Emergency Shutdown Trip

Emergency shutdown trips ( or ESTs) are part of the safety systems of a starship's warp drive. (Star Trek: The Motion Picture)

It is generally believed that the EST works by causing the magnetic constrictors that allow the passage of antimatter into the Matter/Antimatter reaction Chamber to constrict the magnetic field and thereby prevent the passage of antimatter to the chamber. This process most likely takes place incredibly fast and is suspected to cause an immediate shutdown of the ship's warp drive.

It is apparent that this process is not commonly employed by the 2370, since the preferred method of handling potential warp core breaches seems to be to jettison the core. One would think that if the Galaxy Class or Sovereign Class starships were equipped with EST devices that they would be employed rather than losing the ship's warp core.

It is possible that with greater efficiency engines and systems that the Warp Drives were re-engineered thus making the EST no longer an effective method of containing possible breaches. it is also possible that the ESTs were not employed in later classes of Starfleet vessels, because it was practical to jettison the warp core as a result of miniaturization of the warp core components evolved.