Double Girder Beam Gantry Crane

A Double Girder Beam Gantry Crane is a robust and high-capacity lifting system designed for handling heavy loads in demanding industrial environments. It features two parallel horizontal girders supported by rigid legs, which move on ground-level rails or wheels. This type of gantry crane offers greater load-bearing capacity and span compared to single girder designs, making it suitable for intensive, large-scale operations.

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Key Characteristics:

Double Girder Design: Two main girders provide enhanced strength and stability, allowing for higher lifting capacities and longer spans.

Hoist Configuration: The hoist is typically mounted on a trolley that runs between the two girders, offering maximum lifting height and efficient load distribution.

Mobility: Available as rail-mounted or rubber-tired for indoor and outdoor use.

Customization: Can be tailored with adjustable span lengths, lifting heights, speeds, and control systems.

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Typical Applications:

Shipbuilding – For handling large ship parts and engines.

Steel Mills – Moving heavy rolls, billets, or machinery.

Power Plants – Lifting turbines, transformers, and other bulky equipment.

Construction Sites – Hoisting precast concrete sections or steel structures.

Container Yards – Handling large shipping containers and heavy cargo.

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Advantages:

High load capacity (commonly from 10 tons to 300+ tons).

Greater hook height and lifting clearance.

Improved stability and durability for continuous operations.

Suitable for high-frequency, high-intensity usage.

 

Core Components：Engine, Bearing, Gearbox, Motor, Gear

Place of Origin：Henan, China

Warranty：2 years

Weight (KG)：50000 kg

Video outgoing-inspection：Provided

Machinery Test Report：Provided

Application：Outdoor

Keywords：Gantry Crane

Rated Loading Capacity：50Ton

Cross travelling speed：44.6m/min

Long travelling speed：47.1m/min

Control way：cabin

Power supply：Cable reel

Steel track：QU80

Power：3-phase AC 50HZ 380V

 

 

1.Double Bridge Girders

Description: Two parallel horizontal beams forming the crane's primary load-carrying structure.

Function: Support the trolley and hoist; provide a runway for the trolley to travel across.

Design: Fabricated from high-strength steel; may include maintenance walkways.

Support for Lifting Mechanism: It houses the trolley and hoist that carry out lifting tasks.

Stability: Ensures the stability of the crane by evenly distributing loads.

Efficiency: Designed to optimize load movement across the working area.

Design Considerations

Load Requirements: Calculated based on the maximum load and dynamic forces the crane will encounter.

Span and Height: Dictated by the size of the workspace and the required lifting height.

Safety Factors: Includes features like deflection limits, fatigue resistance, and compliance with industry standards (e.g., FEM, CMAA).

Supporting Legs (Gantry Legs)

Description: Vertical structures connecting the girders to the ground or base wheels.

Function: Transfer the load from the girders to the ground.

Types:

A-frame or box-type legs depending on load and span requirements

 

Trolley

Description: A movable platform that runs along the top or between the girders.

Function: Carries the hoist and moves horizontally across the bridge.

 

Hoist

Description: The lifting mechanism, typically electric wire rope type.

Function: Raises and lowers loads using a drum, rope, and hook system.

Mounting: Positioned on the trolley for horizontal movement.

 

 

3.End Carriages / End Trucks

Description: Structures attached to the ends of the girders.

Function: House the wheels that allow the crane to move along ground rails or tracks.

4.Drive Mechanism

Description: Includes motors, gearboxes, and brakes.

Function: Powers the crane's movement (travel, trolley, hoist operations).

Control: Frequency inverter systems often used for smooth acceleration/deceleration.

 

5.Trolley travelling mechanism

1) Structural composition

Trolley frame: The frame is typically made of high-strength steel to support the load and withstand the stresses during operation.

Wheel set: The trolley is equipped with wheels that run on the rails of the main girder. These wheels are often made of hardened steel or cast steel to ensure durability and wear resistance.

Drive device: Electric motors are commonly used to provide the necessary power for the trolley's movement A gearbox is used to control the speed and torque of the trolley's movement.Couplings connect the motor to the gearbox and ensure smooth transmission of power to the wheels.

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2) Function of the trolley operating mechanism

Horizontal Movement: The primary function of the trolley traveling mechanism is to move the trolley horizontally across the length of the main girders. This movement allows the crane to position the hoist over a desired load location.

Load Handling: By moving along the main girders, the trolley helps in positioning the hoist system accurately above the load, which is necessary for lifting and transferring goods efficiently.

Power Transmission: The traveling mechanism typically uses electric motors and gear systems to provide the necessary torque and speed for the trolley's movement. The motors can be either AC or DC, depending on the design and requirements of the crane.

Rails and Wheels: The trolley runs on rails that are mounted on the main girders. The wheels on the trolley are designed to travel along these rails, ensuring smooth and stable movement. The wheels may be fitted with flanges to prevent lateral movement and maintain alignment.

Safety Mechanisms: The traveling mechanism is equipped with safety features such as limit switches, braking systems, and overload sensors to prevent accidents and ensure the safe operation of the crane.

6.Wheel Assemblies

Description: Wheels mounted at the base of the legs or end carriages.

Function: Enable the crane to travel longitudinally on rails.

7.Crane Hook

The crane hook of a double main girder gantry crane is an essential component used for lifting and transporting heavy loads.

Design and Structure

Material: Typically made of high-strength steel to withstand heavy loads and provide durability.

Shape: The hook often has a C-shape or a pointed end for securely holding lifting slings or chains.

Size and Capacity: It is designed to match the lifting capacity of the crane, which can range from a few tons to several hundred tons for large industrial cranes.

Types of Hooks

Single Hook: Common in standard applications, used for lifting a load from a single point.

Double Hook: Utilized when a more balanced load is needed, often in double main girder designs for higher lifting capacities.

Crab Hook: In gantry cranes, the hook may be mounted on a trolley or crab that runs along the girders.

Motor

The motor of a double main girder gantry crane is an essential component that provides the power necessary for lifting, traveling, and sometimes rotating the crane's hoist or trolley system.The motor's power rating must match the crane's capacity and the load it needs to lift. Typically, these motors range from a few kilowatts up to hundreds of kilowatts, depending on the lifting and traveling requirements.

Motors can be equipped with variable frequency drives (VFDs) for smooth speed adjustments and energy savings.Safety and control systems like overload protection, braking systems, and emergency stops are incorporated for safe operation.

The motor should be compatible with the electrical supply available at the operating site, which can vary (e.g., 380V/50Hz, 480V/60Hz).The motor in a double main girder gantry crane is used for operations such as lifting heavy loads, moving the crane along the tracks (longitudinal travel), and sometimes lateral movement (cross travel) of the hoist or trolley.

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Sound and light alarm system & limit switch

1) Sound and light alarm system

A double main girder gantry crane, commonly used in heavy-duty operations, often incorporates safety mechanisms like sound and light alarm systems to ensure safe operations.

Sound Alarm (Horns/Buzzers): These are typically loud, audible devices that emit a distinctive sound to alert people in and around the working area. The sound level is designed to be high enough to be heard over operational noise.

Light Alarm (Flashing Lights/Beacons): Visual signals, such as flashing lights or rotating beacons, help alert personnel visually, especially in noisy environments where sound alarms may be insufficient.

2) Limit switch

A limit switch on a Double Main Girder Gantry Crane is a safety device used to prevent the crane from moving beyond a designated range. This ensures the protection of both the crane and its surroundings, as well as any loads being lifted.

Key Functions of Limit Switches:

Position Control: The limit switch helps monitor and control the position of the crane's trolley, hoist, and gantry to prevent over-travel and collisions.

Safety Shutdown: If the crane moves past its allowed limits, the limit switch signals the control system to stop the motor and prevent damage or hazardous situations.

Emergency Stop: It can act as an emergency cutoff to shut down the crane when it approaches the limits of its track or rail, preventing it from derailing or causing accidents.

Types of Limit Switches Used:

Mechanical Limit Switches: Activated by physical contact, often using a lever or cam that triggers the switch when moved by the crane's motion.

Electronic Limit Switches: Use sensors (e.g., inductive, capacitive, or optical sensors) for non-contact detection, providing higher durability and reducing wear and tear.

Rotary Limit Switches: Typically used in applications where rotational motion needs to be monitored, such as in hoists.

Linear Limit Switches: Used for applications where linear travel is monitored, commonly found in the movement of the trolley.

10.Safety Devices

1) 1. Overload Protection Device

Function: Prevents the crane from lifting loads that exceed its rated capacity.

2. Limit Switches

Function: Prevents the crane from moving beyond a set range during operations.

3. Emergency Stop Button

Function: Allows operators to quickly shut down the crane in case of an emergency.

4. Anti-Collision Device

Function: Prevents collisions between the crane and other structures or equipment.

5. Load Sway Control

Function: Reduces load sway during operations, which can be dangerous if uncontrolled.

6. Brake Systems

Function: Ensures that the crane remains in a stationary position when not in motion.

7. Safety Interlocks

Function: Prevents the operation of the crane if certain safety conditions are not met.

8. Warning Alarms and Signal Lights

Function: Alerts personnel in the vicinity of the crane's movement.

9. Anti-Tipping Device

Function: Protects against crane tipping due to uneven load distribution or excessive loading.

10. Cooling System for Motors

Function: Prevents motors from overheating during extended use.

11. Remote Control Systems

Function: Allows operators to control the crane from a safe distance.

12. Crane Monitoring Systems

Function: Provides real-time monitoring of operational parameters such as load weight, speed, and position.

13. Lighting and Visibility Aids

Function: Ensures that the operator has clear visibility, especially in low-light conditions.

11.Control Mode

1)1. Pendant Control

Description: The crane operator uses a wired control pendant to manage the movement of the crane and hoist.

Advantages: Simple to use, cost-effective, and provides direct control from a safe distance.

Usage: Commonly used in stationary or semi-stationary operations where the operator can be close to the crane.

2. Radio Remote Control

Description: Operators use a wireless control unit, which communicates with the crane via radio signals.

Advantages: Offers more flexibility as the operator can control the crane from a greater distance and access hard-to-reach areas.

Usage: Ideal for more complex operations and environments where operator mobility is essential.

3. Cabin Control

Description: The operator sits in a cabin on the crane itself and controls it using a combination of joysticks, buttons, or other controls.

Advantages: Provides a better view of the working area and greater precision in controlling the crane.

Usage: Suitable for heavy-duty operations or when a higher level of control is needed for positioning and maneuvering.

4. Automated Control (Semi-Automatic and Fully Automated)

Description: The crane can be controlled by programmed commands or integrated with automated systems for autonomous operation.

Advantages: Reduces human intervention, improves precision, and enhances safety for repetitive tasks.

Usage: Often used in large-scale operations where high efficiency and continuous operation are necessary.

5. Hybrid Control

Description: Combines manual operation (using pendant, remote, or cabin control) with automated features that can be engaged as needed.

Advantages: Offers versatility for operators who need to switch between manual and automated modes for specific tasks.

Usage: Common in systems designed to be adaptable to various operational requirements.

12.Sketch

 

Main technical

 

 

 

Advantages of Double Girder Beam Gantry Cranes

A Double Girder Beam Gantry Crane offers superior performance, strength, and versatility for demanding material handling tasks. It is ideal for industries requiring high lifting capacity, long spans, and frequent operation.

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1. High Lifting Capacity

Supports heavy-duty lifting, typically from 10 tons up to 300+ tons.

Suitable for moving large machinery, heavy components, and industrial equipment.

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2. Greater Lifting Height

The hoist is mounted between or on top of the girders, allowing maximum hook height.

Provides more vertical clearance compared to single girder designs.

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3. Long Span Capability

Can cover wide areas with longer spans between supports.

Reduces the need for multiple cranes or lifting points in large facilities.

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4. Increased Rigidity and Stability

Dual girders offer better load distribution and structural integrity.

Ideal for applications with frequent, intensive lifting operations.

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5. Versatile Customization

Can be engineered with specific lifting heights, spans, and control options.

Suitable for indoor or outdoor use, and adaptable to rail-mounted or rubber-tired systems.

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6. Efficient and Safe Operation

Can be equipped with automated controls, sensors, and safety systems.

Supports high-precision positioning and smooth motion with inverter control systems.

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7. Durable and Reliable

Designed for continuous, high-cycle use in harsh environments (e.g., shipyards, steel plants).

Robust construction ensures long service life and lower maintenance costs.

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8. Optional Features Enhance Functionality

Walkways, maintenance platforms, lighting, storm brakes, and wind sensors can be integrated for operational efficiency and safety.

 

 

Applications of Double Girder Beam Gantry Cranes

Double girder beam gantry cranes are designed for heavy-duty, high-performance lifting in environments where strength, stability, and high lifting capacity are essential. Their robust structure makes them ideal for industrial operations requiring wide spans, high hook heights, and frequent use.

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1. Shipbuilding Yards

Use: Lifting ship sections, engines, and heavy components.

Why: High load capacity and wide span accommodate large, irregular loads.

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2. Steel Mills and Foundries

Use: Transporting molten metal containers, steel coils, slabs, and ingots.

Why: Designed to withstand extreme heat and heavy weights in demanding conditions.

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3. Construction Sites

Use: Handling precast concrete, steel beams, and structural panels.

Why: Offers mobility and high clearance needed for large construction elements.

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4. Power Plants

Use: Lifting generators, turbines, transformers, and other massive equipment.

Why: Precision handling and structural reliability are critical for plant operations.

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5. Rail and Metro Yards

Use: Moving railcars, bogies, and track components during maintenance or assembly.

Why: Suitable for long-span applications and high-clearance operations.

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6. Container Terminals and Logistics Hubs

Use: Loading and unloading shipping containers or large cargo units.

Why: Rail-mounted double girder gantries offer efficient container handling over large yards.

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7. Aerospace and Heavy Manufacturing

Use: Lifting aircraft parts, industrial machinery, and tooling assemblies.

Why: High precision and consistent load handling for large and fragile components.

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8. Mining and Heavy Equipment Maintenance

Use: Servicing and relocating crushers, motors, and other massive equipment.

Why: Withstands rugged environments and handles oversized items safely.

 

 

1. Design and Engineering

Blueprint and Structural Design: Engineering teams design the crane based on specifications, considering the weight, span, lifting capacity, and working environment.

Component Specifications: Detailed specifications for components such as the main girders, end beams, hoist system, trolley, and electrical components are prepared.

2. Material Selection and Procurement

Steel Material Selection: High-strength steel materials are chosen for the main girders, columns, and other critical parts.

Procurement: Materials, such as steel plates, sections, bolts, and electrical components, are sourced and inspected for quality.

3. Cutting and Pre-Fabrication

Cutting and Shaping: Steel components are cut, shaped, and welded into preliminary forms according to the design specifications.

Pre-Fabrication Assembly: Components such as beams and girders are pre-assembled to verify that they fit together properly.

4. Welding and Structural Assembly

Welding: Main girders, columns, and other structural components are welded to create a sturdy framework. Specialized welding techniques are used to ensure strength and durability.

Structural Assembly: The main girders and end beams are assembled, ensuring precise alignment for balanced load distribution.

Quality Control: Welding seams and joints are inspected using non-destructive testing (e.g., ultrasonic or X-ray testing) for any structural defects.

5. Machining and Finishing

Machining of Parts: Critical parts such as the wheels, trolley components, and hoists undergo machining for proper fitting and smooth operation.

Surface Treatment: Steel parts are cleaned and subjected to surface treatments like sandblasting and coating to prevent rust and enhance durability.

Painting and Coating: Protective coatings are applied for weather resistance, with a primer followed by top coats.

6. Assembly of Crane Components

Main Girder Assembly: The two main girders are mounted and aligned.

End Beam Installation: End beams are fixed to the main girders, forming the frame of the crane.

Hoist and Trolley Installation: The hoist mechanism and trolley are mounted on the main girder rails and tested for alignment and operational smoothness.

7. Electrical and Control Systems Installation

Wiring and Cabling: Electrical wiring is installed for power supply, control circuits, and safety systems.

Control Panel and Safety Features: The control panel is mounted, with safety features such as limit switches, emergency stops, and overload protection integrated and tested.

Control System Programming: The crane's control system is programmed and tested for correct operation.

8. Testing and Quality Assurance

Load Testing: The crane is subjected to load tests to ensure it can handle its rated capacity without issues.

Operational Testing: Functional tests are performed to check movements, responsiveness, braking systems, and electrical operations.

Inspection and Certification: The crane undergoes final inspections to verify compliance with safety regulations and standards. Certification may be issued by relevant authorities.

9. Final Adjustments and Delivery Preparation

Final Adjustments: Any minor adjustments are made to ensure smooth operation.

Documentation: Operation manuals, maintenance guidelines, and certification documents are prepared for delivery.

Packaging and Shipping: The crane is packaged securely for shipment, ensuring all parts are protected during transit.

10. Installation and Commissioning (at Site)

On-site Assembly: The crane is assembled at the customer's location if required.

Workshop view:

The company has installed an intelligent equipment management platform, and has installed 310 sets (sets) of handling and welding robots. After the completion of the plan, there will be more than 500 sets (sets), and the equipment networking rate will reach 95%. 32 welding lines have been put into use, 50 are planned to be installed, and the automation rate of the entire product line has reached 85%.