Overhead Powerline Projects (The Must-Knows)

Powerlines are an essential part of the way the modern world operates today. With an increase in amount of housing and infrastructure construction throughout the UK, there is no doubt more powerlines are to follow. So, what does this mean for you? Chances are that if you are conducting any construction project involving building, demolition, etc… it’s highly likely they will be in proximity of overhead powerline. In this resource, we want to help prepare you for any type of overhead powerline projects that you might take up in the future.

Throughout this resource, we will cover several areas to avoid putting yourself or your staff at risk of death, injury, or financial penalties for negligence.

Overhead powerline projects: Who do they affect?

Overhead powerline projects can affect a wide range of different trades, it does not specifically have to be in the construction industry. Here is a list of trades that overhead powerlines could affect during their projects.

• Construction/ building
• Agricultural farming
• Roadworks
• Civil engineering
• Forestry
• Arboriculture
• Estate management
• Demolition
• Utilities

Almost every single type of construction trade are will come across overhead powerlines. Regardless of which trade you are in; you should adopt the procedures found in this resource. First things first, you should already be identifying and documenting any overhead powerlines in your risk assessment.

Identifying different types of overhead powerlines

Most overhead powerlines are supported on wooden poles, pylons, or metal towers and are often called transmission or distribution lines. Here are some examples of identifying the type of powerline on your project.

275-400 KVA Pylon

33-11KVA Powerline

400V Distribution line

By using the diagrams that we have provided, you should be able to identify any of the standard overhead lines that you can expect to see throughout the UK. One area of confusion is when trying to correctly identify the type of cable being used on the line.

It is common to come across a light plastic coating or covering around the cabling. Remember that when dealing with high voltage cabling over 1Kva, you must treat them the same as any other HV (high voltage), regardless of if it is insulted or not. Low voltage powerlines are often insulated so that they can be connect to buildings and infrastructure. It is common for the lines to become damaged and exposed wiring to become visible. If you are ever unsure, always seek professional help during your planning and risk assessment stage.

What you need to know when working near powerlines

Contact with any type of powerline can result in a fatal accident occurring. Working too close can also cause a flashover where electricity can jump, again causing serious injury or even death. The most common trade in the UK that come into contact more often with overhead lines are arborists and tree surgeons.  

To avoid any type of accident from happening, you should have a good management plan and consult all parties involved. No matter the period of work, you should produce the same level of detailed documentation in your risk assessment. You should manage the risks, accordingly, and provide the correct and adequate equipment to complete the project with minimum disruption. Proposed work within 10m of an overhead powerline, a risk-based approach should be adopted.

Furthermore, some work can be proposed outside a 10m reach of overhead powerlines. However, may breach that boundary as debris or fallen trees may enter that area. It is essential that when working closely to these types of lines that you contact the supplier. This is to redirect the power or in some cases temporarily remove the line. This will, in turn, allow you to use more suitable equipment to complete the project faster and cause minimal disruption.

Operating plant equipment near live overhead powerlines

It is essential to know that operating plant equipment near live powerlines is extremely dangerous. According to HSE, the exclusion zones for plant equipment depend on the live voltage of the line you are working in proximity to.

• Low-voltage line – 1 m
• 11 kV and 33 kV lines – 3 m
• 132 kV line – 6 m
• 275 kV and 400 kV lines – 7 m

At no point during operation should any plant equipment breach these guidelines. In addtion, you must compensate for wind if working on a gusty day. Transporting equipment or materials, near live powerlines, should be done horizontally and as low to the ground as possible. Work should ideally be taken place during daylight hours and not in poor visibility conditions.

It is therefore extremely important to choose the correct equipment that is suitable for the project. Especially when dealing with live overhead powerlines. Commonly, fatal accidents occur due to the lack of knowledge of operating plant equipment around live powerlines.

Plant equipment should be properly designed, constructed and maintained so it reduces the chance of failing during operation. There are many equipment-specific standards that include safety-related requirements which, if followed, will ensure that the electrical risks are adequately controlled. You must select equipment suitable for the environment in which it is used. For example, cables and equipment in heavy industries such as sheet metal works need to be protected against mechanical damage. You should consider adverse environmental factors when working on equipment.

Examples of powerline providers

If you are conducting work within 10m of the powerlines, you MUST consult the network supplier. Here are some examples of network suppliers across the UK.

The National Grid Group

“Formally Western Power, the UK’s largest electricity distribution network serves nearly 8 million customers in the East and West Midlands, South West and Wales, delivering essential power to millions of homes and businesses across its regions. With a distribution area of 550,000 square kilometres, it’s 6,500 colleagues are committed to providing a safe, stable and reliable electricity supply and ensuring the highest quality of customer service.”

SP Energy Networks

“We operate in three of the UK’s largest cities (Liverpool, Glasgow & Edinburgh) accounting for 1.6m (43%) of our customers, as well as three significant rural areas (North Wales, Scottish Borders and Dumfries & Galloway). SP Energy are a substantial employer with a distribution workforce of 2,600 internal employees made up of field staff, engineers, technical specialists, customer service and support staff based at 17 locations in the South of Scotland and 17 locations in England and Wales.“

UK Power Networks

“We own and maintain electricity cables and lines across London, the South East and East of England and make sure power flows reliably, safely, and securely. Our priorities are to tackle the climate crisis by connecting renewable energy, electric car chargers and low-carbonating, meet our customers evolving needs by improving our services, support our customers in vulnerable circumstances and go above and beyond for the communities we serve. Your electricity supplier is the company you choose to buy your electricity from, and who you pay your bills to. If you look on your bill – part of what you pay is given to UK Power Networks for running and maintaining the power cables in your area.”

It is essential that you receive an electrical permit to work from the supplier, which is written confirmation of the power shut down or isolation prior to work commencing. Without receiving a copy of this document, you could be in breach of health and safety legislation.

Emergency procedures

If someone or something comes into contact with an overhead line, it is important that everyone involved knows what action to take. This will reduce the risk of anyone sustaining an electric shock or burn injuries.

Key points are:

• Never touch the overhead line’s wires.
• Assume that the wires are live, even if they are not arcing or sparking, or if they otherwise appear to be dead.
• Remember that, even if lines are dead, they may be switched back on either automatically after a few seconds or remotely after a few minutes or even hours if the line’s owner is not aware that their line has been damaged.
• If you can, call the emergency services. Give them your location, tell them what has happened and that electrical wires are involved, and ask them to contact the line’s owner.
• If you are in contact with, or close to, a damaged wire, move away as quickly as possible and stay away until the line’s owner advises that the situation has been made safe.
• If you are in a vehicle that has touched a wire, either stay in the vehicle or, if you need to get out, jump out of it as far as you can. Do not touch the vehicle while standing on the ground. Do not return to the vehicle until it has been confirmed that it is safe to do so.
• Be aware that if a live wire is touching the ground the area around it may be live. Keep a safe distance away from the wire or anything else it may be touching and keep others away.

Remember, all accidents should be documented for health and safety investigation. Failure to produce all correct information such as risk assessments, could lead to severe financial penalties. This includes, permits to work, using suitable equipment and qualified operators. The latest UK fine for breaches of health and safety is more than £4 million in Jan 2023. For more information on this please visit : https://press.hse.gov.uk/2023/01/13/civil-engineering-firm-fined-4m-following-m6-works/

Where to hire plant equipment to assist with overhead powerline projects

WHC Hire Services has been supplying the safest and highest-performing plant machinery across the UK for over 25 years. Our detailed level of accuracy has awarded us with a gold medal award from the internationally recognised health and safety group RoSPA. You can ensure that every piece of equipment hired from one of our depots has been thoroughly serviced, and inspected before deployment. For more information about the equipment we supply, click here, or call 01684377977 to discuss your hire needs today.