What is Donut Fender? Advantages & Installation Guide
Donut fenders are floating fenders installed around fixed guide piles or tubular piles. They absorb berthing energy while rotating around piles and moving vertically with tidal changes, making them particularly suitable for breasting dolphins, turning dolphins, ferry terminals, and bridge protection structures in areas with significant tidal variations.
Key Advantages
Compared with fixed fenders such as D fenders and cylindrical fenders, the main advantage of donut fenders is their ability to rotate and move vertically along guide piles.
1. Adaptable to tidal variations
Able to move up and down with changing water levels, donut fenders maintain effective protection across a wide tidal range.
2. Free rotation and reduced friction
When contacted by a vessel, the fender rotates around the guide pile, helping reduce friction and shear forces during berthing and vessel movement.
3. Compact design and simple installation
Fitted directly around guide piles, the fender requires no complex supporting structure, simplifying installation and maintenance.
4. Berthing and guiding functions
Besides absorbing berthing energy, donut fenders help guide vessel movement and are suitable for berthing, turning, and guiding structures.
Proper Installation of Donut Fenders
1. Inspect the guide pile
Check pile diameter, verticality, and surface condition. Fender internal diameter and bearing liner dimensions should match pile diameter and provide specified operating clearance. Remove sharp burrs and protruding welds that could damage bearing liner.
2. Lift and install the fender
Using suitable lifting equipment, align fender with pile and lower it carefully into position. Avoid impact or excessive pressure on outer cover and bearing liner during installation.
3. Check free movement
After installation, ensure fender rotates freely around pile and moves vertically with tide. Check that there is no sticking, abnormal friction, or structural interference.
4. Check stoppers and final position
Where required by design, inspect upper and lower stoppers to ensure they limit fender movement without restricting normal vertical travel. Finally, confirm fender is correctly positioned and can move freely along guide pile.
Nanjing Deers Industrial Co., Ltd
Tel:86-25-84507790
Fax:86-25 84660486
Whatsapp:+86 13376094258
Email: benny@chinarubberfender.com