UK offshore 'underplays UXO risk'
Bombs missed in build surveys an issue in O&M phase, warns 6 Alpha
Developers, utilities and asset owners are failing to take account of the risks posed by munitions moving from their recorded positions during the operation and maintenance phase of offshore wind projects, warns 6 Alpha Associates.
The consultancy said that prior to installation work, where there is a high risk of encountering unexploded ordnance (UXO), it is common to carry out a specialist geophysical survey to detect it.
However, the seabed is often littered with debris that can be mistaken for UXO and the cost of investigating each and every anomaly is prohibitively expensive. Any anomalies that turn out to be UXO and slip through the net may shift on the seabed due to wave and tidal processes and in some cases human activities, such as fishing.
This means they can “move to within dangerous proximity of offshore wind turbine or platform foundations and cables”, 6 Alpha said.
“Unfortunately, while the UXO risk threat is commonly well managed and monitored throughout the development phase, it is our experience that some project construction teams are failing to hand over and share key UXO information to inbound operations and maintenance teams,” said 6 Alpha managing director Simon Cooke.
“Despite an excellent approach to continuous learning, health and safety and cost reduction in the construction phase, as projects become operational and the personnel teams change there is a risk of failure to pass on some of the most important risk management data.”
“Project managers should ensure that UXO risks are not only registered and mitigated throughout the O&M phases of work but also that their assets remain clear of UXO in order to reduce the risks to personnel on site and to avoid expensive delays and down-time.”
6 Alpha Associates has carried out survey work and risk management consultancy on UXO for TenneT at the BorWin, Sandbank and Jade offshore wind zones.
It also took point for RWE when UXO were discovered at the site of the developer’s Gwynt Y Mor offshore wind farm off Wales.
Image: bombs recovered from the Riffgat cable route (TenneT)