How Can You Reduce the Risk of Accidental Damage to Underground Cables?

Excavation and groundworks around underground cables need to be carefully managed.

For electrical cables in particular, accidental damage is not simply an infrastructure issue. The Health and Safety Executive (HSE) warns that damage to underground electrical cables can result in severe or fatal injury through electric shock, electrical arcs and flames. Reducing the risk therefore starts with planning the work, locating underground services and following safe excavation practices.

For infrastructure owners, fibre optic monitoring can provide an additional layer of awareness where excavation or mechanical activity is occurring around an important underground cable route. It should not be treated as a substitute for established safe working practices.

According to the HSE, underground electrical cables can be damaged when they are cut by sharp objects, such as tools, or crushed by heavy objects or powerful machinery.

The consequences can be serious. As well as damaging the infrastructure, contact with underground electrical cables can expose people carrying out the work to electric shock, arcing and severe burns.

The priority when excavation or ground disturbance is planned is therefore to identify underground services and carry out the work safely.

What Does the HSE Recommend When Working Near Underground Cables?

The HSE's HSG47 guidance, Avoiding Danger from Underground Services, describes three basic elements of a safe system of work:

• Planning the work
• Locating and identifying buried services
• Safe excavation
• Planning the Work

The presence of underground services should be considered before excavation begins. Information about buried services should be obtained and the risks assessed when planning the work.

Locating and Identifying Underground Cables

Plans provide useful information about buried services, but they should not be relied upon to establish their exact position. The HSE advises that underground services should be located and identified using suitable locating equipment alongside available plans and other information. Their position should then be clearly marked before excavation begins.

Safe Excavation

Once underground services have been identified, work should follow recognised safe excavation practices. The HSE advises that locating equipment should continue to be used during the work and that appropriate excavation methods should be used around identified services.

Together, planning, locating services and safe excavation remain the foundation of reducing the risk of accidental cable strikes.

Safe excavation procedures are concerned with carrying out work safely around underground services. Infrastructure owners can face an additional challenge: maintaining awareness of physical activity occurring around an important cable route.

Underground infrastructure may extend across areas where excavation, construction or other mechanical activity can take place beyond locations that are continuously observed.

For important cable routes, an infrastructure owner may therefore want greater awareness that potentially damaging physical activity is occurring around the infrastructure.

This is where monitoring can complement, rather than replace, established damage-prevention measures.

Fibre optic monitoring addresses a different part of the problem from cable plans, locating equipment and safe excavation procedures.

Remark Group's solution can detect disturbances associated with excavation and mechanical activity around protected underground cable infrastructure and generate real-time alerts when relevant activity is detected.

This provides an infrastructure owner with awareness of physical activity around the monitored route while it is occurring. It does not tell contractors where it is safe to dig and does not replace:

• Cable plans and service information
• Cable locating equipment
• Risk assessments
• Safe systems of work
• Appropriate excavation practices

Its role is monitoring the protected infrastructure, rather than replacing the controls intended to prevent a cable strike. For an explanation of DAS and the technology behind the monitoring system, read our complete guide to fibre optic monitoring for underground cable protection.

Where an infrastructure owner requires greater awareness of excavation or mechanical activity around an important underground cable route, fibre optic monitoring can provide an additional layer of detection.

Remark Group's Duct Protection Fibre solution uses a dedicated sensing fibre installed alongside the protected cable infrastructure to continuously monitor for physical disturbances, including those associated with excavation and mechanical activity.

Responsible for underground infrastructure exposed to excavation or mechanical activity? Speak to Remark Group about your monitoring requirements.