By Chris Huxley Reynard, creator of the BareFLEET advanced remote monitoring and reporting system, and Managing Director of Reygar Ltd.

Providing operations and maintenance (O&M) services for an offshore wind farm can be a grueling task. Consider the complexity of installing or fixing a machine as large and complex as a wind turbine — a task difficult within itself. Paired with an ocean-bound commute through a variety of weather and sea conditions, and the health and safety considerations only rise in severity and occurrence.

Whether it’s the transfer of crew from vessel to turbine, impact events where the vessel collides with a turbine or large wave, short-term motion sickness, long-term vibration-induced illnesses or stresses caused by a challenging journey from shore to turbine, O&M activity comes with serious health and safety implications that constantly need to be managed and eliminated where possible.

For the workboat sector, an immediate blockade to managing and improving these risks is the isolated nature of working at sea.

Asset owners and operators have typically had little oversight over the vessels that transport their technicians to site. It’s not like sharing an office.

To combat this, wind farm operators make the operational improvements necessary to have control and oversight over an offshore project, while maximizing the effectiveness of their crew and technicians. In the absence of this approach, there’s a risk of an “out of sight, out of mind” mentality manifesting, but asset owners realize that this would be detrimental to the success of their project.

As such, owners ensure that their workboats are equipped with data monitoring tools to provide an “eye in the sky” through data. This data is collected and used to make informed decisions about how to protect crew by changing operations to minimize the risks that have been identified in both real-time and longer-term.

Crew transfer

Photo credit: Orsted

One of the most frequent health and safety risks for workboat crew is the transfer itself. This is when the boat parks up against the turbine, known as “pushing on,” and the crew moves off the boat and onto the turbine.

For this process to go as smoothly as possible, the boat must be stable, with low risk of bow slippage, which causes technicians to become unsteady on their feet. If the tides and wind are too strong, the boat will move up and down excessively, making the crew transfer unsafe to complete.

This poses two immediate issues for asset operators. Firstly, engaging in the crew transfer under poor conditions immediately risks the safety of workboat crew and technicians; and secondly, failure to transfer technicians onto the turbine quickly, if at all, reduces the time-window possible to perform maintenance work. This could lead to the cost of maintenance increasing as failure to reach the site may result in the repair of a broken turbine taking an extra day, making the owner lose out on even more revenue from lost energy production as the turbine remains offline.

Impact events

Similarly, impact events are a health and safety risk to workboat crew, especially if weather conditions or vessel design aren’t accommodating. While approaching a turbine, if the vessel is unstable it could collide with the turbine’s foundations, causing anything between minor vessel damage to complete vessel write-off and injury to staff.

Similarly, in intense weather conditions like storms and hurricanes extremely strong waves can present an impact risk to workboat crews and technicians.

Photo credit: Orsted

These health and safety risks can, however, be reduced if the right data is collected. By consistently measuring the stability of the boat while parking against a turbine, operators can increase their understanding of when bow slippage is most likely to occur.

With this data, vessel operators can make informed decisions about which conditions (and vessels) pose the lowest risk of bow slippage, increasing the probability of the safe transfer of crew. For example, the tidal and weather conditions at a particular site are both measurable factors that can influence the likelihood of bow slippage.

A similar principle can be applied to impact events. By collecting data on which weather and sea conditions are most likely to trigger heavy impact events, operators can aim to get workboat crew to site within weather windows that are more likely to provide safe and stable conditions.

In extreme cases, the collection of this data is essential for ascertaining what went wrong at sea so that it doesn’t occur again — like a blackbox does for an airplane.

Motion sickness

Seasickness is the most frequent health and safety consideration for asset-operators. When spending hours, if not days, travelling via boat to an offshore wind project, it is likely that staff will experience seasickness at some stage of the journey. If, upon arrival to the turbine a technician is not fit to work because the commute has made them unwell, they will not be able to complete maintenance work to an optimal standard or, in some cases, be able to get off the boat at all.

Both of those scenarios can lead to negative implications for asset owners. For example, if the job isn’t completed properly due to sickness, the health of the turbine is at risk as there’s a possibility that the technician will be unable to perform their task to their usual standard. Moreover, if staff refuse to get off the boat due to sickness, another time and date to carry out maintenance work will need to be found, increasing fuel consumption and extending the time the turbine remains offline.

If wind farm operators utilize the advanced vessel motion monitoring systems available, however, they can reduce these risks significantly. By using motion sensors to create a motion sickness index, operators can understand the conditions in which workboat staff are forced to return to shore or when technicians choose to not get off the vessel. This data also enables the crew to adjust their operations to reduce pitch and roll as much as possible, so that motion can be reduced to prevent seasickness.

By using these data-based insights, naval architects can also gather more understanding of which areas of the boat experience the strongest vibrations and apply dampening materials to reduce the strain on the vessel staff.

Moreover, collecting this data at certain sites allows operators to make informed decisions about which vessels to add to their fleet. Understanding the strength of sea conditions and its impact on boats, operators can order vessels that are less reactive to specific conditions and provide more stability for staff on the boat. Alternatively, they can retrofit the existing fleet with hydrofoils that are designed to suppress motion.

Changing nature of offshore wind

As offshore wind projects are developed further from shore, a new health and safety challenge is being presented to vessel operators and O&M teams: Instead of setting sail in the morning and returning in a few hours, some offshore projects require days at sea. Staff are often required to sleep on the vessel overnight and complete their duties the following day at the site. This increased length of travel time exacerbates the other health and safety and comfort challenges outlined earlier, as the presence of those risks are prolonged.

Now, it is imperative that asset owners ensure that they are collecting the right data on motion sickness, vibration and comfort, to prevent short-term efficiency reductions or long-term health consequences in their staff.

Conclusion

The adoption of advanced monitoring allows forward-thinking vessel operators and offshore project owners to optimize the health and safety of their staff. Collecting comprehensive vessel health and performance data as well as cross-referencing with sea conditions, is vital to ensuring crews are empowered to operate the workboat in a way that keeps technicians and other passengers healthy, happy and ready to work efficiently.

However, collecting the data isn’t the end-all. The data won’t make relevant changes for you, but it will direct decision-makers toward the right choices for each vessel, project and job. The measurement of weather, motion, bow slippage, sickness, impact events and comfort can all be used to ensure the highest degree of health and safety measures are implemented to optimize the wellbeing and efficiency of staff and therefore the projects themselves.

In the long-term, this data has implications for naval architecture. As we move further out to sea to produce energy, vessel design needs to shift accordingly to prioritize the health and safety of onboard staff. Collecting and learning from operational data allows this to happen.


Chris Huxley-Reynard is the Managing Director of Reygar Ltd. and creator of the BareFLEET remote vessel monitoring system. Chris has close to two decades of experience in the commercial marine and marine renewables industries. As a former founding director of Rolls Royce subsidiary Tidal Generation Ltd., he understands how to bring cutting edge R&D through to commercialization. An aeronautical engineer by training, his broad experience in hydrodynamics, subsea electro-mechanical and software engineering, combined with his hands-on practical offshore experience, means he brings a multi-disciplinary approach to solving engineering problems. Chris also lectures at Bristol University, England.


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