D on American Crane & Equipment Corp.


Crane and Hoist Equipment and Components by Type > Resource Center > Crane Glossary > D


	D
	Click on a category to drill down.


		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, footwalk, 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 side plates of a box girder, serving a definite purpose in the structural design of the girder.




		DOUBLE GIRDER CRANE A crane which runs on two bridge girders mounted between and supported by end trucks at each runway.




		DRIVE GIRDER The girder on which the bridge drive machinery is mounted.




		DUAL SPEED Two speed travel control, with the second speed at one half or one third of main speed.




		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.




		DYNAMIC LOWERING 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.




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