Dearborn Overhead Crane Glossary

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Abnormal operating conditions	General	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. (ASME B30.2-1990)
Access platform	Overhead Crane	A limited length platform, located on the idler girder to access to the endtruck wheels only.
Adjustable or variable voltage	Bridge Crane Control	A method of Bridge Crane Control by which the motor supply voltage can be adjusted. (CMAA Spec. 70)
Administrative or regulatory authority	Regulatory	Governmental agency or, in the absence of governmental jurisdiction, the employer. (ASME B30.2-1990)
Ambient temperature	General	The temperature of the atmosphere surrounding the hoist. (ASME HST-4M-1991)
Ampacity	Bridge Crane Bridge Crane Electrical	The current carrying capacity expressed in amperes. (ANSI MH 27.1-1981)
Appointed	Regulatory	Assigned specific responsibilities by the employer or the employer’s representative. (ASME B30-17)
Authorized	Regulatory	Appointed by a duly constituted administrative or regulatory authority. (ASME B30-17)
Automatic crane	Overhead Crane	A crane which when activated operates through a preset cycle or cycles. (ANSI MH 27.1-1981)
Automatic dispatch carrier	Monorail	A carrier which when activated operates through a preset cycle or cycles. (ANSI MH 27.1-1981)
Auxiliary hoist	Hoist	A supplemental hoisting unit, usually designed to handle lighter loads at a higher sped than the main host. (CMAA Spec. 70)
Axle, fixed	Drive	A shaft which is fixed in the end truck and about which the wheel revolves. (WCH)
Axle, rotating	Drive	A shaft which is fixed in the wheel and which rotates on bearings fixed in the end truck. (WCH)
B-10 bearing life	General	The B-lO 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. (ANSI MH 27.1-1981)
Base or deck mounted (hoist)	Hoist	A type of mounting where the hoist is mounted to the top side of a horizontal supporting surface. (ASME HST-4M-1991)
Battery system (backup)	Below Hook Device	Batteries used to guard against inadvertent load release due to loss of primary power to magnet system. (ASME B30.20-1985)
Beam	Overhead Crane & Hoist	An overhead standard structural or specially fabricated shape on which the trolley operates. (ASME HST-4M-1991)
Bearing life	General	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. (CMAA Spec. 70)
Bearing, lifetime lubricated	General	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.
Below the hook device
BHN	General	Brinell hardness number, measurement of material hardness. (CMAA Spec. 70)
Block, load	Hoist	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. (WCH)
Block, upper	Hoist	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. (WCH)
Bogie	Overhead Crane	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. (WCH)
Bogie, equalizing	Hoist	A short end truck which is flexibly connected to one girder (or connecting member) by means of a pin upon which the truck can oscillate to equalize the loading on the two truck wheels. This construction uses a very rigid end tie between the girders. (WCH)
Bogie, fixed	Overhead Crane	A short end truck which is rigidly connected to one girder. A flexible end tie is used between the girders to permit equalization of the wheel loads by torsional deflection of the girders and flexing of the end tie. (WCH)
Boom (of gantry cranes)	Overhead Crane	An extension of the trolley runway that may be raised or retracted to obtain clearance for gantry travel. (ASME B30.2-1990)
Boom (of overhead cranes)	Overhead Crane	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. (ASME B30.2-1990)
Box section	Overhead Crane	The rectangular cross section of girders, trucks or other members enclosed on four sides. (CMAA Spec. 70)
Brake	Overhead Crane & Hoist	A device, other than a motor, used for retarding or stopping motion by friction or power means. (CMAA Spec. 70)
Brake, Bridge Crane Control	Overhead Crane & Hoist	A method of Bridge Crane Controlling speed by removing energy from the moving body or by imparting energy in the opposite direction. (ASME B30-16-1993)
Brake, countertorque (plugging)	Hoist	A method of Bridge Crane Control by which the power to the motor is reversed to develop torque in the direction opposite to the rotation of the motor using the motor as a generator, with the energy being dissipated by resistance. (ASME B30-16-1993)
Brake, drag	Overhead Crane & Hoist	A friction brake that provides a continuous retarding force having no external Bridge Crane Control. (ASME B30-17)
Brake, dynamic	Hoist	A method of Bridge Crane Controlling speed by block, load the assembly of hook or shackle, swivel. bearing, sheaves, sprockets. pins, and frame suspended by the hoisting rope or load chain. This shall include any appurtenances reeved in the hoisting rope or load chain. (ASME B30-16-1993)
Brake, eddy current	Overhead Crane & Hoist	A method of Bridge Crane Controlling or reducing speed by means of an Bridge Crane Electrical induction load brake. (ASME B30-17)
Brake, emergency	Overhead Crane	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.(ASME B30-17)
Brake, holding	Overhead Crane & Hoist	A friction brake for a hoist that is automatically applied and prevents motion when power to the brake is off. (ASME B30.2-1990)
Brake, hydraulic	Overhead Crane	A method of Bridge Crane Controlling or reducing speed by means of displacement of a liquid. (ASME B30-17)
Brake, mechanical	Overhead Crane & Hoist	A method of Bridge Crane Controlling or reducing speed by friction. (ASME B30-17)
Brake, mechanical load	Hoist	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. (ASME B30-16-1993)
Brake, parking	Overhead Crane	A brake for bridge and trolley that may be automatically or manually applied to impede horizontal motion by restraining wheel rotation. (ASME B30-17)
Brake, pneumatic	Overhead Crane	A method of Bridge Crane Controlling or powering a drive or brake by means of compressed gas. (ASME B30-17)
Brake, regenerative	Hoist	A method of Bridge Crane Controlling speed in which the electrical energy generated by the motor is fed back into the power system. (ASME B30-17)
Brake, service	Overhead Crane	A brake for bridge or trolley used by the operator, during normal operation, to apply a retarding force. (ASME B30.2-1990)
Branch circuit	Bridge Crane Control	The circuit conductors between the final overcurrent device protecting the circuit and the outlet(s). (CMAA Spec. 70)
Breakaway force	Below Hook Device	The external force that is required to separate the vacuum pad or vacuum lifting device from the load when applied perpendicular to the attachment surface. (ASME B30.20-1985)
Bridge	Overhead Crane	That part of an overhead crane consisting of girders, trucks, end ties, walkway and drive mechanism which carries the trolley and travels in a direction parallel to the runway. (CMAA Spec. 70)
Bridge (crane) travel	Overhead Crane	Crane movement in a direction parallel to the crane runway. (ASME B30.11-1993)
Bridge conductors	Overhead Crane	The electrical conductors located along the bridge structure of a crane to provide power to the trolley. (CMAA Spec. 70)
Bridge crane, top running	Overhead Crane
Bridge Crane, Under running	Overhead Crane
Bridge girder (crane girder)	Overhead Crane	Crane member on which carriers or trolleys travel, horizontally mounted between and supported by the end trucks. Building Structure. The structural members of a building which support the building loads and on which the loads of crane or monorail equipment, and the material to be moved, will be imposed. (ANSI MH 27.1-1981)
Bridge rail	Overhead Crane	The rail supported by the bridge girders on which the trolley travels. (CMAA Spec. 70)
Bridge travel	Overhead Crane	The crane movement in a direction parallel to the crane runway. (ASME B30.2-1990)
Bumper (buffer)	Overhead Crane	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 into contact. (CMAA Spec. 70)
Cab	Overhead Crane	The operator’s compartment on a crane. (ASME B30-17)
Cab Bridge Crane Controlled		Equipment Bridge Crane Controlled from an operator’s cab. (ANSI MH 27.1-1981)
Cab, normal	Overhead Crane	Operator’s compartment used for Bridge Crane Controlling a cab-operated crane. (ASME B30.2-1990)
Cab, skeleton	Overhead Crane	Operator’s compartment used for occasional cab operation of, normally, a floor- or remote-operated crane or carrier. (ASME B30.11-1993)
Cab-operated crane	Overhead Crane	A crane Bridge Crane Controlled by an operator in a cab located on the bridge or trolley. (CMAA Spec. 70)
Camber	Overhead Crane	The slight upward vertical curve given to girders to compensate partially for deflection due to hook load and weight of the Crane. (CMAA Spec. 70)
Cantilever frame	Overhead Crane	A structural member that supports the trolley of a wall crane. (ASME B30.2-1990)
Capacity	General	The maximum rated load (in tons) which a cranes designed. to handle. (CMAA Spec. 70)
Carrier (also known as trolley)	Hoist	A unit that travels on the bottom flange of a monorail track, jib boom, or bridge girder to transport a load. (ASME B30.11-1993)
Carrier (trolley)	Overhead Crane & Hoist	An assembly with wheels which will run on monorail track or crane girders and which will support a load. (ANSI MH 27.1-1981)
Carrier head	Overhead Crane & Hoist	A 2-wheel assembly used with load bars to form a carrier or end truck. (ANSI MH 27.1-1981)
Ceiling mounted	Hoist	A type of hoist mounting where the hoist is mounted to the underside of a horizontal supporting surface. (ASME HST-4M-1991)
Chain, hand	Hoist	The chain grasped by the operator to apply force required for lifting, lowering, or traveling motions. (ASME B30-17)
Chain, load	Hoist	The load-bearing chain in a hoist. (ASME B30-17)
Chain, roller	Hoist	A series of alternately assembled roller links and pin links in which the pins articulate inside the bushings and the rollers are free to turn on the bushings. Pins and bushings are press fit in their respective link plates. . (ASME B30-16-1993)
Chain, welded link	Hoist	A chain consisting of a series of interwoven links fanned and welded. (ASME B30-16-1993)
Circuit breaker	Bridge Crane Electrical	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. (ANSI MH 27.1-1981)
Clamp	Monorail	A type of suspension fitting used to support tracks from an overhead structure fastened to the structure by means of pressure rather than welding or direct bolting. (ANSI MH 27.1-1981)
Clearance	General	Minimum distance from the extremity of a crane to the nearest obstruction. (CMAA Spec. 70)
CMAA	Overhead Crane	Crane Manufacturers Association of America, Inc. (formerly EQOI—Electric Overhead Crane Institute). (CMAA Spec. 70)
Cold current	Below hook device	The current drawn by the magnet when its coil is at 68⁰F (20⁰C) and at rated voltage. (ASME B30.20-1985)
Cold current	Below hook device	That current drawn by the magnet when its coil is at 68⁰F (20⁰C) and at rated voltage. (ASME B30.20-1985)
Collector, shoe	Bridge Crane Electrical	The portion of a collector which makes contact by sliding on the conductor bar. (ANSI MH 27.1-1981)
Collector, wheel	Bridge Crane Electrical	The portion of a collector which makes contact by rolling on the conductor bar. (ANSI MH 27.1-1981)
Collectors	Bridge Crane Electrical	Contacting devices for collecting current from the runway or bridge conductors. The mainline collectors are mounted on the bridge to transmit current from the runway conductors, and the trolley collectors are mounted on the trolley to transmit current from the bridge conductors. (CMAA Spec. 70)
Collectors	Bridge Crane Electrical	Electrical contacting devices providing a path for current flow from stationary conductors to moving equipment. (ANSI MH 27.1-1981)
Collectors, current	Bridge Crane Electrical	Contacting devices for collecting current from runway or bridge conductors. (ASME B30.2-1990)
Conductors, bridge	Overhead Crane	The electrical conductors located along the bridge girder(s) to provide power and Bridge Crane Control circuits to the trolley. (Sometimes incorrectly called trolley conductors). (WCH)
Conductors, enclosed	Bridge Crane Electrical	A bar used to transmit an electrical current, enclosed in a non-conducting material to minimize accidental contact with the conductor. (ANSI MH 27.1-1981)
Conductors, open	Bridge Crane Electrical	A bar used to transmit an electrical current. (ANSI MH 27.1-1981)
Conductors, runway (main)	Bridge Crane Electrical	The electrical conductors located along a crane runway that transmit Bridge Crane Control signals and power to the crane. (ASME B30-17)
Contactor	Bridge Crane Electrical	An electromechanical device for opening and closing an electric power circuit. (ASME HST-4M-1991)
Contactor, magnetic	Bridge Crane Control	An electro-magnetic device for opening and closing an electric power circuit. (CMAA Spec. 70)
Bridge Crane Control actuator	Bridge Crane Electrical	A manual means at the operating station by which hoist Bridge Crane Controls are energized. (ASME HST-4M-1991)
Bridge Crane Control braking means	Overhead Crane & Hoist	A method of Bridge Crane Controlling speed by removing energy from the moving body or by imparting energy in the opposite direction. (ASME HST-4M-1991)
Bridge Crane Control enclosure	Bridge Crane Electrical	The housing containing the electrical Bridge Crane Control component. (ASME HST-4M-1991)
Bridge Crane Control panel	Bridge Crane Electrical	See Bridge Crane Control enclosure.
Bridge Crane Control voltage.	Bridge Crane Electrical	The voltage impressed on the Bridge Crane Control devices. (ANSI MH 27.1-1981)
Bridge Crane Control, multi-speed	Bridge Crane Electrical	A drive Bridge Crane Control system providing more than one speed operation in either direction using multi-speed squirrel cage. motors. (ANSI MH 27.1-1981)
Bridge Crane Control, single speed	Bridge Crane Electrical	A drive Bridge Crane Control system providing one speed operation in either direction. (ANSI MH 27.1-1981)
Bridge Crane Control, variable speed	Bridge Crane Electrical	A drive Bridge Crane Control system providing more than one speed operation in either direction using wound-rotor motors.
Bridge Crane Controller	Bridge Crane Control	A device for regulating in a pre-determined way the power delivered to the motor or other equipment. (CMAA Spec. 70)
Bridge Crane Controller, manual	Bridge Crane Control	A Bridge Crane Controller having all of its basic functions performed by devices which are operated by hand. (ASME B30-17)
Bridge Crane Controller, spring return	Bridge Crane Control	A Bridge Crane Controller that, when released, will return automatically to a neutral (off) positioning, static, hydraulic, pneumatic, etc.) that governs the flow of power to or from a motor or other equipment in response to signals from a master switch, push-button station, remote Bridge Crane Control, automatic program Bridge Crane Control, or other similar device. (ASME B30.2-1990)
Countertorque	Bridge Crane Control	A method of Bridge Crane Controlling speed by applying a variable motor torque in the direction opposite to the direction that the motor is rotating due to being overhauled by the load. (ASME HST-4M-1991)
Couplings (splices)		Mechanical devices used to join the adjacent ends of track sections. (ANSI MH 27.1-1981)
Cover plate	Overhead Crane	The top or bottom plate of a box girder. (CMAA Spec. 70)
Crane		A machine for lifting, lowering, and moving a load with the hoisting mechanism a part of the machine. Cranes may be traveling, portable, or fixed type. Traveling Cranes. Cranes that follow a fixed path Underhung Crane. A traveling crane with a movable bridge running on the lower flanges of an overhead fixed runway structure and carrying a movable or fixed hoisting mechanism. (ANSI MH 27.1-1981)
Crane girder	Bridge Crane	See Bridge Girder. (ANSI MH 27.1-1981)
Crane service, heavy	Bridge Crane	Service that involves operating at 85 to 100% of rated load or in excess of 10 lift cycles/hr as a regular specified procedure. (ASME B30.2-1990)
Crane service, normal	Bridge Crane	Service that involves operating at less than 85% of rated load and not more than 10 lift cycles/hr except for isolated instances. (ASME B30.2-1990)
Crane service, normal	Bridge Crane	That service which involves operation with randomly distributed loads within the rated load limit, or with uniform loads of less than 65% of the rated load, for no more than 15% of the time of a single work shift for manually operated cranes and 25% of the time of a single work shift for electrically or pneumatically powered cranes. (ASME B30-17)
Crane service, severe	Bridge Crane	Service that involves normal or heavy service with abnormal operating conditions. (ASME B30.2-1990)
Crane, automatic	Bridge Crane	A crane which when activated operates through a preset cycle or cycles. (ASME B30-17)
Crane, cab-operated	Bridge Crane	A crane Bridge Crane Controlled by an operator in a cab attached to the bridge or trolley (refer to Fig. 1). (ASME B30-17)
Crane, cantilever gantry	Bridge Crane	A gantry or semigantry crane in which the bridge girders or trusses extend transversely beyond the crane runway on one or both sides (refer to Fig. 2). (ASME B30-17)
Crane, floor-operated	Bridge Crane	A crane that is Bridge Crane Controlled by a means suspended from the crane, operated by a person on the floor or on an independent platform (refer to Fig. 3) (ASME B30-17)
Crane, gantry	Bridge Crane	A 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 rails or other runway (refer to Fig. 4). (ASME B30-17)
Crane, hot molten material-handling	Bridge Crane	An overhead crane used for transporting or pouring molten material. (ASME B30-17)
Crane, manually operated	Bridge 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. (ASME B30.2-1990)
Crane, outdoor storage gantry	Bridge Crane	A gantry-type crane of long span usually used for storage of bulk material such as ore, coal, or other similar items; the bridge girders or trusses are rigidly or nonrigidly supported on one or more legs. It may have one or more fixed or hinged cantilever ends. . (ASME B30.2-1990)
Crane, overhead	Bridge Crane	A crane with a single or multiple girder movable bridge crane a movable or fixed hoisting mechanism and traveling on an overhead fixed runway structure. (ASME B30.2-1990)
Crane, polar	Bridge Crane	An overhead or gantry crane that travels on a circular runway. (ASME B30.2-1990)
Crane, pulpit-operated	Bridge Crane	A crane operated from a fixed operator station not attached to the crane. (ASME B30-17)
Crane, remote-operated	Bridge Crane	A crane Bridge Crane Controlled by an operator who is not in a pulpit or in a cab attached to the crane, by any method other than a means suspended from the crane. (ASME B30-17)
Crane, semi-gantry	Bridge Crane	A gantry with one end of the bridge rigidly supported on one or more legs that run on a fixed rail or runway, the other end of the bridge being supported by an end truck running on an elevated rail or runway. (ASME B30.2-1990)
Crane, single-girder	Bridge Crane	A crane having one bridge girder mounted between, and supported from, the end trucks. (ASME B30.11-1993)
Crane, standby	Bridge Crane	A crane which is not in regular service but which is used occasionally or intermittently as required. (ASME B30-17)
Crane, wall	Bridge Crane	A crane having a cantilever frame 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. (ASME B30.2-1990)
Cranes, fixed	Bridge Crane	Cranes which are non-mobile. Derricks and jib cranes are classified as fixed cranes. (ANSI MH 27.1-1981)
Cranes, portable	Bridge Crane	Cranes having a revolving superstructure with power plant, operating machinery and boom mounted on a fully mobile carriage not confined to a fixed path. Crawler, locomotive and truck cranes are classified as portable cranes.
Creep speed	Bridge Crane Control	A very slow, constant, continuous, fixed rate of motion of the hoist, trolley, or bridge: usually established at 1% to 10% of the normal full load speed. (WCH)
Cross shaft	Crane	The shaft extending across the bridge, used to transmit torque from motor to bridge drive wheels. (CMAA Spec. 70)
Crossover. (fixed transfer section)	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. (ANSI MH 27.1-1981)
Crosstrack switch	Monarail	A track switch containing one straight section of moving track pivoted in the center which can be rotated to align it with other crossing tracks to allow passage of a carrier through the junction without changing the direction of the carrier motion. (ANSI MH 27.1-1981)
Curves	Monorail	Formed sections of monorail track used to change the horizontal or vertical direction of carrier travel. (ANSI MH 27.1-1981)
Cushioned start	Bridge Crane Control	An electrical or mechanical method for reducing the rate of acceleration of a travel motion. (CMAA Spec. 70)
Cushioned start	Bridge Crane Control	An electrical or mechanical method for reducing the rate of acceleration of trolley motion. (ASME HST-4M-1991)
Dead loads	General	The loads on a structure which 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. (CMAA Spec. 70)
Deflection	Bridge Crane	Displacement due to bending or twisting in a vertical or lateral plane, caused by the imposed live and dead loads. (CMAA Spec. 70)
Designated	Regulatory	Selected or assigned by the employer or the employer’s representative as being competent to perform specific duties. (ASME B30.2-1990)
Diaphragm	Bridge Crane	A plate or partition between opposite parts of a member, serving a definite purpose in the structural design of the member. (CMAA Spec. 70)
Disconnecting means	Bridge Crane Electrical	A device, or group of devices, or other means whereby the conductors of a circuit can be disconnected from their power source. (ANSI MH 27.1-1981)
Double girder crane	Bridge Crane	A .crane having two bridge girders mounted between and supported from the end trucks. (ANSI MH 27.1-1981)
Drift point	Bridge Crane & Hoist	A point on a travel motion master switch or on a manual Bridge Crane Controller that maintains the brake released while the motor is not energized. This allows for coasting. (ASME B30.2-1990)
Drive girder	Bridge Crane	The girder on which the bridge drive machinery is mounted. (CMAA Spec. 70)
Driving head.	Bridge Crane & Monorail	A motordriven carrier head which is supported from and propelled by the load bearing wheels. (ANSI MH 27.1-1981)
Drop section (also known as lift section)	Monorail	A mechanism that will permit a section of track(s) to be lifted or lowered out of alignment with the stationary track(s). (ASME B30.11-1993)
Drum	Hoist	The cylindrical member around which rope is wound for lifting or lowering the load. (ASME B30-16-1993)
Dummy cab	Bridge Crane	An operator’s compartment or platform on a pendant or radio Bridge Crane Controlled crane, having no permanently-mounted electrical Bridge Crane Controls, in which an operator may ride while Bridge Crane Controlling the crane. (CMAA Spec. 70)
Dynamic	Bridge Crane Control	A method of Bridge Crane Controlling speed by using the motor as a generator, with the energy being dissipated by resistance. (ASME HST-4M-1991)
Dynamic lowering	Hoist	A method of Bridge Crane Control by which the hoist motor is so connected in the lowering direction, that when it is over-hauled by the load, it acts as a generator and forces current either through the resistors or back into the line. (CMAA Spec. 70)
Eddy current	Bridge Crane Control	See eddy current braking
Eddy-current braking	Bridge Crane Control	A method of Bridge Crane Control by which the motor drives through an electrical induction load brake. (CMAA Spec. 70)
Electric baffle	Bridge Crane Electrical	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. (ASME B30.11-1993)
Electric overhead traveling crane	Bridge Crane	An electrically operated machine for lifting, lowering and transporting loads, consisting of a movable bridge carrying a fixed or movable hoisting mechanism and traveling on an overhead runway structure. (CMAA Spec. 70)
Electrical braking system	Hoist	A method of Bridge Crane Controlling crane motor speed when in an overhauling condition, without the use of friction braking. (CMAA Spec. 70)
Electrically interlocked	Bridge Crane Control	An electrical device in the starter circuit which prevents a short circuit when opposite Bridge Crane Controls are operated at the same time. (ANSI MH 27.1-1981)
Electrification.	Bridge Crane Electrical	The track mounted conductor system by which the moving equipment receives its electrical power. (ANSI MH 27.1-1981)
Enclosed conductor	Bridge Crane Electrical	A conductor or group of conductors substantially enclosed to prevent accidental contact. (CMAA Spec. 70)
Enclosure	Bridge Crane Electrical	A housing to contain electrical components, usually specified by a NEMA classification number. (CMAA Spec. 70)
End approach	Bridge Crane	The minimum horizontal distance, parallel to the runway, between the outermost extremities of the crane and the centerline of the hook. (CMAA Spec. 70)
End stop	Bridge Crane & Runway	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. (CMAA Spec. 70)
End tie	Bridge Crane	A structural member other than the end truck which connects the ends of the girders to maintain the squareness of the bridge. (CMAA Spec. 70)
End truck	Bridge Crane	An assembly consisting of the frame and wheels which support the crane girder(s) and allow movement along the runway. (ASME B30.11-1993)
End truck loa	Bridge Crane
Equalizer	Hoist	A device which compensates for unequal length or stretch of a rope or chain. (ASME B30-16-1993)
Exposed	Bridge Crane Electrical	Applies to hazardous objects not guarded or isolated (capable of being contacted inadvertently). (ASME B30-17)
Fail-safe	General	A provision designed to automatically stop or safely Bridge Crane Control any motion in which a malfunction occurs. (CMAA Spec. 70)
Field wiring	General	The wiring required after erection of the crane. (CMAA Spec. 70)
Fixed axle	Bridge Crane	An axle which is fixed in the truck and on which the wheel revolves. (CMAA Spec. 70)
Fixed Transfer Section		See Crossover. (ANSI MH 27.1-1981)
Fixed transfer section (also known as crossover)	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. (ASME B30.11-1993)
Fleet angle	Hoist	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. (WCH)
Floor Bridge Crane Controlled	Bridge Crane Control	Motor propelled units which are Bridge Crane Controlled by an operator on the floor by means of pushbutton station suspended from the overhead equipment. (ANSI MH 27.1-1981)
Foot walk	Bridge Crane	The full length walkway with handrail and toeboards, attached to the bridge or trolley for access purposes. Not to be confused with an access platform (usually a short platform provided only to access endtruck).
Force, breakaway	Below hook device	— the force that must be applied to a magnet to remove it from a piece of ferromagnetic material to which it is magnetically attached. (ASME B30.20-1985)
Fork	Below hook device	A mechanical device for use on interlocking transfer equipment to mechanically prevent passage. (ANSI MH 27.1-1981)
Friction-type pressure gripping lifters	Below hook device	Lifters that grip the load without significant or harmful permanent deformation of the load surface (see Figs. 17 through 21). (ASME B30.20-1985)
Gantry crane	Bridge Crane	A 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 rails or other runway. (CMAA Spec. 70)
Gantry leg	Bridge Crane	The structural member which supports a bridge girder or end tie from the sill. (ASME B30-17)
Gauge	Bridge Crane	The center-to-center distance between the load carrying flanges of the two crane girders of a double girder crane. (ANSI MH 27.1-1981)
Girder, auxiliary (outrigger)	Bridge Crane	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. (WCH)
Girder, bridge	Bridge Crane	The principal horizontal beam(s) of the crane, which supports the trolley, is supported by the end trucks, and is perpendicular to the runway. (WCH)
Girder, drive (girder “a”)	Bridge Crane	The bridge girder to which the bridge motor and gearcase(s) are attached. For cranes having a drive on each girder, it is the girder to which the Bridge Crane Control panels and/or the cab are attached. (WCH)
Girder, idler (girder “b”)	Bridge Crane	The bridge girder which does not have the bridge drive attached, but which usually carries the bridge conductors. (WCH)
Girder, runway	Bridge Crane	A horizontal beam attached to the building columns or wall, and supporting a runway rail on which the crane travels. (WCH)
Glide switch (sliding switch)	Monorail	A track switch with a movable end frame containing straight and/or curved sections of track. The inner frame can be slid to align these sections of track with other tracks for routing carriers from one track to another. (ANSI MH 27.1-1981)
Grip ratio	Below hook device	The ratio of the sum of the horizontal forces on one side of the load to the live weight of the load. For example, if the total horizontal force on one side of the load is 100,000 lb. and the live load is 50,000 lb. the grip ratio is 2. For purposes of this calculation, the weight of the load does not include the weight of the lifter (see Fig. I). (ASME B30.20-1985)
Gripping force	Below hook device	The force the lifting device exerts on the load. (ASME B30.20-1985)
Ground fault	Bridge Crane Electrical	An accidental conducting connection between the electrical circuit or equipment and the earth or some conducting body that serves in place of the earth. (CMAA Spec. 70)
Guide, chain	Hoist	A means to guide the load chain at the load sprocket. (ASME B30-16-1993)
Hand chain	Hoist	The chain provided to Bridge Crane Control movement of a hand chain operated trolley. (ASME HST-4M-1991)
Hanger rod	Monorail	A steel rod which, together with other fittings, is used to suspend the track from the supporting structure. (ASME B30.11-1993)
Hanger rod.	Bridge Crane & Monorail	Steel rods which, together with other fittings, are used to suspend the track from the supporting structure. (ANSI MH 27.1-1981)
Hazardous (classified) 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. Refer to ANSI/NFPA 70. — 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. (ASME B30-16-1993)
Headroom	Hoist	Headroom is measured with the load hook at its upper limit of travel and is the distance from the saddle of the load hook to the following locations (see Fig. 1) — (a) centerline of the suspension holes on lug suspended hoists [see Fig. 1, sketch (a)]; — (b) saddle of the top hook on hook suspended hoists [see Fig. 1, sketch (b)]; — (c) bottom of the beam on trolley suspended hoists [see Fig. 1, sketch (c)]; — (d) supporting surface on base and deck mounted hoists [see Fig. 1, sketch (d)]; — (e) uppermost point of hoist on wall and ceiling mounted hoists [see Fig. 1, sketches (e) and (f)]. . (ASME HST-4M-1991)
High temperature service	General	A condition where the surface to which the vacuum pad (or pads) is attached is above 250⁰F (120⁰C). (ASME B30.20-1985)
Hoist	Hoist	A suspended machinery unit which is used for lifting or lowering a freely suspended (unguided) load. (ASME HST-4M-1991)
Hoist motion	Hoist	That motion which lifts or lowers a load. (ASME B30-17)
Hoist speed	Hoist	Hoist speed is the rate of motion that the load hook attains while lifting rated load.
Hoist, auxiliary	Hoist	A supplemental hoisting unit, usually of lower load rating and higher speed than the main hoist. (ASME B30-17)
Hoist, main	Hoist	The primary hoist mechanism provided for lifting and lowering the rated load of the crane. (WCH)
Holding brake	Hoist	A friction brake for a hoist which is automatically applied and prevents motion when power is off. (ASME HST-4M-1991)
Hook approach	Bridge Crane & Hoist	The minimum horizontal distance between the center of the runway rail and the hook. (CMAA Spec. 70)
Hook approach, end	Bridge Crane & Hoist	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. (WCH)
Hook approach, side	Bridge Crane & Hoist	The minimum horizontal distance, perpendicular to the runway, between the centerline of a hook (main or auxiliary) and the centerline of the runway rail. (WCH)
Hook suspended	Hoist	Suspension of hoist from a trolley or rigid structure by means of a hook(s) at top of hoist. (ASME HST-4M-1991)
Hook to hook approach	Bridge Crane
Hook; latch type	Hoist	A type of hook with a mechanical device to bridge the throat opening of the hook. (ASME HST-4M-1991)
Horizontal lift	Below hook device	A condition where the surface to which the vacuum pad (or pads) is attached is in a horizontal plane. (ASME B30.20-1985)
Idler sheave	Hoist	A sheave used to equalize tension in opposite parts of a rope. Because of its slight movement, it is not termed a running sheave. (CMAA Spec. 70)
Impact allowance	Bridge Crane	See Impact Factor.
Impact factor	Bridge Crane & Hoist	Additional hook load assumed to result from the dynamic effect of the live load. (CMAA Spec. 70)
Inch (inching)	Bridge Crane & Hoist	See “jog”. Often used incorrectly to refer to “creep speed”. (WCH)
Indentation-type pressure gripping lifters	Below hook device	Lifters that carry the load by applying force to indent the sides of the load (see Figs. 15 and 16). (ASME B30.20-1985)
Indicator, internal Bridge Crane Control function	Below hook device	An indicator which shows that the permanent magnet material in one type of electrically Bridge Crane Controlled permanent magnet has been positioned internally to provide full magnetic attraction. (ASME B30.20-1985)
Inductive load	Below hook device	An electrical load which has a lagging power factor. (ANSI MH 27.1-1981)
Industrial duty crane	Bridge Crane & Hoist	Service classification covered by CMAA Specification No. 70, ‘Specifications for Electric Overhead Traveling Cranes’. (CMAA Spec. 70)
Ingot turnover grab	Below hook device	A manipulating lifter (see Fig). (ASME B30.20-1985)
Insulation class	Bridge Crane & Hoist	Motor winding insulation rating which indicates its ability to withstand heat and moisture. (CMAA Spec. 70)
Interlock mechanism.	Bridge Crane & Monorail	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	Bridge Crane & Monorail	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. (ANSI MH 27.1-1981)
Interlocking mechanism	Monorail	A mechanical device to lock together the adjacent ends of two cranes, or a crane to a fixed transfer section or spur track, to permit the transfer of carriers from one crane or track to the other. (ASME B30.11-1993)
Inverter (variable frequency drive)	Bridge Crane Control	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. (CMAA Spec. 70)
Jib boom	Bridge Crane	A horizontal cantilever track for supporting the carrier. (ASME B30.11-1993)
Jog (inch)	Bridge Crane & Hoist	To move the hook, trolley, or bridge in a series of short, discontinuous, increments by momentary operation of a Bridge Crane Controller. (WCH)
KSI	Bridge Crane	Kips per square inch, measurement of stress intensity. (CMAA Spec. 70)
Kip	Bridge Crane & Hoist	A unit of force, equivalent to 1000 pounds. (CMAA Spec. 70)
Knee brace	General	The diagonal structural member joining the building column and roof truss. (CMAA Spec. 70)
Latch	Below hook device	A device for holding a lifter in the open or closed position. (ASME B30.20-1985)
Latch, automatic	Below hook device	A sequencing latch mechanism operated by lifter motion. (ASME B30.20-1985)
Latch, hook	Hoist	A device used to bridge the throat opening of a hook. (WCH)
Lateral forces	Runway	Horizontal forces perpendicular to the axis of the member being considered. (CMAA Spec. 70)
Lateral hook travel	Hoist	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. (ASME HST-4M-1991)
Lefthand end	Bridge Crane	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. (WCH)
Lift	Hoist	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 (see Fig. 1)
Lift (hook travel)	Hoist	The maximum vertical distance through which the hook(s) can move, as determined by the length of rope and/or the number of grooves on the drum. (WCH)
Lift cycle	Bridge Crane & Hoist	Single lifting and lowering motion (with or without load). (CMAA Spec. 70)
Lift limiting device	Hoist	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. (ASME HST-4M-1991)
Lift section	Monorail	A mechanism which will lift a section of track out of alignment with a stationary track. (ANSI MH 27.1-1981)
Lifting beam (spreader beam)	Below hook device	A load supporting lifter (see Fig. 2). (ASME B30.20-1985)
Lifting devices	Hoist	Devices which are not normally reeved onto the hoist rope or chain, such as hook-on buckets, magnets. grabs. and other supplemental devices used for ease of handling certain types of loads. The weight of these devices is to be considered part of the load to be lifted. (ASME B30-16-1993)
Limit device	Bridge Crane Control	A device which is operated by some part or motion of a power driven hoist to limit motion. (ASME B30-16-1993)
Limit switch	General	A device designed to cut off the power automatically at or near the limit of travel for the crane motion. (CMAA Spec. 70)
Line contactor	Bridge Crane Control	A contactor to disconnect power from the supply lines. (CMAA Spec. 70)
Live load	General	A load which moves relative to the structure under consideration. (CMAA Spec. 70)
Load	Bridge Crane & Hoist	The total superimposed weight on the load block or hook. (ASME B30.2-1990)
Load (capacity), rated	General	The maximum load that the lifting magnet is designated to handle by the manufacturer. (ASME B30.20-1985)
Load (capacity), specified application	General	A load applied to the lifting magnet when it is used to handle a specified load. (ASME B30.20-1985)
Load (maximum), specified	General	A load identified by part number or other Bridge Crane Controlled definition. (ASME B30.20-1985)
Load bar	Hoist	A load-carrying member between carriers load block the assembly of hook or shackle, swivel, bearing, sheaves, pins, and frame suspended by the hoist rope or load chain. This shall include any appurtenances reeved in the hoisting rope or load chain. (ASME B30.11-1993)
Load block	Hoist	The assembly of hook or shackle, swivel, bearing, sheaves, pins, and frame suspended by the hoisting rope or load chain. This shall include any appurtenances reeved in the hoisting ropes. (ASME B30.2-1990)
Load carrying flange.	Bridge Crane & Monorail	The lower flange of the track on which the load bearing wheels roll. (ANSI MH 27.1-1981)
Load cycle	Bridge Crane & Hoist	One lift cycle with load plus one lift cycle without load. (CMAA Spec. 70)
Load hook	Hoist	the hook used to connect the load to the hoist. (ASME HST-4M-1991)
Load suspension parts—	Hoist	The load suspension parts of the hoist are the means of suspension (hook or lug). the structure or housing which supports the drum or load sprocket. the drum or load sprocket. the rope or load chain, the sheaves or sprockets. And the load block or hook. (ASME B30-16-1993)
Load, dead	Bridge Crane & Hoist	The load(s) on a portion of the crane, which remain(s) in affixed position relative to the member being considered. (WCH)
Load, live	Bridge Crane & Hoist	A load which moves or varies relative to the member being considered. For the trolley, the live load consists of the rated load plus the weight of the block. For the bridge, the live load consists of the rated load plus the weight of the trolley. (WCH)
Load, rated	Hoist	The maximum load designated by the manufacturer for which a crane or individual hoist is designed and built. (ASME B30-17)
Lock bar sheer lifter		A supporting lifter (see Fig. II) . (ASME B30.20-1985)
Longitudinal stiffeners	Bridge Crane	Horizontal members attached to the web of the bridge girder to prevent web buckling. (CMAA Spec. 70)
Low temperature service	Below hook device	A condition where the surface to which the vacuum pad (or pads) is attached is below 0⁰F (—18⁰C). (ASME B30.20-1985)
Lug	Bridge Crane & Monorail	A mechanical device fixed to the end truck or wheel yoke which will prevent the crane or carrier from falling in the event of a wheel or axle failure. (ANSI MH 27.1-1981)
Lug suspended	Hoist	A hoist suspended from a trolley or permanent structure by means of bolt(s) or pin(s) through a rigid or swivel type lug. (ASME HST-4M-1991)
Magnet	Below hook device	An electromagnetic device carried on a hoist hook, used to pick up and carry loads magnetically. (ANSI MH 27.1-1981)
Magnet, lifting	Below hook device	(a) electromagnet, battery-powered — a magnet which requires continuous current supplied by a battery to maintain holding force (see Fig. 32) (b) electromagnet, externally powered — a magnet suspended from a crane which requires power from a source external to the crane (c) permanent magnet, electrically Bridge Crane Controlled — a magnet which derives holding force from permanent magnet material and requires current only during the period of attachment or release (see Fig. 33) (d) permanent magnet. manually Bridge Crane Controlled — a magnet which derives holding force from permanent magnet material and requires a manual effort during period of attachment or release (see Fig. 34). (ASME B30.20-1985)
Magnet, lifting, close proximity operated	Below hook device	A lifting magnet used in such a fashion that the operator manually positions the magnet on the load, and manually guides the magnet and load during a lift. (ASME B30.20-1985)
Magnet, lifting, close proximity operated	Below hook device	A lifting magnet used in such a fashion that the operator manually positions the magnet on the load, and manually positions the magnet and load during a lift. (ASME B30.20-1985)
Magnet, lifting, general application	Below hook device	Lifting magnets that are intended by the manufacturer to be used on a number of different geometrical shapes and do not fall under the category of remotely operated lifting magnets. (ASME B30.20-1985)
Magnet, lifting, remotely operated	Below hook device	A lifting magnet which does not require the operator or other personnel to be in close proximity to the magnet or its load while the magnet is in use (see Figs. 35 and 36). (ASME B30.20-1985)
Magnet, lifting, submersible	Below hook device	— a special magnet that has been designed to be immersed in liquid. (ASME B30.20-1985)
Magnet. Lifting, specified application		Lifting magnets that are designed for lifting specified geometrical configurations and weights of designated parts, identified by part number or other Bridge Crane Controlled definition and used in a Bridge Crane Controlled manner. (ASME B30.20-1985)
Magnetic Bridge Crane Control	Bridge Crane Control	A means of Bridge Crane Controlling direction and speed by using magnetic contactors and relays. (CMAA Spec. 70)
Main hoist	Hoist	The primary hoist mechanism provided for lifting and lowering the rated load. (ASME B30.2-1990)
Main line contactor	Bridge Crane Control	A magnetic contactor used in the incoming power circuit from the main line collectors. (CMAA Spec. 70)
Main line disconnect switch	Bridge Crane Control	A manual switch which breaks the power lines leading from the main line collectors. (CMAA Spec. 70)
Man trolley	Monorail	A trolley having an operator’s cab attached to it. (ASME B30.2-1990)
Manipulating lifter	Below hook device	A lifter that rotates the load about one or more axes during the lifting process (see Figs. 22 through 26). (ASME B30.20-1985)
Manual-magnetic disconnect switch	Bridge Crane Control	A power disconnecting means consisting of a magnetic-contactor that can be operated by remote pushbutton and can be manually operated by a handle on the switch. (CMAA Spec. 70)
Master switch	Bridge Crane Control	A manually operated device which serves to govern the operation of contactors and auxiliary devices of an electric Bridge Crane Control. (CMAA Spec. 70)
Match marking	General	Identification of non-interchangeable parts for reassembly after shipment. (CMAA Spec. 70)
Mean effective load	Bridge Crane & Hoist	A load used in durability calculations accounting for both maximum and minimum loads. (CMAA Spec. 70)
Mechanical braking means	Bridge Crane & Hoist	A method of Bridge Crane Controlling or reducing speed by friction. (ASME HST-4M-1991)
Mechanical load brake	Hoist	An automatic type of friction brake used for Bridge Crane Controlling loads in a lowering direction. This unidirectional device requires torque from the motor to lower a load but does not impose additional load on the motor when lifting a load.. (ASME HST-4M-1991)
Mechanically interlocked	Bridge Crane Control	A mechanical device which prevents operation of opposite Bridge Crane Controls at the same time. (ANSI MH 27.1-1981)
Messenger track	Bridge Crane	A horizontal member, mounted along a handrail or girder, supporting movable carriers from which festooned wires are hung. The festooned wires may be used to transmit current from the bridge to the trolley or from the bridge to a pendant Bridge Crane Control unit. (WCH)
Mill duty crane	Bridge Crane & Hoist	Service classification covered by AISE Standard No. 6, ‘Specification for Electric Overhead Traveling Cranes for Steel Mill Service’. (CMAA Spec. 70)
Monorail	Monorail	An overhead track upon which carriers travel, used to transport loads. (ANSI MH 27.1-1981)
Motor circuit switch	Bridge Crane Control	A switch, rated in horsepower, capable of interrupting the maximum operating overload current of a motor of the same horsepower rating as the switch at the rated voltage. (ANSI MH 27.1-1981)
Multiple-pad mechanical vacuum lifter	Below hook device	See Fig. 29 .
Non-coasting mechanical drive	Bridge Crane	A drive with coasting characteristics such that it will stop the motion within a distance in feet equal to 10 percent of the rated speed in feet per minute when traveling at rated speed with rated load. (CMAA Spec. 70)
Normal operating conditions	Bridge Crane & Hoist	Conditions during which a hoist is performing functions within the scope of the original design. (ASME HST-4M-1991)
Normal operating conditions (of cab-operated cranes or carriers)	Bridge Crane	Conditions during which a crane or carrier is performing functions within the scope of the original design. Under these conditions, the operator manually operated hoists, and 25% of the time for electric or pneumatic-powered hoists, of a single work shift. (ASME B30.11-1993)
Normal operating conditions (of floor-operated cranes)	Bridge Crane	Conditions during which a crane is performing functions within the scope of the original design. Under these conditions, the operator is at the operating Bridge Crane Control devices that are attached to the crane but operated with the operator off the crane, and there is no person on the crane. (ASME B30.2-1990)
Normal walking speed.	General	A walking speed assumed to be 150 feet per minute (45.7 meters per minute). of a carrier when the elements are not securely locked. (ANSI MH 27.1-1981)
Operator’s cab	Bridge Crane	The operator’s compartment from which movements of the crane are Bridge Crane Controlled. To be specified by the manufacturer as open, having only sides or a railing around the operator, or enclosed, complete with roof, windows, etc. (CMAA Spec. 70)
Overload	Bridge Crane & Hoist	Any load greater than the rated load.(CMAA Spec. 70)
Overload limit device	Hoist	Refer to Section 4.3 for a complete definition. (CMAA Spec. 70)
Overload protection (overcurrent)	Hoist	A device operative on excessive current to cause and maintain the interruption or reduction of current flow to the equipment governed. (CMAA Spec. 70)
Overspeed lifting	Hoist
Overtravel restraint	Hoist	A device used to prevent the slack load chain from inadvertently being lowered out of the load sprocket. (ASME B30-16-1993)
Parts (lines)	Hoist	Number of lines of rope supporting the load block or hook. (ASME HST-4M-1991)
Patented track	Bridge Crane	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. (CMAA Spec 74)
Pawl	Hoist	A device for holding the machinery against undesired rotation by engaging a ratchet. (ASME B30-16-1993)
Peel-off	Below hook device	A prying action which takes place when deflection of an overhanging load exceeds the compensating ability of the vacuum pad or vacuum lifting device resulting in loss of load. (ASME B30.20-1985)
Pendant pushbutton station	Bridge Crane & Hoist	Means suspended from the crane operating the Bridge Crane Controllers from the floor or other level beneath the crane. (CMAA Spec. 70)
Pitch diameter	Hoist	The distance from center to center of a rope passing over a sheave or wound on a drum, measured across the diameter of the sheave or drum power transmission parts the power transmission parts of the hoist are the machinery components, including the gears, shafts, clutches, couplings, bearings, motors, and brakes. (ASME HST-4M-1991)
Pitch diameter (rope)	Hoist	Distance through the center of ~ drum or sheave from center to center of a rope passed about the periphery. (CMAA Spec. 70)
Plain reversing Bridge Crane Control	Bridge Crane & Hoist	A reversing Bridge Crane Control which has identical characteristics for both directions of motor rotation. (CMAA Spec. 70)
Plugging	Bridge Crane Control	A Bridge Crane Control function which accomplishes braking by reversing the motor line voltage polarity or phase sequence. (CMAA Spec. 70)
Plugging relay	Bridge Crane Control	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. In a direct current Bridge Crane Control panel, the relay performs the same function by establishing a patented sensing circuit at the motor armature. (Sometimes called an anti- plugging relay.) (WCH)
Primary upper limit device	Hoist	The first device that, when actuated, limits hoisting motion in the upward direction. (ASME B30.2-1990) Important, this is not to be used as a operational limit switch.
Process crane	Bridge Crane
Protective panel	Bridge Crane Control	An assembly containing overload and undervoltage protection for all crane motions. (CMAA Spec. 70)
Pulpit Bridge Crane Controlled	Bridge Crane & Monorail	A unit operated from a fixed operator station not attached to the crane. Pushbutton Station. A device consisting of pushbutton operated contacts in an enclosure used by the operator for Bridge Crane Control of the powered motions of the crane, hoist, and other auxiliary equipment. (ANSI MH 27.1-1981)
Push button station	Hoist	An electrical Bridge Crane Control device, consisting of push button operated contacts, used by the operator for the Bridge Crane Control of the powered motions of the crane, hoist, and other auxiliary equipment. (ASME B30-17)
Qualified person	Regulatory	A person who, by possession of a recognized degree or certificate of professional standing or by extensive knowledge, training, and experience, has successfully demonstrated the ability to solve or resolve problems relating to the subject matter and work. (ASME B30-17)
Radio Bridge Crane Controlled	Bridge Crane Control	A unit operated from a radio transmitter located at a point not mechanically attached to the device being Bridge Crane Controlled. (ANSI MH 27.1-1981)
Rail sweep	Bridge Crane	A device attached to the crane and located in front of the crane’s leading wheels to push aside loose obstructions. (ASME B30-17)
Rail, bridge	Bridge Crane	The track supported by the bridge girder(s), on which the trolley travels. (WCH)
Rail, runway	Runway	The track supported by the runway beams, on which the crane travels. (WCH)
Rated load (capacity)	Bridge Crane & Hoist	The maximum load designated by the manufacturer for which a crane or individual hoist is designed and built. (ASME B30.2-1990)
Reach	Hoist	Reach is equal to lift plus headroom. (ASME HST-4M-1991)
Reeving	Hoist	The reeving of the hoist is the path of the rope between the hoist and the load block — (a) double reeving two parts of line leading off of the drum (see Fig. 2). — (b) single reeving one part of the line leading off of the drum (see Fig. 2). (ASME HST-4M-1991)
Regenerative braking means	Hoist	A method of Bridge Crane Controlling speed in which the electrical energy generated by the motor is fed back into the power system rope refers to wire rope unless otherwise specified. (ASME HST-4M-1991)
Regulated speed	Bridge Crane & Hoist	A function which tends to maintain constant motor speed for any load for a given speed setting of the Bridge Crane Controller. (CMAA Spec. 70)
Remote Bridge Crane Controlled	Bridge Crane Control	A unit operated from a Bridge Crane Control station located at a point not mechanically attached to the device being Bridge Crane Controlled. (ANSI MH 27.1-1981)
Righthand end	Bridge Crane	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. (WCH)
Rope	Hoist	Refers to wire rope unless otherwise specified. (ASME B30-17)
Rope drum	Hoist	The cylindrical member around which the rope is wound for lifting and lowering the load. (ASME HST-4M-1991)
Rope sheave	Hoist	A grooved wheel used with a rope to change direction and point of application of a pulling force. (ASME HST-4M-1991)
Rotary switch	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. (ANSI MH 27.1-1981)
Rotating axle	Bridge Crane	An axle which rotates with the wheel.(CMAA Spec. 70)
Running sheave	Hoist	A sheave that rotates as the hook is lifted or lowered. (ASME HST-4M-1991)
Runway	Runway	The rails, beams, brackets and framework on which the crane operates. (CMAA Spec. 70)
Runway conductors	Runway	The main conductors mounted on or parallel to the runway which supplies current to the crane. (CMAA Spec. 70)
Runway rail	Runway	The rail supported by the runway beams on which the bridge travels. (CMAA Spec. 70)
S section	Bridge Crane & Runway	A standard beam shape as defined by the American Institute of Steel Construction. (CMAA Spec. 74)
Safety lug	Bridge Crane	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. (CMAA Spec. 74)
Service platform	Bridge Crane	A means provided for workers to perform maintenance, inspections, adjustments, and repairs of cranes (ASME B30-17)
Service, heavy	Bridge Crane & Hoist	That service which involves operation within the rated load limit which exceeds normal service. (ASME B30-16-1993)
Service, normal	Bridge Crane & Hoist	That distributed service which involves operation with randomly distributed loads within the rated load limit, or uniform loads less than 65% of rated load for not more than 15% of the time for manually operated hoists, and 25% of the time for electric-or air-powered hoists. (ASME B30-16-1993)
Service, severe	Bridge Crane & Hoist	That service which involves normal or heavy service with abnormal operating conditions. (ASME B30-16-1993)
Shall	Regulatory	This word indicates that a rule is mandatory and must be followed. (ASME B30.2-1990)
Shear breakaway force	Below hook device	The external force that is required to separate or slide the vacuum pad or vacuum lifting device on the load when the force is applied parallel to the attached load surface. (ASME B30.20-1985)
Sheave	Hoist	A grooved wheel or pulley used with a rope or chain to change direction and point of application of a pulling force. (CMAA Spec. 70)
Sheave, running	Hoist	A sheave which rotates as the load block is lifted or lowered. (ASME B30-16-1993)
Sheave; nonrunning (equalizer)	Hoist	A sheave used to equalize tension in opposite parts of the rope. Because of its slight movement, it is not termed a running sheave. . (ASME B30.2-1990)
Should	Regulatory	This word indicates that a rule is a recommendation, the advisability of which depends on the facts in each situation. (ASME B30.2-1990)
Side pull	Hoist	The component of the hoist pull acting horizontally when the hoist lines are not operated vertically. (ASME B30-17)
Simple beam	General	A structural member supported and unrestrained at each end and subjected to loads acting transversely to its longitudinal axis. (ANSI MH 27.1-1981)
Single reeved	Hoist
Skeleton cab	Bridge Crane	Same as dummy cab. (CMAA Spec. 70)
Skewing forces	Bridge Crane	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. (CMAA Spec. 70)
Span	Bridge Crane	The horizontal distance center-to-center of runway rails. (CMAA Spec. 70)
Splice	Bridge Crane & Monorail	A mechanical device used to join the adjacent ends of track sections. (ASME B30.11-1993)
Spring return	Bridge Crane Control	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. (WCH)
Sprocket, idle	Hoist	A freely rotating device that changes the direction of the load chain. (ASME B30-16-1993)
Sprocket. Load	Hoist	A hoist component that transmits motion to the load chain. This component is sometimes called load wheel, load sheave, pocket wheel, or chain wheel. (ASME B30-16-1993)
Spur track	Monorail	A fixed track arranged to interlock with an adjacent crane girder to permit passage of carriers from the spur track to the crane, and vice versa. (ASME B30.11-1993)
Squaring shaft	Bridge Crane	A driven shaft which transmits torque to drive wheels operating on two or more tracks. (ANSI MH 27.1-1981)
Standby equipment	Bridge Crane & Hoist	Equipment that is not in regular service but which is used occasionally or intermittently as required. (ASME B30.11-1993)
Static Bridge Crane Control	Bridge Crane Control	A method of switching electrical circuits without the use of contacts. (CMAA Spec. 70)
Stationary track.		A fixed track attached to the building or supporting structure. (ANSI MH 27.1-1981)
Stepless Bridge Crane Control	Bridge Crane Control	A type of Bridge Crane Control system with infinite speed Bridge Crane Control between minimum speed and full speed. (CMAA Spec. 70)
Stepped Bridge Crane Control	Bridge Crane Control	A type of Bridge Crane Control system with fixed speed points. (CMAA Spec. 70)
Stop	Runway	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. (ASME B30-17)
Strength, average ultimate	General	The average tensile force per unit of cross sectional area required to rupture the material as determined by test. (CMAA Spec. 70)
Stress	General	Load or force per unit area tending to deform the material usually expressed in pound per square inch. (CMAA Spec. 74)
Stripper	Hoist	A device that aids the load chain in leaving the load sprocket. (ASME B30-16-1993)
Structural lifting device	Below hook device	A lifter consisting of an assembly of rigid parts designed to hold and attach a load to a hoistway device. (ASME B30.20-1985)
Structural supports	Runways	Structural members provided for the support of runways or monorail track and switches. (ANSI MH 27.1-1981)
Supporting lift	Below hook device	A lifter that carries the load on rigid projection(s) or bearing surface(s) (see Figs. 2 through 14). (ASME B30.20-1985)
Supporting structure.	Runways	The structure used for the support of a monorail or crane system. (ANSI MH 27.1-1981)
Suspension fittings	Bridge Cranes & Hoist	Fittings used to attach the track to the supporting structure. (ANSI MH 27.1-1981)
Sweep	Bridge Crane & Runway	Maximum lateral deviation from straightness of a structural member, measured at right angles to the Y-Y axis. (CMAA Spec. 70)
Switch, cross-track	Monorail	A track switch containing one straight section of track, pivoted about the center, which can be rotated to align with other crossing tracks to allow passage of the carrier through the junction without changing the direction of the carrier motion. (ASME B30.11-1993)
Switch, emergency stop	Bridge Crane Control	A manually actuated switch to disconnect power independently of the regular operating Bridge Crane Controls. (ASME B30-17)
Switch, glide (slide)	Monorail	A track switch with a movable inner frame containing straight or curved sections of track. The inner frame can be moved to align these sections of track with other fixed tracks to permit routing of carriers. (ASME B30.11-1993)
Switch, limit	Bridge Crane Control	A device that is actuated by the motion of a part of a power-driven machine or equipment to alter or disconnect the electric, hydraulic, or pneumatic circuit associated with the machine or equipment. (ASME B30-17)
Switch, main (crane disconnect)	Bridge Crane Control	A switch on the crane Bridge Crane Controlling the main power supply from the runway conductors. (ASME B30-17)
Switch, master	Bridge Crane Control	Switch that dominates the operation of contactors, relays, or other remotely operated devices. (ASME B30-17)
Switch, master, spring-return	Bridge Crane Control	A master switch that when released will return automatically to a neutral (OFF) position. (ASME B30-17)
Switch, runway disconnect	Bridge Crane Control	A switch, usually at floor level, Bridge Crane Controlling the main power supply to the runway conductors. (ASME B30-17)
Switch, tongue	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. (ASME B30.11-1993)
Switch, track	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). (ASME B30.11-1993)
Tagline	Bridge Crane Electrical	An electrical conductor system employing flexible cables. (ANSI MH 27.1-1981)
Technical lifting device	Below hook device	A mechanism composed of two or more rigid parts which move with respect to each other for attaching a load to a hoisting device. (ASME B30.20-1985)
TENC	Bridge Crane Control	Totally enclosed fan cooled. (CMAA Spec. 70)
TENV	Bridge Crane Control	Totally enclosed non ventilated. (CMAA Spec. 70)
Test, application breakaway force	Below hook device	A test that is carried out in accordance with instructions from the manufacturer of the lifting magnet in order to establish the application breakaway force. (ASME B30.20-1985)
Test, rated breakaway force	Below hook device	A test that is carried out per para. 20-3.3.2(b)(2) in order to establish the rated breakaway force. (ASME B30.20-1985)
Tongue switch.	Monorail	A switch that contains one straight section of track, pivoted at one end, which can be swung to various positions to connect with other tracks for transfer of carriers from one to the other. (ANSI MH 27.1-1981)
Top running crane	Bridge Crane	An electric overhead traveling crane having the end trucks supported on rails attached to the top of the crane runway.(CMAA Spec. 74)
Torque, full load (motor)	Bridge Crane Control	The torque produced by a motor operating at its rated horsepower and speed. (CMAA Spec. 70)
Torque, locked rotor	Bridge Crane Control	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 (slip-ring) motors. (WCH)
Torque, motor breakdown	Bridge Crane Control	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. (WCH)
Torque, motor full load	Bridge Crane Control	The torque developed by an electric motor (A.C. or D.C.) to produce its rated horsepower at rated full load speed. (WCH)
Torque, motor pull up	Bridge Crane Control	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. (WCH)
Torsional box girder	Bridge Crane	Girder in which the trolley rail is located over one web. (CMAA Spec. 70)
Torsional forces	Bridge Crane	Forces which can cause twisting of a member. (CMAA Spec. 70)
Track	Monorail	The structural member that supports the carrier or crane wheels. (ASME B30.11-1993)
Track capacity.	Bridge Crane & Monorail	The design load which consists of the rated load, impact allowance and load imposed by the weight of the equipment.(ANSI MH 27.1-1981)
Track curves	Monorail	Curved sections of monorail track used to change the direction of carrier travel. (ASME B30.11-1993)
Track hangers	Monorail	Fittings used to suspend the track from the supporting structure. (ASME B30.11-1993)
Track joint	Monorail	The point at which two sections of track are joined together. (ASME B30.11-1993)
Track joint		The point at which two sections of track are joined together. (ANSI MH 27.1-1981)
Track opener	Monorail	A section of monorail track arranged to lift or swing out of line to make an opening through which a door may pass. (ASME B30.11-1993)
Tractor drive	Bridge Crane & Monorail	A motordriven unit supported from wheels and propelled by drive wheel or wheels bearing on the underside of the track. (ANSI MH 27.1-1981)
Trolley	Hoist	A wheeled mechanism from which a hoist is suspended to provide horizontal motion of the hoist along a beam. (ASME HST-4M-1991)
Trolley		See Carrier.
Trolley (carrier)	Hoist	The unit which travels on the bottom flange of the bridge girder and carries the hoist. (ASME B30-17)
Trolley frame	Hoist	The basic structure of the trolley on which are mounted the hoisting and traversing mechanisms. (CMAA Spec. 70)
Trolley speed	Hoist	Trolley speed is the rate of motion that a motor operated trolley (and hoist) attains while traveling along a beam. (ASME HST-4M-1991)
Trolley suspended	Hoist	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. (ASME HST-4M-1991)
Trolley travel	Hoist	The trolley movement in directions at right angles to the crane runway. (ASME B30-17)
Truck	Bridge Crane	A unit consisting of a frame, wheels, bearings, and axles that supports the bridge girders, the end ties of an overhead crane, or the sill of a gantry crane unattended a condition in which the operator of a crane is not at the operating Bridge Crane Control devices. However, on a floor-operated crane, if the operating Bridge Crane Control devices are within sight of the operator and within a distance equal to the span of the crane, the crane. e should be considered attended. (ASME B30.2-1990)
True vertical lift	Hoist	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. (ASME HST-4M-1991)
Turntable	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. (ASME B30.11-1993)
Two blocking	Hoist	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. (CMAA Spec. 70)
Under running crane	Bridge 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. (CMAA Spec. 74)
Undervoltage protection	Bridge Crane Control	A device operative on the reduction or failure of voltage to cause and maintain the interruption of power in the main circuit. (CMAA Spec. 70)
Upper block	Hoist	A fixed block located on a trolley that, through a system of sheaves, bearings, pins, and frame, supports the load block and its load. (ASME B30.2-1990)
Vacuum	Below hook device	— pressure less than ambient atmospheric pressure. (ASME B30.20-1985)
Vacuum lifter	Below hook device	— a below-the-hook lifting device for lifting and transporting loads in a fixed attitude using a holding force by means of vacuum. (ASME B30.20-1985)
Vacuum manipulator	Below hook device	A vacuum lifter capable of repositioning the load while suspended. (ASME B30.20-1985)
Vacuum pad	Below hook device	A device which applies a holding force on the load by means of vacuum. (ASME B30.20-1985)
Vacuum reservoir	Below hook device	The evacuated portion of the vacuum system whose function is to compensate for leakage into the vacuum system or to provide a vacuum reserve in event of vacuum generator failure. (ASME B30.20-1985)
Variable frequency	Bridge Crane Control	A method of Bridge Crane Control by which the motor supply voltage and frequency can be adjusted. (CMAA Spec. 70)
Vertical lift	Below hook device	A condition where the surface to which a vacuum pad is attached is in a vertical plane. (ASME B30.20-1985)
Voltage drop	Bridge Crane Control	The loss of voltage in an electric conductor between supply tap and load tap. (CMAA Spec. 70)
W section	Bridge Crane & Runway	A wide flange beam shape as defined by the American Institute of Steel Construction. (CMAA Spec. 74)
Wall mounted	Hoist	A type of hoist mounting in which the hoist is mounted to a vertical surface. (ASME HST-4M-1991)
Web plate	Bridge Crane	The vertical plate connecting the upper and lower flanges or cover plates of a girder. (CMAA Spec. 70)
Wheel load	Bridge Crane & Runway	The load without impact on any wheel with the trolley and lifted load (rated capacity) positioned on the bridge to give maximum loading. (CMAA Spec. 70)
Wheel yoke	Bridge Crane & Monorail	A frame on which a pair of carrier (trolley) wheels are mounted. (ANSI MH 27.1-1981)
Wheelbase	Bridge Crane	Distance from center-to-center of outermost wheels. (CMAA Spec. 70)