Scaffold overturns and lands on energised powerlines

Background

In a recent incident at a residential construction site, a prefabricated modular scaffold overturned and came to rest on energised overhead powerlines.

Safety issues

Scaffolds can:

• be large and erected to great heights
• weigh several tonnes
• support heavy materials and debris
• be fitted with containment sheeting which can act as a wind sail.

Scaffolds require careful planning and design to ensure they have been erected with a safe number of scaffold ties to prevent the scaffold from overturning. If scaffold ties are removed by unauthorised persons, the scaffold can be at an increased risk of overturning.

An overturning scaffold may lead to serious or fatal injuries due to:

• persons falling from the scaffold
• the scaffold striking persons below
• the scaffold making contact with powerlines, which can cause electric shock or electrocution.

Recommended ways to control the risk

To reduce the risk of a scaffold overturning due to unauthorised alterations or interference, employers and scaffold installers should:

• At the planning stage, consider what trades will need access to areas where ties will be connected
• Use anti-tamper devices on scaffold ties
• Follow manufacturer, designer or supplier’s instructions for tie methods and spacing. If information is missing or it is not practical to position the ties as shown in the instructions or design, consult a suitably competent engineer to instruct when and where to use scaffold ties
• When incorporating containment sheeting into the scaffold design, a suitably competent engineer needs to approve the scaffold design (including ties). This is to ensure the scaffold and its ties can withstand the introduced loads.
• Develop and maintain an inspection regime of the scaffold
• Provide information, instruction, and training about the risks associated with altering or interfering with a scaffold.

Legal duties

Employers and self-employed people have duties under the Occupational Health and Safety Act 2004 and the Occupational Health and Safety Regulations 2017. Employers and self-employed people must:

• provide or maintain plant or systems of work that are safe and without risks to health, so far as is reasonably practicable
• inspect plant to the extent necessary to ensure that any risk associated with its use is monitored
• take steps to prevent alterations to the plant that have not been permitted by the employer or self-employed person
• take steps to prevent interference with the plant
• ensure that a scaffold is secure and capable of supporting the work being done from it.

A person who installs, erects or commissions plant (for example, a scaffold) at a workplace must ensure, so far as is reasonably practicable, that nothing about the way this is done makes it unsafe to use or a risk to health.