Offshore wind turbines: managing the safety risks

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As we strive to move from reliance on fossil fuels to renewable energy, one area of crucial importance will be wind power – both onshore and offshore. However, there are some important health and safety factors and risks that must be taken into account and carefully managed by those constructing, operating and maintaining offshore wind turbines and farms.

There are general health and safety legal duties and matters that apply to offshore wind structures and some important health and safety considerations for four principal phases of their design, installation and use. These are: planning, construction, operation and maintenance, and decommissioning.

What the laws says

The Health and Safety at Work etc Act 1974 (HSWA) applies to offshore wind structures just as it applies onshore. There are also two sets of regulations which are particularly important.

Bruce Craig: "As the need for renewable energy gathers pace, offshore wind structures become very important. They are however potentially extremely dangerous places."

Firstly, the Management of Health and Safety at Work Regulations 1999 set out a crucial term and duty in this area of the law – the need to carry out “suitable and sufficient” risk assessments at all stages of work. The aim is to identify risks to the health and safety of workers and others so appropriate measures can be taken to protect people from the risk of injury or ill health.

The Management Regs also require employers to effectively plan, organise, control, monitor and review their health and safety preventive and protective measures on an ongoing basis. Of course, what is “suitable and sufficient” will depend on the circumstances of the work, task or project.

The second important regulations are the Construction (Design and Management) Regulations 2015 (CDM). The CDM Regs set out very important provisions relevant to construction work – including the construction of offshore wind turbines and farms. The duty is to plan and carry out the work safely at all stages.

The CDM Regs define various parties involved in all aspects of construction work – including designers, principal designers, contractors, principal contractors and the client. The regulations also apply to the workers themselves.

As always, the duty is not simply to put health and safety procedures in writing; there is also a duty to ensure the procedures are actually being followed.

The various health and safety provisions don’t just apply onshore. They also apply within the UK’s Territorial Sea, which extends 12 miles from the coast. Health and safety law also extends beyond the 12-mile limit in geographical areas covered by the Application Outside Great Britain Order 2013. For all practical purposes the health and safety legislation for offshore wind structures is the same as for onshore.

The HSWA will apply to the offshore wind turbine structure and the workers aboard it, but the MSA will apply to the ships and their crews. Photograph: iStock

Risks from shipping

However, offshore there is a complicating factor because inevitably there will be an involvement of shipping in various ways in relation to offshore structures, including turbines. The potential health and safety risks from shipping arise during the construction phase and during the operation, maintenance and decommissioning of turbines (for example, when ships are used to construct and maintain turbines). However, the interlink between the law that applies to the safety of the offshore wind structure and the law which applies to the safe operation of ships is not always straightforward.

For instance, it’s important to note that the HSWA and the various regulations don’t apply to shipping – in other words, they do not apply to any activities on board a seagoing vessel. The main legislation which applies to shipping in the UK is the Merchant Shipping Act 1995 (MSA) and related regulations.

The MSA applies to all ships within the Territorial Sea and this is up to the 12-mile limit. The Act also applies to UK-registered ships wherever they are operating and sailing. So, when ships are used in some capacity for work on or near offshore wind structures within 12 miles of the UK coast, the legal framework for the ships is under the MSA. The health and safety regime under the MSA (which is designed to ensure the safety of the vessel and crew, such as when a vessel is used to construct offshore turbines), is similar but not identical to the provisions of the HSWA.

The HSWA will apply to the offshore wind turbine structure and the workers aboard it, but the MSA will apply to the ships and their crews. There’s no doubt this can create confusion, especially where there are combined operations involving both the structure and at least one ship. And where there’s confusion, there’s a potential health and safety risk. 

Wind turbine phases

There are also four specific wind turbine phases and they all present their own challenges to health and safety. These are: planning, construction, operation and maintenance, and decommissioning.

Firstly, in relation to planning there needs to be three main things to help ensure the health and safety of everyone who will work on an offshore wind structure – both on the structure itself and on board a ship that interacts with the structure in some way. These are: detailed procedures for the construction, detailed procedures for the role of the ships and crucially a bridging document between the two. The bridging document is perhaps the single most important document in the whole picture, and needs to include detailed procedures for, at least:

  1. The safe transfer of personnel, materials and equipment between the ships and the structure,
  2. Lifting operations, and
  3. Load sharing (where the weight of a load is shared between the offshore wind structure and the ship).

It is vital that the bridging document establishes complete consistency for how the ships will safely and effectively interlink with the workers on the structure. There’s an obvious need for excellent communication during what is potentially very dangerous work.

The construction phase offshore is clearly potentially extremely dangerous. There are numerous risks, all of which need to be thought through carefully to enable them to be engineered out where possible. If it isn’t possible to eliminate the risks then they need to be adequately controlled.

Typical risks during the construction phase are:

  • The fact there may be a large number of personnel on site – perhaps carrying out simultaneous but mutually incompatible tasks
  • The risks involved with lifting operations – especially between ships and the structure, and the fact some of the loads will inevitably be heavy and awkward
  • A possible need for load sharing between ships or between a ship and the structure – for example, when a component is being installed on a turbine and the weight of it is being temporarily shared between the ship’s crane and the turbine structure.

There will also inevitably be a need to keep a close eye on the forecasts for wind, waves, tide and sea current. There will often be tasks that can only be safely undertaken in certain weather conditions and as a result there may be a need to complete a task within a limited timeframe. This can often create real or perceived pressures and if these are not carefully managed it can increase the risk of people making unsafe decisions. There are also risks to the ships – especially if they are involved in heavy lifting or load sharing. Expert advice will be needed when selecting the ships to ensure they have the necessary features and functions to safely carry out the task.

During the construction phase there are also likely to be subsea operations and these clearly will need very detailed planning and careful execution.

Operating and maintaining turbines

The next phase after construction is the operation and maintenance stage once the wind structure is up and running.

Although there may be fewer risks at this stage because there will be far less, if any, heavy lifting, some risks will remain and they will need to be identified, assessed and managed properly.

For example, during the operational phase there will generally be fewer personnel working on the structure and that creates risks associated with remote or lone working.

The decommissioning phase might be many years down the line when the structure is being dismantled. Under the CDM Regs, decommissioning is classed as construction work. Before the construction of the offshore wind structure begins, the dutyholder is generally required to draw up a Decommissioning Plan setting out how the structure will be safely decommissioned and removed. The plan must also be approved by the relevant regulator for offshore wind installations.

The risks associated with dismantling are widespread and they may include:

  • The integrity of lifting points (features which allow part or all of the wind structure to be lifted by a crane on a ship), may have deteriorated over the life cycle of the structure
  • There may be flooded compartments where the weight of the water is unknown, and that may create stability issues
  • There may be the need for subsea work including the cutting of structures on the seabed by divers or equipment that can be remotely operated.

Decommissioning work can be just as hazardous as construction – perhaps even more so because by that point the structure will be so much older. As a result, there can be risks such as a failure of the structure’s components or stability, as they are removed.

Key points

In conclusion, offshore wind structures are playing, and will continue to need to play, a crucial role as the need for renewable energy gathers pace. They are however potentially extremely dangerous places. In my view, there are five key health and safety takeaways for anyone who oversees work on these structures:

  • Ensure thorough and careful planning before the work starts
  • Keep the various risks continually under review
  • Draw up a detailed bridging document to ensure there are no gaps between the safety plan for the structure and the safety plan for the ships
  • If risks cannot be eliminated, ensure measures are in place to control the risks to as low a level as reasonably practicable
  • Keep the control measures continually under review to ensure they remain effective in controlling the risks.

Bruce Craig leads the Pinsent Masons litigation team in Aberdeen as a litigation and regulatory partner specialising in health and safety, shipping and commercial disputes. Contact him at:
[email protected]


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