Four-link Portal Crane

Authentication mark:

This crane is mainly used in commercial ports, fishing harbors, and offshore supply bases.

Capacity:

5 tons – 100 tons

Lifting Height:

15 m – 40 m (customizable based on vessel/port requirements)

Span:

Not Applicable

Voltage/Hertz:

380V / 50Hz / 3-phase

Working Class:

A5 – A8 (ISO / FEM)

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Introduction

Application Scenario

Advantages

Structural Diagram And Parameter Table

INTRODUCTION

What is this?

The four-link portal crane is a combination-jib portal crane widely used in port terminals, bulk cargo loading points, and shipyards. It adopts a four-link luffing mechanism consisting of a topping platform, main jib, tie rods, and slewing platform. Through the lifting and lowering of the hook or grab, the horizontal luffing of the jib, and the 360-degree full slewing of the crane, combined with traveling along rails, it achieves efficient loading and unloading of bulk cargo, general cargo, and containers. If you are operating a bulk cargo terminal, general cargo terminal, or shipyard, and need a portal slewing crane with minimal load horizontal displacement during luffing, high lifting height, and high operating efficiency, then this product is designed for you.

Why choose a four-link portal crane over a single jib portal crane?

Compared to single jib portal cranes, the four-link portal crane offers five core advantages:

First, minimal load horizontal displacement during luffing – the four-link mechanism ensures that the load moves almost horizontally during luffing, eliminating the need for coordinated hoist operation, simplifying control, and improving operating efficiency.

Second, greater lifting height – the combination-jib design achieves a higher lifting height above rail, reaching up to 40 meters or more, making it especially suitable for loading and unloading deep-hold vessels.

Thid, smaller working dead zone – the jib can be luffed down to a lower angle, providing wider coverage near the dock surface and reducing unloading blind spots.

Fourth, better luffing power efficiency – the four-link mechanism offers excellent balance, requiring lower luffing driving torque and consuming less energy than single jib designs of equivalent capacity.

Fifth, smoother operation – superior kinematic characteristics result in minimal load swing, precise landing, and lower requirements for operator skill level.

Enhance your port bulk cargo and general cargo handling capacity with more professional four-link portal cranes.

What can we do for you?

We understand that every terminal has different cargo types, different vessel types, and different operational requirements. Therefore, we offer flexible customization options: lifting capacity from 5 tons to 100 tons; working radius from 15 meters to 40 meters; lifting height from 15 meters above rail to 15 meters below rail; slewing angle of 360 degrees full slewing; attachment options including hook, grab, container spreader, or timber grab; adjustable luffing speed to meet different operational rhythms; control options of cabin operation or remote radio control. Whether you operate a small to medium-sized bulk cargo terminal, a general cargo terminal, or a shipyard, we can match the most suitable lifting capacity and working radius for you.

Unsure? Don't know?

Not sure what working radius is needed to cover your largest vessel type? Not sure what lifting height is needed to reach into deep-hold vessels? No problem. Just tell us: the maximum vessel hold depth and deadweight tonnage of your largest vessel, your dock front water depth, your berth length, and your target operational efficiency (tons per hour or containers per hour). Our engineers will provide you with an accurate quote and CAD drawings within 24 hours. Click the button below or contact us via WhatsApp/email to get your customized solution.

💡 Tip: We offer free selection consulting. Even if you are unsure about specific parameters, feel free to describe your dock conditions and cargo types, and we will calculate for you.

APPLICATION SCENARIO

[1] Ship-to-Shore Cargo Handling – Lifting containers, pallets, and break‑bulk cargo from vessel holds to quayside.

[2] Barge Loading/Unloading – Transferring aggregates, timber, or steel coils between barges and stockpiles.

[3] Fishing Ports – Hoisting nets, fish boxes, and equipment from trawlers.

[4] Container Yards – Stacking empty containers or handling heavy lifts on dock aprons.

[5] Offshore Supply Bases – Servicing vessels with heavy machinery spares and provisions.

ADVANTAGES

[1] Corrosion Resistance – Marine‑grade paint, stainless steel hardware, and sealed electrics for saltwater environment.

[2] Smooth Slewing & Luffing – Hydraulic or variable‑frequency drive for precise load positioning.

[3] Compact Deck Footprint – Pedestal mount saves valuable dockside space.

[4] Heavy‑Duty Duty Cycle – Built for continuous port operations with high reliability.

[5] Easy Maintenance – Local service access and modular components reduce downtime.

STRUCTURAL DIAGRAM AND PARAMETER TABLE

Parameter	Specification
Working Class	A5 – A8 (ISO / FEM)
Capacity	5 tons – 100 tons
Lifting height - Above rail	15 m – 40 m
Lifting height - Below rail	0 m – 15 m
Working radius	15 m – 40 m
Hoisting speed	10 m – 60 m/min
Lifting Speed	Fully loaded: 5 – 20 m/min Empty: 10 – 40 m/min
Slewing speed	0.5 – 1.5 rpm
Wheel base	6 m – 10 m
Slewing Angle	360° continuous (full rotation)
Control Method	Remote radio control / Cabin control / Pendant control
Power Supply	380V / 50Hz / 3-phase
Temperature	-20°C to +50°C
Protection Grade	Motors: IP55 – IP56 Electrical cabinet: IP54 – IP65
Structure Type	Deck-mounted slewing jib crane – Single or double boom with hydraulic or wire rope luffing

Six core advantages

Full Scenario Coverage

Nucleon covers over 20 product categories including ladle cranes, multi-purpose cranes, intelligent cranes, overhead/portal cranes, RTG, RMG, deck cranes, portal cranes, girder launchers, yacht cranes, KBK, and jib cranes. From steel smelting to port handling, bridge construction to ship equipment, Nucleon provides one-stop lifting solutions. Whether standard models or extreme-condition customizations, Nucleon possesses mature technical expertise and proven track records, saving customers from dealing with multiple suppliers.

Military-Grade Quality Standards

We use high-strength steel from Baosteel/Ansteel for key structural components, with 100% NDT inspection and one-clamp CNC gantry machining. Every machine undergoes 120% dynamic load and 125% static load tests before delivery, with continuous operation verification under extreme conditions. Even in 24/7 continuous casting plants, -40°C arctic ports, or high-temperature humid ship cabins, our cranes maintain millimeter-level precision and zero-drift stability—quality that stands the test of time.

Extended Longevity & Low Maintenance Cost

Our main girders are FEA-optimized and double-submerged arc welded, with a design life of ≥30 years. Key bearings are lifetime lubrication-free, and hardened travel wheels extend wear cycles by 3 times. Core components feature modular quick-change interfaces with spare parts commonality exceeding 80%. Annual maintenance costs are reduced by 40%~60%, saving millions in lifecycle operating expenses — truly "invest once, benefit long-term."

Energy Efficiency Leader

Our entire series comes standard with IE5 permanent magnet synchronous motors + energy feedback VFD drives, achieving 25%~35% comprehensive energy savings. Single-motor operation under light loads and adaptive speed control reduce electrical waste by over 30%. High-strength steel lightweight design cuts deadweight by 15%~20%, lowering workshop load requirements. A single ladle crane station saves over RMB 150,000 in electricity costs annually, helping customers achieve green and low-carbon production.

Ultimate Safety Redundancy Design

Our hoisting mechanism comes standard with dual brakes + mechanical overspeed switch + triple limit switches, featuring multiple redundant interlocks to prevent load dropping and over-traveling. Large products use box girder torsion-resistant structures, remaining stable even in level 8 gusty winds. Optional intelligent safety monitoring systems detect anomalies in load, skew, wind speed, etc., with automatic alarms and shutdowns. Overall safety redundancy coefficient > 2.0, maintaining zero crane safety incidents for many consecutive years.

Deep Customization & Full Lifecycle Service

We provide complete front-end support from site survey and mechanical simulation to civil review, delivering custom drawings within 2 weeks, with non-standard lead times only 5~7 days longer than standard products. We establish lifelong digital dossiers for customers, warning of end-of-life components 3 months in advance. Our full lifecycle services cover installation training, regular inspections, and remote O&M. With customer repeat purchase rates exceeding 85% for five consecutive years, we are a trustworthy long-term partner.