Marine borers are also responsible for some of the
treatment, it must be applied at some temperature between
deterioration actions on timbers.
175€ And 200€ Fahrenheit. Another thing to remember is
8-26. There are many types of marine borers, but only
to avoid the use of timber hooks, cant hooks, or other
two general groups (mollusks and crustaceans) are
sharp-pointed tools when you are handing treated timbers.
important to us now. Borers belonging to the mollusks
8-31. Most of our modern treatment plants precut
group enter the timber, burrow themselves, and
timbers to size and notch and bore them before treatment.
honeycomb the interior.
On the other hand, the
This prevent the need for further treatment if you handle
crustaceans operate by forming shallow gullies just under
these timbers with care.
the surface.
8-32. So far, we have discussed the construction
8-27. Wharf or pier construction failures are caused
features of wharves, piers, and quays; the special tools
either by mechanical factors or by deterioration factors.
needed for such work; the general maintenance problems
No matter which is responsible, the damage must be
involved here; and the corrective repairs necessary. Now
repaired So lets take a look at some of the corrective
let's talk about some of the ways to prevent or minimize
repairs which can be made and try to determine which
damage to these structures and safety measures which you
method we should use to repair any particular damaged
use in such work.
pier.
8-33. Preventive Maintenance Measures.
To
8-28. Corrective Repairs. Wharves and piers are
adequately maintain wharves and piers, we must provide
usually repaired by replacing the damaged part. The
and maintain an appropriate preventive maintenance
replacement part should be of the same type of material as
program. This program must outline preventive measures
the part it is to replace. But, if failure is due to
and present specific frequencies for inspections and
overloading and if it is believed that overloading will
corrective actions. Therefore, we are going to discuss the
recur, the structure should be reinforced or otherwise
methods you should use to maintain these structures. As
strengthened.
we have explained above, wharf and per structures are
8-29. Failures by deterioration are the hardest to detect
damaged from wear, deterioration, insect infestation,
and correct. Failure to correctly estimate how far repairs
overloading, storm damage, fire, etc However, the
should be carried out is one of our biggest errors. This is
damaging effect from these factors can be minimized if
specifically true if the failure is due to deterioration.
we follow the procedures and precautions outlined in the
From a visual inspection, some timbers look solid and
following paragraphs.
sound; but when removed, they may be found to be
8-34. To guard against excessive wear to decking, we
hollow shells. This is primarily due to attacks by
must make frequent inspections and keep tracked vehicles
termites. Similarly, fender pile which are sound above
or other iron wheeled equipment from traveling over it
the water line are often damaged near the ground line by
Post notices of this restriction in conspicuous places. All
marine borers. For these reasons, all timbers must be
loose bolts and nuts found during the inspection should be
carefully checked to determine their true condition. Two
tightened. All decking should be securely nailed at every
ways to do this are to hammer on timbers or t drive nail
joist. If decking is 3 inches thick, 60d nails or 6-inch
into them to see whether they have become softened by
spikes should be used. If it is 4 inches thick, 7-or 8-inch
deterioration. If you have doubt as to the soundness of a
spikes should be used. All planking used as decking
structure, you should bore holes into the sides of caps and
material should be of the same thickness to give a smooth
stringers. If you find the timber to be sound, carefully
surface.
plug and paint the holes to keep out further moisture.
8-35. Fender piles should be removed and replaced
8-30. Generally speaking, the materials used for
before excessive wear occurs. Normally, only hardwoods
repairs or replacements should be of the same type and
(such as oak) are used for fender piles; however, if traffic
size as those used in the original design. However, no
is light, creosoted softwood piles may be used. No matter
matter what type of materials are used, you must handle
what type wood is used, make sure that all chocks are
them with care if you intend to get maximum service.
tightly fitted between the piles. These chocks help
Also, to stop the entrance of fungi and insect, you must
prevent the piles from rolling when rubbed by vessels. If
re-treat all low-resistant areas and broken surfaces of
currents are swift, fender log should be used to prevent
treated timbers. If cu are made in the surface of treated
damage to piles. Also, a thorough check of all timber and
timbers, you should paint them with two or more coats of
hardware should be made and any necessary corrective
preservative compound. Now, if creosote is used for this
actions taken.
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