Figure 2-15. Main hoist line reeving.
hoist drum. Secure the line to the drum (fig. 2-14) and
following components are necessary for the
wrap sufficient line on the drum to close the clamshell
equipment conversion; the crane boom components
(3) Reeve the holding line around the right boom
closing lines, tagline winder, and tagline. The crane
point sheave, and to the front hoist drum. Secure the line
hoist cable may be used for the bucket hold- ing line,
to the drum, and wrap line on the drum until the same
but if additional depth below ground level is desired,
number of turns are on both drums. Attach the holding
longer holding and closing lines must be installed.
line loosely to the clamshell bucket.
b. Installation. Install the crane boom, back-
(4) Raise the boom to the working angle. Raise
stops, and boom hoist cable as described in
the clamshell bucket, using both lines, until the second
layer begins on the rear (closing line) drum. The second
layer should begin on the front drum at the same time. If it
does not, adjust the point of attachment of the holding line
(1) Swing the crane boom over the damshell
to the bucket.
bucket. Lower the boom to approximately six feet
(5) Cut both lines and secure them to the bucket.
above the ground beside the clamshell bucket.
(2) Reeve the closing line on the clamshell,
around the left boom point sheave, and to the rear