instrument for measuring and indicating the force or speed of the wind
apex
point of the tower crane at the top where the pendants or top chords meet so that gravitational forces act on the tower, not on the jib or counter jib
ballast
stabilizing component usually placed at the base of a tower crane; does not rotate when the crane swings
becket
small eye for fastening hoist line
bird caging
form of deficiency in wire rope where the strands are separated from the core
catwalk
accessible elevated walkway on the crane structure
controls
all levers, brakes, dogs, switches, buttons, and other devices that the crane operator physically manipulates
counterjib
part of the crane that extends out from the tower to support counterweights and hoisting machinery
counterweight
heavy metal or concrete attachments secured to the counter jib to offset the weight of the extended jib and load and increase lift capacity; it rotates when the crane swings
drum
cylindrical component that is used to store and dispense line; the line is wound or spooled onto the drum when the operator causes the drum to rotate
gantry
component of a luffing tower crane that supports the jibs so that gravitational forces act on the tower, not on the jibs
gross capacity
maximum amount of weight that a specific crane and boom configuration can lift
gross load
weight of the load plus other items, such as the hook block, hoist lines and rigging
hardware
usually refers to rigging hardware, which can be any of a wide range of bolts, hooks, chains, shackles, clamps and other mechanical devices used to secure or attach to loads in preparation for hoisting
hoist line
a line that may be attached to a ball, lift hook or other assembly; the term hoist line may also be used to describe the compound assembly of lines running through the hook block
hoisting
act of manipulating the crane controls to raise or lower a load
hook block
heavy metal block containing sheaves or pulleys; the hook block is equipped with a hook for attachment of loads
hydraulic system
any system that relies on pressurized hydraulic oil to make it function
jib
part of the crane that extends out from the tower and supports the line or lines to which the load is attached
logbook
typically, a book in which the operator is required to record information, such as inspection, equipment certifications, maintenance, locations, hours worked, as well as damage and repair details
multi-crane lifts
in some instances, it is impossible to accomplish certain lifts using only one crane; in these circumstances, two or more cranes may be attached to the same load, and they are used simultaneously to perform the task. Multi-crane lifts must have an engineered lift plan
outriggers
supports that extend from the carrier vehicle to the ground to provide stability; outriggers are composed of beams and jacks
pads (mats)
wood, metal, or synthetic assemblies that are placed under the adjustable ends of the outriggers or tracks; these items increase the amount of bearing and support given by the outriggers or the tracks to the crane
pendant
cable or steel bar which attaches the jib or counter jib to the apex or gantry
radius
horizontal distance from the centre of rotation of a crane to the CoG of a load
reeving
wire rope system in which wire rope travels around sheaves to gain a mechanical advantage
rigger
designated individual whose duty it is to ensure that loads are appropriately attached or rigged
rigging
components and actions used to secure and attach loads to be lifted
self-erecting crane
tower crane in which tower and jib elements are not disassembled into component sections, and which can be transported between sites as a complete unit; the erection and dismantling processes are an inherent part of the crane’s function
sheaves
pulleys located in a hook block, boom heads, or other parts of the crane jib on which the line runs
shock loading
the effect of sudden weight change (release or application) that creates a “sudden shock” in the crane
signaller
designated individual who relays information to the crane operator
sling
any metal or synthetic flexible device used to cradle or support a load
spooling
process of winding line either onto or off of a drum on which it is stored
swing (slew)
rotating the upper works horizontally left or right
track (rail)
rail system on which a travelling undercarriage operates
weathervaning
act of releasing slew brakes to allow the crane to free swing
wire rope
often referred to as cable, this material is made of many extremely strong and flexible metal alloy wires wound in various configurations to suit a range of conditions