Warp Coil

Warp coils are an integral part of a starship's warp drive. Mounted within the warp nacelles, the coils take the plasma generated by the warp core, and use it to create the warp field that allows faster than light travel.

Warp coils are typically composed of cast verterium cortenide surrounding a core of densified tungsten-cobalt-magnesium. (VOY: "Investigations")

Series of Warp Coils - installed

The material was first mentioned in the Star Trek: The Next Generation Technical Manual.

A teraphasic coil was a type of warp coil utilized by the Xyrillians in the mid-22nd century. The Enterprise (NX-01) encountered a Xyrillian starship with damaged teraphasic coils in 2151. (ENT: "Unexpected")

In the mirror universe in 2155, Commander Trip Tucker, when seeing the USS Defiant, mentioned that the size of the ship's warp coils could allow the ship to travel at speeds faster than Warp 7. (ENT: "In a Mirror, Darkly")

Wesley Crusher once stated that his first friend was a warp coil. (TNG: "The Game")

Shuttlecraft removing a warp coil.

William T. Riker considered the warp coil the most important invention of the past two hundred years. Before the coils were invented, "humans were confined to a single sector of the galaxy". (TNG: "A Matter of Time")

In 2372, a subspace inversion in the Bajoran wormhole damaged the USS Defiant and its warp coils were locked into a feedback loop. (DS9: "The Visitor")

In 2377, USS Voyager landed on a planet to make repairs. Among the repairs was the removal and maintenance of several warp coils via shuttle. (VOY: "Nightingale")