Gå til hovedinnhold

Amendment of decision: withdrawal of order for COSL Drilling

The Petroleum Safety Authority Norway (PSA) made an order for COSL Drilling Europe following the fatal accident on COSLInnovator of 30 December 2015. This order has been withdrawn on the basis of new information in the case.


On 23 May 2016,  COSL received an order following the fatal accident on COSLInnovator of 30 December 2015.

The dialogue with COSL in the wake of the order has contributed to new information in the case. The PSA and the Norwegian Maritime Authority (NMA), as the PSA’s technical assistance authority, have assessed the new information and have decided that grounds are present for withdrawing the decision to make the order.

This new information relates to the application of the regulations, and makes it clear that the regulations have been too vague with regard to the applicable calculation methodology for horizontal wave forces on mobile units.

The PSA has amended its investigation report to reflect the fact that conditions related to the air gap and horizontal wave slamming did not represent breaches of the regulations at the time of the incident.

The NMA’s requirements for maritime operations normally govern mobile units on the Norwegian continental shelf (NCS). These refer in turn to the requirements set by a classification society, such as DNV GL.

In collaboration with the PSA, the NMA and DNV GL are now in the process of clarifying their requirements in order to ensure that new lessons which have been learnt in connection with the accident are taken into account. That includes better guidelines for calculating the air gap and horizontal wave slamming on semi-submersible facilities.

Investigating to learn
The main goal for the PSA’s follow-up of the fatal accident on COSLInnovator has been to establish what happened and why so that the industry and the authorities can learn from the incident and prevent such an accident from recurring.

Its investigation has identified weaknesses in the way calculations of wave forces are utilised when designing mobile units. These could also apply to other facilities on the NCS. COSL and other companies are working to utilise the new lessons learnt.

Inger Anda, Director for communication and public affairs
Email: inger.anda@ptil.no | +47 970 54 064