Accessories – Dog Bone Shackle (U-Bolt Turnbuckle)

Dog Bone Shackle - High-Strength Marine & Industrial Connector — Dog Bone Shackle – High-Strength Marine & Industrial Connector

Type	A [mm]	B [mm]	X [mm]	T [mm]	Øc [mm]	Øa [mm]	b [mm]	Weight* [kg]
⌀20	390	260	130	30	120	20	50	5.8
⌀24	390	270	120	30	130	24	56	8.4
⌀30	445	325	120	40	170	30	80	16.4
⌀36	550	390	160	45	210	36	94	28.8
⌀42	670	470	200	55	250	42	108	48.2
⌀48	860	595	265	60	280	48	122	71.9
⌀56	890	620	270	70	330	56	144	110.7
⌀64	820	700	120	80	350	64	160	149.8

Structure of Dog Bone Shackle (U-Bolt Turnbuckle)

1. Turnbuckle Body:
• Cylindrical body with threaded ends to connect U-bolts.
• Manufactured from stainless steel, galvanized steel, or aluminum alloy for anti-corrosion.

2. Dog Bone Shackle (U-Bolt):
• U-shaped shackle used for connecting anchor chains or steel cables.
• Secured with nuts or plates to ensure a tight fit.

3. Adjusting Pin & Lock Nuts:
• Allow chain or cable tension adjustment by rotating threads in opposite directions.
• Equipped with locking nuts to prevent self-loosening during marine operations.

Working Principle of Dog Bone Shackle

• By rotating the turnbuckle body, the dog bone shackle moves closer or apart to adjust chain tension.
• Tightening removes slack, enhancing system safety and stability.
• Loosening allows flexible chain adjustment or removal.

Main Applications of Dog Bone Shackles

1. Marine & Offshore:
• Widely used in anchor chain systems for ships and offshore structures.
• Applied in fender systems to keep marine fenders in the correct position.

2. Industrial & Construction:
• Used to tension steel cables in load-bearing structures.
• Adjusts cable alignment in scaffolding and conveyor systems.

3. Civil Engineering:
• Common in cable fencing, roofing, and lightweight steel structures.

Installation Guide for Dog Bone Shackles

1. Preparation:
• Inspect shackles, bolts, and chains for rust or deformation.
• Select correct dog bone shackle size for the required load.

2. Chain/Cable Connection:
• Insert anchor chain into the shackle and secure with nuts.
• Ensure correct alignment and avoid over-tightening.

3. Tension Adjustment:
• Rotate turnbuckle body until proper tension is achieved.
• Fix position with locking nuts.

4. Final Check:
• Inspect all connections for safety.
• Conduct load test before operation.

Safety Notes for Dog Bone Shackles in Anchor Chains

Avoid overloading: Select shackles according to system load capacity.
Regular inspection: Check for wear and cracks during operation.
Do not overtighten: Prevent damage to threads or bolts.
Wear protective equipment: Use gloves and PPE during installation.

Correct installation of dog bone shackles in anchor chains ensures safe mooring operations and fender performance in ports.

Quality of Dog Bone Shackle Accessories

Dog bone shackles and mooring accessories comply with international standards such as PIANC, BV, and are tested by third-party organizations like TT3 (Vietnam), SGS.
With a lifespan of 50–100 years (depending on usage conditions), these shackles guarantee strength, safety, and durability.

Warranty ranges from 3–5 years, based on port design requirements.

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