Alerts iconSoftware update caused loss of generators in separate redundant groups

Case narrative A DP2 platform supply vessel (PSV) was set up on auto DP whilst conducting trials in open water after extensive upgrades.  The redundancy concept was based on two redundant groups with power generation, thruster supplies, and all DP consumers equally split between them.  Bow thruster 1 was supplied from a dual drive which … Continue reading “Software update caused loss of generators in separate redundant groups”

Alerts iconMaintenance during DP operations leads to – DP undesired event

Comments from the report: The oil level gauge was not reading the actual level.  The duty Engineer did not inform Bridge/DPO`s of maintenance on the header tank of stern thruster.  Future instruction was that the engine room would inform the bridge of scope of work of any maintenance to be carried out whilst the vessel … Continue reading “Maintenance during DP operations leads to – DP undesired event”

Alerts iconSpecialised pipe laying DP mode – DP undesired event

Comments from the report: When the vessel was confirmed stopped and on the setpoint, the operator checked the auto track setting to find the cause of the track change.  Upon checking, it was verified that the ‘waypoint for radius turn’ had changed to ‘operator’ a pre-set value of 200m; the vessel standard setting is ‘waypoint … Continue reading “Specialised pipe laying DP mode – DP undesired event”

Alerts iconLoss of tunnel thruster – DP undesired event

Comments from the report: During diving operations in open water, tunnel thruster No. 1 tripped offline.  Investigation showed that the cause was due to tripping of the thruster hydraulic pump because of voltage instability.  The voltage instability was caused by a spike load on an unrelated circuit breaker on the same switchboard which tripped.  Because … Continue reading “Loss of tunnel thruster – DP undesired event”

Alerts iconPosition reference systems – a timely reminder

The IMCA Marine DP committee has identified a trend of DP station keeping events relating to the incorrect use or selection of PRSs.  Events reported to IMCA include incidents, where station keeping capability has been lost and undesired events where redundancy has been compromised. Recent Events Reported to IMCA Include the Following Learnings: Incorrect selection … Continue reading “Position reference systems – a timely reminder”