EOT Overhead Bridge Crane Terminology

Definitions from CMAA, ASME/ANSI B30, AIST, Whiting Handbook 

ACCESS PLATFORM

A limited length platform, located on the idler girder to access to the end truck wheels only.

ADJUSTABLE OR VARIABLE VOLTAGE/CMAA Spec 70

A method of control by which the motor supply voltage can be adjusted. 

ADMINISTRATIVE OR REGULATORY AUTHORITY/ASME B30.2

Governmental agency or, in the absence of governmental jurisdiction, the employer.  

AMPACITY/ANSI MH 27.1

The current carrying capacity expressed in amperes. 

APPOINTED/ASME B30-17

Assigned specific responsibilities by the employer or the employer’s representative. 

AUTHORIZED/ASME B30-17

Appointed by a duly constituted administrative or regulatory authority.  

AUTOMATIC CRANE/ANSI MH 27.1

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

AUTOMATIC DISPATCH CARRIER/ANSI MH 27.1

A carrier which when activated operates through a preset cycle or cycles. 

AUXILIARY HOIST/CMAA Spec 70

A supplemental hoisting unit, usually designed to handle lighter loads at a higher speed than the main host. 

AXLE, FIXED/Whiting Crane Handbook

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

AXLE, ROTATING/Whiting Crane Handbook

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

B-10 BEARING LIFE/ANSI MH 27.1

The B-10 bearing life of an anti-friction bearing is the minimum expected life, in hours, of a group of bearings which are operated at a given speed and loading. 

BASE OR DECK MOUNTED (HOIST)/ASME HST-4M

A type of mounting where the hoist is mounted to the top side of a horizontal supporting surface. 

BATTERY SYSTEM (BACKUP)/ASME B30.20

Batteries used to guard against inadvertent load release due to loss of primary power to magnet system. 

BEAM/ASME HST-4M

An overhead standard structural or specially fabricated shape on which the trolley operates.  

BEARING LIFE/CMAA Spec 70

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/CMAA Spec 70

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

Device located below the hoist hook to manipulate the object being carried.

BLOCK, LOAD/Whiting Crane Handbook

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 trunion.)

BLOCK, UPPER/Whiting Crane Handbook

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/Whiting Crane Handbook

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. 

BOGIE, EQUALIZING/Whiting Crane Handbook

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. 

BOGIE, FIXED/Whiting Crane Handbook

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.

BOX SECTION/CMAA Spec 70

The rectangular cross section of girders, trucks or other members enclosed on four sides. 

BRAKE/CMAA Spec 70

A device, other than a motor, used for retarding or stopping motion by friction or power means. 

BRAKE, CONTROL/ELECTRICAL/ASME B30-16

A method of controlling speed by removing energy from the moving body or by imparting energy in the opposite direction.  

BRAKE, COUNTERTORQUE (PLUGGING)/ASME B30-16

A method of 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.  

BRAKE, DRAG/ASME B30-17

A friction brake that provides a continuous retarding force having no external control.  

BRAKE, DYNAMIC/ASME B30-16

A method of 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.  

BRAKE, EDDY CURRENT/ASME B30-17

A method of controlling or reducing speed by means of an electrical induction load brake.  

BRAKE, EMERGENCY/ASME B30-17

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. 

BRAKE, HOLDING/ASME B30.2

A friction brake for a hoist that is automatically applied and prevents motion when power to the brake is off. 

BRAKE, HYDRAULIC/ASME B30-17

A method of controlling or reducing speed by means of displacement of a liquid. 

BRAKE, MECHANICAL/ASME B30-17

A method of controlling or reducing speed by friction. 

BRAKE, MECHANICAL LOAD/ASME B30-16

An automatic type of friction brake used for 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.  

BRAKE, PARKING/ASME B30-17

A brake for bridge and trolley that may be automatically or manually applied to impede horizontal motion by restraining wheel rotation.  

BRAKE, PNEUMATIC/ASME B30-17

A method of controlling or powering a drive or brake by means of compressed gas.

BRAKE, REGENERATIVE/ASME B30-17

A method of controlling speed in which the electrical energy generated by the motor is fed back into the power system.  

BRAKE, SERVICE/ASME B30.2

A brake for bridge or trolley used by the operator, during normal operation, to apply a retarding force.  

BRANCH CIRCUIT/CMAA Spec 70

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

BREAKAWAY FORCE/ASME B30.20

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. 

BRIDGE/CMAA Spec 70

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. 

BRIDGE (CRANE) TRAVEL/ASME B30.11

Crane movement in a direction parallel to the crane runway. 

BRIDGE CONDUCTORS/CMAA Spec 70

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

BRIDGE CRANE, TOP RUNNING/CMAA Spec 70

Overhead crane configuration such that the crane end truck wheels ride on the top of the runway rails.

BRIDGE CRANE, UNDER RUNNING/CMAA Spec 70

Overhead crane configuration such that the crane end truck wheels ride on the bottom flange of the runway beam.

BRIDGE GIRDER (CRANE GIRDER)/ANSI MH 27.1

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. 

BRIDGE RAIL/CMAA Spec 70

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

BRIDGE TRAVEL/ASME B30.2

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

BUMPER (BUFFER)/CMAA Spec 70

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. 

CAB/ASME B30-17

The operator’s compartment on a crane.  

CAB CONTROLLED/ANSI MH 27.1

Equipment controlled from an operator’s cab. 

CAB, NORMAL/ASME B30.2

Operator’s compartment used for controlling a cab-operated crane.  

CAB, SKELETON/ASME B30.11

Operator’s compartment used for occasional cab operation of, normally, a floor- or remote-operated crane or carrier.  

CAB-OPERATED CRANE/CMAA Spec 70

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

CAMBER/CMAA Spec 70

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

CANTILEVER FRAME/ASME B30.2

A structural member that supports the trolley of a wall crane.  

CAPACITY/CMAA Spec 70

The maximum rated load (in tons) which a cranes designed to handle.

CARRIER (ALSO KNOWN AS TROLLEY)/ASME B30.11

A unit that travels on the bottom flange of a monorail track, jib boom, or bridge girder to transport a load.  

CARRIER (TROLLEY)/CMAA Spec 70

An assembly with wheels which will run on monorail track or crane girders and which will support a load. 

CEILING MOUNTED/ASME HST-4M

A type of hoist mounting where the hoist is mounted to the underside of a horizontal supporting surface.  

CHAIN, HAND/ASME B30-17

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

CHAIN, LOAD/ASME B30-17

The load-bearing chain in a hoist.  

CHAIN, WELDED LINK/ASME B30-16

A chain consisting of a series of interwoven links fanned and welded. 

CLAMP/ANSI MH 27.1

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.

CLEARANCE/CMAA Spec 70

Minimum distance from the extremity of a crane to the nearest obstruction. 

CMAA/CMAA Spec 70

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

COLD CURRENT/ASME B30.20

The current drawn by the magnet when its coil is at 680F (200C) and at rated voltage. 

COLLECTOR, SHOE/ANSI MH 27.1

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

COLLECTOR, WHEEL/ANSI MH 27.1

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

COLLECTORS/CMAA Spec 70

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.

COLLECTORS/ANSI MH 27.1

Electrical contacting devices providing a path for current flow from stationary conductors to moving equipment.

COLLECTORS, CURRENT/ASME B30.2

Contacting devices for collecting current from runway or bridge conductors.  

CONDUCTORS, BRIDGE/Whiting Crane Handbook

The electrical conductors located along the bridge girder(s) to provide power and control circuits to the trolley. (Sometimes incorrectly called trolley conductors.) 

CONDUCTORS, ENCLOSED/ANSI MH 27.1

A bar used to transmit an electrical current, enclosed in a non-conducting material to minimize accidental contact with the conductor. 

CONDUCTORS, OPEN/ANSI MH 27.1

A bar used to transmit an electrical current. 

CONDUCTORS, RUNWAY (MAIN)/ASME B30-17

The electrical conductors located along a crane runway that transmit control signals and power to the crane.  

CONTACTOR/ASME HST-4M

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

CONTACTOR, MAGNETIC/CMAA Spec 70

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

CONTROL ACTUATOR/ASME HST-4M

A manual means at the operating station by which hoist controls are energized.  

CONTROL BRAKING MEANS/ASME HST-4M

A method of controlling speed by removing energy from the moving body or by imparting energy in the opposite direction.  

CONTROL PANEL

See control enclosure.

CONTROL VOLTAGE/ANSI MH 27.1

The voltage impressed on the control devices.

CONTROL, MULTI-SPEED/ANSI MH 27.1

A drive control system providing more than one speed operation in either direction using multi-speed squirrel cage. motors. 

CONTROL, SINGLE SPEED/ANSI MH 27.1

A drive control system providing one speed operation in either direction.

CONTROL, VARIABLE SPEED/CMAA Spec 70

A drive control system providing more than one speed operation in either direction using wound-rotor motors.

CONTROLLER/CMAA Spec 70

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

CONTROLLER, MANUAL/ASME B30-17

A controller having all of its basic functions performed by devices which are operated by hand.  

CONTROLLER, SPRING RETURN/ASME B30.2

A 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 control, automatic program control, or other similar device.  

COUNTERTORQUE/ASME HST-4M

A method of 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.  

COUPLINGS (SPLICES)/ANSI MH 27.1

Mechanical devices used to join the adjacent ends of track sections. 

COVER PLATE/CMAA Spec 70

The top or bottom plate of a box girder. 

CRANE/ANSI MH 27.1

A machine for lifting, lowering, and moving a load with the hoisting mechanism a part of the machine. 

CRANE GIRDER

See Bridge Girder. 

CRANE SERVICE, HEAVY/ASME B30.2

Service that involves operating at 85 to 100% of rated load or in excess of 10 lift cycles/hr. as a regular specified procedure. 

CRANE SERVICE, NORMAL/ASME B30.2

Service that involves operating at less than 85% of rated load and not more than 10 lift cycles/hr. except for isolated instances.  

CRANE SERVICE, NORMAL/ASME B30-17

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. 

CRANE SERVICE, SEVERE/ASME B30.2

Service that involves normal or heavy service with abnormal operating conditions.  

CRANE, AUTOMATIC/ASME B30-17

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

CRANE, CAB-OPERATED/ASME B30-17

A crane controlled by an operator in a cab attached to the bridge or trolley. 

CRANE, CANTILEVER GANTRY/ASME B30-17

A gantry or semi gantry crane in which the bridge girders or trusses extend transversely beyond the crane runway on one or both side. 

CRANE, FLOOR-OPERATED/ASME B30-17

A crane that is controlled by a means suspended from the crane, operated by a person on the floor or on an independent platform. 

CRANE, GANTRY/ASME B30-17

A crane similar to an Overhead Cranes, 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.

CRANE, HOT MOLTEN MATERIAL-HANDLING/ASME B30-17

An overhead crane used for transporting or pouring molten material.  

CRANE, MANUALLY OPERATED/ASME B30.2

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.

CRANE, OVERHEAD/ASME B30.2

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.  

CRANE, POLAR/ASME B30.2

An overhead or gantry crane that travels on a circular runway.  

CRANE, PULPIT-OPERATED/ASME B30-17

A crane operated from a fixed operator station not attached to the crane.  

CRANE, REMOTE-OPERATED/ASME B30-17

A 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.  

CRANE, SEMI-GANTRY/ASME B30.2

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. 

CRANE, SINGLE-GIRDER/ASME B30.11

A crane having one bridge girder mounted between, and supported from, the end trucks.  

CRANE, STANDBY/ASME B30-17

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

CRANES, FIXED/ANSI MH 27.1

Cranes which are non-mobile. Derricks and jib cranes are classified as fixed cranes.

CRANES, PORTABLE/CMAA Spec 70 

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/Whiting Crane Handbook

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.

CROSS SHAFT/CMAA Spec 70

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

CROSSOVER (FIXED TRANSFER SECTION)/ANSI MH 27.1

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.

CROSSTRACK SWITCH/ANSI MH 27.1

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.

CURVES/ANSI MH 27.1

Formed sections of monorail track used to change the horizontal or vertical direction of carrier travel. 

CUSHIONED START/CMAA Spec 70

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

CUSHIONED START/ASME HST-4M

An electrical or mechanical method for reducing the rate of acceleration of trolley motion.  

DEAD LOADS/CMAA Spec 70

The loads on a structure which remain in a fixed position relative to the structure. On a crane bridge such loads include the girders, foot walk, cross shaft, drive units, panels, etc. 

DEFLECTION/CMAA Spec 70

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

DESIGNATED/ASME B30.2

Selected or assigned by the employer or the employer’s representative as being competent to perform specific duties.  

DIAPHRAGM/CMAA Spec 70

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

DOUBLE GIRDER CRANE/ANSI MH 27.1

A crane having two bridge girders mounted between and supported from the end trucks.

DRIFT POINT/ASME B30.2

A point on a travel motion master switch or on a manual controller that maintains the brake released while the motor is not energized. This allows for coasting.  

DRIVE GIRDER/CMAA Spec 70

The girder on which the bridge drive machinery is mounted. 

DRIVING HEAD/ANSI MH 27.1

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

DROP SECTION (ALSO KNOWN AS LIFT SECTION)/ASME B30.11

A mechanism that will permit a section of track(s) to be lifted or lowered out of alignment with the stationary track(s). 

DRUM/ASME B30-16

The cylindrical member around which rope is wound for lifting or lowering the load.  

DUMMY CAB/CMAA Spec 70

An operator’s compartment or platform on a pendant or radio controlled crane, having no permanently-mounted electrical controls, in which an operator may ride while controlling the crane. 

DYNAMIC LOWERING/CMAA Spec 70

A method of 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.

EDDY CURRENT

See eddy current braking.

EDDY-CURRENT BRAKING/CMAA Spec 70

A method of control by which the motor drives through an electrical induction load brake.

ELECTRIC OVERHEAD TRAVELING CRANE/CMAA Spec 70

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. 

ELECTRICAL BRAKING SYSTEM/CMAA Spec 70

A method of controlling crane motor speed when in an overhauling condition, without the use of friction braking. 

ELECTRICALLY INTERLOCKED/ANSI MH 27.1

An electrical device in the starter circuit which prevents a short circuit when opposite controls are operated at the same time. 

ELECTRIFICATION/ANSI MH 27.1

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

ENCLOSED CONDUCTOR/CMAA Spec 70

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

ENCLOSURE/CMAA Spec 70

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

END APPROACH/CMAA Spec 70

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

END STOP/CMAA Spec 70

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 TRUCK/ASME B30.11

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

END TRUCK LOAD/CMAA Spec 70

The outside dimension (length over all) of an end truck as measured from bumper to bumper.

EQUALIZER/ASME B30-16

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

EXPOSED/ASME B30-17

Applies to hazardous objects not guarded or isolated (capable of being contacted inadvertently). 

FAIL-SAFE/CMAA Spec 70

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

F IELD WIRING/CMAA Spec 70

The wiring required after erection of the crane. 

FIXED AXLE/CMAA Spec 70

An axle which is fixed in the truck and on which the wheel revolves. 

FIXED TRANSFER SECTION/ANSI MH 27.1

See Crossover.

FIXED TRANSFER SECTION (ALSO KNOWN AS CROSSOVER)/ASME B30.11

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/Whiting Crane Handbook

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. 

FLOOR CONTROLLED/ANSI MH 27.1

Motor propelled units which are controlled by an operator on the floor by means of pushbutton station suspended from the overhead equipment. 

FOOT WALK/CMAA Spec 70

The full length walkway with handrail and toe boards, 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 end truck).

FORCE, BREAKAWAY/ASME B30.20

The force that must be applied to a magnet to remove it from a piece of ferromagnetic material to which it is magnetically attached.  

FRICTION-TYPE PRESSURE GRIPPING LIFTERS/ASME B30.20

Lifters that grip the load without significant or harmful permanent deformation of the load surface.  

GANTRY CRANE/CMAA Spec 70

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.

GANTRY LEG/ASME B30-17

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

GAUGE (GIRDER)/ANSI MH 27.1

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

GIRDER, (OUTRIGGER)/Whiting Crane Handbook

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

GIRDER, BRIDGE/Whiting Crane Handbook

The principal horizontal beam(s) of the crane, which supports the trolley, is supported by the end trucks, and is perpendicular to the runway. 

GIRDER, DRIVE (GIRDER “A”)/Whiting Crane Handbook

The bridge girder to which the bridge motor and gear case(s) are attached. For cranes having a drive on each girder, it is the girder to which the control panels and/or the cab are attached. 

GIRDER, IDLER (GIRDER “B”)/Whiting Crane Handbook

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

GIRDER, RUNWAY/Whiting Crane Handbook

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

GRIPPING FORCE/ASME B30.20

The force the lifting device exerts on the load. 

GROUND FAULT/CMAA Spec 70

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

GUIDE, CHAIN/ASME B30-16

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

HAND CHAIN/ASME HST-4M

The chain provided to control move­ment of a hand chain operated trolley.  

HANGER ROD/ASME B30.11

A steel rod which, together with other fittings, is used to suspend the track from the support­ing structure.  

HANGER ROD/ANSI MH 27.1

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

HAZARDOUS LOCATIONS/ASME B30-16

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.  

HEADROOM/ASME HST-4M ASME B30.20

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.

1. Centerline of the suspension holes on lug suspended hoists.

2. Saddle of the top hook on hook suspended hoists.

3. Bottom of the beam on trolley suspended hoists.

4. Supporting surface on base and deck mounted hoists. 

5. Uppermost point of hoist on wall and ceiling mounted hoists. 

HOIST/ASME HST-4M

A suspended machinery unit which is used for lifting or lowering a freely suspended (unguided) load.  

HOIST MOTION/ASME B30-17

That motion which lifts or lowers a load.  

HOIST SPEED/ASME B30-17

Hoist speed is the rate of motion that the load hook attains while lifting rated load.

HOIST, AUXILIARY/ASME B30-17

A supplemental hoisting unit, usually of lower load rating and higher speed than the main hoist. 

HOIST, MAIN/Whiting Crane Handbook

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

HOLDING BRAKE/ASME HST-4M

A friction brake for a hoist which is automatically applied and prevents motion when power is off.  

HOOK APPROACH/CMAA Spec 70

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

HOOK APPROACH, END/Whiting Crane Handbook

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/Whiting Crane Handbook

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/ASME HST-4M

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

HOOK TO HOOK APPROACH

The dimension between two separate cranes as measured between the hooks at their closest proximity.

OR:

The dimension between two separate hoists on the same crane as measured between the hooks at their closest proximity.

HOOK; LATCH TYPE/ASME HST-4M

A type of hook with a mechanical device to bridge the throat opening of the hook.  

IDLER SHEAVE/CMAA Spec 70

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.”  

INDICATOR, INTERNAL CONTROL FUNCTION/ASME B30.20

An indicator which shows that the permanent magnet material in one type of electrically controlled permanent magnet has been positioned internally to provide full magnetic attraction.  

INDUSTRIAL DUTY CRANE/CMAA Spec 70

Service classification covered by CMAA Specification No. 70, ‘Specifications for Electric Overhead Traveling Cranes’. 

INSULATION CLASS/CMAA Spec 70

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

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/ANSI MH 27.1

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. 

INTERLOCKING MECHANISM/ASME B30.11

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.  

INVERTER (VARIABLE FREQUENCY DRIVE)/CMAA Spec 70

A method of control by which the fixed line voltage and frequency is changed to a three-phase system with infinitely variable voltage and frequency. 

JIB BOOM/ASME B30.11

A horizontal cantilever track for supporting the carrier. 

JOG (INCH)/Whiting Crane Handbook

To move the hook, trolley, or bridge in a series of short, discontinuous, increments by momentary operation of a controller. 

KIP/CMAA Spec 70

A unit of force, equivalent to 1000 pounds. 

KNEE BRACE/CMAA Spec 70

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

LATCH/ASME B30.20

A device for holding a lifter in the open or closed position.  

LATCH, HOOK/Whiting Crane Handbook

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

LATERAL FORCES/CMAA Spec 70

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

LATERAL HOOK TRAVEL/ASME HST-4M

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/Whiting Crane Handbook

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 (HOOK TRAVEL)/Whiting Crane Handbook

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. 

LIFT CYCLE/CMAA Spec 70

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

LIFT LIMITING DEVICE/ASME HST-4M

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.  

LIFT SECTION/ANSI MH 27.1

A mechanism which will lift a section of track out of alignment with a stationary track. 

LIFTING BEAM (SPREADER BEAM)/ASME B30.20

A load supporting lifter. 

LIFTING DEVICES/ASME B30-16

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. 

LIMIT SWITCH/CMAA Spec 70

A device designed to cut off the power automatically at or near the limit of travel for the crane motion. 

LINE CONTACTOR/CMAA Spec 70

A contactor to disconnect power from the supply lines. 

LIVE LOAD/CMAA Spec 70

A load which moves relative to the structure under consideration.

LOAD/ASME B30.2

The total superimposed weight on the load block or hook. 

LOAD (CAPACITY), RATED/ASME B30.20

The maximum load that the crane is designated to handle by the manufacturer.  

LOAD (CAPACITY), SPECIFIED APPLICATION/ASME B30.20

A load applied to the crane when it is used to handle a specified load.  

LOAD BAR/ASME B30.11

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.  

LOAD BLOCK/ASME B30.2-19

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.  

LOAD CARRYING FLANGE/ANSI MH 27.1

The lower flange of the track on which the load bearing wheels roll. 

LOAD CYCLE/CMAA Spec 70

One lift cycle with load plus one lift cycle without load.

LOAD HOOK/ASME HST-4M

The hook used to connect the load to the hoist.  

LOAD SUSPENSION PARTS/ASME B30-16

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.  

LOAD, DEAD/Whiting Crane Handbook

The load(s) on a portion of the crane, which remain(s) in affixed position relative to the member being considered. 

LOAD, LIVE/Whiting Crane Handbook

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. 

LOAD, RATED/ASME B30-17

The maximum load designated by the manufacturer for which a crane or individual hoist is designed and built.  

LOCK BAR SHEER LIFTER/ASME B30.20

A supporting lifter.

LONGITUDINAL STIFFENERS/CMAA Spec 70

Horizontal members attached to the web of the bridge girder to prevent web buckling. 

LUG/ANSI MH 27.1

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. 

LUG SUSPENDED/ASME HST-4M

A hoist suspended from a trolley or permanent structure by means of bolt(s) or pin(s) through a rigid or swivel type lug.  

MAGNET/ANSI MH 27.1

An electromagnetic device carried on a hoist hook, used to pick up and carry loads magnetically. 

MAGNET, LIFTING, CLOSE PROXIMITY OPERATED/ASME B30.20

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.  

MAGNET, LIFTING, GENERAL APPLICATION/ASME B30.20

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.  

MAGNET, LIFTING, REMOTELY OPERATED/ASME B30.20

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.  

MAGNET, LIFTING, SPECIFIED APPLICATION/ASME B30.20

Lifting magnets that are designed for lifting specified geometrical configurations and weights of designated parts, identified by part number or other controlled definition and used in a controlled manner. 

MAGNETIC CONTROL/CMAA Spec 70

A means of controlling direction and speed by using magnetic contactors and relays.

MAIN HOIST/ASME B30.2

The primary hoist mechanism provided for lifting and lowering the rated load. 

MAIN LINE CONTACTOR/CMAA Spec 70

A magnetic contactor used in the incoming power circuit from the main line collectors.

MAIN LINE DISCONNECT SWITCH/CMAA Spec 70

A manual switch which breaks the power lines leading from the main line collectors.

MANIPULATING LIFTER/ASME B30.20

A lifter that rotates the load about one or more axes during the lifting process.  

MANUAL-MAGNETIC DISCONNECT SWITCH/CMAA Spec 70

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. 

MATCH MARKING/CMAA Spec 70

Identification of non-interchangeable parts for reassembly after shipment. 

MEAN EFFECTIVE LOAD/CMAA Spec 70

A load used in durability calculations accounting for both maximum and minimum loads. 

MECHANICAL BRAKING MEANS/ASME HST-4M

A method of control­ling or reducing speed by friction. 

MECHANICAL LOAD BRAKE/ASME HST-4M

An automatic type of friction brake used for 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. 

MECHANICALLY INTERLOCKED/ANSI MH 27.1

A mechanical device which prevents operation of opposite controls at the same time. 

MESSENGER TRACK/Whiting Crane Handbook

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 control unit. 

MILL DUTY CRANE/CMAA Spec 70

Service classification covered by AISE Standard No. 6, ‘Specification for Electric Overhead Traveling Cranes for Steel Mill Service’.

MONORAIL/ANSI MH 27.1

An overhead track upon which carriers travel, used to transport loads.

MOTOR CIRCUIT SWITCH/ANSI MH 27.1

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. 

NON-COASTING MECHANICAL DRIVE/CMAA Spec 70

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. 

NORMAL OPERATING CONDITIONS/ASME HST-4M

Conditions during which a hoist is performing functions within the scope of the original design.  

NORMAL OPERATING CONDITIONS/ASME B30.11

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.  

NORMAL WALKING SPEED/ANSI MH 27.1

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.

OPERATOR’S CAB/CMAA Spec 70

The operator’s compartment from which movements of the crane are 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. 

OVERLOAD/CMAA Spec 70

Any load greater than the rated load. 

OVERLOAD PROTECTION (OVERCURRENT)/CMAA Spec 70

A device operative on excessive current to cause and maintain the interruption or reduction of current flow to the equipment governed. 

OVERTRAVEL RESTRAINT/ASME B30-16

A device used to prevent the slack load chain from inadvertently being lowered out of the load sprocket.  

PARTS (WIRE ROPE LINES)/ASME HST-4M

Number of lines of rope supporting the load block or hook. 

PATENTED TRACK(TRAMBEAM, TRAMRAIL)/CMAA Spec 74

A 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/ASME B30-16

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

PENDANT PUSHBUTTON STATION/CMAA Spec 70

Means suspended from the crane operating the controllers from the floor or other level beneath the crane.

PITCH DIAMETER/ASME HST-4M

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. 

PITCH DIAMETER (ROPE)/CMAA Spec 70

Distance through the center of drum or sheave from center to center of a rope passed about the periphery. 

PLAIN REVERSING CONTROL/CMAA Spec 70

A reversing control which has identical characteristics for both directions of motor rotation. 

PLUGGING/CMAA Spec 70

A control function which accomplishes braking by reversing the motor line voltage polarity or phase sequence. 

PLUGGING RELAY/Whiting Crane Handbook

A current relay used on a bridge or trolley 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 control point until the motor rotation has stopped. In a direct current control panel, the relay performs the same function by establishing a patented sensing circuit at the motor armature. (Sometimes called an anti-plugging relay.) 

PRIMARY UPPER LIMIT DEVICE/ASME B30.2

The first device that, when actuated, limits hoisting motion in the upward direction.  

PROTECTIVE PANEL/CMAA Spec 70

An assembly containing overload and under voltage protection for all crane motions. 

PULPIT CONTROLLED/ANSI MH 27.1

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 control of the powered motions of the crane, hoist, and other auxiliary equipment. 

PUSH BUTTON STATION/ASME B30-17

An electrical control device, consisting of push button operated contacts, used by the operator for the control of the powered motions of the crane, hoist, and other auxiliary equipment.  

QUALIFIED PERSON/ASME B30-17

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.  

RADIO CONTROLLED/ANSI MH 27.1

A unit operated from a radio transmitter located at a point not mechanically attached to the device being controlled. 

RAIL SWEEP/ASME B30-17

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

RAIL, BRIDGE/Whiting Crane Handbook

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

RAIL, RUNWAY/Whiting Crane Handbook

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

RATED LOAD (CAPACITY)/ASME B30.2

The maximum load designated by the manufacturer for which a crane or individual hoist is designed and built. 

REACH/ASME HST-4M

Reach is equal to lift plus headroom. 

REEVING/ASME HST-4M

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

• Double reeving two parts of line leading off of the drum.

• Single reeving one part of the line leading off of the drum.  

REGENERATIVE BRAKING MEANS/ASME HST-4M

A method of 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.  

REGULATED SPEED/CMAA Spec 70

A function which tends to maintain constant motor speed for any load for a given speed setting of the controller.

REMOTE CONTROLLED/ANSI MH 27.1

A unit operated from a control station located at a point not mechanically attached to the device being controlled. 

RIGHTHAND END/Whiting Crane Handbook

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. 

ROPE/ASME B30-17

Refers to wire rope unless otherwise specified.  

ROPE DRUM/ASME HST-4M

The cylindrical member around which the rope is wound for lifting and lowering the load.  

ROPE SHEAVE/ASME HST-4M

A grooved wheel used with a rope to change direction and point of application of a pulling force. 

ROTARY SWITCH/ANSI MH 27.1

 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. 

ROTATING AXLE/CMAA Spec 70

An axle which rotates with the wheel. 

RUNNING SHEAVE/ASME HST-4M

A sheave that rotates as the hook is lifted or lowered.  

RUNWAY/CMAA Spec 70

The rails, beams, brackets and framework on which the crane operates.

RUNWAY CONDUCTORS/CMAA Spec 70

The main conductors mounted on or parallel to the runway which supplies current to the crane. 

RUNWAY RAIL/CMAA Spec 70

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

S BEAM SECTION/CMAA Spec 74

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

SAFETY LUG/CMAA Spec 74

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. 

SERVICE PLATFORM/ASME B30-17

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

SERVICE, HEAVY/ASME B30-16

That service which involves operation within the rated load limit which exceeds normal service.  

SERVICE, NORMAL/ASME B30-16

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. 

SERVICE, SEVERE/ASME B30-16

That service which involves normal or heavy service with abnormal operating conditions.  

SHALL/ASME B30.2

This word indicates that a rule is mandatory and must be followed.  

SHEAR BREAKAWAY FORCE/ASME B30.20

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. 

SHEAVE/CMAA Spec 70

A grooved wheel or pulley used with a rope or chain to change direction and point of application of a pulling force.

SHEAVE, RUNNING/ASME B30-16

A sheave which rotates as the load block is lifted or lowered.  

SHEAVE (EQUALIZER) NONRUNNING/ASME B30.2

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

SHOULD/ASME B30.2

This word indicates that a rule is a recommendation, the advisability of which depends on the facts in each situation.  

SIDE PULL/ASME B30-17

The component of the hoist pull acting horizontally when the hoist lines are not operated vertically. 

SIMPLE BEAM/ANSI MH 27.1

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

SINGLE REEVED

Single reeving refers to the number of ropes coming from the drum.

SKELETON CAB/CMAA Spec 70

Same as dummy cab. 

SKEWING FORCES/CMAA Spec 70

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.

SPAN/CMAA Spec 70

The horizontal distance center-to-center of runway rails.

SPLICE/ASME B30.11

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

SPRING RETURN/Whiting Crane Handbook

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

SPROCKET (IDLER)/ASME B30-16

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

SPROCKET (LOAD)/ASME B30-16

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

SPUR TRACK/ASME B30.11

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.  

SQUARING SHAFT/ANSI MH 27.1

A driven shaft which transmits torque to drive wheels operating on two or more tracks. 

STANDBY EQUIPMENT/ASME B30.11

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

STATIC CONTROL/CMAA Spec 70

A method of switching electrical circuits without the use of contacts.

STATIONARY TRACK/ANSI MH 27.1

A fixed track attached to the building or supporting structure.

STEPLESS CONTROL/CMAA Spec 70

A type of control system with infinite speed control between minimum speed and full speed.

STEPPED CONTROL/CMAA Spec 70

A type of control system with fixed speed points. 

STOP/ASME B30-17

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)/CMAA Spec 70

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

STRESS/CMAA Spec 74

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

STRUCTURAL LIFTING DEVICE/ASME B30.20

A lifter consisting of an assembly of rigid parts designed to hold and attach a load to a hoist-way device.  

STRUCTURAL SUPPORTS/ANSI MH 27.1

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

SUPPORTING STRUCTURE/ANSI MH 27.1

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

SUSPENSION FITTINGS/ANSI MH 27.1

Fittings used to attach the track to the supporting structure. 

SWEEP/CMAA Spec 70

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

SWITCH (CROSS-TRACK)/ASME B30.11

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.  

SWITCH (EMERGENCY STOP)/ASME B30-17

A manually actuated switch to disconnect power independently of the regular operating controls.  

SWITCH, GLIDE (SLIDE)/ASME B30.11

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.  

SWITCH (LIMIT)/ASME B30-17

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.  

SWITCH, MAIN (CRANE DISCONNECT)/ASME B30-17

A switch on the crane controlling the main power supply from the runway conductors.  

SWITCH, MASTER/ASME B30-17

Switch that dominates the operation of contactors, relays, or other remotely operated devices.  

SWITCH, MASTER, SPRING-RETURN/ASME B30-17

A master switch that when released will return automatically to a neutral (OFF) position.  

SWITCH, RUNWAY DISCONNECT/ASME B30-17

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

SWITCH, TONGUE/ASME B30.11

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.  

SWITCH, TRACK/ASME B30.11

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).  

TAGLINE/ANSI MH 27.1

An electrical conductor system employing flexible cables. 

TECHNICAL LIFTING DEVICE/ASME B30.20

A mechanism composed of two or more rigid parts which move with respect to each other for attaching a load to a hoisting device. 

TEFC/CMAA Spec 70

Totally enclosed fan cooled.

TENV/CMAA Spec 70

Totally enclosed non ventilated. 

TEST, APPLICATION BREAKAWAY FORCE/ASME B30.20

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. 

TEST, RATED BREAKAWAY FORCE/ASME B30.20

A test that is carried out in order to establish the rated breakaway force.  

TONGUE SWITCH/ANSI MH 27.1

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. 

TOP RUNNING CRANE/CMAA Spec 74

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

TORQUE, FULL LOAD (MOTOR)/CMAA Spec 70

The torque produced by a motor operating at its rated horsepower and speed. 

TORQUE, LOCKED ROTOR/Whiting Crane Handbook

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. 

TORQUE, MOTOR BREAKDOWN/Whiting Crane Handbook

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/Whiting Crane Handbook

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/Whiting Crane Handbook

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/CMAA Spec 70

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

TORSIONAL FORCES/CMAA Spec 70

Forces which can cause twisting of a member. 

TRACK/ASME B30.11

The structural member that supports the carrier or crane wheels.  

TRACK CAPACITY/ANSI MH 27.1

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

TRACK CURVES/ASME B30.11

Curved sections of monorail track used to change the direction of carrier travel.  

TRACK HANGERS/ASME B30.11

Fittings used to suspend the track from the supporting structure.  

TRACK JOINT/ASME B30.11

The point at which two sections of track are joined together.  

TRACTOR DRIVE/ANSI MH 27.1

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

TROLLEY/ASME HST-4M

A wheeled mechanism from which a hoist is suspended to provide horizontal motion of the hoist along a beam. See Carrier.

TROLLEY (CARRIER)/ASME B30-17

The unit which travels on the bottom flange of the bridge girder and carries the hoist.  

TROLLEY FRAME/CMAA Spec 70

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

TROLLEY SPEED/ASME HST-4M

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

TROLLEY SUSPENDED/ASME HST-4M

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/ASME B30-17

The trolley movement in directions at right angles to the crane runway. 

TRUCK/ASME B30.2

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 control devices. However, on a floor-operated crane, if the operating con­trol devices are within sight of the operator and within a distance equal to the span of the crane.

TRUE VERTICAL LIFT/ASME HST-4M

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/ASME B30.11

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/CMAA Spec 70

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.

UNDER RUNNING CRANE/CMAA Spec 74

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/CMAA Spec 70

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

UPPER BLOCK/ASME B30.2

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

VACUUM/ASME B30.20

A pressure less than ambient atmospheric pressure.  

VACUUM LIFTER/ASME B30.20

A below-the-hook lifting device for lifting and transporting loads in a fixed attitude using a holding force by means of vacuum.  

VACUUM MANIPULATOR/ASME B30.20

A vacuum lifter capable of re­positioning the load while suspended.  

VACUUM PAD/ASME B30.20

A device which applies a holding force on the load by means of vacuum. 

VACUUM RESERVOIR/ASME B30.20

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.  

VARIABLE FREQUENCY/CMAA Spec 70

A method of control by which the motor supply voltage and frequency can be adjusted. 

VERTICAL LIFT/ASME B30.20

A condition where the surface to which a vacuum pad is attached is in a vertical plane.   

VOLTAGE DROP/CMAA Spec 70

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

W BEAM SECTION/CMAA Spec 74

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

WALL MOUNTED/ASME HST-4M

A type of hoist mounting in which the hoist is mounted to a vertical surface.  

WHEEL LOAD/CMAA Spec 70

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/ANSI MH 27.1

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

WHEELBASE/CMAA Spec 70

Distance from center-to-center of outermost wheels.