Product Overview
The double girder overhead crane is a heavy-duty lifting solution widely used in industrial workshops, factories, warehouses, and heavy manufacturing facilities. As a bridge-type crane, it features a stable bridge structure supported by two parallel main girders. The crane travels along runway rails installed inside the facility and is equipped with a movable hoist trolley, enabling three-dimensional material handling operations, including vertical lifting, longitudinal travel, and cross travel.
Compared with single girder overhead cranes, double girder overhead cranes offer higher structural rigidity, stronger load-bearing capacity, and improved operational stability. They are designed to handle heavy-duty applications requiring large lifting capacities, frequent operation, and extended working hours. With customizable configurations available, they are widely used for heavy material handling in industries such as machining, metallurgy, mining, chemical processing, building materials, and logistics warehousing.
Basic Parameters:
Lifting Capacity: Standard capacity range from 5t to 500t
Span: Standard span range from 10m to 35m
Lifting Height: Standard lifting height range from 6m to 30m
Product Advantages
1. Strong Heavy-Duty Load Capacity:
With a lifting capacity ranging from 5t to 500t, double girder overhead cranes are the preferred choice for applications above 32t. The two main girders share the load, providing excellent load distribution, controlled girder deflection, and the ability to withstand short-term overload conditions. The crane supports synchronized lifting with dual lifting points, ensuring safer and more stable handling of large and long workpieces.
2. Superior Structural Rigidity and Smoother Operation:
The enclosed box-type double girder frame features excellent bending and torsional resistance, reducing crane vibration during operation. It minimizes impact and vibration when handling precision equipment and hazardous containers, improving positioning accuracy of heavy loads. The crane can be adapted to large-span workshops exceeding 30m, while single girder cranes generally have a span limitation of around 22m.
3. Greater Effective Lifting Height:
The hoist trolley is installed above the two main girders, unlike single girder cranes where the hoist occupies space below the girder. Under the same workshop height conditions, a double girder crane provides a larger actual hook travel distance, making it suitable for applications requiring high lifting heights, such as precast component handling and warehouse operations. The spacious installation area allows the use of larger hoisting mechanisms to meet high-efficiency production requirements.
4. Suitable for High-Intensity Continuous Operation:
With standard A5-A7 duty classifications and customizable A8 metallurgical duty options, the crane supports long-term cyclic heavy-load operation with extended fatigue life. Unlike single girder cranes, which are mainly designed for intermittent operation, double girder cranes are suitable for 24-hour continuous production environments. The bridge structure is equipped with maintenance walkways and guardrails, allowing easier inspection and maintenance without additional elevated access equipment. An enclosed operator cabin can also be installed for improved working conditions.
5. High Expandability of Lifting Attachments and Control Systems:
The crane can be equipped with various specialized lifting devices, including main and auxiliary hooks, electromagnetic chucks, vacuum lifting devices, and rotary lifting attachments for large-tonnage applications. Additional functions such as variable frequency drive control, anti-sway systems, weighing systems, and remote monitoring systems can also be integrated. With a rigid structural foundation, these advanced control features deliver reliable performance in practical applications.
Product Structure
The double girder overhead crane consists of four core components: the bridge structure, trolley travel system, hoisting mechanism, and electrical control system. The bridge structure serves as the main load-bearing framework of the crane, while the trolley travel system and hoisting mechanism perform material handling operations. The electrical control system ensures equipment operation, control, and safety protection.
Bridge Structure
The bridge structure is assembled by connecting two main girders with end carriages at both ends, forming the primary load-bearing framework of the entire crane. The trolley and hoisting mechanism are installed on the bridge structure. The material quality and welding accuracy of the bridge structure directly determine the crane's structural rigidity and resistance to deformation under heavy loads.
Trolley Travel System
The trolley travel system consists of two parts: the bridge travel mechanism and the trolley travel mechanism, which enable horizontal movement of the crane.
The bridge travel mechanism is installed at both ends of the bridge structure and consists of drive wheels, driven wheels, gear reducers, drive motors, and brakes. It moves longitudinally along the workshop runway rails with reliable braking performance, minimizing issues such as sliding and deviation during operation.
The trolley travel mechanism is mounted on the rails of the double main girders and adopts a four-wheel balanced structure. Equipped with dedicated travel gear reducers, it moves laterally along the main girders. The wear-resistant wheels and high-strength transmission components make it suitable for frequent start-stop operations, reducing operational jamming, deviation, and abnormal noise while ensuring stable positioning accuracy.
The bridge travel mechanism moves the entire crane longitudinally, while the trolley travel mechanism moves laterally along the main girders. The coordinated operation of both systems covers the complete working area within the workshop.
Hoisting Mechanism
The hoisting mechanism is responsible for lifting and lowering loads. It consists of a hoisting motor, gear reducer, drum, wire rope, hook assembly, brake, and limit switches. The crane adopts a standard hoisting configuration compliant with national standards, featuring sufficient motor power, high safety factor wire ropes, and forged high-strength hooks equipped with safety latches to prevent accidental disengagement.
Upper and lower limit switches are installed to prevent over-hoisting and excessive lowering, protecting the wire rope from damage. The brake system provides smooth start and stop buffering, ensuring stable lifting and lowering operations while minimizing load swing and impact, improving overall operational safety.
Electrical Control System
The electrical control system serves as the control center of the crane and includes the control cabinet, pendant controller or remote control, and various safety protection components. It manages the start, stop, and speed regulation of the bridge travel system, trolley travel system, and hoisting mechanism. Integrated safety functions include overload protection, limit interlocking, and emergency stop protection, ensuring reliable operation and comprehensive safety control of the crane.
Installation Process
Our double girder overhead cranes follow a standardized installation procedure with compliant construction practices throughout the entire process, ensuring installation accuracy and safe operation. The detailed process is as follows:
Preliminary Survey and Customized Solution Design:
Customers provide information including workshop drawings, building span, runway gauge, supporting beam parameters, and on-site power supply conditions. Based on the equipment requirements, we develop a customized solution, complete inspection and verification of all crane components, and prepare a complete list of required installation spare parts.
Runway Rail Installation and Leveling:
The local construction team is responsible for fixing the runway rails on the top structure of the workshop. According to our technical drawings, the rail levelness, gauge, and parallelism are precisely calibrated, and all components are reinforced and securely tightened to prevent rail displacement or loosening during operation.
Bridge Assembly and Hoisting:
The double main girders and end carriages are assembled and connected on the ground at the project site. The bridge structure is then adjusted for flatness and diagonal tolerances. Using on-site lifting equipment, the assembled bridge structure is hoisted into position onto the runway rails and securely fixed.
Trolley and Mechanism Installation:
The crane trolley is lifted and positioned onto the main girder rails. The hoisting mechanism, travel mechanisms, wire rope, hook assembly, and other key components are installed in sequence. All fasteners are tightened according to the specified torque requirements.
Electrical System Wiring and Commissioning:
Following our electrical drawings, the control cabinet, pendant controller, limit switches, braking system, and alarm devices are installed and wired on site. All circuits are carefully inspected and tested to identify and eliminate wiring faults.
No-Load and Load Testing:
The crane is first tested under no-load conditions to verify the functions of bridge travel, trolley travel, hoisting, lowering, and braking systems. Rated load testing and overload testing are then performed to confirm the crane's operational accuracy and safety protection functions.
Inspection, Delivery, and Operator Training:
Final acceptance is completed according to applicable crane equipment standards. We provide complete factory inspection reports and qualification documents. English operation manuals, routine maintenance guides, and troubleshooting technical documents are also provided for customer operators to study and use, ensuring smooth project handover.
Comparison with Traditional Models
Compared with traditional single girder overhead cranes and outdated simple double girder cranes, the new standardized double girder overhead crane features higher structural rigidity, more comprehensive safety configurations, more stable heavy-duty operation, and wider application adaptability. It effectively eliminates common issues of traditional models, such as structural deformation, excessive load swing, limited lifting capacity, and high failure rates.
| Comparison Criteria | Standard Single Girder Overhead Crane | Traditional Double Girder Overhead Crane | New Standardized Double Girder Overhead Crane |
| Maximum Load Capacity | ≤20t, limited lifting capacity | ≤100t, poor stability under heavy-duty loads | Up to 500t, with support for customized ultra-heavy lifting capacities |
| Structural Stability | Single girder structure, prone to vibration and deformation under heavy loads | Outdated structure, prone to loosening and misalignment after long-term operation | Box-type double girder structure with high rigidity and excellent deformation resistance |
| Operation Frequency | Suitable for light-duty and low-frequency operations | Suitable for medium-frequency operations, not recommended for long-term continuous operation | Suitable for high-frequency continuous operation and industrial production lines |
| Safety Configuration | Basic limit protection with limited safety features | Basic safety protection configuration with more potential safety risks | Multiple safety protections including overload protection, limit protection, braking protection, and power failure protection |
| Maintenance Cost | More wearing parts, requiring frequent maintenance during mid and later service periods | Aging components, difficult maintenance, and higher repair costs | Modular design for easy maintenance and lower operating costs |
| Applicable Scenarios | Light-duty workshops and small warehouses | Conventional operations in general heavy-duty workshops | Applicable to various standard, heavy-duty, and complex special working conditions |
Types of Double Girder Overhead Cranes for Different Working Conditions
Mature structure with low failure rates, making on-site installation, commissioning, and maintenance simple.
Cost-effective design with standardized components, resulting in lower replacement costs.
Covers a wide range of duty classifications, meeting requirements from light-duty to heavy-duty and high-frequency continuous operations.
Enables stable lifting and precise leveling of ultra-long, oversized, and irregularly shaped heavy workpieces.
Effectively prevents tilting and swinging caused by single-point lifting, ensuring higher lifting accuracy.
Provides excellent heavy-load stability and is suitable for high-precision operations involving large structures, wind power components, and heavy-duty molds.
The entire crane meets explosion-proof protection requirements and is suitable for hazardous environments with flammable and explosive materials.
Excellent sealing and protection performance with resistance to dust, corrosion, and harsh operating conditions.
Equipped with comprehensive safety interlocking systems, making it suitable for high-risk operations in chemical plants, oil and gas facilities, and coal dust workshops.
The double drum structure provides strong load-bearing capacity and stable operation, delivering highly efficient bulk material handling.
Suitable for large-volume bulk material applications involving coal, ore, grain, sand, and gravel.
Effectively reduces labor costs and is ideal for high-frequency operations in ports, storage yards, and grain warehouses.
Compact structure with a smaller footprint, effectively improving workshop space utilization.
Low operating noise, smooth start and stop performance, and impact-free operation, making it suitable for precision applications.
Lower energy consumption, excellent durability, and reduced long-term maintenance costs.
Maximizes the utilization of limited workshop height and increases the effective lifting height.
Requires no modification to the existing workshop structure, with nearly zero renovation costs.
Provides excellent adaptability for heavy-duty lifting applications in old workshops and areas with limited headroom.
Conclusion
With its core advantages of strong load capacity, excellent stability, high safety performance, and wide adaptability, the double girder overhead crane has become a key lifting solution for heavy-duty industrial applications. Different structures and configurations are designed for specific operating conditions, and accurate crane selection is essential to maximize equipment value, reduce maintenance costs, and improve operational efficiency.
As a professional manufacturer of double girder overhead cranes, we provide direct factory supply without intermediaries. Based on customers' workshop dimensions, lifting capacity requirements, and working conditions, we offer one-stop services including customized selection, production, and lifetime after-sales support. With complete certifications and reliable quality, our cranes provide dependable solutions for various industrial lifting applications.
References & Sources
1. Crane Safety - OSHA (Occupational Safety and Health Administration), U.S. Department of Labor
2. Bridge Cranes - WorkSafe Western Australia
3. Overhead and Gantry Cranes - OSHA 29 CFR 1910.179
