Gantry Crane With Cantilever

A gantry crane with a cantilever is a type of overhead lifting system that combines the structural design of a gantry crane with the extended reach of a cantilever. Unlike traditional gantry cranes, which are supported on rails or wheels and lift loads within a defined frame, a cantilevered gantry crane includes projecting arms (cantilevers) that extend beyond the legs of the crane. These extensions provide additional overhang, allowing the crane to lift and position loads outside the main span of the crane structure.

This design is especially useful in industrial settings where materials need to be moved beyond the limits of the crane's runway, such as over obstacles or into narrow workspaces. The cantilever section can be located on one or both ends of the gantry and enables better utilization of floor space and greater flexibility in operations.

Key Features:

Increased reach for loading/unloading outside the rail span

Versatility in both indoor and outdoor applications

Enhanced flexibility for handling awkward or oversized loads

Typically used in shipyards, fabrication yards, warehouses, and container terminals

The cantilever design also plays a crucial role in counterbalancing the crane's load, maintaining stability, and improving operational safety. Whether fixed or mobile, gantry cranes with cantilevers are essential in modern material handling operations where conventional cranes may fall short.

Core Components PLC, Engine, Bearing, Gearbox, Motor, Pressure vessel, Gear, Pump

Place of Origin Henan, China

Weight (KG) 9000 kg

Video outgoing-inspection Provided

Machinery Test Report Provided

Product name MG model double girder gantry crane

Crane type Double girder gantry crane

Work Duty A3 ~ A7

Control mode Pendent Line, Remote Control, Cabin Control

Traveling Speed 50 m/min

Voltage 3P 380V 50/60HZ or customized

Main electrical parts Schneider/ABB/Siemens

Color Yellow,Red or Customzied

Working temperature -20 ~ 40 ℃

Control voltage DC-24 / 36V

Main Girder (Bridge Beam)

The horizontal beam spanning across the crane structure.

Supports the hoist and trolley.

In cantilever designs, the girder may extend beyond the supporting legs to form the cantilever arms.

Cantilever Arm(s)

Extended portions of the main girder projecting beyond the crane legs.

Allow the crane to lift or place loads outside the main working area of the crane.

Can be on one or both ends of the crane.

Legs (Support Columns)

Vertical structures that support the main girder.

Transfer the load to the ground or rails.

May be rigid or have wheels for mobility.

Trolley

A movable unit that runs along the main girder.

Carries the hoisting mechanism.

Moves the load horizontally along the span of the crane, including over the cantilevered area.

Hoist

The lifting mechanism attached to the trolley.

Includes a hook, rope or chain, and a motor for lifting/lowering the load.

Can be electric, pneumatic, or manual.

End Carriages / Wheel Assemblies

Located at the bottom of the legs.

May include wheels for crane movement along rails (rail-mounted) or rubber tires (rubber-tired gantry cranes).

Allow the crane to move longitudinally.

4.Crane travelling mechanism

1)The crane's wheels are mounted on the end carriages and are responsible for guiding the crane along the rails (for track-based systems) or directly on the surface (for rubber-tired systems).Rails: For track-based Goliath Gantry Cranes, the rails are fixed on the ground in a straight or curved layout. The wheels of the end carriage follow these rails, allowing the crane to move along a predetermined path. The rails are typically made of heavy-duty steel to handle the weight of the crane and its load.Rubber Tires: In the case of rubber-tired Goliath cranes, the crane moves on large, durable tires, allowing it to move freely across open areas. This system provides greater flexibility and mobility, especially in outdoor environments like shipyards or construction sites.

2)Travel Motors and Drive System;The travel motors are responsible for powering the crane's movement along the rails or surface. These electric motors are typically installed on the end carriages, with a motor on each end carriage for larger cranes or a single motor for smaller models.

Drive Mechanism: The travel motor is connected to a gearbox (often a reduction gearbox) that reduces the motor's speed and transfers the power to the wheels. This setup ensures smooth and controlled movement.

Adjustable Speed Control: The crane traveling mechanism usually allows for adjustable speed control, enabling operators to move the crane slowly or at higher speeds, depending on the operational requirements.

3)Control System for Traveling Mechanism;The crane's control system manages the horizontal movement of the crane, allowing the operator to control the speed, direction, and positioning with ease. This system typically includes:Pendant or Remote Control: Operators can control the crane traveling mechanism using a pendant control or a wireless remote control, which provides flexibility and improved safety by allowing the operator to move away from the crane during operation.

Cabin Control: In larger models, the crane may have a dedicated operator's cabin where the operator controls both the lifting and traveling movements.Variable Frequency Drive (VFD): A VFD can be used to control the speed of the travel motor, ensuring smooth acceleration and deceleration, which is crucial for safe and precise movement, especially when handling heavy or sensitive loads.

5.Trolley travelling mechanism

1)The trolley is a wheeled platform that runs along the crane's main girder, carrying the hoist and the lifting mechanism. It is an essential part of the crane that facilitates the horizontal travel of the load.

The trolley may be a single trolley (in the case of single girder designs) or a double trolley (in the case of double girder designs), depending on the crane configuration and lifting capacity.The trolley can be designed for fixed load carrying capacity or for variable load depending on the design, to accommodate different hoist types and weights.

2)Wheels and Rail System;The trolley wheels are mounted on the rail system (also known as the girder tracks) on the main beam of the crane. These wheels are typically made of steel to withstand the heavy load and provide smooth motion along the girder.

The wheels follow a rail that runs along the entire length of the crane's main girder, allowing the trolley to move horizontally across the span of the crane. In some designs, the wheels are mounted on V-shaped tracks to provide stability and prevent the trolley from derailing.

Wheel Arrangement: Typically, four wheels are used on the trolley (two on each side) to ensure stability and even load distribution. The number and configuration of wheels may vary based on the crane design and load requirements.

Variable Speed Control: The trolley's travel speed can be adjusted using a Variable Frequency Drive (VFD) or other speed control systems. This ensures that the trolley moves at the optimal speed, depending on the load, the type of material being handled, and the specific operational requirements.Manual or Motorized Control: In some systems, manual controls (such as a hand chain or pendant control) can be used for trolley movement. More commonly, the trolley's motion is controlled via an electrical or radio remote control system.

6.Crane wheel

1)Material;Crane wheels are typically made from high-grade, heat-treated steel to ensure durability and strength under heavy loads.The material is often forged steel or cast steel with high tensile strength, offering excellent resistance to wear and deformation.

2)Load Capacity Crane wheels are designed to bear the crane's total weight and the weight of the load being lifted. Their load-bearing capacity depends on the material, size, and design of the wheel.The wheels distribute this weight evenly across the rails or ground surface to ensure stability and prevent damage to the infrastructure.

3)Size and Dimensions The size of the crane wheels (diameter, width, and flange height) is determined based on the crane's capacity, track gauge, and operational environment.Larger wheels are used for higher load capacities, while smaller wheels are suitable for lighter loads or compact cranes.

7.Crane Hook

1)The hook is Material Made of high-strength alloy steel or forged steel to provide superior durability, resistance to wear, and strength under heavy loads.Heat-treated for enhanced toughness and to prevent deformation under extreme stress.

2)The hook is Design;Typically designed with a U-shaped structure for ease of attaching slings, ropes, or chains.Available in various shapes and configurations based on the application:Single Hook: A simple design used for lighter loads or less critical operations.

Double Hook: Designed to evenly distribute heavy loads, reducing stress on the hook.Equipped with a safety latch or spring-loaded locking mechanism to prevent accidental disengagement of the load.

3)Capacity Rated for specific load capacities (e.g., 5 tons, 10 tons, 50 tons, etc.), depending on the crane's lifting requirements.Clearly marked with the safe working load (SWL) or working load limit (WLL) for operational safety.

Rotation Many crane hooks are mounted on a swivel bearing to allow 360-degree rotation, providing flexibility during load handling.This feature reduces stress on the lifting slings or chains and ensures better alignment of the load.

Power Supply System

Provides power to the hoist, trolley, and movement systems.

Can include cable reels, festoon systems, or conductor bars.

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Sound and light alarm system & limit switch

1)Audible Alarm:Emits a loud siren or beeping sound during critical operations such as:Crane movement (traveling along rails).Load lifting or lowering.

Emergency stop activation.Volume levels are typically adjustable to ensure the sound is noticeable in noisy environments, such as shipyards or industrial sites.

Visual Alarm:Includes flashing lights, typically LED, mounted on the crane.Colors are often coded for different warnings (e.g., red for emergencies, yellow for caution).

Automation:The alarm system is integrated with the crane's control panel and activates automatically during specific events, such as:Overload detection.Limit switch activation.Power failure or fault conditions.

4)Durability:Built to withstand harsh environmental conditions, such as dust, moisture, and extreme temperatures, ensuring reliable performance in industrial settings.Benefits of the Alarm System Enhanced Safety: Warns nearby workers of crane operations or hazards, reducing the risk of accidents.Operational Awareness: Keeps operators informed of critical events or system faults in real time.Compliance: Meets industry safety standards and regulations.

10.Safety Devices

1) Purpose: Prevents the crane from lifting loads beyond its rated capacity, reducing the risk of mechanical failure or structural damage.How It Works:Sensors measure the load weight.If the load exceeds the safe working limit (SWL), the system halts lifting operations and triggers an alarm.

2) Features:Displays the current load weight.Can be integrated with digital or analog control systems.Limit Switches Travel Limit Switches:Restrict the horizontal movement of the crane or trolley to prevent collisions or overrun at track ends.Hoist Limit Switches:Stop the hoisting mechanism to prevent over-lifting or over-lowering of the hook block.

3) Emergency Stop System Purpose: Allows operators to stop all crane operations immediately in case of an emergency.How It Works:A large, easily accessible red button is installed on the crane's control panel or remote control.Once pressed, it cuts power to all motors and halts operations instantly.

11.Control Mode

1)Remote Control Overview: Allows operators to control the crane from a distance using a wireless remote control.

Key Features:Radio frequency (RF) or infrared (IR) communication.Compact, ergonomic controllers with buttons, joysticks, or touchscreens.Control range varies depending on the system, typically up to several hundred meters.

2)Cabin Control Overview: The crane is operated from an onboard cabin located on the gantry.Key Features:

Equipped with joysticks, control panels, and monitoring displays for precise operation.Provides the operator with a clear, elevated view of the work area.Climate-controlled cabins for operator comfort.

3) Programmable Logic Controller (PLC) / Automated Control;Overview: The crane is operated automatically or semi-automatically using pre-programmed commands and sensors.Key Features:Integrated PLC systems for automated movements and task execution.

Sensors and encoders ensure precise control and positioning.Customizable programs for repetitive or specialized tasks.

Sketch

Main technical

Here are the key advantages of a gantry crane with a cantilever:

Advantages of Gantry Crane with Cantilever

Extended Working Area

The cantilever arms allow the crane to reach beyond the main span, enabling handling of loads outside the rail tracks or supporting legs.

Useful in scenarios where space is limited or obstructions are present.

Improved Material Handling Flexibility

Allows loading and unloading from areas like trucks, platforms, or docks without needing the load to be moved under the crane frame.

Efficient Use of Floor Space

Cantilever design reduces the need for extra clearances or aisles, maximizing available floor area.

Adaptable to Various Applications

Ideal for shipyards, container terminals, warehouses, steel yards, and other heavy-duty or outdoor environments requiring extended reach.

Cost-Effective

In many cases, gantry cranes with cantilevers are more economical than installing a full overhead crane system, especially in open areas where building support structures are not required.

No Need for Building Modifications

Since gantry cranes are freestanding, they do not need to be attached to a building structure, making installation simpler-particularly for retrofitting existing facilities.

Customizable Design

Cantilever length and crane span can be customized based on specific load handling requirements and site layout.

Increased Operational Efficiency

Reduces the time and effort needed to reposition loads or move them to areas that are not directly under the main crane span.

Goliath gantry cranes are used in a variety of industries due to their versatility, mobility, and heavy lifting capacities. Their design makes them suitable for outdoor applications where large and heavy materials need to be handled. Here are some of the main applications of Goliath gantry cranes

Shipbuilding and Shipyards;Application: Goliath gantry cranes are frequently used in shipyards for constructing and assembling ships, as well as for heavy lifting of ship parts and large equipment.Benefits: These cranes can move along the length of the shipyard, making them highly effective for lifting heavy components, such as ship hulls, large equipment, and prefabricated sections.

Port and Container Handling;Application: In port facilities, Goliath gantry cranes are used to handle containers and large cargo. These cranes are essential for loading and unloading containers from ships, moving cargo across dockyards, and stacking containers.

Construction Sites;Application: On large construction sites, particularly in infrastructure projects such as bridges, dams, or high-rise buildings, Goliath gantry cranes are used to lift and move heavy construction materials, such as steel beams, concrete slabs, and precast structures.

Heavy Industry and Manufacturing;Application: In industries like steel, automotive, and aerospace manufacturing, Goliath gantry cranes are used to move heavy machinery, steel coils, and large fabricated parts during production or assembly.

Mining and Quarrying;Application: Goliath gantry cranes can be used in mining and quarrying industries to move large mining equipment, such as crushers, grinders, and conveyor systems, or to lift and transport extracted materials like rocks and ores.

Steel Mills;Application: In steel mills, Goliath gantry cranes are used to handle large steel products, such as rolls, slabs, billets, and coils.Benefits: These cranes help facilitate the handling of heavy, hot, and bulky materials within the steel production process, where precision and strength are critical.

Crane production procedure

1. Design stage: Understand the specific needs of customers, including load-bearing capacity, span, height and use environment. Carry out preliminary design according to the needs and draw scheme drawings, including structural design, power system and control system design. Carry out structural strength, stability and dynamic analysis to ensure that the design meets relevant standards and specifications.

2. Material preparation: Select suitable materials according to design requirements, such as high-strength steel, aluminum alloy, etc., to ensure good mechanical properties and durability. Purchase the required raw materials and components according to the design drawings, including motors, reducers, hooks, control systems, etc.

3. Processing and manufacturing: Cut the steel and process the main beam, end beam and other structural parts according to the design dimensions. Connect the cut parts by welding to form the main structural frame of the crane. Finish the welded components, including drilling, turning and milling, to ensure the matching accuracy of each component.

4. Assembly: Preliminary assembly of the processed components to check the stability and matching of the structure. Install the lifting mechanism, trolley running mechanism and trolley running mechanism to ensure that all moving parts can run smoothly.

5. Electrical system installation: Install motors, inverters, control panels and other electrical components to ensure that the electrical system is connected correctly. Arrange the cable lines reasonably to ensure safety and beauty, and reduce interference and wear.

6. Commissioning and testing: Test the various functions of the crane, including lifting, moving, braking and alarm systems, to ensure that all functions are normal. Carry out safe load tests to ensure that the crane operates stably under maximum load and meets safety standards.

7. Inspection and quality control: Carry out quality inspections on each link of production to ensure that all components meet design and standard requirements. Carry out qualification certification according to relevant regulations to ensure that the equipment meets national and industry standards.

8. Delivery and installation: Transport the manufactured crane to the customer site. Install it at the customer site, including fixing the foundation, commissioning and connecting the power supply. Provide operation training to customers to ensure that they can use the equipment safely and effectively, and officially deliver it for use.

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%.