| INSTALLATION OF PILES
Pile-driving equipment and
the methods of driving and
pulling piles are covered in
FM 5-480. The equipment is
operated by a special crew,
but the carpenter is present
during the pile driving to
direct the alignment of the
piles.
USING SPECIAL TOOLS
Since most of the heavy timbers used to build waterfront structures
cannot be manhandled, special tools, known as logger's tools (Figure 11-2),
are used to move and place these timbers. They consist of—
· Peavy and cant hooks. Lever-type tools, used mainly to roll
timbers.
· Timber carriers. Two-man tools, used mainly to pick up and carry
timbers.
· Pike poles. Used to hold or steady timbers while they are being
placed.
· Cranes. Normally, two men are assigned to a crane: the operator
and the helper. The helper drives the crane carrier (truck) and hooks
and unhooks loads. Using standard signals, the helper tells the operator
when to lift and lower the load and where to position it. After the heavy
timbers have been moved and placed, the carpenter's level is used to level
them properly.
NOTE: Although the crane cannot be considered
a special tool, it is mentioned here because of its use to raise and lower
heavy timber.
STRAIGHTENING PILES
Piles should be straightened
as soon as any misalignment
is noticed. The desired
accuracy of alignment varies
with each job; however, if a
pile is more than a few inches
out of plumb, it should be set
true. The greater the
penetration along the wrong
line, the more difficult to get
the pile back into plumb. To
realign piles, use one of the
following:
· A block and tackle (Figure
11-3), with the impact of
the hammer jarring the
pile back into line.
· A jet (Figure 11-4, page 11-
4), either alone or in
conjunction with a block
and tackle.
· A block and tackle and an
alignment frame (Figure
11-5, page 11-4) to pull the
piles In a bent into proper
spacing and to align them
after they have been
driven.
When a floating pile driver is
used, a frame (template) for
positioning piles may be
fastened to the hull. A floating
template (Figure 11-6, page 11-6)
is sometimes used to position the
piles in each bent. The spacing of
battens is such that the
centerline between them is on
the pile line desired. Battens are
placed far enough apart so that,
as the pile is driven, the larger
diameter butt end will not bind
on the template and carry it
underwater.
A chain or collar allows the
template to rise and fall with the
tide. If the ends of the battens
are hinged and brought up
vertically, the template may be
withdrawn from between the
bents and floated into position for the next bent. Several templates may
be used for a bent; or a single template is moved, if the pile spacing
is uniform. The position of the piles is controlled as follows:
Step 1. After each bent has been driven, a line is run back from each
pile in the outer bent to the corresponding pile in each of the next several
bents shoreward.
Step 2. The alignment and longitudinal spacing of the outshore bent
are verified.
Step 3. Any deviation in
position of previously
driven piles is made up
when the template is
positioned for the next
bent. Piles that are
slightly out of position
may later be pulled into
place as described
previously in the first
paragraph.
CUTTING PILES
The lengths of pile
selected for a structure
should be such that the
butts are 2 or 3 feet
higher than the desired
finished elevation after
driving to the desired
penetration. Since the
pile capping should bear
evenly on every pile in the bent, trimming should be carried out accurately
by nailing saw guides across all piles in the bent. Figure 11-7 shows
cutting piles.
CAPPING TIMBER PILES
Caps are large timbers placed on top of the timber-bearing piles to
support the superstructure. The pile capping is fastened as shown in Figure
11-8, page 11-6, and as follows:
Step 1. After the piles have been cut, the cap is put in place; a hole
for a driftpin is bored through the cap into the top of each pile; and
the driftpins are driven into the holes.
Step 2. At a joint between pile cap timbers, a splice scab is bolted
across the joint to each side of the pile cap.
Step 3. The working platform, aligning cables, or spacing frame may
then be removed, since the driftpins will hold the piles in the proper
position.
BRACING PILES
Bents are braced as shown in Figure 11-8 and as follows:
Step 1. Bolt diagonal timbers to each pile with the bracing running
in one diagonal direction on one side of the bent and in the opposite
diagonal direction on the other side.
Step 2. If the piles in a bent differ a lot in diameter at the point
of bracing, make one of the
following corrections:
· Large piles may be
flattened down with
an ax (hewed or
dapped).
· Small piles may be
blocked out with filler
pieces.
· The flexibility of the
braces may be used to
pull them tight
against the piles.
(Figure 11-9, page 11-6,
shows transverse
bracing.)
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