dispatch from regional hubs for standard sizes; expedited production for custom orders.
Rapid Logistics: Air freight options for critical shipments, with real-time tracking and customs clearance support.

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Why Choose Star Marine?

Proven Reliability: Over 15 years supplying marine equipment to leading shipyards and operators.
End-to-End Solutions: From design consultation to post-installation support.
Global Compliance: Certifications recognized by all major Class Societies.
Responsive Support: Dedicated account managers for seamless communication.

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Contact Information
Hangzhou Star Marine Technology Co., Ltd.
Address: No. 188, Hangzhou Economic Development Zone, Zhejiang, China
Phone: +86 571 8888 9999
Email: [email protected]
Website: www.star-marine.com

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Packaging & Logistics

Packaging & Global Logistics

Packaging Standards for Marine Hardware Components

All anchor shackle shipments adhere to strict international standards to ensure structural integrity during transit. Packaging is tailored to product specifications, with ISPM 15-compliant wooden crates for standard sizes and steel pallets for heavy-duty applications.

Parameter	Standard Packaging	Heavy-Duty Packaging
Material	ISPM 15 certified hardwood crate	Steel pallet with anti-slip surface
Protection	VCI paper, desiccants, foam padding	Anti-corrosion wrap, steel strapping, corner protectors
Compliance	ISPM 15, IMO/ILO guidelines	ISO 3874, DNVGL-ST-N001
Typical Use Case	Shackles ≤ 30 tons WLL	Shackles > 30 tons WLL

Technical Note: All wooden packaging undergoes heat treatment (HT) or methyl bromide fumigation (MB) per ISPM 15 regulations to prevent pest transmission. Steel pallets feature galvanized coatings to resist marine corrosion during ocean transit.

Logistics Solutions

Hangzhou Star Marine Technology maintains a fully integrated logistics ecosystem, including:
Real-Time Tracking: GPS-enabled shipment monitoring with end-to-end visibility via our proprietary portal.
Customs Expertise: Dedicated teams for documentation (Commercial Invoice, Packing List, Certificate of Origin) and compliance with import regulations (e.g., USCG, EU MARPOL).
Risk Mitigation: Full cargo insurance coverage and contingency protocols for weather disruptions or port delays.
Project-Specific Support: Dedicated logistics coordinators for new shipbuilding projects, ensuring just-in-time delivery to dry docks and shipyards.

Export Capabilities from Ningbo & Shanghai Ports

As a strategic partner for global shipowners and shipyards, we leverage China’s most advanced maritime gateways:

Port	Key Advantages	Typical Transit Time to Major Regions
Ningbo	• Direct vessel services to Southeast Asia, Middle East, and Europe • 24/7 customs clearance for marine equipment • Proximity to Hangzhou (30km) for rapid pre-shipment inspections	7–14 days to Europe 5–10 days to Middle East
Shanghai	• World’s largest container port (47.3 million TEU in 2023) • Integrated rail/road networks for inland distribution • Specialized handling for oversized cargo (e.g., Class 3 anchor shackles)	10–16 days to Americas 8–12 days to Africa

Operational Excellence: All exports from Ningbo/Shanghai include pre-shipment quality verification per ABS/Class Society standards, with batch-specific tensile test certificates and surface treatment reports (galvanized/black paint).

Why Shipowners Trust Our Logistics

As a certified solution provider for new shipbuilding and ship-repair projects, we guarantee:
Zero damage rates for anchor shackle shipments through ISO 9001-certified packaging protocols.
Seamless integration with shipyard schedules via dedicated project managers.
Compliance with UR W18, RR-C-271F, and Class Society requirements for all anchor chain accessories.

“From Hangzhou to the world’s busiest dry docks—our logistics chain ensures your anchor system arrives ready for immediate installation.”

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Contact Star Marine Technology

Anchor Shackles: Technical Specifications & Export Guide

Introduction

Anchor shackles are critical components in marine anchoring systems, ensuring secure connections between anchor chains and other equipment. Hangzhou Star Marine Technology provides high-strength, certified anchor shackles designed to meet stringent international standards, ensuring safety and reliability for new shipbuilding and ship-repair projects worldwide. Our products undergo rigorous quality control and comply with global maritime regulations, delivering optimal performance in harsh marine environments.

Technical Specifications

Our anchor shackles are engineered for precision and durability. Below are key specifications for standard models:

Model	WLL (MT)	Breaking Strength (MT)	Weight (kg)	Pin Diameter (mm)	Surface Treatment	Standards Compliance
HSM-U2	10	50	15.2	25	Galvanized, Black Paint	UR W18, RR-C-271F Type IVB Grade A Class 2
HSM-U3	20	100	32.5	35	Galvanized	ABS, DNV GL, LR
HSM-U4	50	250	95.0	55	Galvanized	ABS, ClassNK
HSM-U5	85	425	210.0	75	Galvanized	ABS, DNV GL (Proof Tested 2.0× WLL)

Note:
– Working Load Limit (WLL) is calculated at a 5:1 safety factor (WLL = Breaking Strength ÷ 5).
– Shackles ≥85 MT WLL undergo individual proof testing at 2.0× WLL per Class Society requirements.
– All dimensions and weights conform to ISO 1704 and DNV GL standards.

Compliance & Standards

Every anchor shackle from Hangzhou Star Marine meets the following critical standards:
UR W18: Ensures compatibility with Grade 3 anchor chains (per Classification Society requirements).
RR-C-271F Type IVB Grade A Class 2: Federal specification for high-strength shackles (US Navy standards).
Class Society Certifications: ABS, DNV GL, LR, and ClassNK approvals with tensile test certificates for traceability.
Material Certification: High-tensile steel (Grade 3) with chemical composition verified per ASTM A479.

Surface Treatment Options

We offer two industry-standard surface treatments to suit operational needs:
Galvanized (ASTM A153):
Zinc coating thickness ≥85 μm for superior corrosion resistance.
Ideal for open-deck and saltwater exposure.
Black Paint (Epoxy-Based):
Non-reflective finish for internal ship compartments or custom coating systems.
Meets ISO 12944-5 for marine environments.

All treatments undergo salt spray testing (≥500 hours) per ASTM B117.

Why Choose Hangzhou Star Marine?

As a certified solution provider for new shipbuilding and ship-repair, we deliver:
End-to-End Technical Support: Custom sizing, load calculations, and installation guidance for complex projects.
Global Compliance: Certificates issued by leading Class Societies (ABS, DNV GL, LR) for regulatory compliance.
Supply Chain Reliability: ISO 9001-certified manufacturing with 99.2% on-time delivery.
Quality Assurance: Every unit is traceable via batch numbers and tensile test reports.

Contact Us

For expert consultation, technical documentation, or procurement support, contact our dedicated Product Manager:

Kacher YE
Product Manager, Marine Equipment Export
Hangzhou Star Marine Technology Co., Ltd.
Tel/WhatsApp: +86-178-16869405
Email: [email protected]

Shipowners, Shipyards & Procurement Officers:
Request a customized quote or technical datasheet today. We provide tailored solutions for new builds, dry-dock repairs, and emergency replacements—backed by 24/7 technical support.

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