What Are Trailing Cables?

Trailing cables, also known as reeling cables or mining trailing cables, are specialized, highly flexible electrical cables designed to power mobile or frequently moving equipment in demanding industrial environments. Engineered to withstand mechanical stresses such as bending, twisting, stretching, and coiling, these cables ensure a reliable connection between power sources and equipment like excavators, cranes, and draglines. They are commonly used in industries such as mining, construction, and heavy manufacturing, where durability and safety are critical. Trailing cables comply with standards like AS/NZS 1747 (for mining cables) and IEC 60245, offering features like flame retardancy and grounding for enhanced safety. Their robust design aligns with the durability of cables like PUR, LSOH, or braided cables discussed previously, but they are optimized for dynamic, high-stress applications unlike standard THHN or PVC cables.

Construction and Features

Trailing cables are built for flexibility, conductivity, and resilience, with a construction that includes:

• Conductor: Stranded copper (59.6 MS/m conductivity) or copper-clad steel (CCS) for flexibility and fatigue resistance, optimized for repeated bending, similar to multi-conductor or lead wires. Sizes range from 10 mm² to 120 mm² for high-current applications.
• Insulation: High-quality materials like ethylene propylene rubber (EPR) or cross-linked polyethylene (XLPE) provide electrical isolation, flexibility, and resistance to heat and chemicals, akin to LSOH or Teflon insulation.
• Shielding: Metallic braids or screens (e.g., tinned copper) protect against electromagnetic interference (EMI), ensuring signal integrity in automation systems, similar to braided cables.
• Outer Sheath: Rugged jackets of polyurethane (PUR), neoprene, or chlorinated polyethylene (CPE) offer abrasion, chemical, and UV resistance, withstanding harsh conditions like those in marine or mining cables.
• Filler: Non-hygroscopic fillers or central strength members (e.g., Kevlar yarns) maintain cable shape and tensile strength, supporting high acceleration and reeling speeds (up to 200 m/min).
• Grounding: Integrated earth conductors or screens ensure fault protection, complying with Mining WHS Code and NEC standards, similar to grounding wires.

Key features include high flexibility (bend radius ≤6x cable diameter), tensile strength (up to 15 N/mm²), flame retardancy (per IEC 60332), and voltage ratings from 415V to 22 kV. These cables resist temperatures from -40°C to 90°C and have a lifespan of 5–10 years under heavy use, depending on maintenance.

Key Benefits of Trailing Cables

Trailing cables offer significant advantages in dynamic industrial applications:

• High Flexibility: Stranded conductors and flexible insulation allow repeated bending and twisting without damage, ideal for reeling systems, unlike rigid THHN or RHW cables.
• Durability: Robust sheaths resist abrasion, chemicals, and environmental stressors, ensuring longevity in harsh settings like mines or construction sites.
• Enhanced Safety: Grounding conductors and flame-retardant materials reduce electrical and fire hazards, complying with AS/NZS 1747 and Mining WHS Code, akin to halogen-free cables.
• EMI Protection: Shielding maintains signal integrity in automation and control systems, similar to braided or multi-pair cables.
• Reduced Downtime: Proper routing and maintenance minimize cable failures, improving productivity, as seen in case studies of manufacturing facilities.
• Trip Hazard Mitigation: When used with cable protectors, trailing cables reduce workplace accidents, aligning with the Health and Safety at Work Act 1974.

These benefits make trailing cables essential for mobile equipment, complementing the safety features of LSOH or grounding systems discussed earlier.

Applications of Trailing Cables

Trailing cables are critical in industries requiring mobile power delivery:

• Mining: Power mobile equipment like draglines, shovels, drills, and conveyors in surface and underground mines, handling voltages up to 22 kV, similar to CCS or MV cables.
• Construction: Supply power to cranes, excavators, and concrete mixers on sites, reducing trip hazards with proper management, akin to grounding wire applications.
• Heavy Industry: Used in cranes, hoists, and festoon systems in manufacturing and ports, supporting high reeling speeds (up to 200 m/min), as in lift trailing cables.
• Oil and Gas: Power pumps and drilling rigs in offshore and onshore rigs, with sheaths resisting chemicals and saltwater, similar to marine cables.
• Automation: Deliver power and signals to robotic arms and automated guided vehicles (AGVs), leveraging EMI shielding, akin to braided cables.
• Quarrying: Support mobile crushers and conveyors, withstanding abrasion and mechanical stress, similar to PUR or armored cables.

These applications highlight their adaptability, mirroring the versatility of silicone or Teflon cables in extreme conditions.

Limitations of Trailing Cables

Despite their advantages, trailing cables have some drawbacks:

• High Cost: Specialized materials (e.g., PUR, EPR) and complex construction increase costs compared to standard PVC or THHN cables.
• Maintenance Needs: Require regular inspection and testing (per AS/NZS 1747) to prevent failures from wear, punctures, or insulation breakdown, especially in mining.
• Trip Hazards: If not properly managed with protectors or trays, trailing cables pose risks in high-traffic areas, as noted in construction safety regulations.
• Weight: High-voltage cables (e.g., 11 kV Type 409, ~15 kg/m) are heavy, requiring handling aids to prevent strain injuries.
• Limited Static Use: Over-engineered for fixed installations, making them less cost-effective than tray or NM cables in static applications.

These limitations echo trade-offs discussed with PUR vs. PVC or braided cables, balancing durability and practicality.

Trailing vs. Standard Cables Comparison Table

Trailing cables differ significantly from standard cables in flexibility and durability. The table below compares their key attributes:

Note: Verify specifications with IEC, NEC, or AS/NZS standards for specific applications.

Tips for Choosing Trailing Cables

Selecting the right trailing cable ensures performance and safety:

• Assess Application Needs: Choose cables suited for specific equipment (e.g., draglines, cranes) and voltage ratings (415V–22 kV), as in mining or construction.
• Evaluate Environment: Select sheaths like PUR or neoprene for chemical, UV, or abrasion resistance in harsh settings, similar to marine or PUR cables.
• Ensure Flexibility: Opt for stranded conductors and EPR/XLPE insulation for high bending cycles, as in reeling or festoon systems.
• Verify Standards: Confirm compliance with AS/NZS 1747, IEC 60245, or Mining WHS Code, ensuring grounding and flame retardancy.
• Plan Management: Use cable protectors, trays, or reeling devices to prevent trip hazards and damage, per Health and Safety at Work Act 1974.
• Monitor Maintenance: Implement a Trailing Cable Management System with regular inspections and testing to extend lifespan, as recommended for surface mines.
• Consult Experts: Work with manufacturers or electricians to customize cables for specific loads, environments, or reeling speeds.

These steps ensure reliable operation, akin to selecting LSOH, braided, or grounding cables for critical applications.

Conclusion

Trailing cables are vital for powering mobile equipment in demanding industrial settings, offering unmatched flexibility, durability, and safety. Their stranded conductors, robust EPR/XLPE insulation, and PUR or neoprene sheaths withstand bending, abrasion, and harsh conditions, making them ideal for mining, construction, and heavy industry. With features like EMI shielding, flame retardancy, and grounding, they ensure reliable power delivery and compliance with standards like AS/NZS 1747 and IEC 60245. While higher costs and maintenance needs pose challenges, proper selection, management, and regular inspections mitigate risks like trip hazards and cable failures. By choosing trailing cables tailored to specific applications and environments, users can optimize performance and safety, building on the resilience of cables like LSOH, PUR, or braided discussed previously.