GLOSSARY OF LIFT- AND HOISTING TERMS, CRANE RELATED TERMINOLOGY

GLOSSARY OF LIFT- AND HOISTING TERMS, CRANE RELATED TERMINOLOGY

A

Abnormal Operating Conditions
Environmental conditions that are unfavorable, harmful, or detrimental to or for the operation of a crane, such as excessively high or low ambient temperatures, exposure to adverse weather, corrosive fumes, dust-laden or moisture-laden atmospheres, and hazardous locations.

Access Platform
A limited length platform, located on the idler girder to access to the endtruck wheels only.

Adjustable or Variable Voltage
A method of Bridge Crane Control by which the motor supply voltage can be adjusted.

Aerial crane
or 'Sky cranes' usually are helicopters designed to lift large loads. Helicopters are able to travel to and lift in areas that are more difficult to reach by a conventional crane. Helicopter cranes are most commonly used to lift units/loads onto shopping centers, multi-story buildings, highrises, etc. However, they can lift basically anything within their lifting capacity, (i.e. cars, boats, swimming pools, etc.). They also work as disaster relief after natural disasters for clean-up, and during wild-fires they are able to carry huge buckets of water over fires to put them out.

All Terrain Crane
A mobile crane which has the necessary equipment to travel with high speed on public roads/highways and on the job site in rough terrain with all wheel and crab steering. AT‘s combine the roadability of Truck-mounted Crane and the manoeuvrability of a Rough Terrain Crane.

Ambient Temperature
The temperature of the atmosphere surrounding the hoist.

Ampacity
The current carrying capacity expressed in amperes.

ANSI
The American National Standards Institute.

Appointed
Assigned specific responsibilities by the employer or the employer's representative.

Attachment point
Designed lifting point that is part of a load

Auxiliary Hoist
A supplemental hoisting unit of lighter capacity and usually higher speed than provided for the main hoist.

Automatic Crane
A crane which when activated operates through a preset cycle or cycles.

Auxiliary Girder (outrigger)
An additional girder, either solid or latticed arranged parallel to the bridge girder(s) for supporting the foot-walk, Bridge Crane Control panels, operator’s cab, etc., to reduce the torsional forces such loads might otherwise impose.

Axle, Fixed
A shaft which is fixed in the end truck and about which the wheel revolves.

Axle, Rotating
A shaft which is fixed in the wheel and which rotates on bearings fixed in the end truck.

B

B-10 Bearing Life
The B-1O bearing life of an anti-friction bearing is the minimum expected life, in hours, of 9O~7o of a group of bearings which are operated at a given speed and loading.

Bearing Life
The L-10 life of an anti-friction bearing is the minimum expected life, hours, of 90 percent of a group of bearings which are operating-at a given speed and loading. The average expected life of the bearings is approximately five times the L-10 life.

Bearing, Lifetime Lubricated
An antifriction bearing which is provided with seals and a high-stability oxidation-resistant grease to permit operation of the bearing without re-lubrication for not less than the specified B-10 life.

Block, Load
The assembly of hook, swivel, bearings, sheaves, pins and frame suspended from the hoisting ropes. In a “short type” block, the hook and the sheaves are mounted on the same member, called the swivel. In a “long type” block, the hook and the sheaves are mounted on separate members. (The supporting member for the sheaves is called the sheave pin and the supporting member for the hook is called the trunnion.)

Block, Upper
A fixed assembly of sheaves, bearings, pins and frame, located on the trolley cross members, and which supports the load block and its load by means of the ropes.

Bogie
A short end truck attached to the end of one girder (or to a connecting member if more than one bogie is used per girder). This type of end truck is used when more than four wheels are required on a crane due to the design of the runway.

Boom (of gantry cranes)
An extension of the trolley runway that may be raised or retracted to obtain clearance for gantry travel.

Boom (of overhead cranes)
A horizontal member mounted on the trolley to permit hoisting and lowering the load at a point other than directly under the hoist, drum, or trolley.

Brake
A device used for retarding or stopping motion by friction or power means.

Branch Circuit
The circuit conductors between the final overcurrent device protecting the circuit and the outlet(s).

Breaking Strength/Ultimate Strength:
Do not use breaking strength as a criterion for service of design purposes. Refer to the Working Load Limit instead.
Breaking Strength is the average force at which the product, in the condition it would leave the factory, has been found by representative testing to break, when a constantly increasing force is applied in direct line to the product at a uniform rate of speed on a standard pull testing machine. Proof testing to twice the Working Load Limit does NOT apply to hand-splice slings.
Remember: Breaking Strengths, when published, were obtained under controlled laboratory conditions. Listing of the Breaking Strength does not mean the Working Load Limit should ever be exceeded.

Bridge
The part of a crane consisting of girders, trucks, end ties, footwalks, and drive mechanism which carries the trolley or trolleys.

Bridge Conductors
The electrical conductors located along the bridge structure of a crane to provide power to the trolley.

Bridge Girder (crane girder)
The principal horizontal beams of the crane, on which carriers or trolleys travel, is supported by the end trucks, and is perpendicular to the runway.

Bridge Rail
The rail supported by the bridge girders on which the trolley travels.

Bridge Travel
The crane movement in a direction parallel to the crane runway.

Building Structure
The structural members of a building that support the building loads and on which the loads of crane or monorail equipment, and the material to be moved, will be imposed.

Bulk-handling crane
Bulk-handling cranes are designed from the outset to carry a shell grab or bucket, rather than using a hook and a sling. They are used for bulk cargoes, such as coal, minerals, scrap metal etc.

Bumper (buffer)
An energy absorbing device for reducing impact when a moving crane or trolley reaches the end of its permitted travel; or when two moving cranes or trolleys come in contact.

Bow shackle
With a larger "O" shape to the loop, this shackle can take loads from many directions without developing as much side load. However, the larger shape to the loop does reduce its overall strength. Also referred to as an anchor shackle.

C

Cab
The operator's compartment on a crane.

Cab-Operated Crane
A crane controlled by an operator in a cab located on the bridge or trolley.

Camber
The slight upward vertical curve given to girders to compensate partially for deflection due to hook load and weight of the Crane.

Capacity
The maximum rated load (in tons) which a crane is designed to handle.

Carrier
Please see “Trolley”.

Chain, Hand
The chain grasped by the operator to apply force required for lifting, lowering, or traveling motions.

Chain, Load
The load-bearing chain in a hoist.

Chain Guide
A means to guide the load chain at the load sprocket.

Circuit Breaker
A device to open and close a circuit by non-automatic means, and to open the circuit automatically on a predetermined overload of current, without injury to itself when properly applied within its rating.

Clearance
The distance from any part of the crane to a point of the nearest obstruction.

CMAA
Crane Manufacturers Association of America, Inc. (formerly EQOI—Electric Overhead Crane Institute).

Collectors
Contacting devices for collecting current from runway or bridge conductors.

Collector Shoe
The portion of a collector which makes contact by sliding on the conductor bar.

Collector Wheel
The portion of a collector which makes contact by rolling on the conductor bar.

Conductors, Bridge
The electrical conductors located along the bridge structure of a crane to provide power to the trolley.

Conductors, Runway
The electrical conductors located along a crane runway to provide power to the crane.

Contactor
An electromechanical device for opening and closing an electric power circuit.

Control Braking Means
A method of controlling crane motor speed when in an overhauling condition.

Control Actuator, Bridge Crane
A manual means at the operating station by which hoist Bridge Crane Controls are energized.

Control Enclosure, Bridge Crane
The housing containing the electrical Bridge Crane Control component.

Control Voltage
The voltage impressed on the Bridge Crane Control devices.

Controller, Bridge Crane
A device for regulating in a pre-determined way the power delivered to the motor or other equipment.

Controller, Spring Return
A controller which when released will return automatically to a neutral position.

Countertorque
A method of control by which the power to the motor is reversed to develop torque in the opposite direction.

Couplings (splices)" – Mechanical devices used to join the adjacent ends of track sections.

Cover Plate
The top or bottom plate of a box girder.

Crane
A machine for lifting and lowering a load and moving it horizontally, with the hoisting mechanism an integral part of the machine. Cranes whether fixed or mobile are driven manually or by power.

Crawler Crane
A crawler is a crane mounted on an undercarriage with a set of tracks (also called crawlers) that provide for the stability and mobility of the crane. Crawler cranes range in lifting capacity from about 40 US tons to 3500 US tons.
Crawler cranes have both advantages and disadvantages depending on their intended use. The main advantage of a crawler is that they can move around on site and then perform each lift with very little set-up, as the crane is stable on its tracks with no outriggers. In addition, a crawler crane is capable of traveling with a load. The main disadvantage of a crawler crane is that they are very heavy, and cannot easily be moved from one job site to the next without significant expense. Typically, a large crawler must be disassembled and moved by trucks, rail cars or ships to be transported to its next location.

Creep Speed
A very slow, constant, continuous, fixed rate of motion of the hoist, trolley, or bridge: usually Control established at 1% to 10% of the normal full load speed.

Cross Shaft
The shaft extending across the bridge, used to transmit torque from motor to bridge drive wheels.

Cushioned Start
An electrical or mechanical method for reducing the rate of acceleration of a travel motion.

Cantilever Gantry Crane
A gantry or semi-gantry crane in which the bridge girders extend transversely beyond the crane runway on both sides.

Chain Sprocket or Drum Groove
Grooved or notched wheel that the hoist rope or chain is seated.

Crane
A machine used to raise, lower or move a load horizontally.

Cargo
All materials carried by a vehicle or trailer including those used to operate the vehicle.

Cross-Docking
The movement of goods directly from receiving dock to shipping dock to eliminate storage expense.

Cubic Capacity
The carrying capacity of a piece of equipment according to measurement in cubic feet.

Custodian, equipment
A person assigned responsibility for a piece of hoisting and rigging equipment

Cyclic Test
A test to determine a cyclic life or acceptable cyclic rating of a tie down component or assembly.

D

Dead Loads
The loads on a structure that remain in a fixed position relative to the structure. On a crane bridge such loads include the girders, footwalk, cross shaft, drive units, panels, etc.

Deck Crane
Located on the ships and boats, these are used for cargo operations or boat unloading and retrieval where no shore unloading facilities are available. Most are diesel-hydraulic or electric-hydraulic.

Deflection
Displacement due to bending or twisting in a vertical or lateral plane, caused by the imposed live and dead loads.

Designated
Selected or assigned by the employer or the employer's representative as being qualified to perform specific duties.

Design Factor: (sometimes referred to as safety factor)
An industry term usually computed by dividing the catalog Breaking Strength by the catalog Working Load Limit and generally expressed as a ratio. For example: 4 to 1

Diaphragm
A plate or partition between opposite parts of a member, serving a definite purpose in the structural design of the member.

Disconnecting Means
A device, or group of devices, or other means whereby the conductors of a circuit can be disconnected from their power source.

Double-Girder Crane
A crane having two bridge girders mounted between and supported from the end trucks.

Drag Brake
A brake which provides retarding force without external control.

Drift Point
A point on a travel motion controller which releases the brake while the motor is not energized. This allows for coasting before the brake is set.

Drive Girder
The girder on which the bridge drive machinery is mounted.

Driving Head
A motor-driven carrier head which is supported from and propelled by the load bearing wheels.

Drum
The cylindrical member around which the ropes are wound for raising or lowering the load.

Dynamic Brake
A method of controlling crane motor speeds when in the overhauling condition to provide a retarding force.

D-shackle
Also known as a chain shackle, D-shackles are narrow shackles shaped like a loop of chain, usually with a pin or threaded pin closure. D-shackles are very common and most other shackle types are a variation of the D-shackle. The small loop can take high loads primarily in line. Side and racking loads may twist or bend a D-shackle.

E

Engineered Lift
A test load that has been identified and evaluated for use in determining the lifting capacity of the hoisting equipment.

Eddy Current Brake
A method of Bridge Crane controlling or reducing speed by means of an Bridge Crane Electrical induction load brake.

Electric Baffle
Conductors that are wired to cut off electric power to approaching motor-driven equipment if track switches, drop sections, and other movable track devices are not properly set for passage of equipment.

Electrical Interlock
An electrical device in the starter circuit which prevents a short circuit when opposite Bridge Crane Controls are operated at the same time.

Electrification
The track mounted conductor system by which the moving equipment receives its electrical power.

Emergency Brake
A method of decelerating a drive when power is not available. The braking effort may be established as a result of action by the operator, or automatically when power to the drive is interrupted.

Emergency Stop Switch
A manually or automatically operated electric switch to cut off electric power independently of the regular operating controls.

Enclosed Conductor
A conductor or group of conductors substantially enclosed to prevent accidental contact.

Enclosure
A housing to contain electrical components, usually specified by a NEMA classification number.

End Approach
The minimum horizontal distance, parallel to the runway, between the outermost extremities of the crane and the centerline of the hook.

End Stop
A device to limit travel of a trolley or crane bridge. This device normally is attached to a fixed structure and normally does not have energy absorbing ability.

End Tie
A structural member other than the end truck which connects the ends of the girders to maintain the squareness of the bridge.

End Truck
An assembly consisting of the frame and wheels which support the crane girder(s) and allow movement along the runway.

Equalizer
A device which compensates for unequal length or stretch of a rope.

Exposed
Capable of being contacted inadvertently. Applied to hazardous objects not adequately guarded or isolated.

F

Fail-Safe
A provision designed to automatically stop or safely control any motion in which a malfunction occurs.

Field Wiring
The wiring required after erection of the crane.

Fixed Transfer Section (also known as crossover)
On a monorail, a connecting track with an interlock mechanism on both ends, mounted between two interlocking cranes, used to transfer a carrier from one bridge to the other.

Fleet Angle
The angle formed by the wire rope and the drum groove or sheave groove in the plane which contains the wire rope and is parallel to the drum or sheave axis.

Floating cranes
Are used mainly in bridge building and port construction, but they are also used for occasional loading and unloading of especially heavy or awkward loads on and off ships. Some floating cranes are mounted on a pontoon, others are specialized crane barges with a lifting capacity exceeding 10,000 tons and have been used to transport entire bridge sections. Floating cranes have also been used to salvage sunken ships.

Floor-Operated Crane
A crane which is pendant or nonconductive rope controlled by an operator on the floor or an independent platform.

Footwalk
The walkway with handrail, attached to the bridge or trolley for access purposes.

G

Gantry Crane
Similar to an overhead crane, except that the bridge for carrying the trolley or trolleys is rigidly supported on two or more legs running on fixed rolls or other runway.
A gantry crane has a hoist in a fixed machinery house or on a trolley that runs horizontally along rails, usually fitted on a single beam (mono-girder) or two beams (twin-girder). The crane frame is supported on a gantry system with equalized beams and wheels that run on the gantry rail, usually perpendicular to the trolley travel direction. These cranes come in all sizes, and some can move very heavy loads, particularly the extremely large examples used in shipyards or industrial installations. A special version is the container crane (or "Portainer" crane, named by the first manufacturer), designed for loading and unloading ship-borne containers at a port.

Gantry Leg
The structural member which supports a bridge girder or end tie from the sill.

Gauge
The center-to-center distance between the load carrying flanges of the two crane girders of a double girder crane.

Ground Fault
An accidental conducting connection between the electrical circuit or equipment and the earth or some conducting body that serves in place of the earth.

H

Hanger Rod" – Steel rods which, together with other fittings, are used to suspend the track from the supporting structure.

Hazardous Locations
Regulatory Locations where fire or explosion hazards may exist. Locations are classified depending on the properties of the flammable vapors, liquids, or gases or combustible dusts or fibers which may be present and the likelihood that a flammable or combustible concentration or quantity is present. Class I locations: Locations in which flammable gases or vapors are or may be present in the air in quantities sufficient to produce explosive or ignitable mixtures. Class 2 locations: Locations that are hazardous because of the presence of combustible dust. Class 3 locations: Locations that are hazardous because of the presence of easily ignitable fibers or filings, but in which such fibers or filings are not likely to be in suspension in the air in quantities sufficient to produce ignitable mixtures.

Headroom
The distance from the load point of the hook, at its upper most position, to the top of the hoist or crane.

Hoist
An apparatus which may be a part of a crane, exerting a force for lifting or lowering a freely suspended load.

Hoist
A device that applies a force for lifting or lowering

Hoist, lever operated
A lever-operated manual device used to lift, lower, or pull a load and to apply or release tension; commonly referred to as a come-along

Hoist, chain operated
A chain operated manual device used to lift or lower a load and to apply or release tension; commonly referred to as a chain-fall

Hoist Chain
The load bearing chain in a hoist.

Hoist Motion
That motion of a crane which raises and lowers a load.

Hoist Speed
The rate of motion that the load hook attains while lifting rated load.

Holding Brake
A brake that automatically prevents motion when power is off.

Hook Approach
The minimum horizontal distance between the center of the runway rail and the hook.

Hook Approach, End
The minimum horizontal distance, parallel to the runway, between the centerline of the hook(s) and the face of the wall (or columns) at the end of the building.

Hook Approach, Side
The minimum horizontal distance, perpendicular to the runway, between the centerline of a hook (main or auxiliary) and the centerline of the runway rail.

Hook Suspended
Suspension of hoist from a trolley or rigid structure by means of a hook(s) at top of hoist.

Hot Metal Handling Crane
An overhead crane used for transporting or pouring molten material.

Hydraulic Brake
A method of Bridge Crane controlling or reducing speed by means of displacement of a liquid.

I

Interlock Mechanism
A mechanical device to lock together the adjacent ends of two cranes or a crane to a crossover or spur track to permit the transfer of carriers from one crane or track to the other.

Interlocking Crane
A crane with an interlock mechanism on one or both ends enabling it to be mechanically locked to another crane, crossover, or spur track for the purpose of transferring a carrier from one to another.

Inspector, crane
Inspector qualified to inspect cranes, hoists, and miscellaneous lifting devices

Inspector, Plate V
Inspector qualified to perform Cal/OSHA Plate V certifications

Inspector, qualified
Person recognized for competence and whose qualification to perform specific inspection activities has been determined, verified, and documented

Idle Sprocket
A freely rotating device that changes the direction of the load chain.

Idler Girder
The bridge girder that does not have the bridge drive attached, but which usually carries the bridge conductors.

Idler Sheave
A sheave used to equalize tension in opposite parts of a rope. Because of its slight movement, it is not termed a running sheave.

Impact Allowance
See Impact Factor.

Impact Factor
Additional hook load assumed to result from the dynamic effect of the live load.

Inch (inching)
See “jog”. Often used incorrectly to refer to “creep speed”.

Insulation Class
Motor winding insulation rating which indicates its ability to withstand heat and moisture.

Inverter (Variable Frequency Drive)
A method of Bridge Crane Control by which the fixed line voltage and frequency is changed to a three-phase system with infinitely variable voltage and frequency.

J

Jib Boom
A horizontal cantilever track for supporting the trolley (carrier).

Jib Crane
A jib crane is a type of crane where a horizontal member (jib or boom), supporting a moveable hoist, is fixed to a wall or to a floor-mounted pillar. Jib cranes are used in industrial premises and on military vehicles. The jib may swing through an arc, to give additional lateral movement, or be fixed. Similar cranes, often known simply as hoists, were fitted on the top floor of warehouse buildings to enable goods to be lifted to all floors.

Jog (inch)
To move the hook, trolley, or bridge in a series of short, discontinuous, increments by momentary operation of a Bridge Crane Controller.

K

Keeper
A device positioned on a hook to prevent the hook from inadvertently releasing.

KSI
Kips per square inch, measurement of stress intensity.

Kip
A unit of force, equivalent to 1000 pounds.

Knee Brace
The diagonal structural member joining the building column and roof truss.

L

Length
The distance between extreme end bearing points of the synthetic web tie down assembly including the fittings.

Level Luffing Crane
A level luffing crane is a crane mechanism where the hook remains at the same level whilst luffing; moving the jib up and down, so as to move the hook inwards and outwards relative to the base.[1]
Some types of crane are inherently level luffing: those with a fixed horizontal jib, such as gantry, hammerhead or the fixed-jib tower cranes commonly used in construction. Usually though, the description is only applied to those with a luffing jib that have some additional mechanism applied to keep the hook level when luffing.
Level luffing is most important when careful movement of a load near ground level is required, such as in construction or shipbuilding. This partially explains the popularity of fixed horizontal jibs in these fields.

Load Binder
A binder incorporating an over center locking action.

Load
The total superimposed weight on the load block or hook.

Load Block
The assembly of hook or shackle, swivel, bearing, sheaves, pins, and frame suspended by the hoisting rope.

Load Sprocket
A hoist component that transmits motion to the load chain. This component is sometimes called load wheel, load sheave, pocket wheel, or chain wheel.

Loader Crane
A loader crane (also called a knuckle-boom crane or articulating crane ) is a hydraulically-powered articulated arm fitted to a truck or trailer, and is used for loading/unloading the vehicle. The numerous jointed sections can be folded into a small space when the crane is not in use. One or more of the sections may be telescopic. Often the crane will have a degree of automation and be able to unload or stow itself without an operator's instruction.
Unlike most cranes, the operator must move around the vehicle to be able to view his load; hence modern cranes may be fitted with a portable cabled or radio-linked control system to supplement the crane-mounted hydraulic control levers.
In the UK and Canada, this type of crane is almost invariably known colloquially as a "Hiab", partly because this manufacturer invented the loader crane and was first into the UK market, and partly because the distinctive name was displayed prominently on the boom arm.
A rolloader' crane is a loader crane mounted on a chassis with wheels. This chassis can ride on the trailer. Because the crane can move on the trailer, it can be a light crane, so the trailer is allowed to transport more goods.

Latch, Hook
A device used to bridge the throat opening of a hook.

Lateral Forces
Horizontal forces perpendicular to the axis of the member being considered.

Lateral Hook Travel
The lateral movement of the load hook between its position at the upper limit of travel and its position at the lower limit of travel.

Left-hand End
A reference to parts or dimensions on the viewer’s left of the centerline of span, established when facing the drive girder side of the crane.

Lift
The maximum vertical distance through which the load hook can travel, and the total allowable hook movement between its upper limit of travel and its position when at the lower limit of travel.

Lift, critical
A lift for which the application of requirements applicable to ordinary lifts would not adequately eliminate or control the likelihood or severity of the following:
Personnel injury or significant adverse health impact (on-site or off-site)
Significant release of radioactivity or other hazardous material or other undesirable conditions
Undetectable damage that would jeopardize future operations or the safety of a facility
Damage that would result in delay to schedule or other significant program impact such as loss of vital data
Lift, ordinary. All lifts that do not meet the requirements of critical or pre-engineered production

Lift, pre-engineered production
A repetitive, production-type lifting operation, independent of the nature of the load to be lifted, in which the probability of dropping, upset, or collision is reduced to a level acceptable to the responsible manager by preliminary engineering evaluation, specialized lifting fixtures, detailed procedures, operation-specific training, and independent review and approval of the entire process.

Lift plan
Pre-job plan or procedure for safely executing a lift

Lifting device
Includes a broad range of equipment used in hoisting and rigging activities:

Lift Cycle
Single lifting and lowering motion (with or without load).

Lift Limiting Device
An electrical, mechanical, or electromechanical device for limiting the upward or downward travel of the load hook at the extremities of lift. This device may limit lift at any point within the extremities of lift, if designed to be adjustable.

Limit Switch
A switch which is operated by some part or motion of a power-driven machine or equipment to alter the electric circuit associated with the machine or equipment.

M

Main Line Disconnect
The controller used to isolate power to the hoisting equipment.

Magnet
An electromagnetic device carried on a crane hook to pick up loads magnetically.

Magnetic Contactor
An electro-magnetic device for opening and closing an electric power circuit.

Main Hoist
The primary hoist mechanism provided for lifting and lowering the rated load of the crane.

Main Switch (Crane Disconnect)
A switch on the crane bridge controlling the main power supply from the runway conductors.

Man Trolley
A trolley having an operator's cab attached thereto.

Manually Operated Crane
A crane whose hoist mechanism is driven by pulling an endless chain, or whose travel mechanism is driven in the same manner or by manually moving the load or hook.

Master Switch
A switch which dominates the operation of contactors, relays, or other remotely operated devices.

Mechanical Brake
A method of speed control by friction.

Mechanical Load Brake
An automatic type of friction brake used for Bridge Crane controlling loads in a lowering direction. This unidirectional device requires torque from the motor or hand chain wheel to lower a load but does not impose any additional load on the motor or hand chain wheel when lifting a load.

N

Non-destructive examination
The development and application of technical methods to examine materials or components in ways that do not impair future usefulness and serviceability in order to detect, locate, measure, and evaluate discontinuities, defects, and other imperfections; assess integrity, properties, and composition; and measure geometrical characteristics

Non-destructive test
Testing that does not destroy or damage the item. Examples include magnetic particle, ultrasonic, liquid penetration, or radiographic testing.

O

Overhead Crane
A crane with a movable bridge carrying a movable or fixed hoisting device that travels on a fixed runway.
Also known as a 'suspended crane', this type of crane work very similar to a gantry crane but instead of the whole crane moving, only the hoist / trolley assembly moves in one direction along one or two fixed beams, often mounted along the side walls or on elevated columns in the assembly area of factory. Some of these cranes can lift very heavy loads.

P

Parts (Lines)
Number of lines of rope supporting the load block or hook.

Patented Track
A generic term referring to crane and monorail equipment built in accordance with the MMA specification utilizing a composite track section incorporating a proprietary bottom flange shape.

Pawl
A device for holding the machinery against undesired rotation by engaging a ratchet.

Pendant Pushbutton Station
Means suspended from the crane operating the Bridge Crane Controllers from the floor or other level beneath the crane.

Person, authorized
A person at SLAC who has completed the required training and is authorized to perform the work

Person, designated
An individual selected or assigned as being qualified to perform specific duties

Person, qualified
A person who, by possession of a recognized degree, certificate, or professional standing, or who by extensive knowledge, training, and experience, has successfully demonstrated an ability and competence to solve or resolve problems relating to the subject matter and work

Person-in-charge
A qualified person responsible for the safe planning and performance of a critical lift

Plate V certification
A Cal/OSHA specified safety inspection in accordance with 8 CCR 5022 (a) through (d) performed on mobile cranes and cranes, hoists, and miscellaneous lifting devices exceeding three tons

Pitch Diameter
Distance of the diameter of a drum or sheave from center to center of a rope passed about the periphery.

Plain Reversing Bridge Crane Control
A reversing Bridge Crane Control which has identical characteristics for both directions of motor rotation.

Plugging
A Bridge Crane Control function which accomplishes braking by reversing the motor line voltage polarity or phase sequence.

Plugging Relay
A current relay used on a bridge or trolley Bridge Crane Control panel which senses current in the motor secondary circuit of an alternating current motor and limits reverse torque of the motor to the first Bridge Crane Control point until the motor rotation has stopped (Sometimes called an anti- plugging relay.)

Pneumatic Brake
A method of Bridge Crane Controlling or powering a drive or brake by means of compressed gas.

Power-Operated Crane
A crane whose mechanism is driven by electric, air, hydraulic, or internal combustion means.

Primary Upper Limit Device
the first device that, when actuated, limits hoisting motion in the upward direction.

Protective Panel
An assembly containing overload and undervoltage protection for all crane motions.

Proof Test load (Proof Load):
The term "Proof Test" designates a quality control test applied to the product for the sole purpose of detecting defects in material or manufacture. The Proof Test Load (usually twice the Working Load Limit) is the load which the product withstood without deformation when new and under laboratory test conditions. A constantly increasing force is applied in direct line to the product at a uniform rate of speed in a standard pull testing machine. The Proof Test Load does not mean the Working Load Limit should ever be exceeded.

Pulpit-Operated Crane
A crane operated from a fixed operator station not attached to the crane.

Pulley
A pulley (also called a block and tackle) is a mechanism composed of a wheel (called a sheave) with a groove between two flanges around the wheel's circumference. A rope, cable , belt or chain usually runs inside the groove. Pulleys are used to change the direction of an applied force, transmit rotational motion, or realize a mechanical advantage in either a linear or rotational system of motion.

Q

R

Rail Sweep
A device attached to the crane and located in front of the crane’s leading wheels to push aside loose obstructions.

Rail, Bridge
The track supported by the bridge girder(s), on which the trolley travels.

Rail, Runway
The track supported by the runway beams, on which the crane travels.

Railroad crane
Is a crane with flanged wheels, used by railroads. The simplest form is just a crane mounted on a railroad car or on a flatcar. More capable devices are purpose-built.

Rated Load
The maximum load for which a crane or individual hoist is designed and built by the manufacturer and shown on the equipment nameplate(s).

Reach
Is equal to lift plus headroom.

Reeving
The reeving of the hoist is the path of the rope between the hoist and the load block.

Regenerative Brake
A form of dynamic braking in which the electrical energy generated is fed back into the power system.

Regulated Speed
A function which tends to maintain constant motor speed for any load for a given speed setting of the Bridge Crane Controller.

Remote-Operated Crane
A crane controlled by an operator not in a pulpit or in the cab attached to the crane, by any method other than pendant or rope control.

Right-hand End
A reference to parts or dimensions on the viewer’s right of the centerline of span, established when facing the drive girder side of the crane.

RMG
Rail Mounted Gantry crane

RTG
Rubber Tired Gantry crane

Rope
Refers to wire rope, unless otherwise specified.

Rotary Switch
On a monorail, a track switch with a movable inner frame containing straight and/or curve sections of track. The inner frame can be rotated around a vertical axis to align these tracks with other tracks for routing carriers from one track to another.

Rough Terrain Crane
A crane mounted on an undercarriage with four rubber tires that is designed for pick-and-carry operations and for off-road and "rough terrain" applications. Outriggers that extend horizontally and vertically are used to level and stabilize the crane for hoisting.
These telescopic cranes are single-engine machines where the same engine is used for powering the undercarriage as is used for powering the crane, similar to a crawler crane. However, in a rough terrain crane, the engine is usually mounted in the undercarriage rather than in the upper, like the crawler crane.

Running Sheave
A sheave which rotates as the load block is raised or lowered.

Runway
An assembly of rails, beams, girders, brackets, and framework on which the crane or trolley travels.

Runway Disconnect Switch
A switch, usually at floor level, controlling the main power supply to the runway conductors.

Runway Girder
A horizontal beam attached to the building columns or wall, and supporting a runway rail on which the crane travels.

Runway Rail
The rail supported by the runway beams on which the bridge travels.

S

Shock Load
A load resulting from rapid change of movement, such as impacting, jerking or swinging of a static load. Sudden release of tension is another form of shock loading. Shock loads are generally significantly greater than static loads. Any shock loading must be considered when selecting the item for use in a system.
Avoid shock loads as they may exceed the Working Load Limit.

Semi-gantry Crane
A gantry crane with one end of the bridge rigidly supported on one or more legs that run along a fixed rail or runway, the other end of the bridge supported by a truck running on an elevated runway or rail.

Self-erecting Crane
Generally a type of tower crane, these cranes, also called self-assembling or "Kangaroo" cranes, lift themselves off the ground using jacks, allowing the next section of the tower to be inserted at ground level or lifted into place by the partially erected crane itself. They can thus be assembled without outside help, or can grow together with the building or structure they are erecting.

S Section
A standard beam shape as defined by the American Institute of Steel Construction.

Safety Factor
Safety factor of a line is the ratio between the breaking strength and the safe working load. Usually, a safety factor of four is acceptable, but this is not always the case. In other words, the safety factor will vary, depending on such things as the condition of the line and circumstances under which it is to be used. While the safety factor should NEVER be less than three, it often should be well above four (possibly as high as eight or ten).

Safety Lug
A mechanical device fixed securely to the end truck or trolley yoke which will limit the fall of the crane or carrier in case of wheel or axle failure.

Shackle
A shackle (also called gyve) is a U-shaped piece of metal secured with a pin or bolt across the opening, or a hinged metal loop secured with a quick-release locking pin mechanism. They are used as a connecting link in all manner of rigging systems, from boats and ships to industrial crane rigging. A carabiner is a variety of shackle used in mountaineering.

Service Platform
A means provided for workers to perform maintenance, inspections, adjustments, and repairs of cranes.

Selvage
The woven or knitted edge of synthetic webbing, so formed to prevent raveling.

Sew/Stitch Pattern
The pattern of the stitches used to sew the webbing together.

Shoring Bar
A structural section placed transversely between the walls of a vehicle to prevent cargo from tipping or shifting.

Stuffer
A longitudinal load bearing yarn in webbing.

Sheave
A grooved wheel or pulley used with a rope or chain to change direction and point of application of a pulling force.
A sheave (pronounced "shiv") is a wheel or roller with a groove along its edge for holding a belt, rope or cable. When hung between two supports and equipped with a belt, rope or cable, one or more sheaves make up a pulley. The words sheave and pulley are sometimes used interchangeably.

Side pull
That portion of the hoist pull acting horizontally when the hoist lines are not operated vertically.

Sidelifter crane
Is a road going truck or semi-trailer that is able to hoist and transport ISO standard containers. Lifting of containers is achieved through the use of parallel crane like hoists, which can be used to lift a container from the ground, or from a railway vehicle.

Simple Beam
A structural member supported and unrestrained at each end and subjected to loads acting transversely to its longitudinal axis.

Single-Girder Crane" – A crane having one bridge girder mounted between, and supported from, the end trucks.

Skewing Forces
Lateral forces on the bridge truck wheels caused by the bridge girders not running perpendicular to the runways. Some normal skewing occurs in all bridges.

Storage Bridge Crane
A gantry type crane of long span usually used for bulk storage of material; the bridge girders or trusses are rigidly or non-rigidly supported on one or more legs. It may have one or more fixed or hinged cantilever ends.

Span
The horizontal distance center to center of runway rails.

Splice
A mechanical device used to join the adjacent ends of track sections.

Spring Return
A device used on a manual Bridge Crane Controller, master switch, or pushbutton to cause the unit to return automatically to the neutral position, when released by the operator.

Stacker Crane
A crane with a forklift type mechanism used in automated (computer controlled) warehouses (known as an automated storage and retrieval system (AS/RS)). The crane moves on a track in an aisle of the warehouse. The fork can be raised or lowered to any of the levels of a storage rack and can be extended into the rack to store and retrieve product. The product can in some cases be as large as an automobile. Stacker cranes are often used in the large freezer warehouses of frozen food manufacturers. This automation avoids requiring forklift drivers to work in below freezing temperatures every day.

Standby Crane
A crane which is not in regular service but which is used occasionally or intermittently as required.

Standby Equipment
Equipment that is not in regular service but which is used occasionally or intermittently as required.

Static Bridge Crane Control
A method of switching electrical circuits without the use of contacts.

Stop
A device to limit travel of a trolley or crane bridge. This device normally is attached to a fixed structure and normally does not have energy absorbing ability.

Strength, Average Ultimate
The average tensile force per unit of cross sectional area required to rupture the material as determined by test.

Stress
Load or force per unit area tending to deform the material usually expressed in pound per square inch.

Stripper
A device that aids the load chain in leaving the load sprocket.

Structural Supports
Structural members provided for the support of runways or monorail track and switches.

STS
Ship te Shore crane. A container crane (also container handling gantry crane, ship-to-shore crane ) is a design of large dockside gantry cranes found at container terminals for loading and unloading shipping containers from container ships.
Container cranes consistent of a supporting framework that can traverse the length of a quay or yard, and a moving platform called a "spreader". The spreader can be lowered down on top of a container and locks on to the container's four locking points ("cornercastings"), using a "twistlock" mechanism. Cranes normally transport a single container at once, however some newer cranes have the capability to up pick up up to four 20' containers at once.
The crane is driven by an operator that sits in a cabin suspend from the trolley. The trolley runs along rails that are located on top or sides of the boom and girder. The operator runs the trolley over the ship to lift the cargo which generally are containers. Once the spreader latches (locks) on to the container with the Spreader, the container is lifted and moved over the dock and placed (discharged) on a truck chassis (trailer) to then be taken to the storage yard. The crane will also lift containers from the chassis to store (load) them on to the ship.
Straddle carriers, sidelifts or container lorries then manoeuvre underneath the crane base, and collect the containers—rapidly moving the containers away from the dock and to a storage yard.

Straddle Carrier
A Straddle Carrier is a non road going vehicle for use in port terminals and intermodal yards used for stacking and moving ISO standard containers. Straddles pick and carry containers while straddling their load and connecting to the top lifting points. These machines have the ability to stack containers up to 4 high. These are capable of relatively low speeds (up to 30 km/h) with a laden container.

Supporting Structure
The structure used for the support of a monorail or crane system.

Suspension Fittings
Fittings used to attach the track to the supporting structure.

Sweep
Maximum lateral deviation from straightness of a structural member, measured at right angles to the Y-Y axis.

Switch
A device for making, breaking, or for changing the connections in an electric circuit.

T

Tower Crane
A vertical crane with a horizontal boom. The boom is balanced asymmetrically across the top of the tower. Its short arm carries a counterweight while the long arm carries the lifting gear.

Tagline
An electrical conductor system employing flexible cables.

TENC
Totally enclosed fan cooled.

TENV
Totally enclosed non-ventilated.

Telescopic crane
A telescopic crane has a boom that consists of a number of tubes fitted one inside the other. A hydraulic or other powered mechanism extends or retracts the tubes to increase or decrease the total length of the boom. These types of booms are often used for short term construction projects, rescue jobs, lifting boats in and out of the water, etc. The relative compactness of telescopic booms make them adaptable for many mobile applications.
Note that while telescopic cranes are not automatically mobile cranes, many of them are. These are often truck-mounted.

Tirfors
Also commonly known as griphoists are winches that instead of using spools to move rope or wire through the winch use self-gripping jaws. Powered by moving a handle back and forth they allow one person to move objects several tons in weight.

Tongue Switch
On a monorail, a track switch containing one straight section of track, pivoted at one end, which can be swung to various positions to connect with fixed tracks for routing of carriers.

Top Running Crane
An electric overhead traveling crane having the end trucks supported on rails attached to the top of the crane runway.

Torque, Full Load (motor)
The torque produced by a motor operating at its rated horsepower and speed.

Torque, Locked Rotor
The minimum torque which a squirrel- cage motor will develop at rest, for all angular positions of the rotor, with rated voltage applied at rated frequency. Not applicable to wound-rotor (slipring) motors.

Torque, Motor Breakdown
The maximum torque which a squirrel-cage or wound-rotor (slip-ring) motor will develop with rated voltage applied at rated frequency, without an abrupt drop in speed.

Torque, Motor Full Load
The torque developed by an electric motor (A.C. or D.C.) to produce its rated horsepower at rated full load speed.

Torque, Motor Pull Up
The minimum torque developed by a squirrel cage or wound rotor (slip-ring) motor during the period of acceleration from rest to the speed at which breakdown torque occurs. For squirrel cage motors with 8% or greater slip, the pull up torque, the breakdown torque, and the starting torque are all equal and occur at zero speed.

Torsional Box Girder
Girder in which the trolley rail is located over one web.

Torsional Forces
Forces which can cause twisting of a member.

Tower Crane
The tower crane is a modern form of balance crane. Fixed to the ground (and sometimes attached to the sides of structures as well), tower cranes often give the best combination of height and lifting capacity and are used in the construction of tall buildings.
The jib (colloquially, the 'boom') and counter-jib are mounted to the turntable, where the slewing bearing and slewing machinery are located. The counter-jib carries a counterweight, usually of concrete blocks, while the jib suspends the load from the trolley. The Hoist motor and transmissions are located on the mechanical deck on the counter-jib, while the trolley motor is located on the jib. The crane operator either sits in a cabin at the top of the tower or controls the crane by radio remote control from the ground. In the first case the operator's cabin is most usually located at the top of the tower attached to the turntable, but can be mounted on the jib, or partway down the tower. The lifting hook is operated by using electric motors to manipulate wire rope cables through a system of sheaves.
In order to hook and unhook the loads, the operator usually works in conjunction with a signaller (known as a 'rigger' or 'swamper'). They are most often in radio contact, and always use hand signals. The rigger directs the schedule of lifts for the crane, and is responsible for the safety of the rigging and loads.

Track Capacity
The design load which consists of the rated load, impact allowance and load imposed by the weight of the equipment.

Track Switch
On a monorail, a device with a moving section of track that can be moved to permit passage of a carrier from incoming fixed track(s) to outgoing fixed track(s).

Tractor Drive
A motor-driven unit supported from wheels and propelled by drive wheel or wheels bearing on the underside of the track.

Trolley
The unit which travels on the bridge rails and carries the hoisting mechanism (also known as a “carrier”).

Trolley Frame
The basic structure of the trolley on which are mounted the hoisting and traversing mechanisms.

Trolley Speed
Trolley speed is the rate of motion that a motor operated trolley (and hoist) attains while traveling along a beam.

Trolley Suspended
Suspension of hoist from a trolley. Hoist can be connected to trolley by hook, clevis, or lug suspension, or the hoist can be integral with trolley.

Trolley travel
The trolley movement at right angles to the crane runway.

Truck
The unit consisting of a frame, wheels, bearings, and axles which support the bridge girders or trolleys.

True Vertical Lift
In true vertical lift, the load hook travels in a true vertical path between the lower limit of lift and the upper limit of lift.

Turntable
On a monorail, a track device with a movable inner frame containing a straight section of track which can be rotated with a loaded carrier on it to align the section of track with other tracks for the transfer of carriers from one track to another.

Two Blocking
Condition under which the load block or load suspended from the hook becomes jammed against the crane structure preventing further winding up of the hoist drum.

U

Under Running Crane
An electric overhead traveling crane having the end trucks supported on track attached to the bottom flanges of the beams; or supported on bottom flanges of beams. These beams make up the crane runway.

Undervoltage Protection
A device operative on the reduction or failure of voltage to cause and maintain the interruption of power in the main circuit.

Upper Block
A fixed block located on a trolley that, through a system of sheaves, bearings, pins, and frame, supports the load block and its load.

V

Variable Frequency
A method of Bridge Crane Control by which the motor supply voltage and frequency can be adjusted.

Voltage Drop
The loss of voltage in an electric conductor between supply tap and load tap.

W

W Section
A wide flange beam shape as defined by the American Institute of Steel Construction.

Wall Crane
A crane having a jib with or without trolley and supported from a side wall or line of columns of a building. It is a traveling type and operates on a runway attached to the side wall or columns.

Web Plate
The vertical plate connecting the upper and lower flanges or cover plates of a girder.

Wheel Load
The load without impact on any wheel with the trolley and lifted load (rated capacity) positioned on the bridge to give maximum loading.

Wheel Yoke
A frame on which a pair of carrier (trolley) wheels are mounted.

Wheelbase
Distance from center-to-center of outermost wheels.

Winch
A device for tensioning a webbing or wire rope tie down that is fitted with means to lock the initial tension.

Working Load Limit
The maximum load capacity hat any given component or assembly should be subject to during use. US Cargo Control highly recommends the ‘’ working load limit’’ does not exceed 1/3 the ‘’breaking strength capacity’’ of the component or assembly being used. Working load limits shown on this website are rated at 1/3 of the minimum breaking strength.

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