UFC 4-152-01
28 July 2005
b. Foam-Filled Fenders. These are constructed of resilient, closed-cell
foam surrounded by an elastomeric skin. Provide additional protection
against abrasion by thicker elastomeric coatings or an external tire net,
similar to the floating pneumatic type. The fender requires a backing
system to distribute the load. Netless fenders cost more due to the need
for thicker skins and coatings. However, the greater hull marking of the
tire net and occasional maintenance need suggest that netless fenders
may be preferred. The unit can either be utilized as a floating fender,
moving up and down with the tide and held in place with chains or can be
suspended from the pier/backing system. The cellular structure of the
foam filling reacts like hundreds of millions of individual pneumatic fenders
in deforming and absorbing the energy. The foam contains the air within
its cellular structure and tends to compress upon itself rather than bulge
peripherally. The foam-filled fenders have a high-energy absorption with
comparatively small reaction force. Surface pressure of the fender is not
quite uniform when it is compressed, so the hull pressure over the contact
area is not quite uniform. Where rough concrete surfaces of the backing
surface or pretressed concrete piles is a concern, use UHMW pads or
strips to protect the skin of the foam filled fender. See Figure 5-5 for a
typical foam-filled fender installation.
5-3.3.5
Combination System.
Any of the above-mentioned fender systems may be combined in the same berth
to make up the deficiency of another. A berth may have either the floating fender
units or directly mounted fenders at discrete points, with the in-between spaces
filled up by the pile/rubber system designed to work with separators. Floating
fenders and directly mounted fenders may be used alternately along solid or
double deck types of piers and wharves.
5-3.3.6
Monopile System.
This fendering system is based on the use of a floating ring-shaped resilient
fender unit that rides up and down on a large steel pile driven to the seabed.
Special low-friction bearing pads are usually installed on the inner surface of the
hull of the ring fender so that the fender unit can rotate and slide freely on the
pile. This unique ability makes the monopile system very suitable for corner
protection of piers and wharves and entrances to a narrow slip. The units can
also work well as breasting and turning dolphins. Energy is absorbed both by the
steel monopile in flexure and by the ring-shaped fender unit. This system is
illustrated in Figure 5-13.
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