What Happened
What Happened
On August 21, 2022, about 1045 local time, the cargo ship Damgracht was inbound in the Sabine Pass Outer Bar Channel en route to Beaumont, Texas, and the cargo ship AP Revelin was outbound when the two vessels collided near Port Arthur, Texas. There were no injuries to the Damgracht’s 16 crewmembers nor to the AP Revelin’s 19 crewmembers, and no pollution was reported. Damage to the AP Revelin was estimated at $3.4 million, and there were no reported damage costs for the Damgracht.
What We Found
What We Found
We determined that the probable cause of the collision between the cargo vessel Damgracht and the cargo vessel AP Revelin was the Damgracht’s loss of propulsion caused by an automatic shutdown of the main engine due to a false alarm, likely triggered by water vapor sensed by the oil mist detector shortly after engine maintenance was completed to replace a failed cylinder head gasket during high humidity conditions.
What We Recommended
Oil Mist Detector Precautions After Engine Maintenance
When certain engine components, such as cylinder head gaskets, fail, cooling water can be introduced into engine lube oil systems. Ambient air conditions, such as high humidity or extreme cold temperatures, can also increase the water content within engine lube oil sumps. The elevated quantity of water in lube oil systems can trigger false alarms in engine crankcase oil mist detectors (and lead to an engine shutdown) due to water droplets passing through the measuring track or the filter glass detecting condensation (mistaking it for oil mist). After an engine’s crankcase is opened and exposed to these conditions during maintenance and repair, it is good practice for engine crews to inspect and test the lubricating oil system for water intrusion and ensure lube oil purifying equipment is functioning properly to remove any water or other contamination in the lube oil.
