Shutout is an achievement gained by defeating the Flame Leviathan without causing a System Shutdown on Normal Difficulty.
Strategy
Shutout is a rather easy achievement. In fact, many first-time groups who hadn't researched the fight managed the achievement by accident, since they did not knowing about killing the turrets and causing the shutdown.
The achievement is easiest to do by simply ensuring that both Demolishers keep up full stacks of the Blue Pyrite DoT, and that both of their passengers keep the Demolisher's ammunition topped off. Keeping up a constant set of 2 Pyrite dots, along with regular damage, will likely end the fight in around a minute, give or take a few seconds.