Floating Fenders Design
Marine fenders have the many kinds fender type, mainly include solid rubber fenders, tugboat fenders, floating fenders (pneumatic fenders and foam filled fenders). Normally, the fenders’ design refer the “Guidelines of the Design of Fenders Systems” PIANC International Navigation Association.
Marine fenders is basically the interface between a vessel and the berth facility. This medium serves to absorb a certain portion of the kinetic energy a vessel without damage to the vessel and the waterfront structure. In the case of rubber fenders, which are generally relatively soft, the majority of the energy is absorbed through elastic deflection of the rubber fenders. But, possibly also the deflection of the berth facility and/or the vessel’s hull will contribute to the absorption of the kinetic energy.
The deflection multiplied by the reaction force with is generated and a certain efficiency factor equals the kinetic energy. The energy that is absorbed by the fender system during compression is partially returned to the vessel and partially dissipated in the form of heat within the material.
Hereby, we introduce the design and selection of pneumatic fenders and foam filled fenders. They are two kinds floating fenders. Used for the ship-to-ship and ship-to-quay operation.
Floating Fenders Advantages
1. Advantage at inclined berthing
Ship usually make initial contact with the dock or another ship on STS operation at oblique angle. Under 15 degrees at inclined compression, the energy absorption of pneumatic fenders doesn’t decrease. The foam fender has a less decrease than solid fenders.
2. Resistance for shearing force
Because of the special shape of semicircle end, it provide the best resistance against shearing force when the ship shift to the correct mooring position
3. Low reaction force
The soft reaction force of floating fenders cannot lead to damage the ship and mooring facilities. The increase of reaction force of floating fender is not sharply. Its performance is better than solid rubber fender. And it’s ruinous for the ship and mooring facilities.
4. Most economical fenders system
The floating fenders have simple construction than the solid rubber fenders system. This simple structure ensure the economical of cost. Meanwhile, because of the floating fenders can float on the water, thefloating fenders can be installed by a guy chain or rope. So it has the advantages of simple and low installation. The use of best material and accessories ensure the low maintenance cost.
5. Adaptable to the tide
The floating fenders can float on the water surface depend on the change of tide. So it’s the best choice for the port or quay with huge tide change. Floating fenders also can be used for the ship-to-ship operation discretionarily.
Floating Fenders Selection Procedure
The fender selection should consider the operation condition: ship-to-ship or ship-to-quay. The basically process is to calculate and compare the energy absorption of floating fenders with berthing energy.
The quick reference is as per the OCIMF Table, to do the fender selection tentatively. If the energy absorption of the tentative selected fenders is larger than the calculated berthing energy, it means that a suitable fender selection has been made. If the fender energy absorption capacity is less than the calculated berthing energy, the selected fender should be upgraded, and selected again.
— To know the performance of pneumatic enders, please visit Pneumatic Rubber Fenders.
Herein is the selection process of ship-to-ship operation. Contact us to know more about the ship-to-jetty operation.
Application and Installation of Floating Fenders
The floating pneumatic fenders can be used for the ship-to-ship operation ad ship-to-dock operation. The large floating fenders are usually floated at the water line as primary fenders to absorb impack energy at berthing and keep proper stand-off distance between ships and dock.
The floating fenders can be hanged to the ship and dock by guy chain or gay rope connect with the shackles and anchor.