A Self-Learning Manual - Institution of Engineers Mauritius

A Self-Learning Manual
Mastering Different Fields of Civil Engineering Works (VC-Q&A Method) Vincent T. H. CHU
Tension chain serves to guard the fender against damage when the fender
is under compression.
Fig. Heeling of a vessel
13. In connecting fenders to pier structures, should single lock nuts
or double lock nuts be used? (F1)
In many pier structures the connection of fenders to piers is achieved by
using single lock nuts. However, they do not perform well because some
timber fenders loosen more easily when subject to vibrating loads due to
berthing, wave and tidal actions. To solve this problem, double lock nuts
should be adopted as they prove to function satisfactory in other structural
elements which are subject to frequent vibration loads.
Note: Double lock nuts mean two nuts are adopted in a single bolt connection between
fenders and marine structures.
14. What are the pros and cons of using timber fenders, plastic
fenders and rubber fenders? (F1)
Timber fenders:
They are low in strength and are subject to rotting and marine borer attack.
Moreover, they have low energy absorption capacity and the berthing
reaction depends on the point of contact. The contact pressure between
fender and vessels are high. They are considered to be environmentally
unfriendly because they consume tropical hardwoods in their production.
Plastic fenders:
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