BS 6708 Mining Cables: Types, Specification & Supply

BS 6708 is the British Standard for flexible trailing cables used at mines and quarries. Electric shovels, excavators, crushers, drills, pumps and conveyors move constantly, so their power cables are dragged, run over, bent and reeled. BS 6708 cables are built to survive that – with fine-stranded tinned copper, rubber insulation and heavy-duty sheaths – while keeping workers safe through earthing and screening. This page explains the main types, how to specify them and what to ask your supplier for.

Where BS 6708 cables are used

• Surface mines and quarries – mobile crushers, screens, excavators and shovels
• Underground mining – continuous miners, shearers, roadheaders, pumps and ventilation fans
• Tunnelling – TBM back-up systems and mobile plant
• Aggregates and cement plants – portable conveyors and stockpile equipment
• Dredging and heavy construction where cables are moved daily

Typical BS 6708 cable construction

Element	Typical design	Why it matters
Conductors	Electrolytic tinned copper, flexible Class 5 stranding (IEC 60228)	Resists fatigue from repeated bending; tinning protects against corrosion in wet mines
Insulation	EPR (ethylene propylene rubber)	Flexible at low temperature, good electrical and thermal performance
Earth / pilot cores	Earth conductor and, on many types, pilot cores for earth-continuity monitoring	Lets protection systems trip the supply if the earth path is damaged
Screening	Collective or individual screens on screened types	A sheath penetration causes an earth fault before a live core can be exposed
Outer sheath	Heavy-duty chloroprene (PCP) or similar elastomer	Abrasion, tear, oil and flame resistance for dragging over rock

BS 6708 cable types we supply

BS 6708 defines a family of numbered types, each for a different duty – from low-voltage trailing cables to screened and higher-voltage designs. Available from stock or to order:

Type	Typical use	Details
Type 7M	Supply to excavating and crushing machines – 640/1100 V	View Type 7M
Type 7S	Screened trailing cable variant for mobile equipment	View Type 7S
Type 11	Excavating and crushing equipment – 640/1100 V	View Type 11
Type 14	Flexible supply to mobile mining machinery	View Type 14
Type 16	Heavy-duty trailing applications	View Type 16
Type FS4	Specialist mining duty	View Type FS4

Voltage rating, number of cores, screening and pilot arrangement differ by type – always confirm against the datasheet for the exact cross-section you order. See the full mining cables range.

How to specify a BS 6708 cable – checklist

1. Type number required by your mine’s electrical standard or the machine manufacturer.
2. Voltage of the supply (for example 640/1100 V for low-voltage equipment).
3. Number of power cores and cross-section – sized for load current, run length and voltage drop. Trailing cables run warm when left coiled on a drum, so apply derating if the cable is not fully unwound.
4. Earth, pilot and screen arrangement to suit your protection and earth-continuity monitoring relays.
5. Length per drum and whether the cable is supplied fitted with couplers or plugs.
6. Environment – ambient temperature, water, oil, UV exposure and any flame-retardance requirement for underground use.
7. Documents – datasheet, test certificate and declaration of conformity with the delivery.

Installation and handling tips

• Respect the minimum bending radius stated on the datasheet – tight bends at the machine entry are the most common failure point.
• Use cable reels, hangers or protective bridges where vehicles cross the cable.
• Do not drag cable over sharp edges; inspect the sheath at every shift change.
• Repair sheath damage with approved vulcanising or cold-repair kits, and retest insulation resistance after any repair.
• Fully unwind drums before running at full load to avoid overheating.

Frequently asked questions

What is a BS 6708 cable?

BS 6708 is the British Standard for flexible trailing cables used in mines and quarries. The cables supply mobile machinery such as excavators, crushers and drills, and are built with flexible tinned copper conductors, rubber insulation and heavy-duty sheaths.

What voltage are BS 6708 cables rated for?

It depends on the type. Many common types, such as Type 7M and Type 11, are rated 640/1100 V for low-voltage equipment; other types cover higher voltages. Check the datasheet of the type and size you need.

What is the difference between BS 6708 types?

Each numbered type has a defined construction for a particular duty: number of cores, screening, pilot cores and voltage. Your mine’s electrical standard or the equipment manufacturer normally states which type is required.

Why are mining trailing cables screened?

Screens around the cores mean that if the sheath is cut or crushed, the damage first creates an earth fault through the screen. The protection system then trips the supply before anyone can touch a live conductor.

Can you supply BS 6708 cable outside the UK?

Yes. Wesourcia supplies BS 6708 mining cables to mines, quarries and contractors across Europe and internationally, with datasheets and test certificates.