Editing Constitution Class (section)

==Technical data==
===Physical arrangement===

The Constitution-class featured the saucer section-engineering section-warp nacelle layout common to most Starfleet vessels. (TOS: "The Cage", Star Trek: The Motion Picture, etc.)

Various science labs, numbering fourteen in all, (TOS: "Operation -- Annihilate!") were located in the primary hull in the class' original configuration. An officer's lounge and dining area would be located in the aft superstructure beneath the bridge after the 2270s refit. (Star Trek: The Motion Picture)

The modular design of the Constitution-class allowed for component separation in times of crisis. The primary and secondary hulls could separate where the connecting "neck" joined the saucer, allowing either section to serve as a lifeboat if the other was too badly damaged. If an emergency was confined to the warp engine nacelles, it was possible to eject them while keeping the bulk of the vessel intact. (TOS: "The Apple", "The Savage Curtain")

Though not an aerodynamic craft, in emergencies, Constitution-class vessels were able to break orbit and enter a Class M planet's upper atmosphere (and maintain attitude control while passing through it) for a limited period of time, conditional on the ship's ability to re-achieve escape velocity. (TOS: "Tomorrow is Yesterday") 

===Command and control systems===

The Constitution-class' primary command center, the main bridge, was located on top of the vessel's primary hull, on Deck 1. From here, the commanding officer supervised the entire starship's operation.

The command chair was located in the recessed area at the center of the room, in a direct line with the main viewer. This position was equidistant from all the control consoles that operated specific areas of the ship. Consequently, the captain could be immediately updated on the condition of the vessel or its crew during missions, and orders could be given clearly with a minimum of effort.

The chair was mounted on a circular pillar, attached to a rectangular footplate that was directly anchored to the deck, giving it considerable support during an attack. It was designed to swivel on the support so that the captain could turn to any member of the bridge crew.

Piloting and navigation functions were carried out at the helm console, located in the center of the room, positioned in front of the command chair. This panel consisted of three main sections.

On the left was a compartment which opened automatically to permit operation of the targeting scanner. Next to this was the main control panel, which operated maneuvering thrusters, impulse engines, and fired the ship's weapons. Directly below this panel was a row of eight flip-switches provided to set warp flight speeds.

The central section of the conn panel was fitted with a number of sensor monitor lights, and was dominated by two main features: the alert indicator and the astrogator, which was used for long-range course plotting.

The navigator's station had a control panel for entering course and heading data and the flight path indicator, and supplied information on any deviations or course corrections in progress. It also had controls for the weapons systems.

Other stations on the bridge were provided for communications, engineering, weapons control, gravity control, damage control, environmental engineering, science and library computer, and internal security. All stations were normally manned at all times.

Mounted into the room's forward bulkhead, on the ship's centerline, was the main viewscreen. Visual sensor pickups located at various points on the Constitution-class' outer hull were capable of image magnification and allowed a varied choice of viewing angles.

The computer systems aboard the Constitution-class starship were duotronic based. (TOS: "The Ultimate Computer"; DS9: "Trials and Tribble-ations")

===Upgrades===

Only one turbolift serviced the bridge of the original configuration Constitution-class ship. In the late 2260s, some were refit with a second lift on the port forward section of the bridge. At the same time, an automatic bridge defense system was installed. (TAS: "Beyond the Farthest Star")

After the major refit in the early 2270s, the bridge aboard Constitution-class vessels would continue to utilize two turbolifts, but both would be located behind the command chair. (Star Trek: The Motion Picture)

The Star Fleet Technical Manual, states that the original bridge was rotated 36° port, which would have the turbolift shaft travel down the centerline of the saucer section. The Technical Manual gives no reason for this offset. With artificial gravity limiting any sense of momentum and electronic displays instead of windows, there may have been no reason for the bridge crew to face directly forward. 

According to production designer Matt Jeffries, dramatic necessity required the turbolift to be moved from its planned centerline position (as seen on the Enterprise model). This off-set placement allowed characters to walk onto the bridge and enter scenes without being blocked by actors sitting in the command chair. 

The bridge of the Constitution-class starships were subject to many minor and major cosmetic changes over their many years of service. In particular, the main bridge of the USS Enterprise seems to have undergone considerable changes in appearance over the years. Most notably, its systems were fully upgraded along with the refit of the early 2270s. (Star Trek: The Motion Picture)

The bridge underwent only a few minor modifications from that point until the destruction of the ship in 2285. The bridge of the USS Enterprise-A, commissioned one year later (in 2286), had mainly cosmetic differences at launch, but, by 2287, it had been drastically upgraded to reflect the advances made in computer control technology.

The bridge module had again been replaced by 2293. The lighter color scheme of the original Enterprise-A bridges had made room for a darker, more militaristic look. (Star Trek II: The Wrath of Khan; Star Trek IV: The Voyage Home; Star Trek V: The Final Frontier; Star Trek VI: The Undiscovered Country)

The controls in the fifth movie were designed to reflect a change towards a more TNG control style, but in the sixth movie the controls went back to a more push button design. While this has not been addressed in the canon one might theorize that the controls were replaced for any variety of reasons.

===Propulsion systems===

The Constitution-class of starships has been fitted with both lithium and dilithium reactor circuits in the warp drive assembly over its service lifetime. The vessel's standard cruising speed was warp 6, while its maximum cruising speed was warp 8. Warp 9 was also possible for this class of starship, although it was highly discouraged because it was an unsafe velocity.

The USS Enterprise was twice modified to achieve a speed of warp 11. The probe Nomad increased the ship's engine efficiency by 57% in 2267, allowing the ship to reach warp 11, but Kirk persuaded Nomad to reverse its "repairs" because the ship's structure could not stand the stress of that much power, and would eventually destroy the ship. (TOS: "The Changeling")

More extensive modifications made to the ship by the Kelvans in 2268, who were able to produce velocities that were far beyond the reach of Federation science, allowing the Enterprise to safely maintain a cruising speed of warp 11 while traveling through the intergalactic void.(TOS: "By Any Other Name")

The maximum warp speed recorded for this class by itself was warp 14.1, achieved by the Enterprise due to sabotage to the vessel's warp drive system. While the ship itself was not structured to take that speed for any length of time, the Enterprise was able to maintain that velocity for nearly 15 minutes. (TOS: "That Which Survives")

The Enterprise also maintained stability at warp 22, while tractored to a ship going warp 32. (TAS: "The Counter-Clock Incident")

Following the 2270s refit of the class, the Constitution was equipped with a linear dilithium-controlled MARA (Matter/Antimatter Reactor Assembly), and a pulse dilithium-controlled assembly was installed by the mid 2290s aboard the USS Enterprise. (Star Trek II: The Wrath of Khan; Star Trek VI: The Undiscovered Country)

The Constitution-class' impulse drive system was a twin-port fusion reactor engine, capable of velocities at least 0.8c. (Star Trek: The Motion Picture) A fusion explosion equivalent to at least 97.835 megatons would result if the impulse engines were overloaded. (TOS: "The Doomsday Machine")

===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)

===Tactical systems===

During the early 2250s, Constitution-class heavy cruisers were armed with a complement of directed energy weapons, that possessed enough power to destroy half a continent in a concentrated bombardment. In addition, these vessels carried on board laser cannons, capable of operating on energy fed remotely from the ship. (TOS: "The Cage", "The Menagerie, Part I", "The Menagerie, Part II")

By 2266, phaser banks were standard complement aboard this class of ship. A bank actually consisted of a single emitter and its power supply, though it was common practice to fire two banks at a time and refer to it as a single firing. (TOS: "The Corbomite Maneuver", "The Doomsday Machine", "The Paradise Syndrome")

Ship mounted phaser banks had a range of approximately 90,000 kilometers, and like hand phasers, were capable of being adjusted to stun, heat, or disintegrate visible targets, including objects or beings in space or on a planet's surface at a focus ranging from narrow to wide beam. When only motion sensor readings are available, ships' phasers could be set for proximity blast and bracket the approximate coordinates of the target. (TOS: "Balance of Terror", "A Piece of the Action", "Who Mourns for Adonais?", "The Paradise Syndrome", "The Tholian Web")

In the original configuration, a battery of 4 to 8 forward phaser banks were located on the lower part of the ventral side of the saucer section. Aft firing banks were located above the shuttlebay on the secondary hull. There were also port, starboard and midship phasers. (ENT: "In a Mirror, Darkly, Part II"; TOS: "Balance of Terror", "The Paradise Syndrome", "Arena", "Friday's Child").

It is not clear where the additional banks mentioned in background dialogue and in several episodes were located. The top view graphic of the original Constitution-class configuration, used on a computer screen in Star Trek III: The Search for Spock, places port and starboard emitters on the dorsal surface of the primary hull. Two emitters cover both flanks. 

The diversion of all but emergency maintenance power to the shields had the adverse affect of reducing phaser power by fifty percent. (TOS: "The Tholian Web")

The Constitution-class originally mounted at least 6 torpedo launchers, one tube covering the aft firing arc. Forward tubes were located in the same area as the forward phaser banks. The aft tube fired from the end of the secondary hull. This combined arsenal was powerful enough to destroy the entire surface of a planet. (TOS: "Arena", "A Taste of Armageddon", "Journey to Babel"; TAS: "More Tribbles, More Troubles"; ENT: "In a Mirror, Darkly, Part II")

Numerous inconsistencies originally existed between the dialogue and the special effects depicting the weapons of a Constitution-class ship. Many of those were corrected by the Remastered episodes effects shots, but some remain, making it impossible to formulate a conclusive assesment of the exact armaments of the original Constitution-class starship. Number of torpedo launchers is based on the line of dialogue: "fire photon torpedoes 2,4 and 6" from "Journey to Babel". 

After the refit of the 2270s, Constitution-class ships mounted three dual-emitter phaser banks on the ventral and three on dorsal faces of the saucer. They covered the forward, port and starboard flanks. Two single emitter aft banks are above the shuttlebay and four midship single emitter banks are located on the ventral surface of the engineering hull.

Phaser power was increased by drawing energy directly from the warp drive. This increase in firepower had a drawback in that the phasers would be cut off if the main reactor was off line. This problem hampered the USS Enterprise on at least two occasions, one in 2272 and again in 2283.

The post-refit vessels had two forward firing torpedo launchers, though each tube could fire at least two torpedoes before reloading. (Star Trek: The Motion Picture; Star Trek II: The Wrath of Khan; Star Trek III: The Search for Spock)
===Transporter systems===

Extravehicular transporter to and from the ship was accomplished by a number of transporter systems, which allowed personnel or equipment to be transported over large ranges. The transporter platform featured six pads, which were numbered clockwise, beginning with the right front. A redesigned field generator matrix was mounted into the rear wall of the chamber aboard the refit configuration Constitution-class starships.

Aboard the refitted Constitution-class vessels, the transporter operator stood within an enclosed control pod, which had a floor-to-ceiling transparent aluminum panel through which he or she could view the transport platform. This panel served to shield the operator from the effects of any cumulative radiations emitted by the new transporter machinery, a side effect of the more powerful system.

A door in the standard transporter room wall led to a staging area where landing parties prepared for transporter.

Refit Constitution-class starships possessed a number of airlocks permitting direct physical access to the ship. One was located at the aft of Deck 1 on top of the saucer section. Two more were located in the lower saucer section, port and starboard, concealed by sliding hull plates. (Star Trek: The Motion Picture)

One of these, [port], is shown in the "Spock walk" sequence. Since nearly every other such airlock has a matching one on the other side of the ship, it is reasonable to assume the presence of one to starboard. 

These lower two are accessed through staging areas. Four spacesuit lockers line one wall; each containing one suit, providing enough to clothe a standard party of four. A small, locked arms cabinet held phasers; communicators, tricorders, translators, and outerwear were contained in a separate cabinet on another wall. (Star Trek: The Motion Picture)

The next set of airlocks were located on the port and starboard sides of the torpedo bays. The final set were located on the port and starboard sides of the secondary hull at the midline. (Star Trek: The Motion Picture; Star Trek II: The Wrath of Khan) These airlocks opened into the ship's main cargo bay. There was also a "gangway"-style airlock on the port edge of the saucer section. (Star Trek: The Motion Picture)

The presence of a similar "passageway" visible in the Tholian drydock holding the USS Defiant suggests that it is a feature of the pre-refit Constitution-class as well. (ENT: "In a Mirror, Darkly")

Located on the upper surface of the saucer section of the refitted Enterprise were numerous small hatches used for entrance/egress during extra-vehicular activities. (Kirk, Spock, Decker, McCoy, and the Ilia probe use one of these hatches to leave the ship when they arrive at V'Gers "core".) (Star Trek: The Motion Picture)
===Landing bay and cargo facilities===

Deck 17 was the main access level of the engineering hull. The aft landing bay provided personnel in small craft with a means of entering or exiting the vessel, as did docking port on either side of the level.

The original configuration of the Constitution-class carried a standard complement of 4 Class F shuttlecraft. (TOS: "The Omega Glory")

The refit configuration Constitution-class starship featured a new landing bay design. A wide range of Starfleet and Federation craft could utilize this state-of-the-art landing facility.

Alcoves on either side of the landing bay provided storage for up to six standard Work Bees, and furnished all necessary recharging and refueling equipment. Additional space was available for the storage of non-ship shuttlecraft.

Just within the landing bay doors was a force field generator unit, which was built into the main bulkheads on either side of the entry area. This field allowed craft to enter the ship, while at the same time retaining the atmosphere and temperature within the landing bay.

Deck 18, the refit configuration shuttlecraft hanger bay, was situated at the widest point of the engineering hull. Much of the deck consisted of open space, as it was the mid-level of the cargo facility; thirty-two cargo pod modules could be stored in the alcoves lining the forward, port, and starboard sides of the bay.

The shuttle hangar had sufficient room for the storage of four craft at any given time. During normal storage situations, these shuttlecraft faced aft ward.

This deck also housed the vessel's lifeboat facilities. These one-man craft, which escaped through blow-away panels in the side of the secondary hull, were provided for those persons were unable to reach the primary hull in case of an emergency. (Star Trek: The Motion Picture)