Mobile Double Girder Crane Gantry

A Mobile Double Girder Gantry Crane is a versatile and highly efficient lifting solution designed for handling heavy loads in various outdoor environments, such as construction sites, shipping yards, or industrial facilities. This crane combines the advantages of a double girder design with a mobile base, providing flexibility and robustness for heavy lifting and material handling.

 

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.Main beam

The main beam of a Mobile Double Girder Gantry Crane is one of the most crucial components of the crane, providing structural support for the crane's operation. It is designed to carry the load and distribute it evenly across the entire crane system. The main beam, in combination with the end carriage and other components, forms the main structure that allows the crane to travel across the worksite while lifting heavy loads.

 

2.Lifting System

The lifting system of a Mobile Double Girder Gantry Crane is fundamental to its ability to handle heavy loads efficiently and safely. Through the combination of hoists, hooks, motors, limit switches, and overload protection, the lifting system ensures that materials are moved vertically with precision, control, and safety. Regular maintenance is key to ensuring that all components of the lifting system remain in good working condition, preventing downtime and increasing operational efficiency.

3.End carriage

1)Support and Stability:

The end carriage is responsible for supporting the weight of the crane's superstructure, hoist, and the load it carries.

It must provide a stable foundation for the entire crane system while maintaining the crane's ability to move smoothly along the track.

2)Movement of the Crane:

The end carriage allows the crane to move horizontally along the rails, covering the entire span of the gantry. This movement enables the crane to transport loads across a wide operational area.

The drive system in the end carriage provides the necessary torque to initiate and control movement, ensuring the crane operates at the desired speed.

3)Track Alignment and Precision:

The end carriage, along with the crane wheels, ensures the alignment of the crane on the track. The wheels, often with a flanged design, ensure the crane remains on its path and does not derail during operation.

Proper track alignment is essential for the smooth and efficient operation of the crane. Misalignment could cause undue wear on the wheels and compromise the safety of the operation.

4.Crane travelling mechanism

1) Crane Wheels:

The wheels are mounted on the end carriages and are the primary component that enables the crane to move along the tracks. These wheels are typically made of high-strength steel or forged steel to withstand heavy loads.

Flanged Wheels: Most cranes use flanged wheels to ensure they stay aligned on the tracks and avoid derailment. The flanges guide the wheels along the tracks, helping the crane stay steady during travel.

Wheel Bearings: Mounted within the wheels, bearings reduce friction, allowing the wheels to rotate smoothly as the crane travels along the track.

2) End Carriages:

The end carriages are the structures that house the crane wheels and drive mechanisms. They are fixed at both ends of the crane and bear the weight of the entire crane, including the load.

The end carriages allow the crane to move horizontally along the rails while maintaining stability. They are built from steel and designed to distribute the load evenly during crane movement.

3) Drive System:

The drive system provides the necessary power to move the crane along the tracks. It generally consists of:

Electric motor: The motor drives the entire traveling system, providing the torque required to move the crane.

Reduction Gearbox: The motor is connected to a reduction gearbox that adjusts the motor's high-speed rotation to lower speeds while increasing the torque required for crane travel.

Coupling and Shaft: The coupling connects the motor to the wheels through a shaft, enabling the transmission of mechanical power from the motor to the wheels.

Controller: The motor and drive system are controlled via an electrical control panel that allows the crane operator to move the crane forward or backward along the rails.

4) Track System:

The crane travels along rails or tracks that are installed on the ground or within the crane's operational space. The track system must be designed to handle the weight and stress exerted by the crane and its load.

Rail Material: Tracks are typically made from steel or alloy steel to handle the heavy load-bearing. The rail surface must be smooth and free from debris to avoid damaging the wheels or causing excessive wear.

The Alignment and leveling of the track are crucial to ensure smooth crane movement. Misalignment can cause uneven wear on the wheels and reduce operational efficiency.

5) Braking System:

The crane traveling mechanism is equipped with brakes to stop or slow down the crane as needed. Brakes are crucial for safety, especially in emergency situations or when the crane needs to stop at a specific location.

Electromagnetic or hydraulic brakes are commonly used to control the crane's movement. These brakes are integrated into the motor or wheel assemblies.

6)Limit Switches:

Limit switches are important safety features in the crane traveling mechanism. They are installed at both ends of the travel path and stop the crane from moving beyond its designated range, preventing collisions or damage.

The limit switches ensure that the crane doesn't travel past the end of the track or collide with obstacles, ensuring smooth and safe operation.

5.Trolley travelling mechanism

1)Trolley Wheels:

Material: Trolley wheels are generally made of high-strength steel or forged steel to withstand the stresses generated during crane operation.

Flanged Design: The wheels typically have a flanged design to ensure proper alignment on the girder rails and prevent the trolley from derailing. The flanges are located on both sides of the wheels and guide them along the rail.

Bearings: The wheels are mounted on bearings, which are crucial for reducing friction and allowing smooth movement. Roller bearings or ball bearings are typically used in this application.

2)Trolley Frame:

The trolley frame supports the hoisting mechanism and is the structure that the trolley wheels are attached to. It is designed to bear the weight of the hoist and the load, ensuring stability while the trolley moves.

The frame is usually made of high-strength steel and is designed to distribute the load evenly during crane operation. It is also designed to minimize any deformation under heavy lifting conditions.

3) Drive System:

The drive system provides the power needed to move the trolley along the girder rails. It typically includes the following:

Electric motor: A reversible electric motor is commonly used to drive the trolley. The motor provides the force needed to move the trolley forward or backward along the crane's girder.

Reduction Gearbox: The motor is usually connected to a reduction gearbox, which helps reduce the speed of the motor and increase the torque required to move the heavy trolley.

Coupling and Shaft: A coupling connects the motor to the trolley's wheel axle, allowing rotational motion to be transferred to the wheels.

Controller: A control system is used to regulate the motor's speed and direction. It allows the operator to move the trolley with precision.

4) Trolley Rails:

The trolley rails are installed on the top of the crane's double girder and serve as the track along which the trolley travels. These rails are designed to handle the weight and stress of the trolley while maintaining smooth movement.

Rail Material: The trolley rails are typically made from steel or alloy steel, designed for high wear resistance.

The rails must be level and properly aligned to prevent wheel wear and ensure smooth movement. Regular inspections of the rails are necessary to avoid issues like rail misalignment or wear.

5)Limit Switches:

Limit switches are used to control the movement of the trolley, ensuring that it does not travel beyond the end of the girder.

These switches act as safety features by automatically stopping the trolley once it reaches its maximum travel limits, preventing damage to the crane or the load.

Safety Mechanisms:

The trolley traveling mechanism may be equipped with additional safety devices, including overload sensors, emergency stop systems, and brake systems that automatically engage when the trolley reaches the end of its travel path or in case of power failure.

6.Crane wheel

1)Material:

The wheels of a Mobile Double Girder Gantry Crane are typically made from high-strength steel or forged steel to withstand the heavy load-bearing and friction forces encountered during crane travel.

Steel wheels are often treated with heat or hardened to enhance wear resistance and strength.

For cranes operating in harsh environments (e.g., outdoor or corrosive environments), the wheels may also be coated or galvanized to prevent rust and corrosion.

2)Design:

Wheel Shape: The wheels typically have a flanged design with a concave tread that ensures the wheel stays aligned with the rail or track. This design prevents the wheels from derailing and helps maintain smooth movement along the crane's track system.

Wheel Diameter: The diameter of the wheels is selected based on the crane's load capacity and operational speed. Larger wheels are used for higher load capacities and smoother movement on the tracks.

Axle Mounting: The wheels are mounted on axles that are fixed to the crane's end carriage. The axles provide a stable platform for the wheels, ensuring smooth rotation during crane movement.

7.Crane Hook

1)Material:

The hook is typically made from high-strength steel or alloy steel to withstand the heavy loads and stresses during lifting operations.

The steel is often heat-treated or forged to improve its strength, durability, and resistance to wear.

Some hooks may be coated with anti-corrosion materials or painted for added protection in harsh outdoor environments, particularly in coastal or industrial areas with high humidity.

2)Design:

Shape: The hook typically features a curved or U-shaped design that allows it to securely hold a lifting sling or load hook while ensuring a proper balance during the lifting operation.

Opening: The hook has an opening at the bottom (the throat) where lifting accessories such as chains, slings, or wire ropes are attached. This opening may be equipped with a latch to prevent accidental detachment of the load.

Latch: The hook often includes a safety latch to secure the lifting equipment or load during hoisting. The latch is typically spring-loaded and can be manually released when needed.

8.Motor

1)Hoisting Motor
Function: Powers the winch system to lift and lower the load. The hoisting motor must provide enough power to lift heavy loads while maintaining safety and stability.

Motor Type: Typically, AC or DC motors are used depending on the load and speed requirements. DC motors are more suitable for precise load control, while AC motors are used for general operations.

Key Considerations:

Overload Protection: The hoisting motor is often equipped with overload protection devices to prevent damage when lifting heavy loads.

Brake Mechanism: The motor is integrated with a brake system to safely hold the load in position when it is not moving.

2)Traveling Motor (for Crane and Trolley Movement)
Function: Powers the crane's movement along its tracks (crane travel) and the movement of the trolley along the girder (trolley travel).

Motor Type: AC motors are most commonly used for traveling mechanisms because they offer high reliability and efficiency for long-distance movement.

Key Considerations:

Speed ​​Control: Traveling motors often include speed controllers for smooth and controlled motion, allowing for precise positioning during crane operations.

Duty Cycle: These motors are designed to operate continuously during the crane's operation, so they need to handle prolonged periods of use.

3) Trolley Hoisting Motor
Function: Powers the movement of the trolley, which moves the load along the crane's girder. This motor is particularly important for controlling the horizontal movement of the load.

Motor Type: AC or DC motors can be used, depending on the need for precise control or high-speed operation.

Key Considerations:

Synchronization: Trolley motors need to work in sync with the hoisting motor to ensure smooth and coordinated movement of the load.

Control Mechanism: This motor often works in conjunction with other motors and control systems, such as frequency converters or soft starters, for gradual acceleration and deceleration.

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9.Sound and light alarm system & limit switch

1)Sound and Light Alarm System
The crane is equipped with a combined audible and visual warning system designed to enhance workplace safety.
Components:
Sound Alarm (Buzzer or Siren):
Emits a loud, continuous or intermittent sound when the crane is operating, moving, or if a fault is detected.
Light Alarm (Flashing Light/Beacon):
A highly visible flashing LED or xenon strobe light to alert nearby workers during crane movements or critical operations.
2)Limit Switch
Limit switches act as safety stop devices, preventing the crane or trolley from over-traveling beyond safe mechanical limits.
Types of Limit Switches:
Lifting Limit Switch:
Stops the hoisting mechanism when the hook reaches its highest or lowest safe point, preventing wire rope over-winding or unwinding.
Trolley Travel Limit Switch:
Prevents the trolley from colliding into end stops at both sides of the main beam.
Crane Travel Limit Switch:
Prevents the entire crane from traveling beyond the designated track boundaries.
Overload Limit Switch (optional):
Detects overload situations and cuts power to the hoist to protect against structural damage.

10.Safety Devices

1) Overload Protection Device
Function: Prevents the crane from lifting loads that exceed its rated capacity, reducing the risk of crane failure, structural damage, and accidents.
2)Limit Switches (Travel and Hoisting)
Function: Protects the crane from moving beyond its operational limits, which could damage the crane, the track, or the load.
3) Emergency Stop Button
Function: Provides an immediate way to stop all crane movements in case of an emergency, preventing accidents or further damage
4) Anti-Collision System
Function: Prevents the crane from colliding with other cranes, structures, or objects in its vicinity.
5)Crane Anti-Sway System
Function: Minimizes the swinging of the load, which can cause instability or even accidents, especially when moving heavy or cumbersome loads.
6) Brake System
Function: Stops the crane and holds it in place when necessary, preventing unintended movement, especially during load lifting, transport, or positioning.

11.Control Mode

1)Pendant Control Mode
Description: In this control mode, the crane is operated using a wired pendant controller that is connected to the crane's electrical system. The operator holds the pendant to control the crane's movements.
2) Wireless Remote Control Mode
Description: A more advanced control mode that allows the crane operator to control the crane's movements from a distance using a wireless remote control. This is often used for large-scale operations where the operator needs flexibility and mobility.
3) Cabin Control Mode
Description: In some larger cranes or in particularly complex operations, the crane is controlled from an operator's cabin mounted on the crane itself. The operator has full visibility of the operation from inside the cabin.

4)Automatic Control Mode
Description: This is an advanced control mode where the crane can be programmed to perform specific tasks automatically without constant manual control. It's typically used for repetitive or highly precise tasks.

5)Combination Control Mode
Description: This mode allows a combination of the above control systems to be used in tandem. For example, A crane may operate primarily through a wireless remote, but manual override through the pendant controller is available if needed.

12.Sketch

 

Main technical

 

 

1. Increased Load Capacity
The double girder design provides better structural strength, allowing the crane to handle higher weight capacities compared to single girder cranes.

Ideal for heavy lifting tasks and industrial operations that involve large loads.

2. Flexibility and Mobility
The mobility of the crane allows it to move around a large yard or facility, providing versatility for lifting tasks across different locations.

Can be relocated easily for different projects or tasks, reducing downtime and increasing operational efficiency.

3. Higher Stability
The double girder structure offers better stability and resistance to torsion, making it more reliable when lifting heavy or oversized loads.

4. Ease of Operation
Remote control or manual control options make the crane user-friendly, improving the ease of operation for the crane operator.

Provides smooth and precise movement of loads, thanks to modern control systems such as VFD (Variable Frequency Drives) for speed control.

5.Safety Features
The crane is equipped with safety devices such as limit switches, overload protection, safety brakes, and alarm systems to prevent accidents.

The crane operator can stay at a safe distance, especially when working in high-risk environments such as ports or shipyards.

6. Durability and Longevity
The use of high-strength steel and advanced engineering ensures that the crane has a long service life with minimal wear and tear.

Built to withstand harsh environmental conditions, including outdoor operations where weather factors like wind, rain, and snow may be present.

 

1. Shipbuilding and Shipyards
Handling Ship Components: Moving large parts of ships, such as hull sections, engines, and propellers, across the shipyard for assembly.

Launching and Dry Docking: Used for launching ships into water or for dry-docking procedures to move ships in and out of the water.

2. Construction Sites
Heavy Equipment Lifting: Used to move heavy equipment, such as construction machinery, concrete beams, and structural components, across construction sites.

Large Materials Handling: Lifting heavy construction materials such as steel beams, columns, and precast concrete panels.

3. Ports and Terminals
Container Handling: Moving large shipping containers, both for unloading cargo from ships and transporting goods within port terminals.

Bulk Material Handling: Lifting and moving large quantities of bulk materials like steel plates, sand, gravel, or equipment in a port facility.

4. Steel and Metal Industries
Steel Coil and Plate Handling: Used in steel mills for lifting and transporting heavy metal coils, plates, and bars.

Machine Maintenance: Lifting large machines and tools during maintenance or replacement.

5. Mining
Handling Mining Equipment: Used for moving large mining machinery or extracted minerals in mining operations.

Construction and Installation: Moving heavy equipment for installation and construction of mining facilities.

6. Rail Yard and Freight Handling
Railcar Handling: Lifting and moving railcars and freight containers within a yard.

Railroad Maintenance: Used for the maintenance and repair of railcars and railway infrastructure.

 

1.Design and Engineering
Initial Design and Conceptualization:

The design begins with assessing the specific requirements for the crane, including load capacity, span, lifting height, and mobility needs.

Structural engineers create detailed 3D models and technical drawings of the crane, ensuring that the design meets relevant safety and operational standards (e.g., ISO, FEM, CE).

Key design considerations include:

Load calculations for the main girder, end carriages, and hoisting systems.

Mobility analysis for the wheeled or tracked base to ensure smooth movement over the intended surface.

Integration of safety systems, control mechanisms, and ergonomics for the operator.

Approval:

Once the design is complete, it undergoes an internal review and is shared with the customer for approval (if custom-designed).

Adjustments are made if necessary based on feedback from the client or engineering team.

2. Material Procurement
Material Selection:

High-quality materials are chosen for the construction of the crane. These include:

Steel plates for the main girder and end carriages.

Forged steel for critical components like the hook, wheels, and axles.

Electrical components such as motors, controllers, limit switches, brakes, and safety alarms.

Coatings such as anti-corrosive paint for all outdoor components.

Material Testing:

Before fabrication, the materials undergo quality control checks, including tests for tensile strength, hardness, and weldability.

Certification is obtained to ensure that all materials meet industry standards.

3. Fabrication of Main Components
Main Girder:

The double girder beams are fabricated by cutting, welding, and assembling steel plates into the desired shape and size.

After welding, the beams are machined to precise specifications to ensure they align perfectly with the crane's structure.

Non-destructive testing (NDT), such as ultrasonic or X-ray tests, is carried out to ensure that the welds are free from defects.

End Carriages:

The end carriages are welded together, including the motor mount, gearbox mount, and wheel axles.

Wheels and axles are fitted to allow the crane to move along the rails or track.

The end carriages are also equipped with brake systems to control the crane's movement.

Hoisting System:

The hoisting unit is assembled, including the hoist drum, wire ropes, and hook.

The trolley system is also fabricated, which runs along the double girders and holds the hoisting system.

4. Mechanical Assembly
Assembly of Girder and End Carriages:

The main girder and end carriages are joined to create the crane structure. This assembly forms the backbone of the crane, allowing it to carry and heavy lift loads.

Welding is used to secure the end carriages to the girder.

Installation of the Hoist and Trolley:

The hoist is mounted on the trolley, which then runs along the girder beams.

Load-testing equipment is installed to ensure that the hoist can safely lift and lower loads within the required capacity.

5. Electrical and Control Systems
Wiring and Electrical Integration:

The crane's motor, limit switches, brake systems, and control panel are installed.

The control systems (manual pendant, remote control, or radio control) are wired into the crane, allowing operators to move the crane, lift and lower loads, and activate safety features.

Safety Devices:

Overload protection, limit switches, safety alarms, and emergency stops are integrated into the electrical system to enhance operator safety.

6. Crane Assembly
Crane Structure Assembly:

The main girder, end carriages, and hoisting system are fully assembled into a working crane.

The crane's traveling wheels are attached to the end carriages to enable it to move along its rails or track.

Control and Safety Systems:

The control panels, limit switches, and safety alarms are tested for functionality.

Radio remote control or pendant control systems are calibrated and integrated for ease of use by the operator.

7. Testing and Quality Control
Initial Testing:

The crane undergoes static tests to ensure all components are functioning correctly before testing with load.

The hoisting system is tested with a dummy load to ensure smooth lifting and lowering operations.

Load Testing:

The crane is tested with a test load (usually 125% of the rated load capacity) to ensure the crane can handle the maximum lifting weight without any issues.

All movements (hoisting, trolley travel, crane travel) are tested under the load.

Dynamic Testing:

Traveling tests are conducted, checking the crane's ability to move smoothly along the rails or track.

Safety systems such as limit switches, brake systems, and overload alarms are tested in action.

8. Surface Treatment and Painting
Surface Preparation:

All crane components are cleaned and sanded to remove contaminants such as rust, oil, and dirt.

Anti-corrosion Coating:

A high-quality anti-corrosive primer is applied to all exposed metal surfaces.

The crane is painted with industrial-grade paint for durability and visibility, typically in bright yellow or orange for safety.

9. Final Inspection and Documentation
Final Inspection:

A comprehensive inspection is conducted to verify the crane's alignment, weld quality, and overall functionality.

A load test certificate and performance report are generated.

Documentation:

Operation manuals, maintenance guides, and safety documentation are provided to the customer.

The crane's serial number and certifications are logged for future reference.

10. Packaging and Delivery
Disassembly (if necessary):

If the crane is being shipped in parts, the components are disassembled and securely packed for transportation.

Delivery:

The crane is either delivered fully assembled or in parts, depending on the customer's requirements.

Assembly instructions and necessary documentation accompany the crane.

11. Installation and Commissioning
On-Site Assembly:

The crane is reassembled at the customer's site if it was delivered in parts.

Final Testing and Operator Training:

Commissioning is done at the installation site to ensure the crane operates as expected.

Operator training is provided, covering safety procedures, maintenance, and crane operation.

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%.