Editing Constitution Class (section)

===Main engineering===

Main engineering was from where the ship's warp was controlled. All thrust and power systems were primarily controlled from this site, and it is also where the main dilithium crystal reactor was located. Life support was controlled separately from Deck 6. (TOS: "The Ultimate Computer", "The Corbomite Maneuver", "The Naked Time", "The Enemy Within", "The Conscience of the King", "Day of the Dove")

During the 2270s Constitution-class refit, the interior design of the engineering section was drastically upgraded, featuring the vertical warp core and the horizontal intermix area.

Main engineering was lodged on Decks 14 and 15. Deck 14 was the uppermost level of the engineering hull, and was the anchoring framework for the connecting dorsal and the warp nacelle pylons.

On the forward end of the deck was the engineering computer monitoring room, which encircled the cortical intermix shaft and opens, to the rear, into the engineering computer bay.

Deck 15 housed the main engineering room. Located in the center of the room, and extending for many levels both above and below the deck, was the vertical linear intermix chamber. This complex, radically new design in intermix technology, provided operational power for the impulse drive system and furnished enough additional energy to power all other shipboard systems.

Both matter and antimatter for this chamber were contained in a series of magnetic bottles, which were housed in pods at the base of the intermix shaft. (Star Trek: The Motion Picture)