50 Ton Double Girder Gantry Crane Industry

A 50-ton double girder gantry crane is a heavy-duty crane system used for lifting and transporting extremely heavy materials in open or semi-open industrial environments. It consists of two parallel girders supported by legs that move along rails on the ground, with a hoist trolley traveling between the girders.

 

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

1)Function
The main beams are the core load-bearing components of the crane.

They support the trolley hoist, which moves along the beams while lifting and transporting loads.

Transmit vertical and lateral forces to the end carriages/legs, which transfer them to the ground.

2)Structure and Material
Type: Double box-type girder (fully welded rectangular box) or I-beam + box hybrid (in some designs).

Material: High-strength, low-alloy structural steel (e.g., Q345B or S355).

Welding: Full-penetration, automatic MIG or submerged arc welding (SAW).

Deflection Limit: Typically ≤ 1/1000 of span length, ensuring rigidity under full load.

Camber (pre-bending): Applied upward to compensate for deflection under load.

2.Lifting System

Hoist/Trolley Mechanism:A motorized trolley moves along the top of the double girders, carrying the hoist.
Lifting Motor:High-power squirrel cage or wound rotor motor with a thermal protector and brake.
Wire Rope Drum:Grooved drum winds/unwinds steel wire rope for vertical motion.
Wire Ropes:Heavy-duty, anti-twist steel ropes, rated for long life and high tension.
Hook Block:Heavy-duty forged steel hook with safety latch; rotates and swivels.
Brake System:Electromagnetic or hydraulic brake ensures secure load holding and stopping.
Gearbox/Reducer:Transfers motor power to the drum with torque reduction and smooth motion.

3.End carriage

Purpose & Function
The end carriages support the main girders and allow the entire gantry structure to travel along the runway rails.

They house the wheels, motors, and drive systems responsible for longitudinal crane movement.

Ensure stability, alignment, and distribution of loads to the ground through the crane's legs.
 

4.Crane travelling mechanism

Safety & Anti-Skewing Features
Anti-Skewing Control:
Monitors and corrects wheel synchronization to avoid structural stress.

Limit Switches:
Installed at both ends of the runway to cut power when crane reaches limits.

Emergency Stop System:
Immediate shutdown in case of system failure or safety hazard.

Ground Fault Protection:
Prevents electrical leakage or short circuits.

5.Trolley travelling mechanism

Safety Features
Limit Switches: Prevent trolley over-travel at both girder ends.

Brakes: Hold the trolley in position during load suspension.

Overload Detection: Integrated with lifting system to prevent excessive movement under overload.

Anti-Collision (optional): Sensors to prevent collision with end stops or other trolleys.

Soft Start/Stop: Via inverter for smooth acceleration and deceleration.

7.Crane Hook

The hook is the main load-grabbing device of the lifting system. It connects the load to the crane and must safely handle high lifting forces, resist wear, and ensure safe operation in industrial environments.
Safety Features
Latch Lock: Spring-loaded latch prevents load slippage

Wear Indicators: Grooves or lines to show when replacement is needed

Hook Deformation Limits: Monitored to comply with FEM/ISO standards

Load Test Certification: Every hook block is tested at 1.25x to 1.5x rated capacity

Heat-treated Surface: To increase fatigue and wear resistance
 

8.Motor

The motor is a critical power source for the crane's major functions, including lifting, trolley traveling, and crane traveling. For a 50-ton crane, multiple motors are typically used, each dedicated to a specific mechanism.
Optional Customizations
Explosion-proof motor (Ex d IIB T4, etc.) for hazardous environments

Motor with encoder for feedback-based control

Dual-speed or frequency-controlled motor for precise operation

Marine-duty motor with anti-corrosion protection

.

9.Sound and light alarm system & limit switch

1). Sound and Light Alarm System
Purpose
The sound and light alarm system provides audible and visual alerts during crane operation to enhance worksite safety by warning nearby personnel of movement, lifting, or potential hazards.
Functions
Sounds automatically when:

Crane starts moving

Load is lifted

Emergency stop is triggered

Optional voice broadcast system (e.g., "Crane in operation, stay clear!")
2) Limit Switches
Purpose
Limit switches are critical safety devices that prevent the crane or trolley from over-traveling, over-lifting, or hitting physical stops, ensuring protection of equipment and personnel.
Optional Upgrades
Smart Sensors: Digital limit switches with programmable ranges

Wireless Alarm Integration: Remote alerts sent to operator or supervisor

Redundant Limit Switches: For critical motion (e.g., dual hoist limit)

10.Safety Devices

1)Overload Protection Device
Purpose: Prevents the crane from lifting loads exceeding its rated capacity (50 tons).

Function: Automatically cuts off the lifting operation when overload is detected.

Types: Load cells, strain gauges, or mechanical overload limiters.

Benefit: Protects structural integrity and prevents accidents caused by overloading.

2)Emergency Stop (E-Stop) System
Purpose: Allows immediate shutdown of all crane operations in emergencies.

Location: Accessible buttons on control pendant, cabin, and remote control.

Function: Cuts power to motors and activates brakes instantly.

Benefit: Quick response to prevent accidents or damage.

3)Anti-Collision Device
Purpose: Prevents collision between multiple cranes operating in the same area.

Function: Uses sensors or radar to detect nearby cranes and stops or slows down travel.

Benefit: Enhances safety in multi-crane operations.

4)Anti-Sway and Anti-Skewing Devices
Anti-Sway: Minimizes load swinging during lifting or traveling, improving control.

Anti-Skewing: Ensures synchronous motion of dual drive motors to avoid twisting the crane structure.

Benefit: Improves operational safety and extends crane lifespan.

5)Limit Switches
Prevent over-travel of crane and trolley.

Prevent over-hoisting or over-lowering.

Integrated with control system for automatic stop.

11.Control Mode

1)Pendant Control
Description:
A handheld control device connected via cable to the crane, allowing the operator to control all crane functions directly.
2)Cabin Control
Description:
An operator cabin is mounted on the crane, usually on the gantry or trolley, providing full control from an elevated, enclosed space.
3)Radio Remote Control
Description:
Wireless remote controller allows the operator to move freely within a safe distance while controlling the crane.
4)Automated or Semi-Automated Control
Description:
Advanced control systems integrated with PLCs, sensors, and sometimes vision systems for partial or full automation.
5)Combination Control
Many cranes offer a combination of control modes (e.g., pendant + radio remote + cabin) to suit different operating needs and preferences.

12.Sketch

 

Main technical

 

 

1. High Load Capacity
Designed specifically for heavy-duty lifting, capable of safely handling loads up to 50 tons.

Suitable for large industrial applications requiring robust lifting.

2. Increased Stability and Strength
Double girder design provides superior structural strength compared to single girder cranes.

Better resistance to bending and torsion under heavy loads.

Ensures safe and stable lifting operations.

3. Greater Lifting Height
Double girders allow the hoisting trolley to be placed between the girders, maximizing the available lifting height.

Ideal for facilities with height restrictions or requiring maximum hook travel.

4. Improved Span Length
Suitable for longer spans between rails, accommodating large work areas or wide bays.

Enables efficient material handling over expansive spaces.

5. Durability and Reliability
Robust construction with high-quality materials extends service life.

Designed for heavy industrial environments with frequent use.

6. Flexible Operation
Compatible with various control modes: pendant, cabin, remote control, or automation.

Allows customization for different operational needs and environments.

7. Safety Features
Equipped with advanced safety devices such as overload protection, limit switches, emergency stops, and anti-collision systems.

Enhances workplace safety and reduces accident risks.

 

1. Heavy Manufacturing Plants
Lifting and transporting large machinery parts, molds, and heavy components.

Assembly line support for automotive, aerospace, and heavy equipment manufacturing.

2. Steel Mills and Foundries
Handling heavy steel coils, billets, and castings.

Moving molten metal containers (with proper heat-resistant adaptations).

3. Shipbuilding Yards
Lifting large ship parts, hull sections, engines, and heavy equipment.

Assembly and installation of ship components.

4. Construction Sites
Handling heavy construction materials such as steel beams, precast concrete segments, and heavy equipment.

Loading and unloading heavy construction elements.

5. Power Plants and Energy Sector
Transporting heavy turbines, generators, transformers, and other power generation equipment.

Maintenance operations requiring heavy lifting.

6. Railway and Transportation Industry
Loading/unloading railcars with heavy cargo.

Handling large train components like bogies and engines.

7. Warehousing and Logistics
Moving heavy containers, pallets, and oversized cargo.

Efficient material handling in large-scale warehouses.

 

1. Design and Engineering
Detailed engineering design based on customer specifications and site requirements.

Structural analysis (stress, deflection, fatigue) using software like AutoCAD, SolidWorks, or ANSYS.

Selection of components (motors, hoists, control systems) adhering to safety standards.

Preparation of fabrication drawings and bill of materials (BOM).

2. Material Procurement
Purchase of raw materials: high-quality steel plates, sections, motors, electrical parts, wire ropes, etc.

Sourcing from certified suppliers to ensure quality and compliance.

3. Steel Fabrication
Cutting steel plates and profiles using CNC plasma or laser cutting machines.

Welding of girders, end carriages, and supporting structures according to drawings.

Use of automated welding processes for consistency and strength.

Pre-assembly of subcomponents for quality control.

4. Machining
Precision machining of crane parts such as wheel journals, motor mounts, and hoist components.

Drilling, boring, and milling to meet dimensional tolerances.

5. Surface Treatment
Sandblasting of steel structures to remove rust and contaminants.

Application of primer and industrial-grade paint coatings for corrosion protection.

Optional anti-rust or special coatings depending on operating environment.

6. Assembly
Assembly of main girder, end carriages, and trolley components in the workshop.

Installation of motors, brakes, gearboxes, wire ropes, and hoisting mechanisms.

Electrical wiring of control panels and integration of safety devices.

7. Testing and Inspection
Static Load Test: Applying weights up to 1.25 to 1.5 times rated load to verify structural integrity.

Functional Test: Testing lifting, trolley travel, crane travel, brakes, and safety devices.

Non-Destructive Testing (NDT): Ultrasonic, magnetic particle, or dye penetrant inspection on welds.

Electrical safety and control system checks.

Compliance checks with ISO, FEM, CMAA standards.

8. Packaging and Shipping
Disassembly (if needed) for transport.

Protective packaging to prevent damage during transit.

Coordination with logistics for delivery to customer site.

9. Installation and Commissioning
On-site assembly and installation by skilled technicians.

Final alignment and calibration.

Operator training and handover documentation.

Site acceptance testing and certification.

10. After-Sales Support
Maintenance plans and spare parts supply.

Technical support and troubleshooting.

Periodic inspections and upgrades.

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%.