its effectiveness after only a few minutes of travel. Romulan plasma torpedoes use trilithium isotopes in their warheads. Gravimetric torpedoes Gravimetric torpedoes are torpedoes used by the Borg. The weapon emits a complex phase variance of gravitons to create a gravimetric distortion capable of tearing starships apart. Quantum torpedo Quantum torpedoes first appear in the Deep Space Nine episode "Defiant" as a weapon aboard the . In the DS9 episode "Paradise Lost", the USS Lakota was also stated to be carrying quantum torpedoes, although they were never used. Additionally, the USS Enterprise-E is equipped with quantum torpedoes in Star Trek: First Contact and Star Trek: Nemesis. The Federation and Cardassian Union are the only known users of quantum torpedoes. The Star Trek: Deep Space Nine Technical Manual states that quantum torpedoes derive their destructive power from vacuum energy. Various in-universe sources describe quantum torpedoes as roughly double the destructive power of standard photon torpedoes, putting their yield somewhere in excess of 100 megatons of TNT. Four of the USS Enterprise-E's quantum torpedoes destroyed an unshielded Borg sphere. The launcher appears on the 1701-E in Star Trek: Insurrection but is never fired. In Star Trek: Nemesis, nine of the Enterprise-E's quantum torpedoes disabled Scimitars cloaking function. Quantum torpedoes are normally shown in a shade of blue. As of Nemesis the following ship classes had quantum torpedoes launcher; Defiant, Intrepid, Luna, Sovereign, Vesta, Akira and Achilles-class, and the unmanned Cardassian spacecraft Dreadnought were the only ships known to be equipped with quantum torpedoes. Polaron torpedo Polaron torpedoes, like the Dominion weapon, are capable of penetrating normal shielding with ease. They appear in various Star Trek games. In Starfleet Command III, it is one of the Klingon's three heavy weapon options, the others being the photon torpedo and the ion cannon. It also appears in Star Trek: Armada and Star Trek: Armada II, as a researchable weapon for the Klingon Empire exclusive to the Vor'cha-class cruiser which takes out one of the targeted ship's systems at random. Transphasic torpedo Transphasic torpedoes appear only once, in the Voyager series finale, "Endgame". They are high-yield torpedoes that are designed specifically to fight the Borg. The future Admiral Janeway brought them back in time in a Federation shuttlecraft and had them installed onboard Voyager in 2378. They are among the most powerful weapons used in the Star Trek universe; just one is capable of obliterating an