Wharves are used for loading and unloading ships. This chapter describes
how a carpenter constructs a timber-pile wharf. The topics covered include—
· Layout and installation of piles for pile-wharf construction.
· Construction of a wharf superstructure.
· Installation of docking hardware.
TYPES OF WHARVES
Wharf is an overall term that applies to any waterfront structure designed
to make it possible for vessels to lie alongside the shore for loading
and unloading. The term wharf is confined in practice to the T- and U-type
marginal wharves (Figure 11-1, page 11-2). A marginal wharf usually consists
of a timber or steel superstructure supported by a series of timber, steel,
or concrete pile bents.
The other structures shown in Figure 11-1 are called piers, except the
quay. A quay is a reinforced landing place made toward the sea or at the
side of a harbor. All structures shown in Figure 11-1 may consist of fill
supported by bulkheads.
TYPES OF PILES
To protect a wharf against normal wear and tear, three types of piles
are used: bearing, fender, and mooring piles. The types of piles are discussed
in the following paragraphs:
Bearing piles support the wharf or pier framework and decking. The piles
should be straight and measure at least 6 inches across the top, 18 inches
across the butt (bottom), and from 60 to 80 feet in length. Pile length
varies according to the depth of the water and condition of the bottom.
Bearing piles should be spaced from center to center 6 to 10 feet apart
in one direction and 5 feet apart in the other direction.
The force of a moving ship coming in direct contact with bearing piles
is enough to collapse an unprotected wharf. To protect and absorb the
initial shock, fender piles are placed about 2 1/4 feet out from the centerline
of the outside row of bearing piles. These piles are placed about 18 feet
apart and along the sides where ships dock.
Mooring piles are aligned with the outside row of bearing piles and
are spaced about 30 feet apart. This type of pile is braced along the
outside row of bearing piles and usually extends to about 4 feet above
the floor (or deck) of the platform. The 4-foot extension provides ample
space to secure mooring lines.
NOTE: Timber piling must be treated with
creosote or some other preservative Compound to protect it from fungi
and marine borer attacks.