event that the master switch is moved to OFF and one
contactor sticks, the second contactor should interrupt
Fall Tensioning Device
The fall tensioning device keeps the hook above the
heads of the boat crew before boat hookup and after
release. This reduces the danger to the boat and to the
crew from a swinging hook assembly. When the hook is
cast off during launching, the fall tensioning device
counter-weighted sheave causes the hook to rise clear of
the boat and crew. Figure 4-16 is an example of a fall
A fluid brake is attached to the output shaft of the
electric clutch on the SLAD hoist drive motor. The
purpose of this fluid brake is to regulate the speed of a
descending boat thus preventing any damage to the
equipment or personnel.
Safety handcranks include an overriding mechan-
a winch motor is energized while the winch is being
manually cranked, no force is exerted on the crank
handle from the winch side and thus prevents back
drive. This device may be used in place of handcrank
electrical interlock switches. For the SLAD, the
formlock clutch prevents the back drive of slewing and
hoist handcranks and thus both drives can be power
driven with the handcranks being engaged.
LEARNING OBJECTIVE: Recognize common
deck fittings found aboard ships and explain
Deck fittings are the various devices attached to the
hull that assist in handling the ship.
The most common fittings are found around the
weather decks. A brief description of some common
ism. This mechanism functions in such a manner that, if
deck fittings (fig. 4-17) follows.
Figure 4-17.Various deck fittings.