The term hull refers to the body or frame of a ship or starship. Warp-worthy vessels must have a hull able to withstand extreme accelerations. The hull of a Starfleet vessel was usually separated into two parts: the primary and secondary hulls. Hull plating was an external armor component of a starship's or shuttle's hull. Hull resiliency was a measurement of how well a hull could withstand damage.
The primary and secondary hulls of Constitution-class, Galaxy-class, and Oberth-class starships further consisted of an "outer" and "inner" hull. (TOS: "The Doomsday Machine"; TNG: "The Best of Both Worlds, Part II", "Hero Worship")
Borg cubes utilized technology that automatically regenerated their hull when damaged. (TNG: "Q Who"; PIC: "Broken Pieces") Like Federation starships, they had an "inner hull" and an "outer hull" (or "outer skin"). (Star Trek: First Contact)
In 2151, Doctor Phlox was telling Miss Malvin's class about locating a colony of spores on the hull of a craft, but was interrupted by Jonathan Archer before he could finish. (ENT: "Breaking the Ice")
- Polyduranide alloy
- Ablative generator
- Ablative hull armor
- Dispersive armor
- Monotanium armor plating
- Parametallic hull plating
- Polarized hull plating
- Reactive armor
The basics of these incidents have been referenced in several episodes. More detailed explanations given by the writing and technical staff when creating the show are contained in the Star Trek: The Next Generation Technical Manual and the Star Trek: Deep Space Nine Technical Manual.