European Double Girder Bridge Crane

DEFINING CHARACTERISTICS & PHILOSOPHY

Core Engineering Principles

Precision Over Tolerance: Components are manufactured to tighter tolerances than minimum standards require (e.g., wheel alignment within 0.5mm over span).

Lifecycle Engineering: Designed for 25-40+ years of reliable service with documented maintenance plans.

System Integration: Holistic design where mechanical, electrical, and control systems are engineered as a unified system.

Preventive Safety: Multiple redundant safety systems prevent failures rather than just mitigate them.

 

Manufacturing Excellence

Premium Materials: Standard use of S355J2+N steel (with impact testing at -20°C), stainless steel fasteners, and marine-grade aluminum for enclosures.

Advanced Fabrication: Laser/plasma cutting with robotic welding for critical joints (welding procedures qualified to EN ISO 15614).

Surface Technology: Multi-stage surface preparation including zinc phosphate pretreatment before powder coating or wet paint application.

 

PERFORMANCE BENCHMARKS

Parameter	European Premium	Standard Industrial
Positioning Accuracy	±1-3mm	±10-20mm
Speed Control Range	1:1000 (0.1-100%)	1:100 (1-100%)
Noise Level	≤65 dB(A) at 1m	≤75 dB(A) at 1m
Energy Efficiency	Regenerative drives (saves 20-30%)	Resistive braking (energy wasted as heat)
Mean Time Between Failures (MTBF)	5,000+ hours	2,000-3,000 hours
Installation Time	30-40% faster (modular design)	Standard assembly time

 

Core Components：Bearing, Gearbox, Motor, Pump

Place of Origin：Henan, China

Warranty：1 Year

Weight (KG)：2000 kg

Video outgoing-inspection：Provided

Machinery Test Report：Provided

Design：Double beam

Effectiveness：high efficiency

Operating speed：High speed operation

Stability：Anti-swing function

Color：Optional

Power Source：110V/220V/230V/380V/440V,customized

Span：7.5-31.5m

1. BRIDGE STRUCTURE SYSTEM

Main Girders (Tragbalken)

Construction: Welded box girders with optimized cross-section (typically 1:1.2 to 1:1.5 height-to-width ratio)

Material: S355J2+N/K2 steel plates (EN 10025-2) with guaranteed -20°C impact toughness

Internal Structure:

Transverse diaphragm plates every 1.5-2m

Longitudinal stiffeners on web and flanges

Diagonal bracing in corners for torsional rigidity

Welding: Submerged arc welding (SAW) for main seams, MAG welding for stiffeners

Quality Control: 100% ultrasonic testing of critical welds, magnetic particle testing for non-critical welds

End Trucks (Laufkatzen)

Frame Construction: Welded box section with integrated motor/platform brackets

Wheel Assemblies:

Double-flanged forged steel wheels (34CrNiMo6 material)

Induction-hardened tread (55-60 HRC to 8mm depth)

Spherical roller bearings (FAG/SKF/INA) with labyrinth seals

Hydraulic jacking points for wheel replacement

Connection to Girders: High-strength friction-grip bolts (HV system per EN 14399-10)

Runway System (Laufbahn)

Rails: EN 14811-1 A75-A120 crane rails with EN 13674-1 profiles

Fastening: Spring-loaded rail clamps (GANTREX, RÜBIG) allowing thermal expansion

Alignment: Laser-leveled to ±1mm over 20m, ±2mm total span

2. TROLLEY SYSTEM (FAHRWERK)

Trolley Frame

Design: Welded steel construction with integrated gearbox/motor mounts

Wheel Arrangement: 8-wheel configuration (4 driven, 4 idler) for load distribution

Wheels: Case-hardened (60-62 HRC) with crowned tread for rail alignment

Trolley Drive System

Component	European Specification
Motor	IEC frame (e.g., 160M) with IE4 premium efficiency, brake motor optional
Gearbox	Helical-bevel units (SEW, Nord, Flender) with ≥1.25 service factor
Coupling	Elastic pin/bush type (R+W, KTR) with fail-safe design
Brake	Spring-applied, electrically released disc brake (SBG, Mayr)

3. HOISTING SYSTEM (HEBEWERK)

Main Hoist Unit

Drum Assembly:

Machined steel drum with undercut grooves for rope guidance

Rope retention system (EN 13135 compliant)

Integral rope guide with proximity sensor

Gearing: 3-stage planetary/helical gearbox with ≥1.4 service factor

Motor: Dual-speed or VFD-controlled with Class F insulation (155°C)

Braking: Dual independent systems:

Motor brake: Disc brake on high-speed shaft

Safety brake: Mechanical load brake on gearbox output

 

Rope System

Wire Ropes: 19x7 or 35x7 IWRC rotation-resistant (Casar, Pfeifer, Kiswire)

Sheaves: Forged steel with hardened grooves (55-60 HRC)

Terminations: Wedge sockets with load monitoring pins

Load Handling Attachments

Hook Block: Forged steel hooks (Grade T or V per EN 1677-1)

Grab System (if equipped):

Motorized grabs with IP67-rated internal motors

Rope-operated grabs with separate closing mechanism

Load cells integrated in spreader beam

4. ELECTRICAL & CONTROL SYSTEMS

Power Supply System

Conductor System: Insulated conductor bars (DUCT-O-BAR, ALU-TRAK) with:

Self-cleaning collectors

Phase indication markers

Expansion joints every 40-60m

Cable Management: Energy chains (igus, Kabelschlepp) for trolley movements

 

Safety & Monitoring Components

Device	Standard	Function
Load Limiter	EN 13155	2-channel system with cross-checking
Limit Switches	EN 60947-5-1	Magnetic proximity type with manual reset
Encoder Systems	EN 61508	Absolute multi-turn for hoist, incremental for travel
Anti-Collision	EN 12999	Laser/LiDAR based with warning/stop zones
Anemometer	EN 61400-12-1	Cup/vane type with 4-20mA output

 

Electrical Cabinets

Construction: Powder-coated steel (RAL 7035) with IP54/IP55 rating

Internal Layout: Form 3b/4 segregation (EN 61439-1/2)

Components:

Main circuit breaker with RCD protection

Line filter for EMC compliance

24V DC UPS for safety circuits

PLC with SD card for data logging

 

5. GRAB BUCKET SYSTEM (SPECIALIZED)

Motorized Grab Components

Head Assembly:

Gearmotor: Brake motor (SEW/Bauer) with IP67 protection

Gearbox: Planetary reducer with 150-300:1 ratio

Torque limiter: Mechanical slip clutch to prevent overload

Jaw Mechanism:

Jaws: Hardox 500 wear plates with replaceable teeth

Hinges: Bushed pins with automatic lubrication

Seals: Multi-lip radial seals to retain grease

Electrical System:

Slip ring assembly: Fiber brush technology for power transfer

Temperature sensors: In motor and gearbox

Position sensors: For jaw opening angle

Rope-Operated Grab Components

Closing Mechanism: Differential pulley system for mechanical advantage

Rope Guides: Self-aligning sheaves to prevent rope twisting

Weight Optimization: Counterweights for empty grab stability

6. AUXILIARY & SPECIAL COMPONENTS

Lubrication System

Centralized automatic lubrication (Lincoln/Trafo) for:

Wheel bearings

Open gear meshes

Rope sheave bearings

Progressive divider valves for precise oil distribution

Monitoring & Diagnostics

Vibration sensors: On all major bearings (SKF/ifm)

Temperature sensors: Motors, gearboxes, brakes

Oil condition sensors: In gearboxes

Wear sensors: On brake linings

Data gateway: MQTT/OPC UA interface to plant network

Special Environment Components

Environment	Special Components
Cold (-40°C)	Low-temperature steel, heated bearings, Arctic grease
Corrosive	AISI 316 stainless fasteners, zinc-aluminum coating
Explosive	ATEX-certified motors, brakes, sensors
Clean Room	Stainless steel, smooth surfaces, positive pressure

7. MATERIALS & FINISHES

Surface Protection System

Preparation: Sa 2.5 blasting to 50-75μm profile

Priming: Zinc-rich epoxy (80μm dry film thickness)

Intermediate: Micaceous iron oxide epoxy (125μm DFT)

Topcoat: Polyurethane (50μm DFT) in RAL colors

Critical Material Specifications

Structural Steel: EN 10025-2 S355J2 (with CE marking and 3.1 certificate)

Fasteners: EN 15048-1/2 HV system bolts, A4-80 stainless for corrosive areas

Electrical: Harmonized cables (H07RN-F) with low smoke zero halogen option

Bearings: ISO 281 L10 life calculation ≥100,000 hours

8. QUALITY DOCUMENTATION PER COMPONENT

Each major component includes:

Material certificates (3.1 or 3.2 per EN 10204)

Welding procedure qualifications (WPQR)

Non-destructive testing reports

Dimensional inspection reports

Factory acceptance test protocols

CE Declaration of Incorporation

Sketch

Main technical

 

 

1. Engineering & Performance Superiority

Advantage	Technical Implementation	Impact
Precision Engineering	FEA-optimized box girders (L/1000 deflection), laser-aligned components (±1mm tolerance)	Ultra-smooth operation, minimal vibration, extended component life
Predictable Performance	Statistical process control, component matching, system integration	Consistent operation within specifications for entire lifecycle
Advanced Motion Control	VFDs on all motions with CANbus synchronization, anti-sway algorithms	Pinpoint positioning (±2mm), shock-free load handling
Superior Longevity	Premium materials (S355J2+N), corrosion protection (C5-M), precision bearings	30-40+ year design life with 90%+ uptime

 

2. Safety & Reliability Excellence

Multi-layer Safety Systems:
• Primary: Load limiters (2-channel), limit switches (magnetic)
• Secondary: Underspeed detection, emergency stop (Category 0/1)
• Tertiary: Structural overload protection, anti-collision systems

Fail-Safe Design: Dual independent brakes, redundant PLCs, safety-rated components (SIL2/PLd)

Predictive Maintenance: Integrated sensors (vibration, temperature, wear) with cloud analytics

Documented Reliability: MTBF >5,000 hours, 99.5%+ availability in continuous operation

 

3. Operational Efficiency

Efficiency Area	European Technology	Result
Energy Efficiency	Regenerative VFDs (feed 20-30% back to grid), IE4 motors, LED lighting	40-60% lower energy cost vs. conventional cranes
Maintenance Efficiency	Centralized lubrication, quick-change components, diagnostic ports	50% less maintenance time, 70% fewer unplanned stops
Space Optimization	Compact design, high hook approaches, minimal deflection	Maximum usable floor/height space
Speed & Productivity	Optimized acceleration profiles, simultaneous motions	15-25% faster cycle times

 

4. Economic Advantages

 

Higher Residual Value: 60-70% after 10 years vs. 20-30% for standard cranes

Insurance Benefits: 20-40% lower premiums due to certified safety systems

Regulatory Compliance: Zero non-compliance risks in European markets

 

5. Technological Leadership

Digital Integration: OPC UA, MQTT interfaces for Industry 4.0 integration

Smart Features:
• Digital Twin: Virtual model for simulation and optimization
• Predictive Analytics: AI-driven failure prediction
• Remote Diagnostics: Secure manufacturer access for troubleshooting

Future-Proofing: Modular design allowing technology upgrades

 

1. Automotive & Advanced Manufacturing

Automotive Assembly Lines

Requirements: High precision (±2mm), clean operation, 24/7 reliability

European Advantages: Vibration-damped trolleys, absolute encoders, white room variants

Specific Uses:
• Body-in-white handling: High-precision positioning for welding stations
• Battery production: Cleanroom cranes for lithium-ion cell handling
• Paint shops: Explosion-protected cranes with special finishes

Aerospace Manufacturing

Applications: Wing assembly, fuselage joining, engine handling

Critical Needs: Micro-positioning (±0.5mm), anti-sway, variable geometry handling

European Solutions:
• Active load control: Counter-mass systems for delicate components
• 6-axis positioning: Combined bridge/trolley/hoist/rotation/tilt control
• Carbon fiber handling: Static-dissipative systems

 

2. Energy & Heavy Industry

Power Generation

Plant Type	Application	European Features
Nuclear	Fuel rod handling, maintenance	SIL3 safety systems, seismic qualification, radiation-resistant materials
Thermal	Coal/biomass handling	High-duty grabs (FEM 8m), dust-proofing, automated blending
Hydro	Turbine maintenance	High-capacity (500T+), precision lowering, remote operation

Steel & Metals

Scrap Yards: 24/7 operation with 50T+ magnet or grab handling

Aluminum Smelters: Hot metal handling (up to 400°C) with heat shielding

Special Features:
• Spark-resistant components for explosive atmospheres
• High-cycle designs for continuous casting applications
• Automated inventory management with RFID tracking

 

3. Logistics & Infrastructure

Ports & Intermodal Terminals

Container Handling: Spreader cranes with automatic twistlock systems

Bulk Terminals: Grab cranes with automated stockpile management

European Advantages:
• Wind-resistant design: EN 13001-2 compliance for 150km/h winds
• Saltwater corrosion protection: C5-M coating, stainless components
• Remote operation: Operator centers with VR integration

Rail & Transportation

Locomotive Maintenance: Under-bridge cranes for engine handling

Tunnel Construction: Segment handling with millimeter precision

Bridge Construction: Launching gantries with synchronized multi-crane control

 

4. Process Industries

Chemical & Pharmaceutical

Clean Room Applications: Stainless steel (AISI 316L) construction, IP65 sealing

Hazardous Areas: ATEX-certified complete packages (Zone 1/21)

Precision Features:
• Vibration isolation: Air-spring mounted hoists for sensitive processes
• Contamination control: Smooth surfaces, positive pressure enclosures
• Weight batching: Integrated load cells with 0.1% accuracy

Food & Beverage

Hygienic Design: USDA/FDA compliant materials, easy-clean surfaces

Automation: Fully automated pallet/case handling with vision systems

Temperature Zones: Freezer applications (-40°C) with cold-proof components

 

5. Specialized Applications

Research & High-Tech

Particle Accelerators: Non-magnetic cranes (aluminum construction)

Semiconductor Fabs: Vibration class VC-D/E, ESD protection

Observatories: Ultra-smooth motion for telescope components

Disaster Response & Specialized Handling

Nuclear Decommissioning: Remote-operated cranes with camera systems

Art & Museum Handling: Micro-speed control (0.1 m/min), climate control

Shipbuilding: Gantry cranes with 1000T+ capacity for block assembly

 

Phase 1: Design and Engineering

This is the foundational phase before any physical work begins.

Customer Requirements Analysis: Engineers review the specific requirements: capacity (e.g., 32/5 tons), span, lifting height, duty class (e.g., A5, A6), and any special needs (e.g., explosion-proof, high-temperature environment).

Structural Design: Using CAD (Computer-Aided Design) software, engineers design the main girders, end carriages, and trolley frame. Finite Element Analysis (FEA) is often used to simulate stress, deflection, and dynamic loads to optimize the design for strength and weight.

Mechanical and Electrical Design: This includes selecting and designing the drive systems (motors, gearboxes, wheels), the hoisting mechanism, and the complete electrical control system with panels, variable frequency drives (VFDs), and safety devices.

Bill of Materials (BOM) Creation: A detailed list of all raw materials (steel plates, profiles) and purchased components (hoist, motors, brakes, wire rope, wheels) is generated.

 

Phase 2: Raw Material and Component Procurement

Steel Plates and Profiles: High-quality steel plates (typically Q235B or Q345B according to Chinese standards, equivalent to S235JR/S355JR) are procured in required dimensions and thicknesses.

Purchased Components: Critical components are sourced from reputable suppliers. These include:

Hoist unit (may be manufactured in-house or purchased)

Electric motors for bridge and trolley travel

Reducer gearboxes

Wheels and axles

Brakes

Electrical components (controllers, contactors, limit switches, VFDs, cabling)

Bearings

 

Phase 3: Main Steel Fabrication & Machining

This is the core of the manufacturing process.

1. Main Girder Fabrication:

Cutting: Steel plates are cut to the required size and shape using CNC plasma or flame cutting machines for high precision.

Web/Flange Preparation: The vertical web plates and horizontal top/bottom flange plates are prepared. For long spans, the girders are often designed as a tapered "I-beam" profile (wider in the middle) to optimize strength-to-weight ratio.

Assembly and Welding: The girders are assembled on large jigs to ensure straightness and correct camber (a pre-set upward bend to counteract deflection under load). This is a critical step. Submerged Arc Welding (SAW) is commonly used for its deep penetration and high-quality, consistent welds on long seams.

Stress Relieving: After welding, the main girders often undergo stress relieving heat treatment in a large furnace. This process removes internal stresses created during welding, preventing future distortion and ensuring dimensional stability.

Machining: The mating surfaces for the end carriages and trolley rails are machined using a planer or milling machine to ensure a perfectly flat and level surface.

2. End Carriage (End Truck) Fabrication:

The end carriages are fabricated from steel sections and plates.

They house the wheels, drive motors, and gearboxes for the bridge movement.

The wheel bases are drilled and machined to precise tolerances to ensure proper alignment and that all wheels make contact with the runway rails.

 

Phase 4: Mechanical Assembly

1. Bridge Assembly:

The two main girders are positioned parallel to each other and connected to the end carriages using high-strength bolts or by welding, forming the complete bridge structure.

The trolley rails are precisely aligned and bolted onto the top of the main girders.

2. Trolley Frame Assembly:

The trolley frame is assembled, and its wheels, drives, and the main hoisting unit (including the wire rope drum, motor, gearbox, and hook block) are mounted onto it.

3. Drive System Installation:

The travel drive units (motor, gearbox, coupling) are installed on the end carriages (for bridge motion) and on the trolley frame (for trolley motion).

All mechanical components are aligned to prevent binding and premature wear.

 

Phase 5: Electrical System Installation

Cable Reeling System: The main power supply system for the crane (e.g., conductor bars or festoon systems) is installed along the bridge girder.

Control Panel Installation: The main control panel, VFDs, and other electrical components are mounted in a protected enclosure, usually on the bridge girder.

Wiring: All motors, brakes, limit switches, and safety devices are wired according to the electrical schematic.

Operator Control Station: The pendant control station (hung from the crane) or a radio remote control system is connected and tested.

 

Phase 6: Surface Treatment and Painting

Surface Preparation: The entire crane structure is shot-blasted to remove mill scale, rust, and welding slag, creating a clean, rough surface for optimal paint adhesion.

Priming: A rust-inhibitive primer is applied immediately after blasting to prevent oxidation.

Painting: Multiple coats of high-quality industrial enamel paint are applied. Color is often according to customer specification or standard factory practice (e.g., international orange/yellow for visibility). The painting process protects the crane from corrosion in industrial environments.

 

Phase 7: Factory Acceptance Testing (FAT)

Before disassembly for shipment, the fully assembled crane undergoes rigorous testing.

Visual Inspection: Checking dimensions, weld quality, and assembly.

No-Load Test: Running the crane, trolley, and hoist in all directions to verify smooth operation, correct speed, and functionality of all controls and limit switches.

Static Load Test: The hoist is lifted with a test load 25% greater than the rated capacity (as per FEM/ISO standards). The load is held for 10-15 minutes to check for structural deformation, weld integrity, and brake holding capacity.

Dynamic Load Test: The crane is operated with a test load 10% greater than the rated capacity. All motions are tested to ensure performance under dynamic stress.

Electrical Safety Tests: Insulation resistance, grounding continuity, and proper functioning of all emergency stops and safety circuits are verified.

 

Phase 8: Dismantling, Packaging, and Shipping

After passing FAT, the crane is carefully dismantled into transportable sections (main girders, end carriages, trolley, electrical panels).

All components are professionally packaged and protected against damage during transit.

They are shipped to the customer's site, where they will be reassembled and installed by technical crews.

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%.