Portal Crane

Product Specifications

Technical details and manufacturing context for Portal Crane

Definition

A portal crane, also known as a gantry crane, is a type of overhead crane built on a gantry structure consisting of vertical legs connected by a horizontal beam. It operates by moving along fixed rails or wheels on the ground, providing a large working area for lifting, moving, and positioning heavy loads in industrial facilities, ports, shipyards, and construction sites. Unlike bridge cranes that run on elevated runways, portal cranes have ground-level mobility and can span wide areas without requiring extensive building support structures. The crane's structural steel and high-strength alloy steel components ensure durability and stability under heavy loads. Typical specifications include a lifting capacity of 5 to 100 tonnes, a span length of 10 to 40 meters, and a lifting height of 6 to 30 meters. Travel speed ranges from 20 to 60 meters per minute, while hoisting speed ranges from 5 to 20 meters per minute. The power supply is typically 380V/50Hz, and the operating temperature range is -20°C to 40°C, with special steel required below -20°C. The maximum wind speed for out-of-service conditions is 20 m/s, and the duty class is A5 to A7 based on utilization and load spectrum. Control modes include radio remote or cabin operation. The approximate total weight ranges from 20 to 150 tonnes. These values are reference ranges and must be confirmed for the specific model and application. Portal cranes are selected based on load requirements, span, and site conditions. Verification of model-specific values and standards with the legal manufacturer or supplier is essential before procurement or use.

Working Principle

The portal crane operates through a combination of structural support and mechanical lifting systems. The gantry structure provides stability and spans the working area, while the hoist mechanism moves along the horizontal beam (bridge) to position the lifting hook. Electric motors drive the crane's travel along rails, the bridge movement across the gantry, and the hoist's vertical lifting. Control systems allow operators to precisely maneuver loads in three dimensions: longitudinal travel along the rails, transverse movement across the bridge, and vertical lifting/lowering via the hoist mechanism.

Common Materials

Structural Steel, High-Strength Alloy Steel

Technical Parameters

Parameter	Typical range	Notes & selection driver
Lifting CapacityRequired	5–100 tonnes	Maximum safe working load the crane can liftISO 4301-1
Span LengthRequired	10–40 meters	Distance between the centerlines of the two gantry legs
Lifting HeightRequired	6–30 meters	Maximum vertical distance the hook can travel from ground level
Travel SpeedRequired	20–60 meters/minute	Maximum speed of crane movement along the rails
Hoisting SpeedRequired	5–20 meters/minute	Maximum speed of vertical load movement
Power SupplyRequired	380V/50Hz volts	Electrical system voltage and phase requirementsIEC 60038
Wheel LoadRequired	100–400 kN	Maximum load exerted by each wheel on the rail
Operating Temperature	-20–40 °C	Below -20°C requires special steelISO 4301-1
Max Wind Speed	20 m/s	For out-of-service conditionGB/T 3811
Duty Class	A5–A7	Based on utilization and load spectrumISO 4301-1
Control Mode	Remote/ Cab	Radio remote or cabin operation
Weight	20–150 t	Approximate total weight

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Components / BOM

Gantry Structure
Provides the main structural framework and supports all crane components and loads

Material: Structural steel beams and columns
Bridge Girder
Horizontal beam that spans between gantry legs and supports the hoist trolley

Material: Box girder or truss structure made of high-strength steel
Hoist Mechanism
Lifts and lowers loads using wire rope or chain with electric motor drive

Material: Steel wire rope, alloy steel gears, electric motor components
Trolley
Moves the hoist mechanism along the bridge girder for transverse positioning

Material: Steel frame with wheels and drive components
End Trucks
Support the bridge girder and contain the drive mechanisms for longitudinal travel

Material: Steel fabrication with wheels, bearings, and drive motors
Electrical Control System
Provides power distribution, motor control, and operational interface for crane movements

Material: Electrical panels, wiring, PLC controllers, and operator interface
Safety Devices
Includes limit switches, overload protection, emergency stops, and warning systems

Material: Various electrical and mechanical safety components
Operator Cabin
Enclosed space for crane operator with controls and visibility

Material: Steel frame with safety glass and climate control
Remote Control System
Wireless or wired remote control for operating the crane from ground level

Material: Electronic transmitter/receiver with control interface

Application & selection

Application Fit & Sizing Matrix

Operational Limits

pressure:	N/A (mechanical lifting device)
other spec:	Max wind speed: 20 m/s (operational limit), Max lifting capacity: 500 tons (typical range), Max span: 120 meters
temperature:	-20°C to +40°C (operational range)

Media Compatibility

✓ Steel coils and plates ✓ Shipping containers ✓ Heavy machinery components

Unsuitable: Explosive or highly corrosive chemical storage areas (due to spark risk and material degradation)

Sizing Data Required

Maximum lifting capacity required (tons)
Span length between legs (meters)
Lifting height and required hook travel (meters)

Risk, maintenance & compliance

Reliability & Engineering Risk Analysis

Failure Mode & Root Cause

Wire rope degradation

Cause: Fatigue from cyclic loading, corrosion due to environmental exposure, and abrasion against sheaves or drums leading to broken wires, reduced diameter, or loss of core lubrication.

Gearbox failure

Cause: Inadequate lubrication causing overheating and wear, misalignment from foundation settlement or improper installation, and contamination from ingress of moisture or debris leading to pitting, scoring, or tooth breakage.

Maintenance Indicators

Unusual grinding or knocking noises from hoisting or trolley mechanisms, indicating potential gear or bearing failure.
Excessive sway or vibration during crane operation, suggesting structural looseness, wheel flange wear, or rail alignment issues.

Engineering Tips

Implement a predictive maintenance program using vibration analysis and thermography to monitor gearboxes, motors, and bearings, enabling early detection of anomalies before catastrophic failure.
Establish rigorous inspection and lubrication schedules for wire ropes, sheaves, and rails, including regular cleaning to remove contaminants and application of corrosion inhibitors in harsh environments.

Indicative industry ranges for design and RFQ preparation. Confirm the exact figures and applicable standard with the manufacturer before specifying.

Compliance & Manufacturing Standards

Applicable Standards

ISO 12488-1: Cranes - Tolerances for wheels and travel and traversing tracks ANSI/ASME B30.2: Overhead and Gantry Cranes (Top Running Bridge, Single or Multiple Girder, Top Running Trolley Hoist) DIN 15018: Cranes - Steel structures - Principles for design and construction

Quoted from the published standard.

Manufacturing Precision

Wheel alignment: +/-0.5mm per meter of track
Bridge girder camber: +0.1% to +0.2% of span length

Quality Inspection

Load test (static and dynamic) to 125% of rated capacity
Non-destructive testing (NDT) of critical welds using ultrasonic or magnetic particle inspection

Procurement Evaluation Criteria

A practical evidence checklist for RFQ preparation and supplier evaluation.

Technical documentation

Request current drawings, revision history, and a signed specification sheet.

Manufacturing capability

Verify equipment lists, process limits, capacity, and representative production evidence.

Inspection readiness

Confirm test methods, calibrated equipment, sampling plans, and traceable reports.

Supplier transparency

Check the legal entity, factory address, ownership, certifications, and direct contacts.

Compare the published product scope and source details, then include your specifications and quantity in an enquiry.

Manufacturers of Portal Crane

9 companies list this product among what they make. Company figures are quoted from each company's own website; every card states where the relationship came from.

DGCRANE

Xinxiang, Henan, CN

The official website lists double-girder gantry cranes supplied as hoisting trolley, gantry structure and travel system. Provide capacity, span, lifting height and site rail conditions and distinguish complete cranes from component kits; harbour portal cranes are checked separately by working radius.