Yokohama Fenders: 50 kPa vs 80 kPa

08/20/2025

If you’ve ever searched for Yokohama fenders, you’ve probably noticed two common ratings: 50 kPa and 80 kPa. At first glance, they look the same. Both are pneumatic fenders, both are designed to protect ships during berthing or ship-to-ship (STS) transfers, and both comply with ISO 17357 1:2014 and ISO 17357 2:2014 standards.

So, why do we have two pressure classes? And which one is right for your project? Let’s break it down in simple terms.

Quick Comparison Table

Parameter	50 kPa yokohama Fenders	80 kPa yokohama Fenders	What It Means
Energy Absorption	Lower	Higher	80 kPa handles more energy per size
Reaction Force	Lower	Higher	Check hull pressure limits
Size for Same EA	Larger	Smaller	80 kPa can downsize fender diameter
Weight & Handling	Heavier (if upsized)	Lighter (if downsized)	Logistics can change based on choice
Cost	Usually lower	Higher upfront	But smaller size can offset cost
Maintenance	Easier	Slightly stricter	80 kPa needs more frequent pressure checks
Best Use Cases	Sheltered berths, STQ ops	STS transfers, LNG, VLCCs	Match rating to environment

What Does “kPa” Mean Anyway?

The kPa rating tells you the initial internal pressure of the pneumatic fender. A 50 kPa Yokohama fender starts with 50 kilopascals inside, while an 80 kPa Yokohama fender starts at 80.

Higher pressure gives the fender better energy absorption (EA) and shape stability. However, it also leads to a higher reaction force on both the ship and berth structure. That’s why your choice should always match your berthing energy calculations and hull pressure limits.

Performance Differences You’ll Notice

1. Energy Absorption (EA)

This is the biggest difference. At the same size, an 80 kPa fender can absorb more energy than a 50 kPa model. That means if your ships are heavy or your approach speeds are high, 80 kPa is safer.

2. Reaction Force

Higher internal pressure also means more push-back. If your berth structure or hull plating has strict pressure limits, a 50 kPa fender might be safer.

3. Fender Size

Here’s the interesting part: for the same EA requirement, you can often downsize when you choose 80 kPa. Smaller fenders are easier to handle and sometimes cheaper to ship.

Cost, Logistics & Maintenance

Initial Cost → 80 kPa models are usually more expensive, but you might need a smaller size, which can offset the cost.
Handling → Downsizing an 80 kPa yokohama fender makes it lighter and easier to move, but otherwise, there’s little difference in installation.
Maintenance → Both need pressure checks, but 80 kPa yokohama fenders are less forgiving if you skip them. Monthly checks are a good rule of thumb.

When to Choose 50 kPa vs 80 kPa

Choose 50 kPa if:

You’re handling general cargo ships, bulk carriers, or container vessels
The berth is in a sheltered port with mild sea conditions
Budget is a concern
You want lower reaction force on berth structures

Choose 80 kPa if:

You’re doing STS transfers with VLCCs, LNG carriers, or offshore operations
The berth faces strong waves or currents
Space is tight and you want a smaller fender with the same EA
You need better shape stability under heavy loads

Safety and Standards Matter

Not all pneumatic rubber fenders are created equal. Always ask for:

ISO 17357-1:2014 certification
Performance curves for 50 kPa and 80 kPa ratings
Third-party inspection reports

And remember: don’t overinflate a 50 kPa fender to 80 kPa. The layer design, reinforcement, and safety factors are different.

Step-by-Step Fender Selection Workflow

Understand your scenario → STS or STQ? Vessel types?
Calculate berthing energy → Based on ship size, speed, and tide.
Check hull and berth limits → Match EA and reaction force carefully.
Choose pressure class → Decide between 50 kPa and 80 kPa based on conditions.
Pick fender size → Use certified performance tables.
Select accessories → Nets, chains, swivels—ensure ratings match.
Plan maintenance → Set up a regular inspection schedule.

Common Mistakes to Avoid

Inflating a 50 kPa fender to 80 kPa (unsafe).
Ignoring reaction force when upsizing or switching pressure classes.
Using non-certified fenders without test reports.
Skipping regular pressure checks—especially on 80 kPa units.

Real-World Examples

STS LNG Transfer: 80 kPa fenders are preferred because of high berthing energy and tight stand-off limits.
Container Berth in a Sheltered Port: 50 kPa is usually more than enough.
Exposed Offshore Berth: 80 kPa provides better shape stability during swells.

FAQs

Q1. Can I use a 50 kPa fender at 80 kPa?
No. They are designed differently and it’s unsafe.

Q2. Does 80 kPa always perform better?
Not always. It’s “better” for high-energy scenarios, but comes with higher reaction force and stricter maintenance.

Q3. Will 80 kPa reduce my fender size?
Yes, often you can pick a smaller diameter to meet the same energy absorption.

Q4. How often should I check the pressure?
At least once a month or before major STS operations.

Final Thoughts

When it comes to Yokohama fenders, there’s no universal “better” option between 50 kPa and 80 kPa. The right choice depends on your ship size, berthing energy, environment, and budget.

If you’re unsure, always ask your fender supplier for ISO-certified performance curves and let the numbers guide you. The wrong choice can mean higher costs—or worse, structural damage.

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