Electric Single Girder Gantry Crane

Definition and Structure
A marble gantry crane is a type of gantry crane designed for handling heavy marble slabs or blocks in stone processing plants, quarries, or logistics yards. It consists of:

Gantry frame: Typically made of high-strength steel, with legs that can be fixed or wheeled for mobility.

Hoist mechanism: Equipped with electric or hydraulic lifting systems to handle marble slabs (often using vacuum lifters or slings for secure gripping).

Control system: Includes ground-operated pendants or remote controls for precision handling.

Key Features
Load capacity: Ranges from 5 to 50+ tons, depending on the application (e.g., raw block lifting vs. finished slab handling).

Span & height: Adjustable to accommodate marble processing lines or storage racks.

Specialized attachments: Some models use vacuum lifters or C-hooks to prevent damage to marble surfaces.

Stability: Reinforced legs and anti-sway systems ensure safe handling of fragile marble slabs.

Case Studies & Innovations

Place of Origin:Henan, China

Warranty:2 years

Weight (KG):60000 kg

Video outgoing-inspection:Provided

Machinery Test Report:Provided

Application:warehouses,factory and other place

Crane type:box type gantry crane

Travelling speed:20m/min

Lifting mechanism:Electric Hoist

Control method:Ground Control+ Remote Control (customized)

Working duty:A5

Working Temperature:-20~+40℃

Industrial voltage:380V50HZ3Phanse or other

Color:Customised

Customization:Accepted

1. Main Girder (Bridge Beam)
The horizontal beam(s) that support the trolley and lifting device; can be single or double girder.

2. Supporting Legs (Gantry Legs)
Vertical structures connecting the girder to the end carriages or wheels. Can be A-frame or box-type.

3. End Carriages
Fitted with steel wheels, these allow the crane to move along rails embedded in the stone yard.
4. Hoisting Trolley
Moves laterally along the girder and contains the lifting mechanism (winch or hoist).

5. Lifting Device
Customized based on stone type: hook, stone clamp, vacuum lifter, or lifting beam.
6. Power Supply System
Provides electricity to the hoist and movement systems. Can be via cable reel, festoon system, or busbar.

5. Lifting Device
Customized based on stone type: hook, stone clamp, vacuum lifter, or lifting beam.
 

6. Power Supply System
Provides electricity to the hoist and movement systems. Can be via cable reel, festoon system, or busbar.

7. Control System
Operated by wireless remote, pendant control, or cabin control. Some systems offer inching or variable speed.
8. Rails (if rail-mounted)
Embedded tracks that guide the gantry crane in a straight line along the worksite.

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9. Electrical Cabinet
Houses controls, circuit breakers, and converters to manage electrical flow and crane logic.
10. Safety Devices
Includes limit switches, overload protection, emergency stop, and anti-collision sensors.

11. Lighting System
Optional, for operations during low-light or night hours.
12. Rain Cover / Weather Protection
Protects electrical and hoisting systems for outdoor use.

Sketch

Main technical

Heavy Load Handling
Easily lifts stone blocks and slabs weighing several tons-far safer and more efficient than manual or forklift handling.
High Precision
Enables precise lifting, rotation, and placement of fragile, expensive materials without causing cracks or damage.
Yard Optimization
Covers large workspaces without the need for a building structure-perfect for outdoor marble storage and loading areas.
Customizable Lifting Tools
Can be equipped with stone clamps, vacuum lifters, or lifting beams to match different stone shapes and surfaces.
Versatile Configuration
Available in single girder, double girder, semi-gantry, or rail-mounted formats to fit site size and budget.
Cost-Effective Material Flow
Reduces material waste, damage, and manual labor-improving productivity and lowering costs.
Durable & Weatherproof
Made of robust steel, with optional rain covers and corrosion protection for long-term outdoor use.
Easy to Operate
Remote control or pendant systems allow for safe, simple, one-person operation.

Marble & Granite Yards
Unloading, stacking, and organizing large stone blocks or slabs.
Stone Cutting Workshops
Positioning slabs for cutting, polishing, or profiling machines.
Port Terminals & Logistics
Loading/unloading containers with cut or raw stone.
Slab Warehouses
Lifting and storing thin slabs vertically with clamps or vacuum lifters.
Construction Sites
Lifting and installing marble elements like staircases, facades, or floor panels.
Quarries (with flat yards)
Moving rough-cut blocks within the quarry or to transport areas.

1. Requirement Analysis & Technical Design
Client Consultation: Understand the customer's specific needs (load capacity, span, lifting height, working environment, control system, safety features).
Site Assessment: Evaluate the installation site, environmental conditions, and any special constraints.
Engineering Design:
Develop detailed 3D CAD drawings and structural calculations for the girder, end carriages, trolley, hoist, and electric systems.
Customize components such as motors, brakes, control panels, and safety devices based on project specifications.
Ensure compliance with international standards (ISO, FEM, CMAA, etc.).
2. Material Procurement
Steel Structure Materials: Source high-quality steel plates, beams, and profiles (Q235B/Q355B or equivalent) for the girder and frame.
Electrical & Mechanical Components: Purchase motors, gearboxes, brakes, hoists, control panels, limit switches, cables, and other electrical components from approved suppliers.
Specialty Items: Order additional customized parts (e.g., explosion-proof motors, stainless steel components, or corrosion-resistant finishes if needed).
3. Steel Structure Fabrication
Cutting: Use CNC cutting machines or laser cutters to process steel plates and profiles according to design specifications.
Beveling: Perform edge preparation for welding using beveling machines.
Welding:
Weld the main girder, end carriages, and other structural components according to certified welding procedures.
Conduct weld inspections (visual inspection, ultrasonic or X-ray testing if required).
Straightening: Use hydraulic presses to ensure the girder and frame are straight and dimensionally accurate.
Machining: Machine key connection points (e.g., wheel bases, trolley rails) for precise assembly.
4. Surface Treatment
Sandblasting/Shot Blasting: Remove rust, scale, and surface impurities from the steel structure to achieve SA2.5 or better surface grade.
Painting/Coating:
Apply primer and finishing coats based on the environmental working conditions (e.g., marine-grade paint for outdoor cranes).
Optional: Apply anti-corrosion, anti-static, or explosion-proof coatings depending on the client's requirements.
5. Component Assembly
Hoist & Trolley Assembly:
Assemble the electric hoist and trolley system, including motors, gear reducers, wire ropes or chains, and hook blocks.
Pre-install limit switches, brakes, and cable reels.
End Carriage Assembly:
Install traveling wheels, bearings, buffers, and drives onto the end carriages.
Electrical Wiring:
Pre-wire key components (e.g., hoist motor, trolley motor) in accordance with the electrical layout.
Install control systems, power supply cables, festoon systems, or cable carriers.
6. Pre-Assembly & Trial Fitting
Pre-assemble the girder, end carriages, hoist, trolley, and electrical system at the factory to ensure proper fit and alignment.
Conduct tolerance checks on critical dimensions (e.g., span, wheelbase, and diagonal measurements).
7. Factory Testing (Pre-Delivery Inspection)
Mechanical Testing: Perform no-load and partial-load tests on hoisting, trolley travel, and crane travel systems to verify smooth and reliable operation.
Electrical Testing: Verify proper functioning of motors, control panels, limit switches, alarms, and safety devices.
Safety Inspection:
Overload protection testing.
Emergency stop and brake system verification.
Check for proper function of sound and light alarms.
Note: A third-party inspection can be arranged if required by the client.
8. Disassembly & Packaging
Disassemble major components (girder, trolley, hoist, end carriages) for transport.
Protect all surfaces with anti-corrosion oil or protective wraps.
Use reinforced wooden crates or steel frames for sensitive components like motors, control systems, and electrical parts.
9. Delivery & Logistics
Organize transportation (by truck, rail, or sea) to the customer's site.
Provide detailed installation manuals, electrical diagrams, and operation guides along with the shipment.

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%.