1 Product Introduction and Applications

The 50/10t Double Girder Double Hook Gantry Crane represents a class of robust material handling solutions engineered for applications where overhead runway systems are impractical or where open-area material handling is required. As a leading manufacturer in the hoisting machinery industry, Dongqi Crane designs and manufactures this mid-heavy duty crane type to address the challenging demands of various industrial sectors. This crane model, also known as a goliath crane, features a double girder configuration with two independent hoisting mechanisms—a main hook of 50-ton capacity and a auxiliary hook of 10-ton capacity—mounted on a single trolley or separate trolleys that traverse along the bridge.

Dongqi’s 50/10t gantry crane is characterized by its exceptional structural integrity and versatile operational capabilities. The top main girder is mounted on two A-shaped or U-shaped columns that rest on wheel-mounted end carriages, creating a stable lifting platform that can span wide areas without requiring fixed overhead support structures. This design makes it particularly valuable for outdoor applications where traditional overhead cranes cannot be installed, or in facilities where columns cannot be accommodated for structural reasons.

The applications of this crane model span multiple industries, demonstrating its versatility across different material handling scenarios:

• Material stockyards and storage facilities for handling bulk materials, steel plates, coils, and structural components
• Granite and stone processing industries for moving large slabs and blocks
• Construction industry for erecting prefabricated structures and handling building materials
• Engineering industry for equipment installation and maintenance operations
• Port operations and logistics centers for loading and unloading cargo containers and heavy machinery
• Manufacturing facilities for handling large workpieces and production materials

With its robust construction and adaptable design, Dongqi’s 50/10t Double Girder Double Hook Gantry Crane delivers reliable performance in diverse operating environments, from temperate indoor settings to harsh outdoor conditions with varying weather elements.

2 Key Technologies and Design Features

2.1 Structural Design and Construction

Dongqi’s 50/10t Double Girder Double Hook Gantry Crane incorporates advanced engineering principles and premium materials to achieve optimal performance characteristics. The crane’s primary structure consists of welded steel construction using high-grade steel plates that provide exceptional rigidity and strength-to-weight ratio. This construction methodology results in lower dead weight with a high degree of vertical and horizontal rigidity, consequently generating smaller wheel loads on the runway system compared to conventional designs.

The double girder configuration offers distinct advantages over single girder designs, particularly for heavy-duty applications:

• Enhanced stability during lifting operations, minimizing load swing and improving positioning accuracy
• Higher hook height due to the hoist being mounted between the girders rather than under them
• Capability to accommodate multiple hoists and auxiliary devices on the same bridge
• Increased longevity through redundant load paths and superior fatigue resistance

The leg support system employs a rigid frame structure that effectively distributes loads to the end carriages, maintaining alignment and stability under full capacity loads. For longer span applications, Dongqi utilizes trapezoidal truss structures or box girder designs with reinforced stiffening plates to counteract deflection and ensure consistent performance across the entire span length.

2.2 Power and Control Systems

The driving system of Dongqi’s gantry crane incorporates soft-start technology that enables smooth acceleration and deceleration, eliminating sudden jerks that could destabilize loads or cause structural stress. The travel mechanisms utilize separate drives on each side, synchronized through Dongqi’s proprietary control system to prevent skewing during long-travel movements.

The electrical systems feature components from internationally recognized brands such as Siemens or Schneider, ensuring reliability and compatibility with global standards . The power supply system operates on 3-phase AC power with voltage options ranging from 220V to 480V at 50/60Hz, making the crane adaptable to different regional electrical infrastructures .

For operator interface, Dongqi offers multiple control options tailored to specific application requirements:

• Pendant control with ergonomic design for convenient floor-level operation
• Radio remote control systems for unrestricted mobility and optimal visibility
• Enclosed operator cabins with climate control for demanding environments

2.3 Safety Features

Safety is integral to Dongqi’s design philosophy, with the 50/10t gantry crane incorporating multiple protective systems to ensure secure operation:

• Overload protection devices that monitor lifting capacity and prevent hazardous overload conditions
• Emergency brake systems that engage automatically in unexpected situations
• Limit switches for hoisting and traversing motions to prevent over-travel
• Anti-collision devices for installations with multiple cranes operating in proximity
• Rubber buffers at the end carriages to absorb energy during accidental contacts
• Hooks with safety latches to prevent accidental disengagement of loads

The crane’s electrical protection includes thermal and current protection for the main lifting motor, emergency stop buttons at strategic locations, and comprehensive circuit protection for all electrical components.

Table: Comparison of Key Design Features

Feature Category	Dongqi 50/10t Gantry Crane	Conventional Alternatives
Girder Configuration	Double girder design	Single or double girder
Structural Material	High-grade steel with optimized section	Standard steel sections
Hoisting Mechanism	Independent main and auxiliary hooks	Single hook or combined system
Control System	Branded components (Siemens/Schneider)	Varying component quality
Safety Systems	Comprehensive protection package	Basic safety devices

3 Detailed Technical Parameters

The technical specifications of Dongqi’s 50/10t Double Girder Double Hook Gantry Crane reflect its robust performance capabilities and adaptability to various operational requirements. The following parameters provide a comprehensive overview of the crane’s technical characteristics:

• Rated Load: Primary hook: 50 tons; Secondary hook: 10 tons
• Span Length: Range of 10-40 meters, customizable based on application requirements
• Lifting Height: Standard of 30 meters, with customization available for specific needs
• Lifting Speed:
  • Main hook: 5.9 m/min at 50-ton capacity
  • Auxiliary hook: Higher speed appropriate for lighter loads
• Trolley Travelling Speed: 38.4 m/min for the 50-ton model
• Crane Travelling Speed: 30 m/min (consistent across different capacity points)
• Work Duty Classification: A5 (compatible with FEM standards) with an average utilization of 2M
• Total Weight: Ranges from 112 to 185 tons depending on span and specific configuration
• Wheel Configuration: 8-wheel arrangement for the 50-ton model, providing optimal load distribution
• Maximum Wheel Pressure: 288-375 KN, determining runway design requirements
• Recommended Rail: QU70 steel rail section for the runway system

The span specification represents one of the most critical parameters, directly influencing the structural design, weight, and cost of the crane. Dongqi engineers the girder section and supporting structure specifically for each span length to maintain optimal deflection characteristics under load. The lifting speed varies between the main and auxiliary hooks, with the higher speed on the auxiliary hook enabling quicker handling of lighter loads, thereby optimizing cycle times for mixed-load applications.

The A5 duty classification indicates that the crane is designed for applications with moderate to heavy usage, where the equipment operates regularly but not in continuous heavy-duty cycles. This classification ensures that all components—structural, mechanical, and electrical—are sized appropriately for the expected service life.

Table: Detailed Technical Parameters for Different Configurations

Parameter	50/10t	75/15t	100/20t
Span Range (m)	10-40	10-40	10-40
Lifting Speed (m/min)	5.9	6.0	4.4
Trolley Speed (m/min)	38.4	38.4	33.8
Crane Speed (m/min)	30	30	30
Total Weight (t)	112-185	148-220	172-265
Number of Wheels	8	16	16
Max Wheel Pressure (KN)	288-375	210-255	255-310
Recommended Rail	QU70	QU100	QU100

4 Customization and Service Support

4.1 Tailored Engineering Solutions

Dongqi Crane recognizes that standard configurations may not always address specific operational requirements, and therefore offers comprehensive customization options for the 50/10t Double Girder Double Hook Gantry Crane. The company’s engineering team engages directly with clients to develop tailored solutions that optimize the crane’s performance for particular applications and operating environments.

The custom design process begins with a detailed assessment of the client’s requirements, including:

• Operational parameters: Lifting capacity, span, lifting height, and speed requirements
• Physical constraints: Available space, headroom limitations, and existing infrastructure
• Environmental conditions: Indoor/outdoor application, temperature extremes, and potential exposure to corrosive elements
• Operational regimen: Number of lifts per day/shift, frequency of maximum capacity lifts, and expected service life
• Integration needs: Compatibility with existing material handling systems, automation interfaces, and special attachments

Based on these requirements, Dongqi engineers develop conceptual designs followed by detailed engineering drawings for client review and approval. This iterative process ensures the final product precisely matches operational needs while maintaining structural integrity and compliance with relevant standards.

4.2 Installation and Commissioning

Dongqi provides comprehensive installation support for the 50/10t gantry crane, ranging from technical guidance for local contractors to turnkey installation services performed by Dongqi’s own technicians. The company’s approach to installation emphasizes precision alignment and systematic verification of all components to ensure optimal performance and longevity.

The installation process typically includes:

• Site preparation guidance, including foundation and runway requirements
• Supervision of erection activities to ensure proper assembly sequence and connection integrity
• Alignment verification of runways, girders, and end carriages
• Electrical installation and connection of power supply and control systems
• Commissioning tests including no-load tests, load tests at various capacities, and safety device verification
• Operator training on proper use, daily inspections, and basic maintenance procedures

For international clients, Dongqi can dispatch experienced engineers to oversee the installation process, ensuring the equipment is commissioned correctly and operators are adequately trained before the crane enters service.

4.3 Maintenance and Technical Support

The service support for Dongqi’s 50/10t gantry crane extends throughout the equipment’s entire lifecycle, with a focus on maximizing availability and minimizing downtime. The service package includes:

• Lifetime maintenance support with detailed manuals, recommended spare parts lists, and troubleshooting guides
• Remote technical assistance for diagnosing and resolving operational issues
• On-site service by qualified technicians for complex repairs or periodic inspections
• Parts support with genuine Dongqi components to ensure compatibility and performance
• Modernization services for upgrading existing cranes with enhanced features or increased capacity

Dongqi’s preventive maintenance program helps identify potential issues before they lead to unscheduled downtime, with recommended inspection intervals and procedures for different components based on usage intensity and environmental conditions.

5 Why Choose Dongqi Crane

5.1 Manufacturing Expertise and Quality Assurance

Dongqi Crane brings substantial industrial experience to the design and manufacturing of double girder double hook gantry cranes, with over 30 years of specialized expertise in hoisting equipment . The company’s manufacturing facilities encompass 240,000 square meters of dedicated production space, equipped with 2,000 sets of manufacturing and detection devices that enable comprehensive quality control throughout the production process .

The manufacturing workforce includes 500 technicians and 70 senior engineers who apply their specialized knowledge to crane design and production optimization . This substantial engineering capability allows Dongqi to address complex technical challenges and continuously improve product designs based on field experience and evolving industry requirements.

The quality assurance process incorporates multiple verification stages:

• Material certification and incoming inspection for all primary structural components
• Process controls during fabrication, including precision welding with qualified procedures
• Dimensional verification at critical assembly stages to ensure proper fit and function
• Functional testing of completed assemblies under simulated operating conditions
• Final inspection and documentation before shipment

This systematic approach to quality management has resulted in international certifications including CE, ISO9001, and SGS, demonstrating compliance with global standards for safety and quality .

5.2 Global Supply and Support Capability

Dongqi Crane has established a robust supply chain that enables efficient delivery of cranes and components to clients worldwide. The company’s experience with international projects includes successful installations in the United States, Canada, Australia, European countries, and various emerging markets .

The logistics capability encompasses professional packaging, containerization, and coordination with international freight forwarders to ensure equipment arrives undamaged and on schedule. For the 50/10t gantry crane, Dongqi typically quotes CIF (Cost, Insurance, and Freight) prices to major ports, simplifying the import process for international clients .

The after-sales service network includes technical representatives in multiple regions, supported by a central response team at the manufacturing headquarters. This structure enables prompt attention to client needs, whether for routine spare parts requirements or urgent technical assistance.

5.3 Value Proposition and Competitive Advantages

Dongqi’s 50/10t Double Girder Double Hook Gantry Crane delivers exceptional value through a combination of technical performance, reliable operation, and lifecycle cost efficiency. The crane’s design emphasizes durable performance with low maintenance requirements, reducing the total cost of ownership over its service life.

The competitive advantages of choosing Dongqi include:

• Integrated manufacturing of structural, mechanical, and electrical systems, ensuring compatibility and single-source accountability
• Technical consultation during the selection and specification process, preventing under- or over-sizing of equipment
• Competitive pricing resulting from manufacturing efficiencies and vertical integration
• Comprehensive service support from installation through ongoing operation
• Proven track record with numerous installations across diverse industries and operating environments

For businesses seeking a reliable material handling solution for demanding applications, Dongqi’s 50/10t Double Girder Double Hook Gantry Crane represents a technically sound investment that will deliver years of productive service with proper operation and maintenance.

6 Conclusion

The 50/10t Double Girder Double Hook Gantry Crane from Dongqi Crane embodies a balanced integration of robust structural design, precise control systems, and comprehensive safety features. This equipment addresses the material handling requirements of industries ranging from metal production and construction to logistics and general manufacturing, providing reliable lifting capability where overhead runway systems are impractical.

With customizable parameters including span, lifting height, and operational speeds, the crane can be tailored to specific application needs, while maintaining the structural integrity and performance characteristics essential for heavy-duty service. Dongqi’s manufacturing expertise and comprehensive support services further enhance the value proposition, ensuring proper installation, operation, and maintenance throughout the equipment’s service life.

For prospective clients considering the acquisition of a 50/10t gantry crane, Dongqi offers technical consultation to develop equipment specifications that accurately address operational requirements while optimizing investment value. The company’s approach combines engineering rigor with practical application knowledge, resulting in crane solutions that deliver reliable performance in demanding operating environments.