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05/09/2025Why Are Marine Fenders Provided on Docking Platforms?
05/12/2025What is a D fender?
A D fender is a type of marine rubber fender designed to protect vessels and dock structures from impact damage. Named for its distinctive “D” shape, this fender commonly serves on tugboats, barges, workboats, pontoons, and small quays. Its semi-circular profile efficiently absorbs energy while maintaining a compact form, making it ideal for applications where space is limited.
Why Is This Issue Necessary and Urgent?
In the maritime industry, maintaining the integrity of vessels and dock structures is vital. Even minor collisions during docking or mooring can cause significant damage, leading to costly repairs and delays. For example, a tugboat in a busy port may often bump into other vessels or dock walls. Without proper protection—such as D fenders—these repeated impacts can gradually weaken the hull. Thus, implementing effective fendering solutions is essential for both safety and cost-efficiency.
Key Features and Benefits of D Fenders
- High Energy Absorption: D fenders efficiently absorb substantial kinetic energy, reducing the impact force transmitted to vessels and structures.
- Versatile Applications: They suit various marine settings, including small quays, tugboats, barges, and pontoons.
- Easy Installation: Their design allows straightforward installation using bolts and mounting hardware, facilitating quick replacements and maintenance.
- Customizable Dimensions: Available in a range of sizes and lengths, D fenders can be tailored to specific requirements, ensuring optimal protection.
Types of NANHAI D Fenders: DD and DO Variants
- DD Fender: Features a D-shaped inner hollow, providing enhanced flexibility and energy absorption.
- DO Fender: Incorporates a round-shaped inner hollow, offering a balance between rigidity and cushioning effect.
Both types are selected based on specific application needs, such as the type of vessel and docking conditions.
DD rubber fenders size
| SPEC. | A (mm) | B (mm) | C (mm) | D (mm) | ΦE (mm) | ΦF (mm) | G (mm) | H (mm) | Bolt Size |
| DD80 | 80 | 70 | 45 | 30 | 30 | 15 | 90-130 | 200-300 | M12 |
| DD100 | 100 | 100 | 50 | 45 | 30 | 15 | 90-130 | 200-300 | M12 |
| DD125 | 125 | 125 | 60 | 60 | 40 | 20 | 110-150 | 250-300 | M16 |
| DD150 | 150 | 150 | 75 | 75 | 40 | 20 | 110-150 | 250-300 | M16 |
| DD200 | 200 | 150 | 100 | 80 | 50 | 25 | 130-180 | 300-400 | M20 |
| DD200 | 200 | 200 | 100 | 100 | 50 | 25 | 130-180 | 300-400 | M20 |
| DD250 | 250 | 200 | 125 | 100 | 60 | 30 | 140-200 | 350-450 | M24 |
| DD250 | 250 | 250 | 125 | 125 | 60 | 30 | 140-200 | 350-450 | M24 |
| DD300 | 300 | 300 | 150 | 150 | 60 | 30 | 140-200 | 350-450 | M24 |
| DD350 | 350 | 350 | 175 | 175 | 75 | 35 | 140-200 | 350-450 | M30 |
| DD380 | 380 | 380 | 190 | 190 | 75 | 35 | 140-200 | 350-450 | M30 |
| DD400 | 400 | 300 | 175 | 150 | 75 | 35 | 140-200 | 350-450 | M30 |
| DD400 | 400 | 400 | 200 | 200 | 75 | 35 | 140-200 | 350-450 | M30 |
| DD500 | 500 | 500 | 250 | 250 | 90 | 45 | 160-230 | 400-500 | M36 |
DO rubber fenders size
| SPEC. | A (mm) | B (mm) | ΦC (mm) | ΦD (mm) | E (mm) | F (mm) | G (mm) | H (mm) | Bolt Size |
| DO100 | 100 | 100 | 30 | 15 | 25 | 10 | 90-130 | 200-300 | M12 |
| DO150 | 150 | 150 | 65 | 20 | 30 | 12 | 110-150 | 250-350 | M16 |
| DO200 | 200 | 200 | 75 | 25 | 45 | 15 | 130-180 | 300-400 | M20 |
| DO250 | 250 | 250 | 100 | 30 | 50 | 20 | 140-200 | 350-450 | M24 |
| DO300 | 300 | 300 | 125 | 30 | 60 | 25 | 140-200 | 350-450 | M24 |
| DO350 | 350 | 350 | 150 | 35 | 70 | 25 | 140-200 | 350-450 | M30 |
| DO400 | 400 | 400 | 175 | 35 | 80 | 30 | 140-200 | 350-450 | M30 |
| DO400 | 400 | 400 | 200 | 35 | 80 | 30 | 140-200 | 350-450 | M30 |
| DO500 | 500 | 500 | 250 | 35 | 100 | 30 | 140-200 | 350-450 | M36 |
Applications of D Fenders
- Tugboats and Workboats: Protect hulls during frequent docking and maneuvering operations.
- Barges and Pontoons: Provide cushioning against impacts when moored or in transit.
- Small Quays and Piers: Safeguard dock structures from vessel-induced stresses.
- Inland Waterways: Ensure safe navigation and docking in confined or busy channels.
People Also Ask
What is a marine fender?
A marine fender is a device used to absorb the kinetic energy of a vessel berthing against a jetty, quay wall, or another vessel, preventing damage to both structures.
How does a rubber fender work?
Rubber fenders deform under pressure, absorbing and dissipating energy from impacts, thereby reducing the force transmitted to the protected structure or vessel.
What is the difference between DD and DO fenders?
The primary difference lies in the shape of their inner hollows: DD fenders have a D-shaped hollow, while DO fenders feature a round-shaped hollow, affecting their flexibility and energy absorption characteristics.
Where are D fenders commonly installed?
D fenders are commonly installed on the sides of vessels like tugboats and barges, and on dock structures such as quays and piers to protect against impact damage.
Therefore, understanding the role and benefits of D fenders is essential for anyone involved in maritime operations. Their ability to protect vessels and structures from impact damage ensures safety and contributes to the longevity and efficiency of marine assets.