DAVIT CRANE: A jib type crane with a vertical mast and fixed arm, rotating as a unit. The hook lifts from the end of boom only. Can be manually or electrically operated and usually uses a winch for lifting.
DEAD LOADS: 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: Displacement due to bending or twisting in a vertical or lateral plane, caused by the imposed live and dead loads.
DIAPHRAGM: A plate or partition between opposite parts of a member, serving a definite purpose in the structural design of a member.
DUMMY CAB: 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, from a pendant or remote control station.
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ELECTRIC OVERHEAD TRAVELING 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.
ELECTRICAL BRAKING SYSTEM: A method of controlling crane motor speed when in an overhauling condition, without the use of friction braking.
ELECTRIFICATION: A system of conductors used to transmit power to motors or control enclosures.
ENCLOSED CONDUCTOR(S): A conductor or group of conductors substantially enclosed to prevent accidental contact.
ENCLOSURE: A housing to contain electrical components, usually specified by a NEMA classification number.
END APPROACH: The minimum horizontal distance, parallel to the runway, between the outermost extremities of the crane and the centerline of the hook.
END TRUCK: The unit consisting of truck frame, wheels, bearings, axles, etc., which supports the bridge girder.
EXPLOSION PROOF: National Electric Code (NEC) ratings for various explosive environments. Refers to electrical devices only. See Spark Resistance.
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FESTOONED CONDUCTORS: A system of conductors typified by electrical cable hanging between glides or trolleys creating an accordion effect as it slides out and back.
FIELD WIRING: The wiring required after erection of the crane.
FIXED AXLE: An axle which is fixed in the truck and on which the wheel revolves. Wheels normally have a ring gear and are driven by a spur gear.
FLAT CABLE FESTOON: Festooned conductors using a cable with conductors that are placed side by side (flat). Cable is draped over a curved saddle suspended from trolleys riding in an enclosed track.
FLOOR OPERATED CRANE: A crane which is pendant controlled by an operator on the floor or on an independent platform.
FLYING PENDANT: A pushbutton station suspended from an independent track allowing the pendant to “fly” along the bridge independent of the hoist.
FOOT WALK: The walkway with handrail and toe boards, attached to the bridge for access purposes.
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GAGE: Distance measured center to center of bridge rails on a double girder crane.
GANTRY CRANE: A traveling beam(s) elevated on side frames, spanning between and running on parallel rails supported on the ground.
GIRDER: The principal horizontal beam of the crane bridge which supports the trolley and is supported by the end trucks.