The main shuttlebay in a Federation Excelsior-class starship variant, such as the USS Enterprise-B, was located across the rear of the primary hull. It was split into two sections, having a port and starboard side. (TNG movie: Generations; TNG reference: Star Trek: The Next Generation Sketchbook: The Movies)
- In the ST reference: USS Enterprise Owners' Workshop Manual, the main shuttlebay is labelled as being at the aft of the secondary hull where the cargo bay is located. The primary hull main shuttlebay is not depicted at all.
The upper main shuttlebay was situated on deck three. It was surrounded by a viewing balcony, where crewmembers and other starship personnel could observe the goings-on below. In the central tower, there were two flight crew lounges, a shuttle systems programming office and the shuttlebay control room, which looked out over the entrance to the bay.
The main shuttlebay deck was located on deck four. It was a cavernous eliptic toroidal area surrounding the central tower, with four banks of six shuttle fueling docks on the bay's inner bulkheads. The central tower housed two shuttle maintenance bays, the main computer core data trunks, turbolift shafts and the main stairwell. Separate from the tower, to port and starboard, were internal cargo elevators that ran from top to bottom of the primary hull. And on the port and starboard inner bulkheads was access to the deck's cargo bays and cargo transporters. Just inside the bay door were three shuttle lifts to the deck below.
The lower shuttle maintenance floor on deck five was directly below the shuttlebay entrance, serviced by the three shuttle lifts. (TNG reference: Star Trek: The Next Generation USS Enterprise NCC-1701-D Blueprints)
In 2368, Commander William T. Riker ordered the venting of the USS Enterprise-D's main shuttlebay in order to propel the ship away from a collision course with the USS Bozeman. (TNG episode: "Cause and Effect")
The Sovereign-class had two shuttlebays, with the main one located in the aft primary hull on decks six and seven. Shuttle maintenance levels were situated directly below, on decks eight, nine and ten (with some shuttle lift mechanisms within deck eleven). The lower levels of the shuttlebay were part of the secondary hull, and as such, were still accessible following saucer separation. (ST references: Star Trek: The Next Generation Sketchbook: The Movies, Ships of the Line 2015)