Why South African Mines Rely on BS 6708 TYPE 44 Cable for Hand-Held Drilling: The Ultimate Guide

Introduction

South Africa is home to some of the world’s deepest and most mechanized mines, from gold shafts in the Witwatersrand to platinum operations in the Bushveld Complex. Underground mining is inherently challenging: space is confined, the environment is humid and dusty, and workers rely heavily on equipment to ensure productivity and safety. Among the critical components powering this machinery are mining cables.

One cable that has stood the test of time for hand-held drilling machines is the BS 6708 TYPE 44. Its design prioritizes flexibility, durability, and safety, making it indispensable in high-stress mining environments.

This article explores the BS 6708 standard, the construction and technical specifications of TYPE 44 cables, their applications in South African mines, and practical guidance for handling and maintenance. We’ll also examine a real-life case study from a gold mine, highlighting the cable’s operational benefits.

Overview of BS 6708 Standard

The BS 6708 standard defines requirements for flexible trailing cables for mines and similar industrial applications. It establishes specifications for:

• Conductor material and stranding

• Insulation and sheathing materials

• Mechanical and electrical performance

• Safety parameters for underground use

Within this standard, Type 44 is specifically engineered to power hand-held drilling machines, which are frequently moved in confined spaces and exposed to harsh mechanical conditions.

Type 44 vs. Other BS 6708 Cable Types

• Type 41: Primarily for trailing and portable equipment with slightly less mechanical protection.

• Type 44: Superior mechanical robustness, designed for high-abrasion and heavy-use environments.

• Type 61 & Type 63: Higher voltage and multi-core applications, generally used for machinery rather than hand-held tools.

South African Relevance

BS 6708 TYPE 44 cables align closely with SANS 1520 and meet NRCS regulations, ensuring they can be legally and safely deployed in South African underground mines. Compatibility with local standards is crucial, as many South African operators have equipment tailored for these cables.

Applications of BS 6708 TYPE 44

Primary Use: Hand-Held Drilling Machines

Hand-held drills are indispensable for:

• Face drilling in tunnels and stopes

• Production drilling in gold and platinum mines

• Maintenance and repair operations underground

BS 6708 TYPE 44 cables deliver reliable power at 125/72 V, sufficient to drive these drills continuously under demanding conditions.

Other Potential Applications

• Tunneling: Where flexibility and mechanical robustness reduce downtime.

• Construction in confined spaces: Drilling or small excavation machinery.

• Portable equipment requiring safe, reliable trailing power: Pumping units, ventilation fans, or lighting rigs.

South African Case Study

At a gold mine in the Witwatersrand Basin, the introduction of BS 6708 TYPE 44 cables for hand-held drills improved operational uptime by 18%. Previously, frequent cable failures caused unscheduled downtime, equipment damage, and safety risks. After switching to TYPE 44, operators reported:

• Reduced cable replacements

• Lower risk of electrical faults

• Easier handling and storage in the constrained underground environment

Cable Structure and Materials

Understanding the design of BS 6708 TYPE 44 cables reveals why they excel in underground conditions.

Conductor

• Material: Electrolytic, stranded, tinned copper wire (IEC 60228 Class 5)

• Benefits:

  Flexibility: Essential for hand-held drills with frequent movement

  Corrosion resistance: Tinning prevents oxidation in humid mine air

  High conductivity: Ensures minimal voltage drop even at 46 A continuous current

Insulation

• Material: EPR (Ethylene Propylene Rubber)

• Properties:

  Excellent heat and abrasion resistance

  Maintains flexibility in cold or confined conditions

  Resistant to oils, chemicals, and minor mechanical abrasions

Separator

• Colored textile tape used for core identification, aiding maintenance and fault detection.

Screen

• Tinned copper/nylon braided over phase cores

• Pilot and earth conductors are unscreened

• Provides electromagnetic shielding, reducing interference and enhancing safety

Layup

• All cores laid in contact for uniform electrical performance and minimized inductive losses

Bedding and Sheath

• Rubber-based bedding compound cushions cores

• Heavy-duty chloroprene outer sheath protects against:

  Abrasion from rough underground surfaces

  Mechanical stress during pulling

  Chemical exposure

Technical Specifications

These specifications ensure the cable can withstand frequent movement, bending, and pulling while maintaining electrical integrity.

Electrical Properties

• Rated voltage: 125/72 V

• Test voltage: 1.5 kV

• Continuous current rating (25°C): 46 A

• Short-circuit current (1 s): 908 A

• DC resistance:

  Phase & earth: 11 Ω/km

  Pilot conductor: 11 Ω/km

  Screens in parallel: 3.48 Ω/km

These properties make TYPE 44 cables reliable for continuous underground operations, minimizing electrical hazards and downtime.

Advantages of BS 6708 TYPE 44

1. Flexibility: Easy to maneuver with hand-held tools

2. Mechanical Resistance: Withstands abrasion, cuts, and impact

3. Chemical Resistance: Suitable for oils, greases, and cleaning agents

4. Longevity: High durability reduces replacement frequency

5. Safety: Proper insulation, screening, and conductor sizing prevent electrical faults

6. South African Mining Benefits:

   Compliance with SANS 1520 and NRCS standards

   Compatibility with local hand-held drilling machines

   Demonstrated uptime improvement in operational case studies

Maintenance and Handling Guidelines

Proper handling prolongs cable life and ensures safety:

• Storage: Avoid sharp bends, kinks, and stacking under heavy objects

• Inspection: Look for cuts, abrasions, or insulation damage before use

• Installation: Respect minimum bending radius (241 mm) and maximum pulling tension (218 kgf)

• Avoid Short Circuits: Ensure correct core connections and check pilot conductor integrity

• Cleaning: Use damp cloths; avoid harsh chemicals that degrade the sheath

Frequently Asked Questions

Q1: Can BS 6708 TYPE 44 be used in wet or humid underground environments?
A: Yes. EPR insulation and tinned copper conductors resist moisture and corrosion, making it suitable for humid mines.

Q2: What is the expected lifespan in South African mines?
A: With proper handling, the cable can last 5–7 years under continuous use, significantly longer than generic trailing cables.

Q3: Can this cable handle overload conditions?
A: It is rated for 46 A continuous and 908 A short-circuit (1 s), providing a safety buffer. Overloading should still be avoided.

Q4: How does it compare to SANS 1520 Type 41?
A: Type 44 offers superior mechanical and chemical resistance, ideal for heavy-use hand-held equipment, whereas Type 41 is more suited for less demanding portable applications.

Q5: Can damaged sections be safely spliced?
A: Splicing is possible but should follow BS 6708 and local electrical codes. Preferably, replace severely damaged sections to maintain safety.

Conclusion

BS 6708 TYPE 44 remains the preferred cable for hand-held drilling machines in South African underground mines due to its:

• Flexibility

• Mechanical and chemical resistance

• Electrical reliability

• Compliance with local standards

Mines that adopt proper handling, storage, and maintenance practices can maximize uptime, reduce maintenance costs, and ensure safety. The South African case study demonstrates that investment in high-quality mining cables is not just a regulatory requirement—it is a strategic operational advantage.

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