What Is An Overhead Crane

An overhead crane, or bridge crane, is a crucial industrial lifting solution for heavy-duty handling. It features a bridge-shaped main girder supported by end trucks on overhead rails, with a hoist trolley that moves vertically and horizontally to lift and transport loads. In daily life, an overhead crane is widely used in manufacturing factories, warehouses, workshops, harbors, etc. Available in single-girder type (for lighter loads, 1-20 tons) or double-girder type (for heavier tasks, 5-500 tons), an overhead crane optimizes industrial workspace utilization by leveraging overhead space.
Here, an overhead crane is introduced in detail, including its definition, structure and components, working principle, application, specs etc. This guide will provides the information you need to select the right overhead crane.

What is an overhead crane
An overhead crane, also known as a bridge crane, is a heavy-duty lifting equipment specifically for industrial load handling. It is installed above workspaces like factories, warehouses, and manufacturing plants. It operates along fixed overhead rails, unlike mobile cranes that require ground space. It frees up floor space for other operations.​ Designed to meet international safety standards (CE, ISO, EAC certificate etc.), it eliminates the need for manual handling of bulky items and reduces workplace injuries while boosting efficiency.
Its core structure consists of high-strength steel main girders, end trucks with frequency-conversion motors, a hoist trolley, and a hoisting mechanism equipped with brakes and wire ropes. It can handle loads ranging from light 1-32 ton (for small workshops) to heavy 500 tons (for heavy industry). The overhead crane has three flexible control methods: a cab (for complex operations with visual assistance), a remote control (for long-distance operation away from hazardous areas), or a handheld pendant (for close-range fine adjustments).​

Overhead Crane Structure and Parts
An overhead crane consists of main girder, end girder, trolley running mechanism, Overhead Travel Mechanism, hoisting mechanism, rail, cab, walking platform and other parts. The functional characteristics of each part are as follows:
Main beam: Installation of rails for lateral movement of the trolley.
End beam: Mounting Bridge Travel Mechanism.
Lifting mechanism: Device to move the hook up and down.
Cable: Powering the trolley.
Walkway: Walking paths for overhaul and post-maintenance.
Cabs: The operator’s control station for safe and precise operation.
Trolley Travel Mechanism: Lateral movement of the trolley.
Overhead Travel Mechanism: Longitudinal movement of the crane.

Overhead Crane Component Functions
An overhead crane plays a central role in modern industrial material handling, facilitating the seamless movement of heavy loads within factories, ports, and warehouses.

This lifting system operates on a modular design principle, with its primary structural component being the robust main girder. Resembling a horizontal bridge, the main girder spans the width of the designated working area, thus maximizing operational coverage.
Supporting this main structure are the end trucks, which are equipped with high-capacity wheel sets and precision bearings. They glide along elevated I-beam rails. This ensures smooth lateral movement of the equipment within the facility. The stability and maneuverability of the end trucks are critical, as they bear the total weight of the main girder, hoist trolley, and suspended loads.
The hoist trolley serves as the crane's dynamic lifting mechanism. Integrated with a powerful electric or hydraulic hoisting unit, it enables the vertical movement with exceptional control precision.
The trolley's traversing system allows for horizontal displacement along the main beam's length. The synergy between vertical lifting and horizontal traversing allows the bridge crane to position loads with millimeter-level precision. This makes them indispensable for tasks ranging from heavy machinery assembly to container handling operations in busy port terminals.

How Does An Overhead Crane Work？
Overhead cranes achieve three-dimensional load handling through the coordinated operation of core components, relying on electric power and mechanical transmission.​
Longitudinal Movement: The end trucks installed at both ends of the main girder are equipped with frequency conversion motors and driving wheels. When powered on, the motors drive the wheels to roll along the fixed overhead rails, enabling the entire crane to move back and forth across the workspace, covering the length of the operation area.​
Transverse Movement: The hoist trolley is mounted on the guide rail of the main girder. Its built-in motor drives the trolley wheels to run along the girder. This allows the trolley and the hoisting mechanism to move left and right, thus covering the width of the operation area.​
Vertical Lifting: The hoisting mechanism on the trolley consists of a motor, a wire rope drum, and a hook. The motor drives the drum to rotate forward or reverse, winding or unwinding the wire rope to lift or lower the hook, thereby completing the vertical movement of loads.​
A cab room (remote or pendant control) controls all the movements with built-in brakes and overload protection to ensure stable and safe operation.

Different Overhead Crane Types
An overhead crane can move in a workshop, production line and warehouse to lift materials. There are different types of bridge cranes. And the features and application environments of different types are also different. ORETEK Crane, as a professional overhead crane manufacturer and supplier, offers diverse overhead cranes. Such as single girder overhead crane, double girder overhead crane, suspension overhead crane, KBK light overhead crane etc.
If you want to choose the most suitable overhead crane to enhance productivity of your factory’s productivity, the following section provides a comprehensive overview of the different types of bridge cranes and their application scenarios.

Single Girder Overhead Crane

A single girder overhead crane is a lightweight industrial lifting device with a single main girder as its core structure, supported by end trucks running on overhead rail. It consists of a single bridge, two end trolleys, and a trolley hoist.
Typically, it has a lifting capacity of 1-32 tons, ideal for medium-light duty tasks. Its compact design uses less material than double-girder models, reducing installation and building load costs.
We often use single girder electric overhead travelling(EOT) cranes in factories, warehouses, and workshops. They maximize floor space while meeting CE/ISO/EAC international safety standards. So single girder overhead cranes are cost-effective solutions for efficient material handling.The hoisting mechanism on a single girder crane is typically an electric chain hoist, which offers compact dimensions, lower cost, and easier maintenance compared to wire rope hoists — making it the ideal match for the single-girder design philosophy of simplicity and affordability.

Double Girder Overhead Crane
The double girder overhead crane features two parallel steel main girders, for heavy-load tasks (20-500 tons) that exceed single-girder cranes’ capacity.
It consists of two bridges, two end cars and one or two trolley hoist assemblies. The trolley hoist travels on tracks mounted on top of the bridges. Its dual-girder design boosts stability, minimizing deflection when lifting ultra-heavy items like steel coils or ship hull parts.
Among them, the European double girder bridge crane is an important material handling equipment. Users prefer to choose them because of their simple structure, good stability, smooth operation, and large lifting capacity.
Customers often use them in industrial and mining enterprises, steel and chemical industries, etc.