HSE: Rise in collisions of attendant ships with offshore structures

The Health and Safety Executive has identified a rise in the number of incidents of attendant ships colliding with offshore oil and gas and renewable energy structures. Failure of navigational watch processes and systems, is resulting in collisions or risk of collisions.

Incidents are occurring because:

1. personnel who are responsible for watchkeeping and the safe navigation of a vessel are being distracted with non-navigational tasks
2. situational awareness is not being maintained at all times
3. there is insufficient communication between all members of a bridge team

Duty holders and vessel operators should have in place processes and systems, as part of a wider safe system of work, to ensure that, during connected activities, vessels are operated in a way that ensures, so far as is reasonably practicable, the safety of people on nearby installations.

Outline of the problem

The following cases all involve a vessel engaged in an operation in connection with an offshore installation, or an activity connected with an offshore windfarm, within the last five years.

Loss of situational awareness

Case 1. A platform supply vessel (PSV) was requested to enter the 500m zone of a fixed installation. The Chief Officer and a watchkeeping officer were on the bridge. Pre-entry checklists were completed, and the Chief Officer began manoeuvring the vessel towards the 500m zone. The Chief Officer allowed the speed of the vessel to increase above the normal rate and the watchkeeping officer was engaged in other tasks. The Chief Officer made attempts to control the movement of the vessel, during which time it struck the leg of the installation.

Failure to keep a proper lookout

Case 2. A multi-role emergency response and rescue vessel (ERRV) was standing-by outside the 500m zone of a jack-up drilling installation. The Master had just handed over to the Officer of the Watch (OOW). It was dark, the weather was good, and there was a lookout on the bridge. The OOW became engaged in non-navigational tasks, including writing minutes to a recent meeting and testing the bridge radios. The lookout asked the OOW if he could use the bridge computer and was given permission to do so. Neither the OOW nor the lookout noticed that a change in environmental conditions meant the vessel was now drifting towards the jack-up. A PSV was alongside the jack-up and raised concern that the ERRV had entered the 500m zone and was on a collision course with the installation. The jack-up control room attempted to call the ERRV and instructed them to leave the zone. The ERRV collided with one of the legs of the jack-up.

Distracted by administrative tasks

Case 3. A PSV was standing by a jack-up drilling installation. It was daytime, the weather was good and there was a single OOW on the bridge. The vessel was configured in ‘green dynamic positioning’ (DP) meaning the DP system was controlling surge but not sway. The OOW began some administrative tasks on the bridge computer but kept an eye on the installation through the bridge front window, knowing that if he kept the installation ahead of the vessel, the ‘green DP’ configuration meant he would not drift towards it. The view from the OOW’s position at the bridge computer out the side window was blocked by the bridge toilet and ships funnel. The OOW was therefore unaware that the vessel was drifting sideways towards a neighbouring fixed installation. The PSV drifted inside the 500m safety zone and collided with the leg of the installation.

Failure to assess environmental conditions

Case 4. A PSV was engaged in cargo operations alongside a mobile drilling installation. It was dark, weather conditions were marginal, and the vessel was in a drift-on position with the bow into the wind. The Master was in control of the DP system and a watchkeeping officer was supporting him on the bridge. The crane operator on the installation asked if the vessel could change heading to enable access to cargo outside the reach of the crane. The Master pulled away from the installation a short distance and changed the vessel heading. This action resulted in the DP system being unable to maintain position and the vessel drifted towards and collided with the drilling installation.

Lack of communication between bridge team

Case 5. A windfarm service operation vessel (SOV) was transiting through the windfarm. It was daylight, weather was good, the vessel was in DP mode and there was an OOW and Dynamic Positioning Officer (DPO) on the bridge. The DPO had control of the vessel and was changing heading to pass a wind turbine. The OOW was engaged in a non-navigational task. The change of heading resulted in the vessel being on a collision course with a wind turbine. The Master, who had gone to the bridge for another purpose, noticed the developing situation and took control of the vessel, but was unable to prevent collision with the wind turbine.