The Marine Safety Forum (MSF) draws lessons learned from an incident where a vessel experienced a leak during offshore operations due to an open strainer vent cock.
What happened
During offshore operations, the vessel was lined up to receive Offshore Contaminated Bulk Liquid (Slops) from the rig. When the transfer started, the bridge crew noticed a spray/mist from the strainer on the port side. An “All stop” was called, and the rig quickly stopped the transfer. Approximately 4 liters were estimated to have leaked onto the vessel’s deck through an open strainer vent cock, and 1 liter is estimated to have been sprayed onto the sea.
Cause
After recent strainer checks and maintenance, the vent cock had not been closed. Pre-start checks for the bulk transfer did not capture the fact that the vent cock was open.
Lessons learned
- A Time Out For Safety was held by both shifts.
- The wet bulk transfer risk assessment, toolbox talk, and checklist have been updated to include checks of the strainer vent cocks.
- An experience transfer was raised to share findings with other vessels within the fleet.
- The Planned Maintenance System task was updated to include confirming all valves are in the correct position upon completion of maintenance.
