Overhead Crane Components & Terminology
Identify bridge girders, end trucks, runway beams, trolleys, and understand top-running vs. underhung configurations and girder types.
- Identify the major structural components of an overhead crane
- Explain the function of bridge girders, end trucks, and trolleys
- Distinguish between top-running and underhung crane configurations
- Describe runway beams, foot walks, and torsion box girder advantages
Lección 1
Bridge Girders, End Trucks & Crane Span
The Structural Core
An overhead crane is built around several key structural components. Understanding what each part does is essential for safe operation and for passing the NCCCO exam.
Bridge Girders
The bridge girder is the main horizontal beam that spans the width of the building. The function of a bridge girder is to support the trolley and hoist and transfer the load to the end trucks. Bridge girders carry all the vertical forces from the lifted load and distribute them to the supporting structure.
End Trucks
An end truck is the wheeled assembly supporting bridge girders on the runway. There are two end trucks - one at each end of the bridge girder. Each end truck contains wheels that ride on the runway rails, along with bridge drive motors and brakes (on driven end trucks).
Crane Span
The crane span is the distance between runway rails. This is a fixed dimension determined by the building structure. The span directly affects the bridge girder length and the area the crane can cover.
The bridge girder supports the trolley/hoist and transfers load to the end trucks. An end truck is the wheeled assembly on the runway. Crane span is the distance between runway rails.