Steel Gantry Crane

 

1. Overview
The Double Girder Steel Gantry Crane is a heavy-duty lifting solution designed for outdoor and indoor industrial applications. It consists of two main girders supported by legs that move on ground rails, providing superior strength and stability. This crane is widely used in construction sites, shipyards, ports, warehouses, manufacturing plants, and steel yards for handling large and heavy materials efficiently.

2. Key Features
High Load Capacity: Designed for lifting loads ranging from 5 tons to 500 tons, making it suitable for heavy industrial applications.
Robust Steel Structure: Built with high-strength steel to ensure durability and long service life.
Stable Double Girder Design: Offers better load distribution and higher lifting height compared to single girder gantry cranes.
Efficient Lifting Mechanism: Equipped with electric hoist or trolley for smooth and precise lifting operations.
Customizable Options: Available in various spans, lifting heights, and configurations to meet specific customer requirements.

 

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

Structure and Design
1)Double Girder Configuration: Two steel girders run parallel to each other, distributing the load evenly and allowing for higher lifting capacities and longer spans.
2)Box-Type or Truss-Type Design:
Box-Type Beam: Made from welded steel plates, offering high strength, rigidity, and low deflection.
Truss-Type Beam: Made from steel sections and lattice structures, ideal for large spans and outdoor applications to reduce wind resistance.
Material: High-strength structural steel (Q235B, Q345B, or equivalent) ensures durability and long service life.
Reinforcement: The beam may include rib plates and diaphragms to enhance strength and reduce stress concentration.

 

Lifting System

(1) Hoisting Mechanism (Trolley & Winch System)
Electric Hoist (For Light & Medium Loads, 5T–50T)
Compact structure and easy installation.
Uses wire rope or chain hoists with a motor-driven lifting mechanism.
Suitable for standard material handling applications.
Open Winch Trolley (For Heavy Loads, 50T–500T)
High-performance lifting system designed for extra-heavy loads.
Equipped with powerful motors, reducers, and drum systems.
Provides higher lifting speeds, stability, and durability.
(2) Wire Rope System
High-strength steel wire ropes ensure durability and load stability.
Grooved drum prevents rope overlapping and ensures smooth winding.
Rope guides and pulleys reduce wear and extend lifespan.
(3) Lifting Motor & Gearbox
Heavy-duty electric motor ensures high efficiency and smooth operation.
Precision gearbox with multiple speed options for accurate positioning.
Variable frequency drive (VFD) available for adjustable speed control.
(4) Braking System
Electromagnetic or hydraulic brakes ensure instant stopping for safety.
Equipped with overload protection to prevent excessive weight lifting.
(5) Safety Features
Overload limiter to prevent exceeding the weight capacity.
Upper and lower limit switches to avoid over-travel.
Anti-sway technology for better load control.
Emergency stop system to handle unexpected failures.

 

 

3.End carriage

(1) Steel Frame Structure
Constructed from high-strength Q235B/Q345B steel.
Designed as a box-type welded structure for high rigidity and durability.
Reinforced with rib plates and diaphragms to reduce stress concentration and deformation.
(2) Wheel System
Equipped with high-quality wheels made of forged steel (65Mn or 42CrMo) for wear resistance.
Wheels are mounted on self-aligning roller bearings to ensure smooth operation.
Options for single-flanged, double-flanged, or no-flange wheels depending on rail type.
(3) Traveling Mechanism
Driven by electrical motors with gearboxes and brake systems.
Uses inverter control (VFD) for variable speed adjustment, ensuring smooth acceleration and deceleration.
Includes precision-machined gears for noise reduction and high efficiency.

4.Crane travelling mechanism

(1) Drive System (Motor & Gearbox Assembly)
High-performance motors: Typically three-phase asynchronous motors provide strong and consistent power.
Gearbox with hardened gears: Ensures smooth torque transmission and minimal wear.
Variable Frequency Drive (VFD) optional: Enables soft start, adjustable speed control, and energy efficiency.
(2) Wheel Assembly
High-strength forged steel wheels (material: 65Mn, 42CrMo) for wear resistance and durability.
Single-flange, double-flange, or no-flange wheels, depending on rail design.
Self-aligning bearings for reduced friction and longer service life.
Anti-friction bearings to enhance smooth rolling motion.
(3) Rail & Guidance System
Runs on embedded or fixed ground rails, ensuring accurate movement.
Equipped with rail clamps or guiding wheels to prevent derailment.
Anti-skew correction system available for precise alignment.
(4) Braking System
Electromagnetic or hydraulic brakes ensure fast and safe stopping.
Emergency braking mechanism for sudden stops in case of failure.
Automatic brake holding function when power is off.
(5) Safety Features
Overload protection to prevent excessive weight stress.
Limit switches to stop movement at pre-set points.
Anti-collision devices to prevent crashes with other equipment.
Windproof devices (e.g., rail clamps, anchor bolts) for outdoor applications.

5.Trolley travelling mechanism

(1) Drive System (Motor & Gearbox Assembly)
High-performance motor: Typically uses a three-phase asynchronous motor for stable power.
Gearbox with hardened gears: Provides smooth and efficient torque transmission.
Variable Frequency Drive (VFD) optional: Enables soft start, adjustable speed control, and energy savings.
(2) Wheel System
High-strength forged steel wheels (65Mn, 42CrMo) for wear resistance and long service life.
Mounted on precision bearings to reduce friction and ensure smooth rolling motion.
Runs on machined rail tracks fixed on the main beams.
(3) Rail & Guidance System
Moves on steel rails mounted on the double girders.
Equipped with guide rollers to maintain straight movement.
Anti-skew detection system for accurate positioning.
(4) Braking System
Electromagnetic or hydraulic brakes ensure instant stopping when needed.
Emergency braking system prevents uncontrolled movement in case of failure.
Automatic brake holding function when the motor is off.
(5) Safety Features
Overload protection to prevent excessive weight stress.
Travel limit switches to stop movement at pre-set points.
Anti-collision sensors to avoid crashes with end stops.
Speed control system for precise and safe movement.

6.Crane wheel

1)Overview
The crane wheels of a double girder steel gantry crane are essential components that support and guide the movement of the crane along the rails. These wheels are designed to withstand heavy loads, high impact forces, and continuous operation, ensuring smooth and stable crane travel.
2)Types of Crane Wheels
Single-Flange Wheels – Used for guided rail systems to prevent derailment.
Double-Flange Wheels – Provides extra stability, commonly used in outdoor gantry cranes.
No-Flange Wheels – Used with guiding rollers or special track designs.

7.Crane Hook

1)Types of Crane Hooks
Single Hook – Suitable for light to medium loads (5T–50T), offering simple operation and flexibility.
Double Hook – Used for heavy-duty lifting (50T–500T), providing better load balance and stability.
C-Type Hook – Designed for coils or rolls, ensuring secure handling of specialized loads.
Rotating Hook (Swivel Hook) – Equipped with 360° rotation, allowing for precise load positioning.
2)Material & Manufacturing Process
Forged Carbon Steel (20Mn, 34CrMo4, 42CrMo) for high strength and durability.
Heat Treatment:
Quenching & tempering to increase hardness and impact resistance.
Surface hardening (HRC 35-45) for wear resistance.
Load Testing: Hooks are tested with 125% to 150% of rated load capacity to ensure safety.

8.Motor

Types of Motors
(1) Hoisting Motor
Type: Asynchronous AC motor
Purpose: Drives the hoisting mechanism, responsible for lifting and lowering loads.
Power Rating: Typically ranges from 2.2kW to 200kW, depending on crane capacity.
Features:
High torque for heavy lifting.
Variable speed control for smooth load handling.
Built-in overload protection for safety.
(2) Trolley Traveling Motor
Type: Asynchronous AC motor or DC motor (depending on crane type)
Purpose: Drives the movement of the trolley along the girder.
Power Rating: Usually between 1.5kW to 50kW.
Features:
Smooth acceleration and deceleration.
Regulated speed control (with variable frequency drive, VFD).
Compact design to fit within the crane's trolley assembly.
(3) Crane Traveling Motor
Type: Asynchronous AC motor or DC motor
Purpose: Responsible for the horizontal movement of the entire crane along the rails.
Power Rating: Can range from 5kW to 150kW, depending on the size of the crane.
Features:
High torque to move heavy structures.
Precise speed control for accurate positioning.
Heavy-duty protection to prevent overheating and wear.

.

Sound and light alarm system & limit switch

1)Sound and Light Alarm System
The Sound and Light Alarm System is designed to warn operators and nearby workers of the crane's movements, abnormal conditions, or potential hazards. It is essential for safety, communication, and accident prevention in busy industrial environments.
2)Limit Switch
A limit switch is a safety device that automatically stops or limits the movement of the crane when it reaches a pre-set position or an unsafe limit. Limit switches are essential for preventing over-travel or overload situations that could damage the crane or cause accidents.

10.Safety Devices

(1) Overload Protection Device
Purpose: Prevents the crane from lifting loads that exceed the rated load capacity.
(2) Limit Switches
Purpose: Automatically stops or limits the crane's movement when it reaches a pre-set boundary or unsafe position.
(3) Emergency Stop System
Purpose: Quickly halts crane operation in the event of an emergency to avoid accidents or damage.
(4) Anti-Collision System
Purpose: Prevents collisions between cranes or between the crane and obstacles in the work area.
(5) Swing Limit Device
Purpose: Prevents the crane hook from swinging uncontrollably, which can cause load instability.
(6) Emergency Power-off Device
Purpose: Disconnects the crane from its power source in the event of an emergency, preventing further movement and protecting both the crane and the workers.
(7) Warning Lights and Audible Alarms
Purpose: Alerts nearby personnel to crane operations, ensuring safe movement and load handling.

11.Control Mode

1)Cabin Control (Operator Cabin Control Mode)
Overview:
In this mode, the crane is operated from an operator cabin attached to the crane structure, typically located at the top of the gantry frame. The cabin provides the operator with a comprehensive view of the crane's operation and the work area.
2)Pendant Control (Wired Control Mode)
Overview:
In pendant control, the crane is operated via a wired controller (pendant) that is connected to the crane's control system through a cable. The pendant is typically handheld and used by the operator from the ground.
3)Radio Remote Control (Wireless Control Mode)
Overview:
In radio remote control, the crane is operated via a wireless control unit using radio frequency (RF) signals. This mode offers greater flexibility compared to pendant control since it does not require a physical connection.
4)Automatic or Fully Automated Control
Overview:
Automated control is used in highly advanced double girder steel gantry cranes where specific operations are controlled by a computerized system with minimal human intervention.

12.Sketch

 

Main technical

 

 

 

1. High Load Capacity
Heavy Lifting: Double girder cranes have a higher load capacity compared to single girder cranes. They can lift heavier loads, making them ideal for industrial applications that require moving large and bulky materials.
Stability: The dual girder design provides greater stability when lifting large or heavy loads, reducing the risk of swaying and increasing precision in material handling.
2. Increased Lifting Height
Better Reach: The design of the double girder system allows for greater hook height, which is essential when lifting materials at greater heights or in high-bay warehouses.
Flexibility: With a taller lifting height, the crane can operate in more varied environments, including tight spaces with higher overhead clearances.
3. Superior Strength and Durability
Strong Construction: Made with high-strength steel, double girder cranes are built to withstand demanding industrial environments and heavy-duty operations.
Longer Service Life: The robust design allows these cranes to have a longer lifespan, even under extreme conditions, reducing maintenance costs and downtime.
4. Enhanced Stability and Safety
Better Load Distribution: The two parallel girders ensure that the load is evenly distributed, reducing the strain on individual components like hoisting equipment, motors, and wheels.
Reduced Swaying: Due to the dual girder design, double girder cranes experience less load sway during lifting and transportation, making it safer for operators and other personnel nearby.
Safety Features: Advanced safety devices such as limit switches, overload protection, and emergency stop systems further enhance operational safety.
5. Increased Span and Reach
Wider Span: Double girder cranes can span a much wider distance compared to single girder cranes. This is especially useful in applications where the crane needs to cover a wide area, such as loading/unloading large shipping containers or heavy construction materials.
Versatility in Applications: The ability to span larger distances means that these cranes are ideal for use in large manufacturing plants, construction sites, and outdoor environments, increasing their versatility.
6. Higher Speed and Efficiency
Faster Hoisting and Traveling: Double girder cranes can achieve higher lifting speeds and faster trolley and gantry traveling speeds due to the more powerful motors and the robust design.
Efficiency in Operations: With greater speed and lifting capacity, these cranes can complete more tasks in less time, improving productivity and efficiency on the job site.
7. Low Maintenance and Operating Costs
Less Wear and Tear: The sturdy design of double girder cranes means they experience less stress on individual components, leading to lower maintenance costs over time.
Durability: With high-quality materials and robust construction, the crane is less prone to breakdowns, reducing downtime and the need for frequent repairs.
Cost-Effective in the Long Run: Although the initial cost may be higher, the long-term benefits of durability, safety, and higher performance can result in lower operating costs and better return on investment (ROI).
8. Flexibility in Control
Multiple Control Modes: Double girder gantry cranes can be equipped with various control options, including manual pendant control, radio remote control, and automatic control. This allows operators to choose the best control system based on their needs.
Adaptability to Specific Tasks: Depending on the crane's application, operators can use it in different settings, such as indoor or outdoor environments, with the ability to customize the control mode for various tasks.

 

1)Manufacturing & Heavy Industry
Application: Lifting and moving heavy components in factories and production facilities.
2)Construction Industry
Application: Handling construction materials at building sites, bridges, and infrastructure projects.
3)Shipbuilding & Marine Industry
Application: Moving heavy ship components, engines, and hull sections in dockyards and shipyards.
4)Railway & Transportation Industry
Application: Lifting rail components, train carriages, and containers in railway yards and depots.
5)Ports & Logistics Warehouses
Application: Handling cargo, shipping containers, and bulk materials in ports, harbors, and warehouses.
6)Power Plants & Energy Sector
Application: Moving turbine components, transformers, and generators in hydropower, nuclear, and thermal plants.

 

 

1. Raw Material Preparation
Purpose: Ensure high-quality steel and materials for the crane's components.
Key Steps:
Selection of high-strength steel plates and profiles.
Material cutting using CNC plasma cutting, laser cutting, or flame cutting.
Quality inspection of raw materials to ensure structural integrity and compliance with standards.
2. Main Girder & Structure Fabrication
Purpose: Construct the core structure of the crane.
Key Steps:
Welding and assembly of the double girder beams.
Bending and shaping steel plates for precise girder dimensions.
Weld inspection using ultrasonic or X-ray testing to ensure structural strength.
Surface treatment (e.g., sandblasting, rust removal, primer coating).
3. End Carriage & Trolley Fabrication
Purpose: Manufacture and assemble the components for crane movement.
Key Steps:
Cutting and welding of end carriage frames.
Precision machining of wheelsets and end carriage components.
Installation of trolley frame, wheels, and travel mechanisms.
Quality check for dimensional accuracy and alignment.
4. Hoisting & Lifting Mechanism Assembly
Purpose: Install the hoist system for lifting operations.
Key Steps:
Mounting of electric hoist or winch on the trolley.
Motor, gearbox, and brake system installation.
Fitting of wire rope drum, pulleys, and hook block.
Load and operational tests for smooth lifting function.
5. Electrical & Control System Installation
Purpose: Ensure seamless operation with automated controls.
Key Steps:
Installation of motors, limit switches, sensors, and safety devices.
Electrical wiring and connection to the control panel.
Configuration of remote control, pendant control, or cabin control.
Testing of electrical circuits and emergency stop functions.
6. Surface Treatment & Painting
Purpose: Protect the crane from corrosion and environmental damage.
Key Steps:
Sandblasting and surface cleaning.
Application of anti-corrosion primer.
Final painting with industrial-grade coatings.
Marking and labeling of safety signs and load capacity indicators.
7. Assembly & Pre-Delivery Testing
Purpose: Ensure the crane meets operational and safety standards.
Key Steps:
Full assembly of the crane structure.
Load testing to check lifting capacity and stability.
Operational testing of all mechanical and electrical components.
Fine-tuning and quality inspection before shipment.
8. Packing & Delivery
Purpose: Secure components for safe transport.
Key Steps:
Disassembly (if required) for transportation.
Packaging of motors, control panels, and electrical components.
Loading onto trucks or containers for delivery to the customer.
Providing installation and maintenance manuals for customer reference.

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%.