Choosing the Right Foam-Filled Fender
During ship-to-ship (STS) transfers, berthing, and docking operations, impacts and friction inevitably occur between a vessel’s hull and dock structures. To minimize potential damage and ensure operational safety, marine fender systems play a vital role as energy-absorbing buffers.
Among various fender types, the foam-filled fender stands out for its excellent energy absorption, high buoyancy, and minimal maintenance requirements. It has become a reliable and cost-effective solution for both port and vessel applications worldwide.
Structure of Foam-Filled Fender
A foam-filled fender is mainly composed of three key components:
- Closed-Cell Foam Core – Energy Absorption and Buoyancy
The inner core is made of resilient, closed-cell foam that provides high energy absorption and superior water resistance. Even if the outer skin is punctured, the fender maintains its buoyancy and structural integrity.
- Reinforced Nylon Cord Layer – Strength and Durability
This layer adds strength and impact resistance, ensuring the fender can withstand repeated berthing operations and harsh marine environments.
- Outer Skin Options – Polyurea vs. Rubber
The outer skin protects the fender from abrasion, UV, and weathering. Common materials include:
- Polyurea
Advantages: Excellent abrasion resistance, smooth surface, and lightweight design — easy to install and clean.
Disadvantages: Slight reduction in flexibility under extremely low temperatures.
- Rubber
Advantages: Superior elasticity and shock absorption, remaining flexible even in cold climates.
Disadvantages: Heavier than polyurea and requires more effort for surface cleaning and maintenance.
Comparison of Foam-Filled Fender Types
Netless Foam-Filled Fender
Structure
Cylindrical foam-filled body with an internal steel bar or chain, without an external chain-net
Feature
Low friction, easy maintenance, clean and aesthetic appearance
Typical Applications
Yachts, passenger terminals, commercial berths
Chain-Net Type
Structure
Cylindrical foam-filled body with an internal steel bar or chain, protected by an external chain-net
Feature
High impact resistance, excellent wear protection, suitable for harsh conditions
Typical Applications
Oil terminals, container berths, STS platforms
Donut Fender
Structure
Ring-shaped foam-filled body that rotates freely around a fixed pile
Feature
High energy absorption, floating and self-centering, simple installation and replacement
Typical Applications
Breasting dolphins, bridge or pier protection, lock entrances, ferry terminals
As shown above, netless fenders are ideal for lighter-duty applications where appearance and cleanliness are priorities. Chain-net fenders provide maximum protection in heavy-duty or exposed berthing conditions, while donut fenders are best suited for structures requiring continuous protection and self-adjusting performance.
Selecting the Right Foam-Filled Fender
When choosing a foam-filled fender, port and vessel operators should consider factors such as:
Berthing energy and vessel size
Environmental conditions (wave, tide, temperature)
Installation method and available space
Maintenance and lifespan expectations
By understanding the structure, material, and type characteristics, operators can select the most suitable foam-filled fender to protect both ships and dock facilities. The right choice not only enhances safety but also ensures long-term operational efficiency and cost-effectiveness.