Installation method of cylindrical rubber fenders

When ships come alongside a pier or dock, they need protection from hard impacts. That’s where cylindrical rubber fenders come in. These fenders are soft but strong rubber tubes that absorb energy when a vessel touches the dock. They help keep both the ship and the structure safe.

Many port operators and designers choose cylindrical rubber fenders because they are simple, durable, and easy to install. But not everyone knows the right way to install them. In this article, we’ll show you how to install cylindrical rubber fenders step by step. We’ll look at the three most common methods—rod and bar fitting, chain fitting, and ladder fitting—and explain when each one works best.

1. What Are Cylindrical Rubber Fenders?

Cylindrical rubber fenders are hollow rubber tubes with smooth outer and inner surfaces. They come in different diameters and lengths, depending on the vessel size and berth type. A common size might be Ø400 × Ø800 × 1500 mm.

The hollow design lets the fender compress easily and absorb energy during contact. The material is usually high-quality natural or synthetic rubber that resists saltwater, UV light, and weather damage.

These fenders can be installed horizontally or vertically, on quay walls, dolphins, or floating structures. Because of their shape, they fit well on curved surfaces and handle repeated contact very well.

Main advantages:

• Simple and reliable design
• Easy to replace and maintain
• Works well for many types of docks and vessels
• Strong energy absorption with low reaction force

2. Choosing the Right Installation Method

Before installation, port designers or operators must choose the right fitting method. The best choice depends on:

• The berth structure (fixed wall, floating dock, or barge)
• Vessel size and berthing speed
• Tidal range and wave conditions
• Maintenance access and service life

There are three main installation methods for cylindrical rubber fenders:

1. Rod and Bar Fitting
2. Chain Fitting
3. Ladder Fitting

Each has a slightly different structure and performance, but all serve the same purpose—to hold the fender firmly and allow it to move just enough to absorb energy.

3. Preparation Before Installation

Before starting, make sure all tools and materials are ready:

• Cylindrical rubber fenders (check dimensions)
• Chains and shackles
• Steel rods or bars
• U-anchors or mounting plates
• Bolts, nuts, and washers (stainless or galvanized)
• Anti-rust paint or grease

Inspect the wall surface where the fenders will be mounted. It must be flat, clean, and strong enough to hold the load. Always check measurements twice to make sure the alignment and spacing are correct.

Safety first:
Workers should wear safety gear, use cranes properly, and follow dockside safety rules. Working near water always needs extra care.

4. Rod and Bar Fitting

This is the most common and strongest installation method. A steel bar passes through the center of the cylindrical rubber fender, and both ends of the bar connect to chains and U-anchors fixed on the quay wall.

Where to use:

• Fixed quay walls
• Medium or large ships
• Areas with low tidal movement

How to install:

1. Mark the fender positions on the wall and drill anchor holes.
2. Install U-anchors firmly with chemical or expansion bolts.
3. Pass a steel bar through the center hole of the fender.
4. Attach both ends of the bar to chains using shackles.
5. Connect the chains to the wall-mounted U-anchors.
6. Check the alignment—both horizontally and vertically.
7. Apply grease or anti-corrosion coating to metal parts.

Tips:

• Keep chain tension balanced.
• Do not over-tighten; a small movement helps absorb impact.
• Always check torque values for anchor bolts.

Advantages:

• Very stable installation
• Even load distribution
• Long service life with low maintenance

5. Chain Fitting

In this method, the cylindrical rubber fender is suspended by chains at both ends. There is no steel rod through the center, making it lighter and easier to install.

Where to use:

• Smaller berths or dolphins
• Floating structures or barges
• Where quick replacement is needed

How to install:

1. Fix U-anchors or steel eye plates on the quay wall.
2. Attach chains to both ends of the fender using shackles.
3. Connect the other ends of the chains to the anchors.
4. Adjust the chain length so the fender hangs evenly.
5. Leave about 10–15% slack in the chain for tidal movement.
6. Check that the fender can swing slightly but not hit the wall.

Tips:

• Add rubber or nylon sleeves around the chain to reduce wear.
• Inspect chains often for rust or stretching.

Advantages:

• Simple and flexible design
• Easy to install or replace
• Allows movement during waves or tides

6. Ladder Fitting

The ladder fitting method uses two or more chains arranged vertically—like the sides of a ladder—to hold the fender in place. This setup keeps the fender more stable when the tide rises or falls.

Where to use:

• Berths with large tidal range
• Barge operations and floating docks
• Locations where vertical movement is common

How to install:

1. Fix upper and lower anchors on the quay wall.
2. Attach chains to both the top and bottom of the fender.
3. Connect all chains to the wall anchors using shackles.
4. Adjust tension so the fender hangs straight.
5. Test by pulling slightly to ensure movement is smooth.

Advantages:

• Prevents vertical sway
• Handles tidal changes better
• More secure under rough conditions

Maintenance tips:

• Check the upper and lower chains for equal tension.
• Tighten or replace corroded shackles regularly.

7. Layout and Spacing

Correct layout ensures safety and smooth berthing.
Here are some simple rules of thumb:

• Keep even spacing between fenders. For most berths, the gap should be about 1.5 to 2.0 times the fender length.
• Position the fenders so that the vessel’s contact area hits the fender’s centerline.
• For small berths or curved walls, reduce spacing slightly for better coverage.
• The bottom of the fender should stay above the lowest water level by at least 300 mm.

When in doubt, always check with your berth designer or fender supplier. Proper layout saves money and avoids damage later.

8. Quality Inspection After Installation

After all fenders are in place, inspect them carefully.

Checklist:

• Are all anchors tight and corrosion-free?
• Is the fender aligned horizontally and vertically?
• Are chains equally tensioned and not twisted?
• Does the fender move slightly when pushed by hand?
• Are metal parts coated with anti-rust paint?

Take photos and record installation data (position, torque, date). These records help during future inspections.

9. Maintenance and Inspection

Even though cylindrical rubber fenders are tough, regular inspection keeps them safe and long-lasting.

Routine maintenance tips:

• Inspect monthly for cracks, cuts, or deformation.
• Check chains, shackles, and anchors every six months.
• Remove marine growth and dirt buildup.
• Apply grease or anti-rust coating once or twice a year.
• Replace damaged chains or shackles immediately.

Service life:
With proper care, a high-quality cylindrical rubber fender can last 10 to 15 years or even longer.

10. Common Problems and How to Fix Them

Problem 1: Fender tilts or moves sideways
→ Reason: Chain length mismatch or uneven tension.
→ Solution: Adjust chain length and alignment.

Problem 2: Cracks appear on the rubber surface
→ Reason: Overload or aging rubber.
→ Solution: Replace the fender if cracks are deep.

Problem 3: Chains corrode quickly
→ Reason: Saltwater exposure or poor protection.
→ Solution: Use galvanized or stainless chains and reapply grease often.

Problem 4: Fender touches the wall during high tide
→ Reason: Chain too long or wrong spacing.
→ Solution: Adjust chain length or move the fender outward.

11. Example from a Port Project

At a medium-sized cargo port, operators installed rod and bar fitting cylindrical rubber fenders on a 120-meter quay.
After one year, the inspection showed:

• Zero structural damage
• Fewer vessel scratches
• Easier maintenance and cleaning

At another small barge dock, the team used ladder fitting for better control during high tides. The vertical chains kept the fenders steady even in rough weather. Maintenance time dropped by 40%.

These examples show that the right installation method greatly improves safety and reduces repair costs.

12. Why Cylindrical Rubber Fenders Are a Smart Choice

Cylindrical rubber fenders are one of the most cost-effective ways to protect your dock and ships. They are simple to use, easy to maintain, and adaptable to many conditions.

Whether you manage a small marina or a busy commercial port, installing them correctly is key. Poor installation can cause uneven load, faster wear, or even accidents. Following the methods above ensures your fenders work safely and last for many years.

13. Final Tips for Port Designers and Operators

• Always select fenders that match vessel size and approach angle.
• Choose high-quality rubber with good wear resistance.
• Use reliable fittings: galvanized chains, shackles, and anchors.
• Inspect regularly and keep a maintenance log.
• For complex berths, ask experts for layout design or installation support.

14. Conclusion

Cylindrical rubber fenders play a small but vital role in keeping ports safe and efficient. With the right installation—rod and bar, chain, or ladder fitting—they can protect ships and structures for many years.

If you are planning a new dock or upgrading an old one, take time to plan the installation carefully. Good preparation and regular inspection make all the difference.

For reliable fender systems and technical help, NANHAI offers customized cylindrical rubber fenders that meet global standards and provide excellent long-term performance.