Back to the original thread subject I think we
may be looking at a total of 4 to 5 engine rooms aboard
USS Enterprise and would like to present my case.
To start with I think it’s safe to assume that at the beginning of Season One the premises of the show were still in a state of flux illustrated by Kirk’s and McCoy’s quarters (on Engineering Deck 12) with cabin windows (“Rank hath its privileges.” “How well we both know that. Hehehe” McCoy replies to Kirk in “Arena”, a late echo?) and the same could be assumed for the location of the engine room in Season One.
The studio set for the Season One engine room differed noticably from the one they started to use from Season Two on (personally I’m not a big fan of “upgrade rationalizations”, thus prefer to regard these as independent rooms that continued to co-exist during the later two seasons).
The studio set plan from the first season is pretty straightforward and presented us with an engine room that would fit at the saucer’s stern and still leave enough space for a turbo shaft system connecting the saucer with the engineering hull (great forward thinking of Matt Jefferies!):
http://s757.beta.photobucket.com/us...f.html?&_suid=1355157921796022812363632874782
This kind of engine room can’t possibly be in the center of the saucer or the engineering hull and Mytran did a simulation to illustrate the issue:
http://s757.beta.photobucket.com/us...if.html?&_suid=135515790078106064546028420048
(The corridor of the “Engineering Control Room” on the port side seen in “The Naked Time” was a dead end with no turbo lift and therefore not obstructing turbo lift passage down to the engineering hull!).
Greg Tyler did a great job illustrating the evolution and design changes (production order) of the Season One engine room:
http://www.trekplace.com/article14.html
What I found really interesting was the extra effort and the changes applied to the engine room set for “The Conscience of the King” as if the producers wanted to present this engine room now to be at a different location aboard the ship by making it look apparently dissimilar:
a) addition of an extra horizontal pipe in the ‘cathedral’ (the part of the engine room with the glowing lights and pipes behind the grated wall opening)
b) addition of three chairs in front of the wall consoles
c) large GNDN prop (“transformers” according to Greg Tyler) turned 90° degrees and
d) an angled-in engineering master control console (a foretaste of things to come for the second season?).
Of course, this could have been simply a production design upgrade
BUT they mostly changed it back to its initial appearance in the three episodes following, especially “Court-Martial” and “Space Seed” where “Court-Martial” suggested the final confrontation taking place in the impulse engine room near “B deck” (or “Berth deck” which would be Main Deck 6 aboard the
Enterprise).
The notion that the engine room from Season One was retro-actively located at the saucer’s end - standard engine room port side, “Tomorrow is Yesterday” engine room starboard side? -
is also hinted by Whitfield’s
Making of Star Trek (written some time after Season One) which clearly distinguishes between an “impulse engine section” and the “star-drive
sections”:
“The impulse engine section is located at the bottom rear end of the saucer. Headquarters for the engineering division is also located in this same area, as are main engineering control facilities plus sufficient repair, storage and other facilities to service the primary section when detached from the star-drive sections of the vessel”.
Possibly, with the notable exception from “The Conscience of the King” all engine rooms in Season One where located at the saucer’s stern where Scotty remote-supervised and commanded the other “engine rooms” (“The Naked Time”) in the engineering hull from the saucer’s “Engineering
Control Room” (notice that the wall panels of the upcoming Auxilary
Control Room were cannibalized from the Season One engine room set).
The new Season Two engine room made its debut on another starship, the
Constellation in “The Doomsday Machine”. The new design put it in the center of the corridor axis, quite a contrast to the previous off-center version of the Season One studio set which already in itself suggested a different kind of engine room at a different location of the ship (additionally the room’s ceiling was elevated!):
http://s757.beta.photobucket.com/us...f.html?&_suid=1355234539593015999243404428004
A noticable addition was the caged Emergency Manual Monitor, overlooking the new engine room (labelled in the
Star Trek Sketchbook, which appears to quote production designer Matt Jefferies, “secondary engineering control room”!).
It’s first appearance aboard the Enterprise took place in “The Changeling” which also established the direct warp drive control mechanisms the Nomad probe improved to be on a panel to the right side of the ladder leading to the new “balcony”.
But already the next episode featuring a prominent display of the engine room in “Journey to Babel” could seem to show another, previously unseen “engine room”:
a) the main control console isn’t operated by Scotty or a member of the engineering crew but Spock (!!!)
b)
"This is the engineering section. There are a number of emergency back-up systems for the main controls. Over here are a number of control computers." Kirk
c) The warp drive control mechanisms seem to house the essential computer systems instead
Could this be an engine room facing forward (to the bow) feeding the main sensor- deflector dish where the data collected by the main sensor is stored and processed and therefore explaing the presence of the senior science officer working with the computers (required by this episode’s script

)?
The location of this engine room would also match the exit point where the alien entity from “Day of the Dove” left the
Enterprise in the original version.
It wouldn’t be the first time the engine room set had been used to represent a different location: In Season One the set was re-vamped to stand in for the Gymnasium (“Charlie X”) and/or the Event Room (“The Conscience of the King”), the Phaser Control Room (“Balance of Terror”) and the Starbase 11 Computer Center in “The Menagerie” (though admittedly, one would rather expect the Sensor Room of the
Enterprise to look more like the Computer Center of Starbase 11).
In “The Immunity Syndrome” the secondary engineering control room / Emergency Manual Monitor featured the semi-circular control console of the Auxilary Control Room, suggesting this to be another EMM than the one previously seen in “Mirror, Mirror” and “I’Mudd” (and in later episodes) with a rectangular console.
Moreover, the momentary loss of inertial dampers both on the bridge and in this engine room suggested a ‘cathedral’ facing forward to the bow (however, it’s obscured by the GNDN “transformers” so one might take this as an excuse to be looking at a twin engine room with a cathedral facing aft / stern instead).
The engine room presented in “The Ultimate Computer” is a double-edged sword. It could either be in the forward Main Sensor-Deflector Engine Room (where it takes over from the control computers already there)
or the Warp Engine Room aft suggested by the power socket below the grated wall opening (sealed shut in Season Three because of the “M-5 experience”?).
Had there been any doubt whether the Enterprise had one or more engine rooms, “The Omega Glory” provided a very clear answer (i.e. assuming the interior configuration of the
Exeter and the
Enterprise is essentially identical). During Kirk’s shipwide intercom call from the dim-lighted engine room (with the remains of Exeter’s engineering crew and an interesting location of the intercom monitor...)
we see another illuminated but deserted engine room which obviously can’t be the same one Kirk is making his call from (footage recycled from “The Ultimate Computer”).
There appears to be a high probability that the Warp Engine Room is the one where the EMM has the rectangular console (e.g. “I, Mudd”, “By Any Other Name”, “Is There In Truth No Beauty”, “Lights of Zetar”) and was first seen aboard the
Enterprise in “The Changeling”.
“Elaan of Troyius” could have taken place in the forward Main Sensor-Deflector Engine Room of the engineering hull (suggested by the floor mounted shield generator device). Did Kryton sabotage the dilithium crystal converter assembly in this engine room (the moment the ship goes to warp the forward main deflectors will activate) or the grossly negligent guarded Warp Engine Room?
The open GNDN space near the room’s main entry (a small design change of this area previously seen in “The Ultimate Computer”) may suggest the Main Sensor-Deflector Engine Room as in “That Which Survives” that same area featured a closed room with indicators that connect straight to the matter-antimatter reactor in the engineering hull (“Reactor number three” where Spock located the alien entity in “Day of the Dove”?) and appears to be the Warp Engine Room towards the aft / stern of the engineering hull.
It appears the producers had decided to present the Season Two “Engineering Section” to be located in the engineering hull.
But then came the script for “Day of the Dove” that required the use of the Season One (impulse) engine room no longer available. The deliberate re-dressing of the Season Two engine room set (on a smaller scale than the one for “The Conscience of the King”) could suggest an attempt to simulate yet another engine room (in the saucer), but then would basically be a production compromise for a television “show” that shouldn’t be taken to serious or literal in an in-universe context:
a) The doorway got a new sign saying “Engineering Officer Scott"
(“headquarters for the engineering division”?)
b) the enigmatic soccer ball spheres on the structure housing the "dilithium crystal converter assembly" were painted gold
Summary: There is sufficient evidence to suggest the existence of at least two engine rooms located in the engineering hull.
The big question that now remains, is whether there could be three, i.e. that towards the aft / stern we have a twin engine room arrangement that essentially could look like this (post # 25):
http://www.trekbbs.com/showthread.php?t=119751&page=2
(Of course the Emergency Manual Monitor is missing and the Season One engine room should probably rather look like the one from “The Conscience of the King”).
The advantage would obviously be that all engine room variations seen during the series would be be there (more or less).
The disadvantage would obviously be that the circular corridor outside the Season Two engine room would be severely compromised if there was a twin-engine room arrangement towards the aft / stern of the engineering hull.
Bob