Warp engine relay
Warp engine relays, also called warp relays, were primary components of the warp engines aboard a starship. 

In an attempt to reconfigure the power matrix of a , in order to operate the ship's cloaking generator, Chief engineer  attempted to route more  from warp relays. Later as he and Travis Mayweather piloted the ship to the surface of a planet, it was discovered that there was a power drain in the cloaking generator, causing the ship to decloak, caused by both the primary and backup warp relays going offline. ()

As the  was caught in the tractor beam of a Dyson sphere discovered in 2369, Data noted that the beam's resonance frequency was incompatible with the Enterprises power systems, and as such, both the warp and impulse engine relays had been overloaded. ()

Propulsion technology