MZ Type Double Girder Gantry Grab Crane

Key Features:

Double Girder Design

Provides higher lifting capacity (typically 5–50 tons or more) and better stability compared to single girder designs.

Allows for larger spans and heavier loads.

Grab Bucket Mechanism

Equipped with a motorized grab bucket for efficient loading/unloading of loose materials.

Can be rope-operated (4-rope or 2-rope) or electrically driven.

Gantry Structure

Runs on rails for smooth horizontal movement.

Adjustable span and lifting height based on application needs.

Can be semi-gantry (one side supported by legs, the other by runway) or full gantry (both sides on legs).

Hoisting Mechanism

Dual hoists (main and auxiliary) for grab operation.

High-speed and low-speed lifting options for precision control.

Travel Mechanism

Electric-driven trolley and gantry travel with frequency control for smooth operation.

Anti-collision and limit switches for safety.

Control System

Cabin-operated, remote-controlled, or pendant-controlled.

Advanced PLC and variable frequency drive (VFD) for smooth operation.

Customization Options

Weatherproofing (for outdoor use).

Explosion-proof (for hazardous environments).

Special grab types (clamshell, orange peel, etc.).

 

Comparison with Other Crane Types

Feature	MZ Double Girder Grab Crane	Single Girder Grab Crane	Overhead Crane with Grab
Max Capacity	Up to 100+ tons	Up to 20 tons	Up to 50 tons
Span Flexibility	Large spans (30m+)	Limited spans	Limited by building
Material Handling	Best for bulk materials	Lighter bulk materials	Needs grab attachment
Outdoor Use	Yes (gantry design)	Limited	No (indoor only)

 

Lifting Capacity 320 tons
Span (Width) 3 - 12 meters (adjustable)
Lifting Height 3 - 10 meters
Working Class A3-A5 (light to medium duty)
Hoisting Speed 0.5 - 8 m/min (variable)
Main Beam Type Single/double girder (box-type)
Power Supply 220V/380V 3-phase or manual
Control Mode Pendant control/wireless remote
Hoist Type Electric chain hoist/wire rope hoist
Travel Drive Manual push or motorized
Corrosion Protection Hot-dip galvanized or marine-grade paint
Wind Resistance Up to Beaufort scale 6 (for outdoor use)
Operating Temp -20°C to +50°C

 

The MZ Type Double Girder Gantry Grab Crane consists of several key mechanical and electrical components that work together to ensure efficient bulk material handling. Below is a detailed breakdown of its main components:

 

1. Main Structural Components

A. Gantry Frame

Double Girders (Main Beams) – Two parallel box-section or truss girders that support the trolley and load.

End Carriages (Legs & Cross Beams) – Support the girders and house the wheels for gantry travel.

Runway Rails – Steel tracks on which the gantry moves.

B. Trolley Assembly

Trolley Frame – Moves along the girders and carries the hoisting mechanism.

Trolley Wheels & Drive – Electric motor, gearbox, and brakes for trolley movement.

 

2. Lifting & Grab Mechanism

A. Hoisting System

Main Hoist – Handles the primary lifting of the grab bucket.

Hoist Motor – Powers the lifting mechanism.

Wire Rope & Drum – Lifts and lowers the grab.

Hook Block & Sheaves – Guides the wire ropes.

Auxiliary Hoist (if applicable) – Assists in grab opening/closing.

 

B. Grab Bucket

Clamshell Grab (for bulk materials like coal, grain, sand) – Two or more hinged jaws.

Rope-Operated (4-Rope or 2-Rope) – Uses separate hoisting and closing ropes.

Motorized Grab – Electrically operated for better control.

 

3. Travel Mechanism

A. Gantry Travel System

Travel Motors – Drive the gantry along the runway rails.

Wheels & Axles – Support the crane's movement.

Buffers & Rail Clamps – Prevent overtravel and secure the crane when parked.

B. Trolley Travel System

Trolley Drive Motors – Move the trolley along the girders.

Guide Rollers – Keep the trolley aligned.

4. Electrical & Control System

A. Power Supply

Festoon System / Cable Reel – Delivers electricity to the moving crane.

Control Panel & Cabin – Houses PLC, VFDs, and operator controls.

 

 

B. Operator Controls

Cabin Control – Operator sits in an enclosed cabin.

Remote Control (Radio/Wireless) – For flexible operation.

Pendant Control – Manual push-button station.

C. Safety Devices

Limit Switches – Prevent over-hoisting and over-travel.

Load Moment Indicator (LMI) – Monitors load capacity.

Anti-Collision System – For multi-crane operations.

Emergency Stop (E-Stop) – Instantly cuts power.

5. Supporting Components

A. Braking System

Hoist Brakes – Hold the load when stopped.

Travel Brakes – Stop gantry/trolley movement.

B. Lubrication System

Automatic Greasing – For wheels, gears, and bearings.

C. Weather Protection (for outdoor use)

Corrosion-Resistant Coating – Protects against rust.

Cabin Heater/Air Conditioning – For operator comfort.

 

6. Optional Add-Ons

Weighing System – Measures material weight.

Dust Suppression – For handling fine materials.

Explosion-Proof Components – For hazardous areas.

Automation & Smart Controls – For integration with plant systems.

SKETCH

 

Main technical

 

Advantages of MZ Type Double Girder Gantry Grab Crane

1. High Load Capacity & Stability

Double girder design provides superior strength compared to single girder cranes, allowing for higher lifting capacities (5–100+ tons).

Rigid structure minimizes deflection, ensuring safe handling of heavy bulk materials.

2. Efficient Bulk Material Handling

Motorized or rope-operated grab bucket enables fast loading/unloading of loose materials like coal, grain, and ore.

High-speed hoisting & trolley travel improves productivity in demanding environments.

3. Customizable for Various Applications

Adjustable span, lifting height, and grab type (clamshell, orange peel, etc.).

Options for indoor/outdoor use, explosion-proofing, and corrosion resistance.

4. Smooth & Precise Operation

Variable Frequency Drives (VFDs) ensure smooth acceleration/deceleration, reducing load swing.

PLC-based controls allow for automation and integration with plant systems.

5. Enhanced Safety Features

Load limiters, anti-collision systems, and emergency brakes prevent accidents.

Limit switches & overload protection ensure safe operation.

6. Low Maintenance & Durability

Heavy-duty construction with high-quality steel and sealed bearings for long service life.

Automatic lubrication systems reduce wear and maintenance downtime.

7. Flexible Operation Modes

Can be cabin-operated, remote-controlled, or fully automated for different workflow needs.

 

Applications of MZ Type Double Girder Gantry Grab Crane

1. Ports & Terminals

Loading/unloading ships with coal, iron ore, grain, and fertilizers.

Stockyard management for bulk material stacking and reclaiming.

2. Power Plants

Coal handling (from storage to boiler feed).

Ash disposal (fly ash, bottom ash handling).

3. Steel & Metal Industries

Scrap handling in steel mills.

Raw material (iron ore, limestone) transfer.

4. Grain & Fertilizer Storage

Loading/unloading silos with grain, soybeans, or chemical fertilizers.

Bulk material distribution in agricultural processing plants.

5. Mining & Quarrying

Ore handling in mining operations.

Sand, gravel, and crushed stone transportation.

6. Waste Management & Recycling

Handling municipal solid waste (MSW) in recycling plants.

Scrap metal sorting and processing.

7. Cement & Construction Material Plants

Clinker, gypsum, and raw meal handling.

Bulk cement loading/unloading.

 

The production process of a 200-ton mobile boat/marine lift crane involves several stages, from design and engineering to fabrication, assembly, and testing. Below is a detailed breakdown of the typical production process:

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1. Design & Engineering

Conceptual Design: Engineers create initial sketches and 3D models based on load capacity (200 tons), reach, mobility, and environmental conditions (marine use).

Structural Analysis: Finite Element Analysis (FEA) ensures the crane can handle dynamic loads, wind, and wave forces.

Hydraulic & Electrical Systems: Design of hydraulic cylinders, winches, and control systems for smooth lifting operations.

Material Selection: High-strength steel (e.g., ASTM A514) for corrosion resistance in marine environments.

Regulatory Compliance: Meets standards like DNV-GL, ABS, or Lloyd's Register for marine cranes.

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2. Material Procurement

Steel Plates & Beams: Sourced for the boom, chassis, and structural framework.

Hydraulic Components: Pumps, cylinders, hoses, and valves from certified suppliers.

Electrical Systems: Motors, sensors, and control panels (often waterproof for marine use).

Wire Ropes & Sheaves: High-grade steel cables for lifting.

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3. Fabrication

A. Structural Fabrication

Cutting & Shaping: CNC plasma/laser cutting for precision parts.

Welding: Automated and manual welding (Submerged Arc Welding for thick sections).

Boom Construction: Lattice or telescopic design for strength and mobility.

Chassis & Outriggers: Reinforced for stability during lifts.

B. Hydraulic & Mechanical Assembly

Hydraulic System: Installation of pumps, cylinders, and hoses.

Winches & Drums: Mounted for lifting and lowering operations.

Slewing Mechanism: Allows 360° rotation (if applicable).

C. Electrical & Control Systems

Control Cabin: Waterproof operator station with joysticks/sensors.

Load Monitoring: Load cells and limit switches for safety.

Power Supply: Diesel engine or electric motor (marine-grade).

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4. Assembly & Integration

Boom Installation: Mounted onto the chassis with pivot points.

Counterweights: Added for balance (if required).

Final Wiring & Plumbing: Connecting hydraulic and electrical systems.

Painting & Coating: Anti-corrosion paint (epoxy or zinc coatings).

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5. Testing & Quality Control

Load Testing: Lifting 200 tons (+25% overload test, per standards).

Functional Tests: Checking hydraulic movements, rotation, and stability.

Environmental Tests: Salt spray tests for marine durability.

Safety Checks: Emergency stop systems, overload alarms.

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6. Delivery & Commissioning

Transport: Disassembled for shipping or delivered as a mobile unit.

On-Site Assembly: Reassembled at the dock or shipyard.

Operator Training: Handling and safety protocols.

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%.