single girder crane consist of single bridge girder supported on two end trucks. It has a trolley hoist mechanism that runs on the bottom flange of the bridge girder. Single girder bridge cranes generally have a maximum span between 6 to15 meters with a maximum lift of 5-15 meters. they are used for light to moderate service and are cost effective to use as a standby crane (not frequently used). Total cost of single girder cranes on crane components, runway structure and building is low.