Inadvertent activation of Emergency Shut down(ESD) during loading LPG cargo

Recently one vessel experienced an inadvertent activation of Emergency Shut down(ESD) twice while loading LPG cargo in port. Following the incident, the vessel is blacklisted by the port and Oil Majors declassified the vessel until further notice. During this incident, there were no injuries or cargo spill. This incident has caused damage to the operating company reputation with the Oil Majors.
From the preliminary investigation, the following are identified as causes for activating the ESD in both cases:

Cause of 1st ESD activation immediately after starting loading operation

1. Cargo liquid manifold drain valves opened for releasing the manifold pressure at the time of manifold connection were left open and vessel commenced loading. This led to filling of Flash tank which in turn activated ESD.

2nd ESD activation occurred after few hours when the vessel was loading at a full rate

1. Instead of draining the liquid from the flash tank by opening the drain valve, vessel waited for the liquid to vaporize from the flash tank through vent riser.

2. ESD was reset from CCR after half an hour of 1st ESD activation and cargo operation was resumed without confirming the liquid level in the flash tank.

3. As the Flash tank level was still in high level, it triggered the ship ESD again after few hours of resuming the cargo operation. At this time vessel was loading at full rate.

A thorough investigation has been initiated to find out the root cause leading to this incident.

Masters and officers of LPG Carriers must review the cargo line lining-up and draining procedures. Propper familiarization to be conducted for all crew involved.