Star Trek the original series featured a Constitution class starships Auxiliary Control in several episodes TNG featured the Battle Bridge in several episodes. And the Franz Josef Enterprise plans I think used to make reference to the "Emergency Bridge"? Are they all the same thing? The Auxiliary Control Room looked to have far more simplified stations than the regular bridge. The Battle Bridge appeared more "bridge like" but somewhat simplified. According to the plans the Emergency Bridge was supposed to be an exact duplicate of the Main Bridge. All that and no Combat Information Center...
I Suspect Aux. Control in TOS was more meant to be used jst to get the ship back to a shipyard so only minmal stations would be needed. As for TNG you might want more a simple design for combat situations.
I started to say that we never saw the weapons fired from Auxiliary Control but then I remembered that Capt. Kirk fired the Constellation's phasers from there in "The Doomsday Machine". In terms of the Battle Bridge they probably didn't need the row of stations that the main bridge had at the rear.
According to the MSD for the Enterprise-D, the starship had both an auxiliary control and a battle bridge. They were located in the "neck".
Kirk's old ship clearly didn't have those as separate things, as all battle was conducted either from the main bridge or the auxiliary facility. However, the ship had a facility known as the Emergency Manual Monitor and represented by the same basic set as the Auxiliary Control. The alternate (?) name emphasizes the emergency use nicely enough. Although when the set is used in "Lights of Zetar", it serves in a non-emergency role, giving Scotty and Romaine a bit of privacy and perhaps a possibility to "dry rehearse" things they'd ultimately do on the bridge (and, yes, things they would not - Kirk clearly sees what's going on there when suggesting the two retire to EMM). I'd thus assume the Bridge and its counterpart are fundamentally different in that the latter is indeed more "manual", having special controls that are less likely to fail and subsequently are less capable (or else the Main Bridge would have those, too). Going Manual gets things done, but were Kirk to move there during battle, he'd lose capabilities he'd need in the battle. Timo Saloniemi
Which basically will be true in tomorrow's seagoing warships, too, as the only reason to have a "bridge" separately from the CIC is if your mast-mounted TV cameras are of inferior quality for the purposes of docking or other maneuvering. Distributing of assets makes no sense in a starship. If the ship somehow survives a hit, then the damage incurred will just cut the distributed assets off each other and render them useless. All-or-nothing is a valid military stratagem and tended to be the winning one in naval warfare of yore, too. Timo Saloniemi
Perhaps you're right. In "The Doomsday Machine" Constellations bridge was rendered uninhabitable but Kirk and Washburn managed to get Auxiliary Control up and running without too much trouble. Of course the bigger accomplishment was Scotty's getting the Impulse Engines, one phaser bank, and the shields operational with just him and a small damage control team working for an hour or so.
Distribution no, duplication yes. Being able to centralize control in a new location upon the main bridge being damage beyond a certain point make all kinds of sense
One would need to also duplicate the personnel using that equipment, tho. Yet Auxiliary Control doesn't appear to be crewed by more than a token guard at the best of times. Is losing the main bridge survivable in Trek? In "Twilight", the ship was history no matter what. In "Starship Down", fighting went on. In "Brothers" and certain TOS outings, outside combat, there was a power struggle between the command centers, clearly something Starfeet was not prepared for. But what is Starfleet prepared for with Auxiliary Control? Timo Saloniemi
Traditionally a ship would have three or four shifts worth of crew. If the Bridge gets blown up, the surviving shift or two should be able to take over Auxiliary Control from whatever battle stations they might have normally and control the ship. However when not at Red Alert...those shifts are generally off duty. The only ones that can't be replaced would be the captain and first officer, since on Starfleet ships they tend to be on shift at the same time. So it would fall to some other officer to take command, and unlike on the USS Enterprise (NCC-1701-D) there is usually not a android that can be on every shift if needed, though he tends to be on only two of the shifts...Serving as Ops when the Captain is up, and as the Night Watch commanding officer.
One thing I never understood in TNG was why, when they have a perfectly serviceable battle bridge) they always used Engineering when the main bridge was unavailable? (I'm sure that IRL the reason was down to engineering being a standing set so they didn't need to reconstruct the battle bridge). dJE
If you want a hand-wave, you could say the Battle Bridge is specifically meant to control the Battle Section, while Engineering is built to be engineering for the combined ship. Sure, in the world of touch-screen panels and pervasive computer networks, any station could serve as any other station and the only reason to pick one place over the other would seem to be ergonomic, but logically certain sections of the ship would be closer to the "main lines" of data and power, so from the perspective of being "close to the metal," Engineering is the preferred backup for the Main Bridge, while if you were going to use the Battle Bridge to control the combined ship, you may as well use one of the kid's classrooms, or a bridge being simulated on the holodeck, since you wouldn't be on the main trunk.
I always thought they were two different areas. Battle Bridge being meant either for combat situations (it's positioning not being on the outer hull making it more secure for senior staff) or for multi-vector operations to function as a bridge for the drive section. I envisioned Auxilary Control being more of a backup for the Engineering department, say if Engineering is flooded with something hazerdous to the staff there. Of course, since the ship can be controlled from Engineering, it could be controlled from the backup engineering section as well. On the D, it would likely make sense to have Aux control in the saucer section, having direct control over the fusion impulse drive on the saucer.