A rubber fender (also called a marine fender) is a critical safety device made of specialized rubber, used in ports, docks, and ships to absorb impact energy during vessel berthing (docking) or ship-to-ship operations. Its primary purpose is to protect both the vessel and the dock structure from damage caused by collision forces.
Core Purpose & How It Works
When a ship docks, its kinetic energy (from momentum, wind, or currents) is converted into heat through rubber compression. This reduces impact force by 50–80%, preventing structural damage.
Formula: Kinetic Energy = 1/2(mass × velocity²).
Example: A 50,000-ton ship docking at 0.3 m/s generates ~2,250 kJ of energy – absorbed by the fender.
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Prevents dents in ship hulls, cracks in concrete docks, and deformation of steel piers.
Key Features & Materials
| ASPECT | DETAILS |
| Material | High-grade synthetic rubber (e.g.,EPDM for UV/salt resistance, CR for oil resistance) + embedded steel plates/fabric layers for strength. |
| Critical Traits | - Seawater/UV/ozone resistant - Operates in -40°C to +70°C - Low rebound force (avoids "bounce-back" damage) - Long lifespan (5–15 years) |
| Not Automotive! | Different from car bumpers– marine fenders handletons of force(e.g., 1,000+ kN) in harsh saltwater environments. |
Common Types & Uses
TYPE | BEST FOR | VISUAL CLUE |
D-Shaped ![]()
| Small/medium docks, cost-effective | Flat back, curved front (like "D") |
Cylindrical ![]() | Large ships (tankers/cruise ships), 360° impact | Tube-shaped, often hung vertically |
Pneumatic ![]() | Floating docks, tidal zones | Air-filled, adjusts to water level |
Why It Matters
Prevents Costly Damage: A single unprotected docking can cause $100,000+ in repairs (e.g., hull deformation, dock collapse).
Safety Compliance: Required by international standards (ISO 17357, PIANC guidelines) for all major ports.
Efficiency: Enables faster, safer berthing – critical for busy ports handling 100+ ships daily.
Key Industries Using Rubber Fenders
Ports & Harbors (container terminals, oil jetties)
Shipyards (during vessel construction/maintenance)
Offshore Platforms (FPSOs, LNG terminals)
Naval Fleets (warship docking)
In Simple Terms
Think of a rubber fender as a "shock absorber for ships" – it’s the thick, black, often cylindrical/ring-shaped rubber block you see lining docks or hanging from ships. When vessels touch it, the rubber squishes to safely soak up the crash, like a pillow for giants.
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