Abstract:
This study aims to analyze and optimize the cargo tank cooling (cooldown) process before
methane loading on LNG/C Golden Isaia. The cooldown process is essential to ensure
safe temperature conditions and prevent thermal shock. However, operational issues such
as schedule changes and instability of Boil Off Gas (BOG) often reduce cooling efficiency
and increase heel LNG consumption. This research uses a descriptive qualitative method
with data collected through observation, interviews, and documentation during sea
practice. The data were analyzed using Fishbone Analysis to identify the root causes of
inefficiencies. The results show that schedule changes affect cooling planning and
duration, while unstable BOG causes pressure fluctuations that disrupt the process. These
factors reduce operational efficiency and may increase safety risks. To improve the
process, adaptive planning, stable BOG control, and efficient use of heel LNG and spray
systems are recommended.
