“Power in Motion: How SANS Type 61A Cables Keep South Africa’s Mines Safe and Productive”

Introduction

When it comes to South African mining operations, particularly in gold, platinum, and coal sectors, electricity isn’t just convenience—it’s survival. Underground loaders, drilling rigs, submersible pumps, and conveyors all depend on reliable power, delivered safely through robust cables designed for harsh environments. Among these, the SANS Type 61A mining cable stands out as a specialised flexible trailing cable engineered to withstand South Africa’s unique mining challenges.

Developed under the SANS 1520-1 standard, the Type 61A cable is more than a bundle of wires—it’s a lifeline. Its design prioritises safety, mechanical durability, and operational flexibility, crucial for underground and surface mining where harsh conditions, explosive atmospheres, and high mechanical stress are daily realities.

South Africa’s mining heritage—stretching from the gold-rich Witwatersrand Basin to the platinum fields of the Bushveld Complex—demands equipment that can operate reliably in extreme conditions. The SANS Type 61A cable reflects decades of engineering experience, localised standards compliance, and real-world insights from mines across the country.

Structure of SANS Type 61A Cable: Engineering Flexibility and Strength

Understanding what makes SANS Type 61A cables uniquely suited for mining begins with their construction. Every component serves a purpose, combining mechanical resilience with electrical integrity.

1. Core Configuration:

   Three tinned copper/nylon braid screened power cores, plus one unscreened pilot core, laid up in a right-hand lay around a rubber filler (RD1).

   This arrangement balances flexibility with mechanical stability, allowing the cable to twist and bend without damaging conductors.

2. Layering Overview:

   Conductor: Flexible tinned copper strands.

   Insulation: Ethylene Propylene Rubber (EPR) providing thermal and electrical stability.

   Braid/Screening: Nylon and tinned copper wire for mechanical protection and electromagnetic shielding.

   Inner Sheath: Polychloroprene Rubber (CR) for mechanical and chemical protection.

   Reinforcement Braid: Open nylon braid (16+ strings) for tensile strength and abrasion resistance.

   Outer Sheath: Thermoplastic Polyurethane (TPU), often transparent with orange reflective tape for visibility.

3. Flexibility Considerations:

   Designed for dynamic applications, the minimum bending radius is 6 times the overall diameter, making it suitable for both reeling (spooling onto drums) and non-reeling operations in mining machinery.

In essence, the Type 61A cable is mechanically engineered for movement, yet robust enough to survive harsh mining environments.

Materials Used: Tailored for Harsh South African Conditions

Material selection in the SANS Type 61A cable is critical to balancing flexibility, durability, and safety. Let’s examine each major component:

1. Conductors:

   Class 5 flexible stranded tinned annealed copper.

   Offers excellent corrosion resistance in humid underground environments.

   High conductivity ensures minimal power loss over long cable runs, critical in large underground mines like South Africa’s platinum operations.

2. Insulation:

   EPR thermosetting compound.

   Provides thermal stability, maintaining integrity from -25°C to +90°C.

   Resistant to water, ozone, and various chemicals commonly found in mining environments.

3. Braid and Screening:

   Nylon and tinned copper wires serve mechanical reinforcement and EMI reduction, preventing interference with sensitive control systems in mining equipment.

4. Sheaths:

   Inner Sheath: Polychloroprene Rubber (CR), protecting against abrasion and chemical exposure.

   Outer Sheath: TPU, sometimes transparent with reflective orange tape, allowing visual inspection of internal cores—a practical feature for South African safety audits.

5. Additional Reinforcement:

   Open nylon braid, minimum 16 strings, gives tensile strength to withstand pulling forces during installation or reeling.

6. Environmental Resilience:

   Materials resist UV, ozone, sunlight, oil, and mechanical wear—essential for South Africa’s dusty and chemically harsh mines.

The combination of these materials results in a cable that is both flexible and highly durable, capable of operating in some of the toughest mining conditions on Earth.

Technical Specifications: Numbers That Matter

The technical profile of SANS Type 61A cables reflects careful engineering aligned with local and international standards:

• Standards Compliance:

  SANS 1520-1 (South African mining cable standard)

  SANS 1411-1 and 1411-3 (conductor and insulation requirements)

  ICEA S-75-381 Tab. 3-3 (international compatibility for low-voltage flexible cables)

• Physical Dimensions Example (95 mm² conductor):

  Maximum wire diameter: 0.51 mm

  Conductor diameter: 13.5 mm

  Overall cable diameter: 59.1 mm

  Weight: 6340 kg/km

  Maximum tension: 4.3 kN

• Mechanical Properties:

  Tensile strength: ≥10-15 N/mm²

  Elongation: ≥200-300%

  Tear resistance: ≥30 N/mm

  Abrasion loss: ≤150 mm³

• Environmental Resistance:

  Ozone: No cracking at 50 pphm, 40°C

  Oil: Volume change ≤40%

  Water absorption: ≤5%

  UV stability: 720 hours xenon arc

These specifications ensure the cable survives reeling operations, underground abrasion, chemical exposure, and temperature extremes typical in South African mines.

Electrical Parameters: Power Delivered Safely

The SANS Type 61A is not just mechanically resilient; it is also electrically robust, meeting strict safety criteria for low-voltage mining applications:

• Voltage Rating: Uo/U 640/1100V, suitable for portable mining equipment.

• Conductor Resistance: Varies with size; 0.0817–0.859 Ω/km at 20°C (per SANS 1411-1).

• Insulation Resistance: ≥1000 MΩ·km after water immersion (SANS 5526).

• Voltage Withstand Test: 2.5 kV AC for 5 minutes (IEC 60502).

• Short Circuit Rating: Up to 29.3 kA for 1 second.

• Thermal Limits: Continuous conductor temperature 90°C, short circuit 250°C for 5 seconds.

• Fire Safety:

  Flame propagation ≤2.5 m (IEC 60332-3)

  Smoke density ≥60% transmittance (IEC 61034)

  Halogen content ≤0.5% HCl

These parameters make Type 61A cables safe to use in hazardous areas, minimizing risk in explosive atmospheres while ensuring uninterrupted power delivery.

Applications in Mining: Flexibility Meets Functionality

The SANS Type 61A is used extensively in portable electrical equipment and machinery:

• Reeling and Non-Reeling Applications:

  Submersible pumps: Handling water ingress in underground operations.

  Loaders and dumpers: Connecting mobile equipment in confined tunnels.

  Drilling rigs: Flexible connections in dynamic drilling operations.

  Conveyors: Long runs with minimal downtime.

• South African Mine Suitability:

  Ideal for gold, platinum, and coal mines, where underground and surface mobility is critical.

  Enhanced flexibility reduces mechanical fatigue, minimizing maintenance.

• Advantages Over Standard Cables:

  Superior flexibility for dynamic equipment.

  Abrasion-resistant outer layers reduce replacements.

  Screened cores mitigate risk in explosive atmospheres.

In practice, a Type 61A cable is the backbone of portable power in South African mining, ensuring equipment remains operational under heavy stress.

South African Mining Operations

Platinum Mine, Rustenburg

A large Rustenburg platinum mine implemented Type 61A cables to power submersible pumps in deep underground shafts. Prior to their installation, standard flexible cables often failed due to abrasion and chemical exposure. Type 61A cables operated continuously for over 12 months without replacement, demonstrating superior durability.

Gold Mine, Witwatersrand Basin

During re-equipping of mobile underground loaders, Type 61A cables provided reliable power to drilling and loading machines in confined spaces. Transparent sheaths allowed technicians to identify insulation wear visually, reducing maintenance time by 25%.

Coal Mine, Mpumalanga

Surface haulage systems required cables that could handle reeling over long distances in dusty, high-temperature environments. Type 61A’s TPU outer sheath and nylon reinforcement endured mechanical stress and UV exposure, providing safe, long-lasting connections for mobile equipment.

These cases underscore the practical benefits of Type 61A cables in real South African mining operations: safety, reliability, and longevity.

Frequently Asked Questions (FAQ)

Q1: What makes SANS Type 61A suitable for hazardous areas?
A: Its screened cores and resistant materials prevent sparks and ignition, ensuring safety in explosive atmospheres.

Q2: How does the transparent sheath benefit users?
A: Allows visual inspection of internal damage without disassembly—a key requirement in South African mining safety protocols.

Q3: What are common failure modes?
A: Abrasion from reeling, chemical degradation, and excessive bending beyond minimum radius. Preventable with proper handling and adherence to mechanical specifications.

Q4: Is it compatible with international equipment?
A: Yes. Compliance with ICEA standards ensures global compatibility, while optimizations meet South African mining regulations.

Q5: Maintenance tips?
A: Store above -25°C, inspect for cuts or abrasion, maintain insulation resistance testing, and avoid exceeding mechanical bending limits.

Conclusion

The SANS Type 61A mining cable is more than a technical specification—it is a strategic asset in South African mines. By combining mechanical durability, electrical reliability, and flexible design, it ensures that mobile and stationary equipment operates safely in harsh, hazardous environments.

From the gold tunnels of the Witwatersrand Basin to the platinum shafts of Rustenburg, Type 61A cables are quietly powering operations that drive South Africa’s economy. They are a testament to engineering excellence, standards-driven design, and practical experience, reflecting decades of localised innovation.

In an industry where downtime can cost millions and safety is non-negotiable, SANS Type 61A cables are the unsung heroes, keeping the power flowing and the mines running efficiently.

Contact Anhui Feichun Special Cable Co., Ltd.

For comprehensive technical specifications and quotations, please contact our specialized mining cable engineering team:

Technical Engineering Support:

tech@feichuncables.com

Sales Engineering Department:

Li.wang@feichuncables.com

WhatsApp Contact:

Manufacturer: Anhui Feichun Special Cable Co., Ltd. (安徽飞纯特种电缆有限公司)

Manufacturing Headquarters: Building A, Private Science and Technology Park, Hefei Economic and Technological Development Zone, Anhui Province, People’s Republic of China

+86 17333223430