Accessories – Marine Fender Tensioning System

Marine Fender Accessories – Turnbuckles & Mooring Bollards | Nguyen Tai Rubber

Fitting Table – Chain Installation -1

Nominal dia [mm]	Lc [mm]	Lu [mm]	Ls [mm]	L [mm]	Breaking Test Load [kN]
25	100	100	88	N@100+249	322.6
30	120	120	102	N@120+276	465.0
34	136	136	116	N@136+318	596.4
38	152	152	129	N@152+341	745.6
42	168	168	142	N@168+369	910.4
46	184	184	156	N@184+391	1092.8
50	200	200	170	N@200+413	1291.0
52	208	208	187	N@208+438	1396.9
54	216	216	187	N@216+438	1504.9

Structure of the Tensioning System includes U-Bolt Turnbuckles connected to the chain

1. Turnbuckle Body:
• Usually cylindrical with threaded ends to connect bolts or U-bolts.
• Made from stainless steel, galvanized steel, or aluminum alloy for corrosion resistance.

2. U-Bolt:
• U-shaped bolt with threaded ends to connect chains or cables.
• Secured with nuts or plates to fix cables or chains.

3. Adjustment Pins and Nuts:
• Used to adjust chain/cable tension by rotating threads in opposite directions.
• Lock nuts may be added to prevent loosening during operation.

Working Principle of U-Bolt Turnbuckle
• Rotating the turnbuckle body makes the bolts at both ends extend or retract, adjusting chain or cable tension.
• Tightening reduces sag and improves chain stability.
• Loosening allows flexible chain adjustment or removal.

Applications of U-Bolt Turnbuckle in Chain Connection

1. Marine & Ports:
• Used in mooring systems to secure and adjust chain tension, preventing vessel drifting.
• Installed in fender systems to keep fenders stable during vessel berthing.

2. Industrial & Construction:
• For tensioning cables in structural systems or suspensions.
• Adjusting conveyor belts or scaffolding systems.

3. Civil Applications:
• Applied in cable fences, roofing, or structures requiring steel cable tensioning.

Installation Guide – U-Bolt Turnbuckle for Chain Connection

1. Preparation:
• Inspect bolts, turnbuckles, and chains for corrosion or damage.
• Select correct U-bolt and turnbuckle size per load requirements.

2. Chain/Cable Installation:
• Place chain link into U-bolt, then tighten nuts or plate for secure fixing.
• Ensure U-bolt is aligned properly and not overtightened to avoid deformation.

3. Tension Adjustment:
• Rotate turnbuckle to achieve required chain/cable tension.
• Secure with lock nuts after adjustment.

4. Inspection & Testing:
• Check all joints to ensure secure connections.
• Test under load to confirm stability.

Safety Notes when Installing Shackles to Mooring Chains

No Overloading: Ensure shackles and mooring chains are selected according to load requirements.
Regular Inspection: Inspect shackles and chains periodically to detect damages.
Avoid Over-Tightening: Do not overtighten shackles to prevent thread damage or pin jamming.
Use Safety Gear: Wear gloves and protective equipment to prevent injuries during handling.

Proper shackle installation ensures not only effective fender performance but also safety during vessel berthing and port operations.

Quality of Mooring Bollard Accessories

The quality of mooring bollard accessories complies with international standards such as PIANC, BV, or certified by third-party inspectors like TT3 (Quartest 3) Vietnam, SGS… With a service life of 50–100 years (depending on port operation conditions), the products guarantee consistent energy absorption and reaction force throughout their use.

Additionally, products come with a warranty of 3–5 years depending on port design requirements.

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