How To Do The Pneumatic Fender Performance Testing?

Introduction

Pneumatic fenders are used to protect ships, terminals, and offshore structures during berthing or ship-to-ship transfer. If the fender does not perform as expected, the result can be hull damage, berth damage, or serious safety risk.

That’s why performance testing is not optional. Most international projects require testing based on ISO 17357 and sometimes ASTM F2192. These standards define how to measure three key things:

• Energy absorption
• Reaction force
• Deflection behavior

ASTM F2192 focuses on how performance data is tested and reported, especially energy and reaction values under controlled conditions.

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What Standards Are Used for Pneumatic Fender Testing?

ISO 17357 — Main Design and Performance Standard

ISO 17357 defines how pneumatic fenders must be designed, manufactured, and tested.

For example:

• Guaranteed energy absorption is verified around 60% deflection (±5%)
• Reaction force tolerance at that point is typically ±10%
• Prototype testing is required for new designs
• Compression performance must be verified by testing, not just calculation

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ASTM F2192 — Performance Test Method Reference

ASTM F2192 explains how fender energy and reaction should be measured in a controlled test environment.

Typical reference conditions include:

• Initial test velocity around 0.15 m/s
• Velocity reduces during compression
• Standardized test reporting for engineering comparison

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The Most Important Test: Parallel Compression Performance Test

This is the core performance test for pneumatic fenders.

How It Works

The fender is placed between two rigid plates.
Then a compressive force is applied perpendicular to the fender body.

The test continues until:

• The required energy absorption is reached
• Reaction force and internal pressure are recorded

ISO requires:

• Compression speed not exceeding about 80 mm/min
• Reaction force and pressure recorded at small deflection intervals

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Why Energy Absorption and Reaction Force Matter

Energy Absorption

This tells you how much ship impact energy the fender can safely absorb.

Energy is calculated from the load vs deflection curve generated during compression testing.

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Reaction Force

This is the force transferred to the ship hull or structure.

If reaction force is too high:

• Hull damage risk increases
• Mooring stability becomes harder

ISO allows only limited tolerance around certified values.

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Prototype Testing vs Production Testing

Prototype Testing

Required when:

• New structure
• New design
• New material system

Purpose:
Confirm full performance meets ISO requirements before mass production.

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Routine Production Testing

Usually includes:

• Dimension inspection
• Air leakage test
• Pressure test
• Material property checks

These tests make sure production units match certified design.

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Real Testing Conditions Used in Industry

Real testing is done under controlled conditions so results can be compared globally.

Typical ASTM reference testing may include:

• Controlled velocity compression starting near 0.15 m/s
• Defined temperature test environment
• Standardized reporting format

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Additional Durability and Safety Tests

Depending on project or certification body, tests may also include:

Compression Cycle Fatigue Testing

Checks long-term durability.

Some ISO frameworks require thousands of compression cycles depending on fender type.

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Puncture Resistance Testing

Some ISO frameworks check resistance to steel protrusion damage during compression.

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What Data Is Recorded During Testing?

Typical performance test report includes:

• Reaction force vs deflection curve
• Energy absorption calculation
• Internal pressure change curve
• Test conditions and calibration data

This data becomes the official performance certificate.

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Common Testing Mistakes to Avoid

Wrong initial pressure
Testing at wrong temperature
Compression speed too fast
Using theoretical data instead of physical testing

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Conclusion

Pneumatic fender performance testing is mainly about proving real energy absorption and safe reaction force under controlled compression.

ISO 17357 provides the design and acceptance framework.
ASTM F2192 provides the performance test method and reporting logic.

If testing is done correctly, operators can trust that the fender will perform safely during real berthing operations.

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FAQ

What is the most important test for pneumatic fenders?

The parallel compression test is the most important because it directly measures energy absorption and reaction force.

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At what deflection is performance usually verified?

Most ISO performance verification is done around 60% deflection, with small tolerance range.

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Why is energy absorption more important than hardness?

Because berthing safety depends on how much impact energy the fender can absorb, not just rubber hardness.

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Do all fenders need prototype testing?

Only new designs or construction methods require prototype testing. Existing certified designs may not.

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Why is test velocity controlled?

Because fender performance changes with speed. Standards define reference velocity to ensure fair comparison.