A comprehensive review has been carried out to assess incidents that jeopardize DP operations, derive valuable lessons, and prevent future dangerous occurrences. These case studies are sourced from the IMCA DP Event Bulletin.
Overview
On an FPSO, the DP event took place. Although the FPSO has two stern azimuth thrusters and a bow tunnel thruster, the bow thruster was turned off for continuous diving operations during the event, and the starboard aft thruster was not in use because of upgrades. From a light diving craft (LDC), diving was done. To safeguard the LDC while diving, the FPSO was positioned sideways to the wind. The diving isolation matrix was used to secure the FPSO turret.

What occurred?
The on-duty engineer was lubricating the steering gear pump for the port azimuth thruster as part of routine maintenance. After determining that the steering pump that required greasing was being operated by the local controls of the port azimuth thruster, the engineer changed the control to make pump 1 the lead steering pump. Pump 2 stopped and pump 1 started as intended when he changed the duty pump, but the pressure decreased and the low-pressure alarm continued to sound after the allotted amount of time had passed.
For safety, the system turned off pump 1, which resulted in no steering on the port azimuth thruster. Pump 2 did not start on its own. With no other thrusters operating and no steering for the port azimuth thruster, the FPU’s heading was unabated. Diving operations were halted after the CCR notified the LDC diving supervisor of a thruster’s power outage. While the LDC coxswain kept an eye on the FPSO heading, the divers made their safe and incident-free return to the surface.
Furthermore, it is essential to establish a robust emergency response protocol that is well-communicated and understood by all team members involved in diving operations and SIMOPS. Regular drills and training should be conducted to ensure that all personnel are familiar with emergency procedures, and that communication channels are clear and effective.
The investigation highlights the need for improved incident reporting and awareness among all team members. The CCR must ensure that all relevant information about the status of divers and operations is accurately communicated to the LDC and other relevant parties. This includes real-time updates during operations to prevent any misunderstanding of the situation.
In addition, a culture of safety must be fostered within the organization, encouraging personnel to speak up about any concerns or uncertainties regarding operations. This includes empowering all team members, regardless of rank or position, to halt operations if they feel that safety is compromised.
To address the identified gaps, the following recommendations are proposed:
- Enhanced Communication Protocols: Develop and implement standardized communication protocols for all parties involved in diving operations, ensuring that critical information is shared in real-time.
- Comprehensive Risk Assessments: Prior to any diving operations or critical maintenance, conduct thorough risk assessments that consider various failure scenarios, including their potential impacts on heading control and other critical systems.
- Emergency Preparedness Training: Regularly conduct emergency preparedness training specific to diving operations, ensuring that all personnel are well-versed in their roles during an emergency.
- Redundancy Measures: Evaluate and implement redundancy measures on critical systems to provide additional safety layers during operations, particularly when performing high-risk activities like diving.
- Post-Event Reviews: After any incident or near-miss, perform a detailed review to analyze what went wrong, identify lessons learned, and update procedures accordingly to prevent recurrence.
By taking these steps, we can enhance the safety and efficiency of diving operations and ensure that all personnel are equipped to respond effectively to any incidents that may arise. Continuous improvement in safety practices and a commitment to proactive risk management are essential to safeguarding personnel and assets in complex operational environments.
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