Auxiliary Hoist |
A supplemental hoisting unit,
usually of lower load rating and higher speed than the main
hoist. |
|
Axis of Rotation |
The vertical axis around
which the crane's superstructure rotates. |
|
Boom |
In cranes and derricks usage, an
inclined spar, strut, or other long member supporting the
hoisting tackle. Also defined as a structural member attached to
the revolving superstructure used for guiding and acting as a support
for the load. |
|
Boom Angle
Indicator |
An accessory device that measures
the angle of the boom base section centerline to horizontal.
|
|
Boom Stops |
A devise used to limit the
angle
of the boom at its highest position.
|
|
Brake |
A device used
for retarding or
stopping motion by friction or power means.
|
|
Block |
Sheaves or grooved pulleys in a
frame provided with hook, eye, and strap.
|
| Crane |
A machine consisting of a rotating
superstructure for lifting and lowering a load and moving it
horizontally on either rubber tires or crawler treads.
|
|
Counterweight |
Weights used for balancing
loads and the weight of the crane in providing stability for
lifting. |
|
Deck |
The
revolving superstructure or
turntable bed.
|
|
Drum |
The spool or cylindrical member around
which cables are wound for raising and lowering loads.
|
|
Gantry |
A structural frame work (also known as
an A Frame) mounted on the revolving superstructure of the crane
to which the boom supporting cables are reeved.
|
|
Headache Ball |
A heavy weight attached above
the hook on a single line or whip line to provide sufficient
weight to lower the hook when unloaded. |
|
Holding Brake |
A brake that
automatically
sets to prevent motion when power is off.
|
|
Jib |
An extension attached to the boom point
to provide added boom length for lifting specified loads.
|
|
Load |
The weight of the object being lifted or
lowered, including load block, ropes, slings, shackles, and
any other ancillary attachment.
|
|
Load Block |
The assembly of the hook or
shackles, swivel, sheaves, pins, and frame suspended from the boom point.
|
|
Main Hoist |
Hoist system or boom used for
raising and lowering loads up to maximum rated capacity. |
| Mechanical
Load Brake |
An
automatic type of friction brake used for controlling loads in the
lowering direction. This device requires torque from the motor to lower a
load but does not impose additional loads on the motor when lifting a
load. |
| Outriggers
|
Support members attached to the crane's carrier
frame which are used to the crane and may be blocked up
to increase stability. |
| Pawl |
Also
known as "dog". It is a gear locking device for positively
holding the gears against movement. |
| Pendants |
Stationary
cables used to support the boom. |
| Radius |
The
horizontal distance from the axis of rotation of the crane's
superstructure to the center of the suspended load. |
| Reeving |
The
path that a rope takes in adapting itself to all sheaves and drums of a
piece of equipment. |
| Running
Sheave |
Sheaves
that rotate as the hook is raised or lowered |
| Superstructure |
The
rotating frame, gantry and boom or other operating equipment. |
| Test Load |
Any
load or force, expressed in pounds, used for testing or certifying the
limitations within acceptable tolerances of the anticipated load. |
| Two-Block |
The
condition in which the lower load lock or hook assembly comes in contact
with the upper load block or boom point sheave assembly. |
| Quadrant of
Operation |
The
area of operation that the lift is being made in. Usually divided into
four quadrants, i.e. front, rear and side(s) - left side and right side. |
