QE Double Trolley General Bridge Crane: The Optimal Heavy-Lifting Solution for Modern Industry

I. Product Introduction & Overview

Two QE cranes in a large workshop

1. Product introduction

The QE Double Trolley General Bridge Crane is a specialized lifting device designed to handle hefty loads or long, bulky goods. Its introduction marked a significant advancement in the heavy industry, solving complex lifting challenges that standard cranes couldn't address.

What makes this crane unique is its two trolleys, which can operate independently or in sync. This feature not only increases its capacity to handle diverse load types but also ensures superior safety and precision compared to a single-trolley double-girder crane.

With an impressive load capacity ranging from 5 to 500 tons, a span of 10.5 to 31.5 meters, and a lifting height of 6 to 18 meters, the QE Double Trolley General Bridge Crane meets a wide range of needs, from moving materials within a factory to installing equipment in large-scale industrial projects. This broad capacity range allows it to serve both moderately heavy lifting needs and the most demanding requirements in key industries.

2. Role in modern industry

As industries such as metallurgy, steel production, shipbuilding, and energy demand higher precision and safety in their handling processes, the QE Double Trolley General Bridge Crane has become the ideal solution.

• Power plants: It assists in the installation and maintenance of turbines and generators weighing hundreds of tons. For example, during the construction of a thermal power plant, the QE crane is used to lift and precisely position generator rotors, ensuring absolute safety for millions of dollars worth of equipment.

• Metallurgy & steel: It safely and stably transports billets, steel coils, or massive structural components, even in harsh, high-temperature environments. The two trolleys can lift a steel beam dozens of meters long, saving time and labor.

• Shipbuilding: It is used to assemble large hull blocks, which require synchronized lifting to ensure balance and precise positioning, thus accelerating production schedules.

• Warehouses & manufacturing: It moves large volumes of materials, increasing productivity and reducing the risk of accidents. The flexible operation of the two trolleys helps handle different types of goods in the same working area.

Thanks to its flexible operation, high precision, and superior lifting capacity, this crane is increasingly being used in critical industrial projects.

II. Technical specifications

1. Technical specification table

The QE Double Trolley General Bridge Crane is designed to meet a wide variety of operational requirements.

2. Comparison with other Crane types

The QE Double Trolley General Bridge Crane offers several distinctive advantages compared to other common types of bridge cranes.

Comparison summary:

• For high-capacity lifting, handling long loads, and applications requiring high precision, the QE Double Trolley model is the optimal choice.

• For medium or light loads within smaller working spaces, a single trolley or single-girder crane is more economical.

III. Structure & operating principle

1. Main structure

Close-up of the trolley system

The QE Double Trolley General Bridge Crane is built on a robust framework, incorporating advanced technology and high-quality components.

• Main girder & end beams: The crane features a double-girder structure made from high-quality steel. FEM (Finite Element Method) structural analysis is used during the design phase to optimize weight, increase the load-bearing capacity, and extend the lifespan of the main girder by minimizing stress concentrations. This design ensures both exceptional strength and reduced dead weight, leading to energy savings.

• Double trolley system: Each trolley is designed to European standards, boasting a compact structure, lightweight design, and high assembly precision. They can operate independently to handle two separate loads simultaneously or synchronously to lift long or bulky objects, such as large pipelines or steel beams. The synchronous operation is a key advantage, ensuring load balance and preventing accidents.

• Hoisting mechanism: This system includes a welded steel rope drum, rolling pulleys, and forged wheels. It employs a hardened surface gearbox for an extended service life and a frequency-conversion hoist motor for smooth operation, reduced vibration, and minimized load shock. This technology protects both the crane and the valuable loads it handles.

• Travel mechanism: Utilizes forged wheels with high load capacity and a direct-drive transmission to minimize mechanical wear.

• Electrical & control system: Features a PLC + frequency converter control for all motions. A modular CTS electrical system ensures easy maintenance. The system features a monitoring display, remote control, and reserved interfaces for intelligent functions including anti-sway, automatic positioning, and remote diagnostics.

• Safety components: To ensure maximum safety, the crane is equipped with essential protective devices, including load limiters, travel limit switches, anti-collision devices, and a real-time operational condition monitoring system.

Double girder structure from above

2. Operating principle

The crane with two trolleys operates through the coordinated actions of its hoisting, traveling, and control mechanisms.

• Trolley operation: Each trolley travels along the main girder via a forged wheel drive system. The operator can easily switch between independent mode (each trolley handles its load, effectively doubling the crane’s utility) or synchronous mode (both trolleys lift a single, heavy load together), ensuring perfect load balance and stability.

• Lifting & lowering: The frequency-conversion hoist motors enable smooth, controlled lifting and lowering, which is crucial for handling fragile or expensive equipment. In synchronous mode, the PLC (Programmable Logic Controller) acts as the brain, meticulously ensuring both hoisting mechanisms operate at the same speed and height to maintain perfect load balance.

• Bridge crane traveling: The main girders move along the ground rails via the drive mechanisms on the end beams. Stepless speed control allows the operator to precisely adjust the crane's speed, preventing sudden movements that could cause load sway or impact the crane's structure.

• Monitoring & safety system: All movements are continuously monitored electronically. In the event of a fault or overload, the system triggers automatic alerts, shuts down operations, and logs the event for later analysis. Functions like anti-sway technology use sensors to actively counteract load oscillations, ensuring the crane can handle high-speed movements without compromising safety. This not only protects personnel and assets but also significantly extends the equipment's lifespan.

IV. Features & advantages

1. Key features

The QE Double Trolley General Bridge Crane is equipped with advanced technologies and design improvements to enhance performance, safety, and durability:

• Frequency conversion + PLC control: Ensures smooth and stable lifting and traveling operations. Minimizes vibration and noise during operation.

• European-standard design: Compact structure with high assembly precision, reducing overall weight while maintaining strength.

• FEM structural analysis: Optimizes weight, increases load-bearing capacity, and extends the main girder’s lifespan.

• Fast on-site installation without welding: Reduces construction time and labor costs.

• Modular CTS electrical system: Convenient for inspection, replacement, and maintenance.

• Pre-configured for smart technologies: Includes interfaces for anti-sway, precision control, automatic positioning, and remote monitoring.

2. Outstanding advantages

• Extremely high lifting capacity: Ideal for handling oversized and ultra-heavy loads that conventional cranes cannot accommodate.

• Enhanced productivity: Dual trolleys can operate independently or synchronously, optimizing working time and lifting efficiency.

• Precision positioning: Advanced control systems allow for highly accurate load placement with minimal deviation.

• Operational flexibility: Suitable for various types of loads and different working environments.

• High safety standards: Fully equipped with protective devices and monitoring systems to minimize operational risks.

V. Applications, Purchasing Guide, and Installation Instructions

500-ton lifting capacity demonstration

The QE Double Trolley General Bridge Crane is a versatile and reliable solution, widely used across multiple industries that demand heavy-duty lifting with high precision and operational safety. Its dual trolley system offers greater flexibility, allowing for simultaneous or independent operation to handle oversized or complex loads.

1. Key applications

• Power plants & energy facilities: Used for handling generators, turbines, transformers, and other large electrical components, ensuring safe and efficient maintenance and installation.

• Metallurgy & steel industry: Ideal for transporting molten metal ladles, heavy steel plates, coils, and structural parts in high-temperature and high-dust environments.

• Heavy manufacturing workshops: Perfect for lifting oversized machinery components or for assembly operations that require synchronized trolleys.

• Shipbuilding & marine engineering: Handles large hull sections, engines, and ship modules with precise placement to support faster production timelines.

• Warehouses & logistics centers: Improves efficiency in loading, unloading, and stacking bulky items while reducing manpower requirements.

• Paper industry & other sectors: Moves large paper rolls and heavy equipment in paper mills; also applicable in wind power, chemical processing, and infrastructure projects.

2. Purchasing Guide: How to Choose the Right Crane

When selecting a QE Double Trolley Bridge Crane, consider the following criteria to ensure optimal performance and cost-effectiveness:

• Required lifting capacity: This is the most crucial factor. Choose a crane with a rated load capacity that matches or exceeds your heaviest lifting needs. Do not just consider the current requirements, but also future expansion plans to avoid costly upgrades later.

• Workshop dimensions and space: Evaluate the span, lifting height, and available clearance to ensure compatibility with your facility layout. The crane's path, the location of support columns, and the height of the ceiling all play a vital role.

• Power supply and control: Confirm the crane’s operating voltage and decide between pendant control, wireless remote, or cabin operation. The choice of control system should be based on your workflow, safety protocols, and the complexity of the tasks to be performed.

• Service and maintenance: Consider the manufacturer's after-sales support, warranty, and availability of spare parts. A well-supported crane will have a longer lifespan and lower total cost of ownership.

• Specialized features: Evaluate if you need additional features like anti-sway technology, advanced safety sensors, or specialized hoists for corrosive or high-temperature environments.

3. Installation & maintenance guidelines

Standard installation steps:

1. Conduct a thorough site inspection to ensure structural readiness.

2. Assemble the main beam, trolleys, and end trucks according to the manufacturer's specifications.

3. Install the electrical system, including the control panel, wiring, and safety devices.

4. Perform load testing to verify operational safety and compliance.

Periodic maintenance schedule:

• Daily: Inspect wire ropes, hooks, and safety switches for wear or damage.

• Monthly: Lubricate moving parts, check trolley alignment, and test all limit switches.

• Annually: Conduct a comprehensive inspection, replace worn components, and recalibrate load limiters.

VI. Company introduction

1. Frequently Asked Questions - FAQs

What's the difference between a QE Double Trolley Bridge Crane and a single-trolley crane?

The QE Double Trolley crane is equipped with two trolleys, allowing it to lift two different loads simultaneously or independently. This provides greater flexibility for tasks that require coordinated lifting or moving heavy, bulky goods.

Can the two trolleys operate independently?

Yes, absolutely. The advanced control system is designed to allow the operator to control each trolley independently or in sync, depending on the job's requirements.

How long does delivery and installation take?

On average, delivery takes 25–40 days, depending on the configuration and technical specifications. On-site installation typically takes 3–7 days, subject to actual site conditions.

Do operators need a specific license?

Yes. Operators must be professionally trained and hold a valid crane operation certificate following current occupational safety regulations.

2. Company introduction

With over 10 years of experience in industrial lifting and drive solutions, TXLET is a proud and trusted partner for hundreds of factories, industrial parks, and construction projects nationwide.

We specialize in the complete manufacturing, supply, and installation of:

• Single & Double Girder Cranes: Including overhead cranes, box girder cranes, L-type, and A-type cranes.

• Electric Hoists: Electric chain hoists and wire rope hoists from reputable brands.

• Mechanical Drive Systems: Gearboxes (K, F, S, R series), worm gearboxes (NMRV), screw jacks (SWL), drum couplings (AGBS), and more.

• Lifting Accessories: Crane hooks, pulleys (sheaves), rope drums, and various other specialized lifting components.

All our products are designed to meet high technical standards, undergo strict quality inspections before delivery, and can be customized to meet specific client needs.

Discover Our Related Lifting Solutions

• Electric Hydraulic Grab Bucket: The perfect solution for port and waste-handling.

• K Series Gearbox: Offers durable and efficient power transmission.

• SWL Screw Jack: Provides precise height adjustment and robust support.

• AGBS Drum Coupling: Ensures smooth and reliable torque transfer in hoisting systems.

Contact TXLET today for expert technical consultation and a quick quotation!