Hi everyone

I want to share how we nearly lost our reliquefaction plant in the middle of the Atlantic—and the universal lessons every marine engineer should take away.

We were steaming from Qatar to Japan fully loaded with LNG, maintaining constant boil-off gas to fuel our diesel generators. One evening, on my routine check in the engine room, I saw an alarm: the seal-gas pressure on our main turbo-compressor had dropped. Without proper seal gas, the turbine can’t maintain balance pressure, risking metal-on-metal contact and catastrophic failure. I immediately called the Chief Engineer and the 1st Engineer: we had to move fast.

First, we switched the system to our standby turbo-compressor, buying us time. Next, we removed and inspected the seal-gas filter—it was clogged with microscopic particles from a missed wash-down, blocking the valve block. While the mechanics painstakingly cleared the mesh, I ordered additional nitrogen from our emergency bottles to keep minimum seal-gas pressure. Simultaneously, the Chief Engineer checked the heating trace cables on the seal-gas piping: one cable had failed, allowing condensate to freeze on a cold section and worsen the blockage.

After two intense hours—filter cleaned, heating traces back online, and nitrogen boost—we safely restored seal-gas pressure and gradually brought the main turbo-compressor back online. I monitored every gauge and recorded pressure curves, piping temperatures, and switchover timings to build a detailed incident report. Those data became the foundation of our new maintenance procedures.

From this dramatic incident we learned critical lessons for every LNG engineer: first, seal-gas filters require daily inspection and wash-down, not just scheduled servicing—they can save your turbine. Second, never underestimate heating trace cables: a single failed cable can allow condensate to freeze and lock valves. Third, always have spare nitrogen or gas-nitrided bottles on hand—quick pressurization can be the difference between a hiccup and a plant shutdown. Lastly, crystal-clear communication is vital: when every minute counts, every crew member must know their role and act without hesitation.

Since then we’ve updated our maintenance schedule, added daily seal-filter checks, and integrated heating-trace status into our SCADA alarms. This experience not only saved our reliquefaction system but became a learning case for our entire fleet. Remember: even the most advanced automated plant depends on your hands, your eyes, and your judgment.

— Shannon Peters, Second Engineer on an LNG Carrier