A crane
is a machine used for lifting and lowering a
load, and moving it horizontally. A crane's
drives may be manual, powered or a
combination of both. Cranes are typically
used when there is insufficient (or
intermittent) flow volume such that the use
of a conveyor cannot be justified. They
provide more flexibility in movement than
conveyors, and less flexibility in movement
than industrial trucks. Loads handled by
cranes are more varied with respect to their
shape and weight than those handled by a
conveyor. Most cranes utilize hoists for
vertical movement, although manipulators can
be used if precise positioning of the load
is required.
Many different types of cranes are used for
material handling applications. These
include overhead cranes as well as cherry
picker type boom lifts, mobile and
self-propelled cranes, straddle and
counterbalanced (cantilevered) cranes.
Portable and mobile floor cranes can be
equipped with fixed or telescopic booms as
well as mast rotation when equipped with
outriggers. Lifting can be performed with
the boom itself or a winch operated cable
lift.










