Port Crane Cable Selection: Reeling Cable vs. Festoon Cable Guide for STS Cranes & RMG Gantries

Introduction:

Solving Your Crane Cable Selection Dilemma

Port operations demand maximum reliability and safety from every component, especially the electrical cables that power massive container handling cranes. Whether you're specifying cables for a new Ship-to-Shore (STS) crane installation or upgrading an existing Rail-Mounted Gantry (RMG) system, choosing between reeling and festoon cables can significantly impact operational efficiency, maintenance costs, and equipment longevity.

The wrong cable selection leads to premature failures, costly downtime, and potentially dangerous situations. With container throughput increasing globally and port automation expanding rapidly, understanding the critical differences between reeling and festoon cable systems has never been more important for port engineers, crane manufacturers, and maintenance teams.

This comprehensive guide examines both cable types, their optimal applications, and provides clear recommendations for different crane configurations to help you make informed decisions that maximize performance while minimizing operational risks.

What is a Reeling Cable?

Reeling cables, also known as trommel cables, are specifically engineered for continuous winding and unwinding operations on drum systems. These cables feature robust construction with specialized sheathing compounds and internal structural elements designed to withstand the mechanical stresses of repeated coiling cycles.

The construction typically includes very finely stranded copper conductors (Class FS), high-grade EPR insulation such as PROTOLON MS, and a unique dual-sheath system. The inner sheath provides electrical protection while the outer sheath, often made from specialized PCP compounds, delivers exceptional abrasion and tear resistance. Anti-torsion braids between sheath layers help maintain cable integrity under rotational stress.

STS crane reeling cable selection guide considerations include maximum tensile loads up to 30 N/mm², travel speeds reaching 240 m/min, and operating temperature ranges from -35°C to +80°C during flexible operation. The low-voltage trommel cable for port cranes typically features models like CORDAFLEX (SMK) with designation (N)SHTOEU, offering 0.6/1 kV ratings suitable for power transmission and control applications.

Key design features include:

• Symmetrical three-core construction with split earth conductors for optimal electromagnetic compatibility

• Reinforced braid between sheaths for enhanced tensile strength

• Optimized bending radius characteristics (typically 5-10 times cable diameter)

• Integrated fiber optic capabilities for data transmission in advanced models

What Is a Festoon Cable?

Festoon cables operate in suspended cable management systems where the cable moves in controlled loops or curves rather than being wound on drums. These cables are designed for horizontal travel applications where the cable follows a trolley or carriage system along a predetermined path.

The festoon system layout includes cable carriers, guides, and support structures that maintain proper cable positioning throughout the travel range. Unlike reeling cables, festoon cables experience less severe bending stresses but must accommodate longer unsupported spans and different mechanical loading patterns.

RMG crane festoon cable types commonly include round polyurethane-sheathed designs such as FESTOONFLEX PUR-HF with designation D12Y11Y. These cables feature halogen-free compounds, flame-retardant properties, and are suitable for permanent use in water up to 50-meter depths, making them ideal for port environments with high humidity and salt exposure.

Festoon energy chain cable for gantry cranes applications typically involve:

• Travel speeds up to 210 m/min for standard applications

• Tensile loads up to 15 N/mm² on conductors

• Torsional stress ratings of ±25°/m

• Operating temperature ranges from -40°C to +80°C

• Specialized designs for energy chain compatibility with controlled bending radii

The cable arrangement in festoon systems allows for predictable stress patterns and easier maintenance access compared to reeling systems, though they require more complex support infrastructure.

Core Differences: Reeling vs Festoon Cables

Critical performance distinctions become apparent in demanding applications. Reeling cables excel in high-speed, high-load scenarios with their superior tensile strength and anti-torsion capabilities. The dual-sheath PROTOFIRM system provides exceptional durability under continuous flexing cycles. Conversely, festoon cables offer advantages in applications requiring frequent maintenance access and where support infrastructure can accommodate the suspension system requirements.

Temperature performance differs significantly, with reeling cables maintaining flexibility at lower temperatures (-35°C vs -40°C), while festoon cables often provide superior performance in extreme heat conditions due to specialized polyurethane compounds.

Best Cable Choice by Crane Type

STS Ship-to-Shore Cranes → Recommend Reeling Cable

STS cranes present the most demanding cable applications in port operations. The combination of extreme travel distances (often exceeding 50 meters), high speeds (up to 240 m/min), and significant load variations makes reeling cables the clear choice. The gantry travel system requires cables capable of handling both the mechanical stress of drum winding and the electrical demands of high-power trolley motors.

CORDAFLEX (SMK) series with models like 3x185+3x95/3 provide 26.46 kA short-circuit current capacity and 461A continuous current rating, suitable for the high-power requirements of modern STS operations. The integrated aramid support elements and specialized sheathing compounds ensure reliable operation under the severe duty cycles typical of container ship loading operations.

RMG Rail-Mounted Gantries → Recommend Festoon Cable

RMG applications typically involve shorter travel distances with more predictable operational patterns, making festoon systems ideal. The horizontal rail-based movement allows for effective cable management through suspended systems, while maintenance accessibility remains excellent throughout the operational envelope.

FESTOONFLEX PUR-HF cables in configurations like 4x95 provide 316A current capacity with 13.59 kA short-circuit rating, meeting the power requirements of most RMG applications while offering superior environmental resistance through halogen-free polyurethane sheathing.

Specialized Port Equipment Applications

E-RTG (Electric Rubber-Tired Gantry) operations benefit from reeling cables due to the confined reel space and need for maximum power density. Models like CORDAFLEX(SMK) for E-RTGs feature optimized designs for the unique mechanical constraints of rubber-tired equipment.

Spreader reeling applications require specialized vertical reeling cables with central aramid support elements, such as CORDAFLEX(SMK)-V models, designed specifically for gravity-fed operations with enhanced tensile load capabilities.

Basket operation systems utilize specialized cables like SPREADERFLEX 3GSLTOE, featuring unique core arrangements optimized for the specific mechanical stress patterns of gravity-fed collector baskets.

Consequences of Incorrect Cable Selection

Selecting inappropriate cable types leads to cascading operational problems that extend far beyond initial cost considerations. Field experience demonstrates that cable failures account for up to 30% of crane downtime in port operations, with incorrect cable specification being a primary contributing factor.

Mechanical Failure Patterns: Using festoon cables in reeling applications typically results in premature conductor breakage due to insufficient tensile strength design. The single-sheath construction cannot withstand the combined stresses of drum winding, tensile loads, and torsional forces. Failure modes include conductor strand breakage, insulation cracking, and eventual complete power loss.

Electrical Performance Degradation: Reeling cables in festoon applications often experience electromagnetic compatibility issues due to their specialized three-core symmetrical design being underutilized. This can lead to data transmission problems in automated systems and increased electrical noise affecting sensitive control circuits.

Maintenance Cost Escalation: Incorrect cable selection dramatically increases maintenance requirements. Festoon cables forced into reeling service may require replacement every 6-12 months instead of the typical 3-5 year service life of properly selected reeling cables. The resulting maintenance costs often exceed 300% of the original cable investment over a five-year period.

Safety Risk Assessment: Cable failures in port operations pose significant safety risks due to the high-energy electrical systems and massive mechanical loads involved. Sudden power loss during container handling operations can result in load drops, equipment damage, and potential personnel injury. Emergency shutdown procedures, while effective, cannot eliminate all risks associated with unexpected cable failures.

A documented case study from a major Asian port involved STS crane downtime exceeding 72 hours due to festoon cable failure in a reeling application. The incident occurred during peak shipping season, resulting in vessel delays and estimated economic losses exceeding $500,000. Post-failure analysis revealed that the festoon cable experienced conductor breakage due to insufficient tensile strength design for the drum winding application.

Feichun's Expertise and Solutions

Feichun Cable Technology leverages extensive experience in port crane applications to provide optimized cable solutions tailored to specific operational requirements. Our engineering team works directly with port operators, crane manufacturers, and maintenance contractors to develop custom specifications that maximize performance while minimizing lifecycle costs.

Custom Cable Design Capabilities: Our design process begins with detailed application analysis including travel distances, speed profiles, environmental conditions, and electrical load requirements. Standard models serve as the foundation, with modifications addressing specific operational challenges such as extreme temperature ranges, corrosive environments, or specialized mechanical constraints.

Proven Model References: Our product portfolio includes comprehensive coverage of port crane applications:

• NSHTOEU series for standard reeling applications with tensile loads up to 30 N/mm²

• D12Y11YU11Y models for polyurethane-sheathed reeling with enhanced environmental resistance

• N7YRDGOEU configurations for EVA-sheathed spring-reeling applications

• Specialized E-RTG variants with optimized power conductor arrangements

Free Technical Consultation: Expert Cable Selection Support

Request Your Consultation Today: Contact our technical team to schedule your complimentary cable selection consultation. Our engineers are available to address your specific challenges and provide tailored solutions that optimize both performance and cost-effectiveness.

Phone: +86-153-7530-2641

Email: hongjing.Wang@feichuncables.com