Overhead Crane Terminology Overhead CranesMove in 3 Directions: Length, the length of a building or bay. Width, the width of a building or bay. Height, up or down. The part of the crane moving the length is called the Bridge. The part of the crane moving the width is called the trolley. The part of the crane moving up and down is called the hoist. These  three parts, bridge, trolley, and hoist together are called a crane or overhead crane. The following is a glossary of terms