Factory Direct Sales Double Girder Gantry Crane

Our Double Girder Gantry Cranes are available factory direct, offering you high performance, competitive pricing, and reliable delivery-all without the middleman. Designed for heavy-duty lifting applications, this crane system ensures maximum efficiency and stability in a variety of industrial settings such as shipyards, container yards, steel mills, power plants, and construction sites.

 

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 is the core load-bearing structure of the double girder gantry crane, designed to provide maximum strength, rigidity, and stability during heavy lifting operations. At our factory, each main beam is precision-engineered and fabricated using advanced welding and machining techniques, ensuring long service life and consistent performance under demanding conditions.

2.Lifting System

Hoisting Mechanism:

Includes a motor, gearbox, drum, and wire rope assembly.

Designed for high efficiency and low noise, suitable for frequent and intensive use.

Optional double-speed or variable frequency (VFD) control for smooth acceleration and deceleration.

Electric Hoist or Trolley Winch:

Typically mounted on a motorized trolley that travels along the top of the main girders.

For high-capacity models, a winch-type trolley is used, integrating the hoisting and trolley mechanisms into one robust unit.

Lifting Motor:

Uses famous-brand motors such as Siemens, ABB, or Nanjing Special Motor.

High starting torque, thermally protected, and optional VFD or soft-start function for extended service life.

3.End carriage

Robust Welded Box Design:

Constructed with rectangular steel tubes or steel plates welded into a rigid box structure.

Provides excellent torsional and bending resistance, ensuring structural stability during crane travel and load handling.

Precision Machining:

All mounting surfaces for wheels, motors, and buffers are CNC machined to ensure alignment and smooth operation.

Connection with Main Beam:

High-strength bolted or welded joints connect the end carriages securely to the main girders.

Design ensures easy assembly and disassembly for transport and maintenance.

4.Crane travelling mechanism

The crane traveling mechanism is responsible for the longitudinal movement of the entire gantry crane along the rails, enabling it to cover a wide working area. Our factory direct cranes use a high-performance, precision-aligned drive system that ensures smooth, stable, and synchronized motion, even under heavy loads and continuous operation.

5.Trolley travelling mechanism

The trolley traveling mechanism enables the horizontal movement of the trolley along the main girders, allowing precise positioning of the load over the full span of the crane. Built for smooth operation, durability, and high load capacity, our factory-direct double girder gantry cranes feature a high-performance trolley system that ensures accurate, stable, and efficient material handling in demanding work environments.

7.Crane Hook

Material & Manufacturing:
Made from high-grade forged alloy steel (e.g., 34CrMo4 or equivalent).

Heat-treated for optimal strength, toughness, and wear resistance.

Designed to handle high dynamic loads and resist deformation under heavy use.

Hook Types:
Single hook: Used for lower-capacity cranes (commonly under 20 tons).

Double hook (cradle or tandem): For high-capacity applications (20 tons and above), offering better load balance and reduced hook twist.

8.Motor

The motor is the powerhouse of the double girder gantry crane, driving its critical functions including lifting, trolley travel, and crane travel. Our factory-direct cranes are equipped with high-performance, industrial-grade motors designed for heavy-duty operation, energy efficiency, and long service life.

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9.Sound and light alarm system & limit switch

Sound and Light Alarm System
Functions:
Provides audible and visual warnings during crane startup, operation, or in emergency situations.

Alerts personnel in the vicinity of crane movement, lifting operations, or overload conditions.

Required in most industrial safety standards for overhead and gantry cranes.
Limit Switches
Types of Limit Switches Used:
Lifting Limit Switch (Upper & Lower Limits):

Prevents the hook from over-hoisting or over-lowering, which can cause rope breakage or motor damage.

Usually mechanical rotary or lever-type limit switches mounted near the hoist drum or hook block.

Trolley Travel Limit Switch:

Stops the trolley at its preset boundary points along the main girder.

Prevents collision with end stops or damage to the rails.

Crane Travel Limit Switch:

Installed on the end carriages to prevent crane over-travel and structural impact.

Typically used in outdoor gantry cranes or where multiple cranes run on the same track.

Overload Limit Switch (Optional):

Activates when the lifted load exceeds the crane's rated capacity.

Automatically cuts off the lifting power and triggers the alarm system.

10.Safety Devices

Overload Protection Device
Detects when the lifted load exceeds the rated capacity.

Automatically interrupts lifting operations and activates alarm signals.

Prevents structural damage, rope failure, or tipping caused by excessive load.
Lifting Limit Switch
Installed on the hoisting mechanism to stop the hook at predefined upper and lower points.

Prevents over-hoisting (which can damage the drum or hook block) and over-lowering (which can release tension in the wire rope).

Travel Limit Switches (Trolley & Crane)
Prevents the trolley and crane bridge from over-traveling beyond the track ends.

Ensures precise travel and avoids collision or derailment.

Emergency Stop Button
Manually operated button located on the control pendant, cabin, or wireless remote.

Instantly shuts down all crane operations in the event of a hazard.

Sound and Light Alarm System
Emits audible alarms (≥85 dB) and flashing lights during motion, start-up, or fault conditions.

Enhances site awareness and worker safety, especially in noisy or outdoor environments.

Buffer and End Stopper
Polyurethane or rubber bumpers installed at the ends of crane and trolley travel routes.

Absorb impact energy and prevent mechanical damage during end-of-track approach.

11.Control Mode

Cabin Control
Operator works from an enclosed, ergonomically designed cabin mounted on the crane.

Provides full visibility of the work area and controls for all crane movements.

Cabin is equipped with joysticks, push buttons, and emergency stop switches.

Ideal for long shifts, heavy loads, and precise handling tasks.

Climate-controlled options available for indoor and outdoor use.

Pendant Control (Wired Remote)
Compact and lightweight pendant station suspended from the crane or connected by cable.

Operator can stand near the load for better visibility and control.

Simple, intuitive push-button or joystick operation.

Safe design with dead-man switch (requires continuous pressure to operate).

Cost-effective and widely used for small to medium crane operations.

Wireless Remote Control
Radio remote control unit allowing the operator to control the crane from a safe distance.

Improves operator mobility and visibility in complex or hazardous environments.

Equipped with emergency stop button, signal strength indicators, and multiple control channels.

Resistant to interference and built with failsafe mechanisms.

Increasingly popular for outdoor yards, construction sites, and congested work areas.

12.Sketch

 

Main technical

 

 

High Load Capacity & Stability
The double girder design provides a robust, rigid structure capable of handling heavier loads (up to 200 tons and beyond) with minimal deflection.

Wider Span & Greater Lifting Height
Compared to single girder cranes, double girders allow larger spans and higher hook lifting points, making them ideal for wide industrial yards, shipyards, and large workshops.

Enhanced Safety & Reliability
Equipped with advanced safety devices including overload protection, limit switches, sound and light alarms, and emergency stop systems, ensuring secure operations.

Durable & Long-Lasting Construction
Manufactured from high-quality steel with precision welding and machining, combined with corrosion-resistant coatings for extended service life in harsh environments.

Customizable Design
Tailored to your specific project needs including span length, lifting capacity, lifting height, and control modes.

Cost-Effective Factory Direct Pricing
Eliminates middlemen, offering you competitive prices without sacrificing quality or delivery times.

Energy Efficient & Low Maintenance
Incorporates high-efficiency motors and gearboxes, VFD control options, and easy-access components for quick maintenance and reduced downtime.

 

Steel Industry
Handling heavy steel coils, plates, billets, and structural components in steel mills and fabrication workshops.

Shipbuilding Yards
Lifting large ship sections, engines, and heavy equipment with precision and safety.

Container Handling & Logistics
Loading and unloading shipping containers, cargo handling at ports, and yard stacking operations.

Construction Sites & Infrastructure Projects
Moving precast concrete elements, structural steel frameworks, and other heavy construction materials.

Power Plants & Energy Sector
Installation and maintenance of heavy machinery, transformers, and turbines.

Railway Yards & Workshops
Handling railcars, engines, and large components during assembly and repair.

Manufacturing & Assembly Plants
Transporting heavy parts and assemblies across production lines.

Mining & Heavy Equipment Maintenance
Lifting and positioning of mining equipment, engines, and large components.

 

1. Design & Engineering
Requirement Analysis: Gather client specifications-capacity, span, working environment, control preferences.

Structural & Mechanical Design: Use CAD and FEM software to design main girders, end carriages, trolley, hoist, and control systems.

Component Selection: Choose motors, gearboxes, electrical parts, and safety devices.

Client Approval: Finalize and approve design drawings and technical specs.

2. Material Procurement
Purchase high-quality steel plates and profiles (e.g., Q345B).

Source electrical components from certified suppliers.

Inspect all incoming materials for quality and standards compliance.

3. Fabrication
Cutting: CNC laser/plasma cutting of steel plates.

Welding: Full-penetration submerged arc welding (SAW) for main girders and structural parts.

Machining: Precision machining of connection points, wheel hubs, shafts, and hoist parts.

Assembly: Pre-assembly of subcomponents like end carriages and trolley frames.

4. Surface Treatment
Cleaning: Sandblasting to remove rust and scale.

Coating: Primer, epoxy, and polyurethane topcoat applied for corrosion resistance.

Inspection: Coating thickness and adhesion tested according to standards.

5. Electrical & Control System Installation
Install wiring, control panels, motors, limit switches, and alarms.

Integrate PLC, VFDs, and human-machine interfaces.

Test electrical continuity, safety circuits, and control functions.

6. Final Assembly
Assemble main girders onto end carriages.

Mount trolley, hoist, and control systems.

Install hooks, wire ropes, and safety devices.

7. Testing & Quality Assurance
No-Load Tests: Verify movement and control of crane, trolley, and hoist without load.

Load Tests: Perform rated load and overload tests to confirm lifting capacity and safety systems.

Functional Tests: Check limit switches, alarms, brakes, emergency stops, and safety interlocks.

Alignment & Calibration: Ensure smooth travel and precise load positioning.

8. Packing & Delivery
Disassemble as necessary for transport.

Protect components with corrosion inhibitors and secure packaging.

Arrange shipment to customer site.

9. Installation & Commissioning (On-Site)
Assemble crane on runway beams or rails.

Connect power and control systems.

Perform final commissioning tests and operator training.

10. After-Sales Support
Provide maintenance manuals and spare parts.

Offer technical support, periodic inspections, and preventive maintenance services.

1. Design & Engineering
Customer requirements gathered (load capacity, span, lifting height, environment).

Structural, mechanical, and electrical design using CAD and FEM analysis.

Preparation of technical drawings and production plans.

Material selection and procurement planning.

2. Material Preparation
Steel plates, profiles, and sections cut to size by CNC machines.

Quality inspection of raw materials (chemical composition, mechanical properties).

3. Fabrication of Main Components
Main Beams: Welding of box girders or H-beams, including reinforcement.

Gantry Legs & End Carriages: Steel fabrication and assembly.

Trolley Frames & Hoist Parts: Machining and welding.

4. Surface Treatment
Sandblasting to remove rust and impurities.

Application of primer and anti-corrosion paint coats.

Curing and drying under controlled conditions.

5. Assembly of Mechanical Parts
Installation of rails on main beams.

Mounting of wheels, motors, gearboxes on end carriages and trolley.

Assembling of hoisting mechanism (drum, wire rope, hook block).

6. Electrical System Installation
Wiring of control panels, motors, limit switches, alarms, and sensors.

Integration of control modes (pendant, remote, cabin).

Testing of electrical components and safety devices.

7. Quality Control & Testing
Dimensional inspection and alignment check.

Load testing (static and dynamic) to verify lifting capacity.

Functional testing of all motions: hoisting, trolley travel, crane travel.

Safety system verification (alarms, limit switches, brakes).

8. Packaging & Delivery
Disassembly of components if required for shipment.

Protective packaging to prevent damage during transport.

Loading and dispatch to customer site.

9. On-site Installation & Commissioning
Assembly of crane structure on site.

Alignment and rail installation.

Electrical connection and system calibration.

Final load testing and operator training.

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%.