UFC 4-152-01
28 July 2005
CHAPTER 4. STRUCTURAL DESIGN
4-1
CONSTRUCTION MATERIALS.
4-1.1
Timber.
For the major functional types of piers and wharves such as ammunition,
berthing, repair, fitting-out/refit, and supply facilities subject to high concentrated
wheel loads, timber construction should not be considered. Timber may be more
effective and optimal for fender systems, dolphins, walkways, utility trays, and
deck-supported small buildings. For light-duty piers and wharves, such as
fueling, temporary, and Magnetic Treatment and Electromagnetic Roll piers,
timber framing for deck and piling may be considered. Consult with the local
activity and Facilities Engineering Command (FEC) for local requirements and
restrictions on the use of treated timber. Obtaining permits for treated timbers,
especially creosoted fender pile, is becoming very difficult in various areas of the
country.
4-1.1.1
Preservative Treatment.
All timber members, with the exception of some fender piling, exposed to the
marine environment and immersed in salt water or fresh water should be
pressure treated with oilborne (creosote, pentachlorophenol) or waterborne
(salts) chemical preservatives to protect against deleterious effects of decay,
insects, and marine borers. In warmer waters, where severe marine borer
activity can be anticipated, employ dual treatment using both creosote and salt.
Consult the staff entomologist at the cognizant FEC for specific information on
marine organisms present and the treatment required.
If possible, make pressure treatment after all holes and cuts are made. When
holes and cuts are made in the field, treat timber members with preservative to
prevent decay from starting in the holes or cuts. Consult a staff entomologist for
the proper preservative. Field treatments are difficult in the tidal zone and are
typically not very effective against marine borers. Therefore, whenever possible,
design and detailing should avoid the necessity for making cuts or holes on
underwater timber members. For example, avoid bracing or connections below
mean high water. All connection hardware should be suitable for the saltwater
exposure. For above water construction, waterborne salt treatment is preferable
to creosote treatment due to the staining effect that creosote treatment produces.
4-1.1.2
Timber Species.
Douglas fir and southern pine are the most popular species for waterfront
construction. Southern pine piles are limited to 65 ft (19.8 m) in length, whereas
Douglas fir piles and poles can be used in up to 100-ft (30.5 m) lengths. Large
beams and timber sizes needed for chocks and wales are generally available
only in Douglas fir and southern pine. Treat chocks and wales with waterborne
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