Glossary

air system

any machine system that is dependent on compressed air; the brakes on certain carriers would be an example of this type of system

all-terrain (AT) crane

all-terrain cranes typically can be configured to be driven from both the carrier and the upper; they usually have a “pick and carry” chart, and can be driven on public roads; they are rubber mounted (on tires); they have hydraulic suspension, which can be adjusted by the operator into “road” or “jobsite”; they always have hydraulic booms; these cranes usually have multiple axles, some of which may be “dead” and are for weight distribution only; they have manual rear steering in crab or cramp mode; many have automatic rear steering in cramp mode

anemometer

instrument for measuring and indicating the force or speed of the wind

attachments

accessories supplied by manufacturers to aid in crane operations

boom

the part of the crane that extends above the house (upper works or superstructure) and supports the line or lines to which the load is attached

car body

the frame of a chassis for a crawler crane to which the tracks and upper works attach

chassis

that part of the carrier that includes the steering and braking mechanisms, suspension, drive train and tracks or wheels

clamshell

special assembly installed at the lifting end of the hoist line that is designed to open and close in order to move mud, sand or other loose materials

controls

these include all levers, brakes, dogs, switches, buttons and other devices that the crane operator physically manipulates

counterweight

heavy metal or concrete attachments secured to the back of the upper works to offset the weight of the extended boom and load and increase lift capacity

crane log book

typically, a book in which the operator is required to record information, such as inspection, maintenance, locations, hours worked as well as damage and repair details

crawler crane

any mobile crane that uses a track-driven carrier

dragline

accessory installed at, and suspended by, the lifting end of the hoist line that is designed to scrape earth or other material into it as it is dragged toward the crane by a second drum

drum

a cylindrical component on the mobile crane 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

extend the boom

hydraulic cranes, in most cases, have one or more telescoping sections to the main boom; this is one feature that allows the operator to control the length of the boom

gross capacity

this is the maximum amount of weight that a specific crane and boom configuration can lift

gross load

the weight of the load plus other items, such as the hook block, hoist lines, rigging, etc.

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

this may be a single line 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

the act of manipulating the crane controls in order to move a load

hook block

a heavy metal block containing sheaves or pulleys, located at the end of the hoist line on some cranes; the hook block is equipped with a hook for attachment of loads

house

that part of the mobile crane above the carrier which rotates and supports the boom, winches, cylinders and other components; also known as upper works or superstructure

hydraulic system

any system that relies on pressurized oil to make it function; the boom on hydraulic cranes is manipulated through the use of oil under pressure

jib

an extension attached to the boom point to provide added boom length for lifting specified loads; the jib may be in line with the boom or offset to various angles and is normally wire rope supported

levelling

the process of positioning the crane so that it is level prior to lifting a load

magnet

an attachment installed at the lifting end of the hoist line in order to lift and move metal

master clutch

some cranes are equipped with a control known as the master clutch which can be manipulated to engage and disengage the power source

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

net capacity

this term applies to the weight of the item to be lifted by the crane (i.e. the gross capacity minus all capacity deductions)

net load

the load to be lifted without any deductions

outriggers

supports that extend from the carrier vehicle to the ground to provide stability; outriggers are composed of beams and jacks

overhaul ball

an iron ball placed above the hook on a lead line, which furnishes weight to allow the line to be lowered when no load is attached; also known as headache ball

pads

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

parts of line

the number of parts (individual ropes) of hoist line are calculated in accordance with the amount of weight to be hoisted; in some cases the operator must ensure that the load is lifted using a hook block that allows sufficient parts of line between the head, sheave and hook block to effectively move the load; all the parts of line are known as the hoist line

pawl

this term applies to any device or control that locks or stops machinery or components (usually winches) from rotating

piledriver

an attachment used to force metal, concrete or wooden pilings into the ground

radius

this is the horizontal distance from the centre of rotation of a crane to the centre of gravity of load with the load suspended

reeving

a method of rigging a block which results in even line pull on all sheaves; when viewed from the side, the line typically forms a “figure eight” profile

rig

describes the act of attaching loads to the hoist line

rigger

a designated individual whose duty it is to ensure that loads are appropriately attached or rigged to the hoist line of the crane

rough-terrain (RT) crane

rough-terrain cranes are driven from the upper; they are rubber mounted (on tires) and may be two wheel or all wheel drive; they may have automatic or manual rear steering; they have solid suspension and axle lockouts. RT cranes have off-road capability and typically can not be configured to drive on public roads; they have “on-rubber” charts

sheaves

the wheels or pulleys located in a hook block, boom heads, or other parts of the crane boom on which the line runs

signaller

an designated individual who relays information to the crane operator

sling

any metal or synthetic flexible device used to cradle or support a load

specialty equipment

equipment used for a specific operation

spooling

the process of winding line either onto or off of a drum on which it is stored

swing

rotating the upper works horizontally through part or all of the radius or circle

swing-away

a lattice extension pinned to the boom of a hydraulic crane; also called a jib or a fly

telescopic boom

a boom consisting of a base boom from which one or more boom sections are telescoped for additional length

tracks

the carrier system used to move certain cranes requires the use of tracks rather than wheels

truck-mounted crane

truck mounted cranes may have either lattice or hydraulic booms; the cranes are rubber mounted (on tires); these cranes must be driven from the carrier; they can be configured to be driven on public roads

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

wire rope cutter

a mechanical device especially designed to cut wire rope

Abbreviations