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Original Configuration
Type:Heavy Cruiser
Length:289 meters
Beam:132 meters
Draft:73 meters
Mass:190,000 metric tons
Crew:430 (43 officers, 387 enlisted)
Maximum Speed:Warp 8 (Cochrane scale)
Armament:2 to 6 phaser emitters, 2 to 6 photon torpedo launchers
Defenses:Deflector shields
Refit Configuration
Type:Heavy Cruiser
Length:305 meters
Beam:141 meters
Draft:71 meters
Mass:200,000 metric tons (est)
Crew:500 (72 officers, 428 enlisted)
Armament:6 phaser emitters (dual mounts), 6 phaser emitters (single mounts), 2 photon torpedo launchers
Defenses:Deflector shields

The Constitution class starships were the premiere front-line Starfleet vessels in the latter half of the 23rd century. They were designed for long duration missions with minimal outside support. They are best known for their celebrated missions of galactic exploration and diplomacy which typically lasted up to five years.


The Constitution class starships were launched in 2245 (Star Trek Encyclopedia), and served as Starfleet's front-line vessel for the rest of the century. The Constitution class starships also served as a mighty deterrent to both the Klingon and Romulan Empires, several times taking part in combat actions which determined the fate of the entire Federation if not the Alpha Quadrant itself.

The ship was probably refurbished some time between 2254, when there were 203 people aboard, (TOS: "The Cage") and 2266, when the Constitution class had a crew complement of over 400 (TOS: "Charlie X").

USS Enterprise

The most famous Constitution class starship was the USS Enterprise, launched under the command of Captain Robert April in 2245. The Enterprise gained its reputation during its five year mission (2265-2270) under the command of Captain James T. Kirk. (VOY: "Q2")

Refit Configuration

In the late 2260s, the Constitution class starships underwent a major refit program. The actual refitting took eighteen months of work and essentially a new vessel was built onto the bones of the old, replacing virtually every major system. Thus the Constitution class starships continued in service for a further twenty years.

File:Wrath of khan enterprise.jpg

Refit configuration Enterprise.

Essential upgrades were made to the Constitution class' warp systems; the old cylindrical nacelles were replaced with new angular ones, and also the warp nacelle strust were new, as they were connected to the engineering hull much closer to the neck than before. The engineering hull roughly retained its original shape - while the original hull was essentially a conical cylinder, the refit was much more rounded. As for the interior of the hull, the most obvious upgrades were the englargment of the shuttle deck and landing bay, as well as the addition of an horizontal matter-anitmatter reaction assembly and a vertical intermix chamber.

New also was the installment of the double photon torpedo launcher with its rectangular housing in the neck of the vessel. Furthermore, the saucer section was considerably extended with almost 20 metres, while the rest of the surface remained about the same. Major changes were made to the interior of the Constitution class starship, however; many new systems were added and existing onces upgraded. Summerizing, only the internal structure of the saucer and very few of the engineering hull and neck may have survived the 2271-upgrade.

Technical Data

Original configuration saucer module.
Constitution class refit engineeringhull.jpg
Refit configuration engineering hull.
Refit configuration warp jump.
Constitution class refit impulsedrive.jpg
Refit configuration impulse drive.
Constitution class refit torpedo.jpg
Refit configuration torpedo bay.

Physical arrangement

The Constitution class starships were one of the first to feature the saucer-engineering hull design, which would later become recognizable for most other Starfleet vessels. The hulls were capable of saucer separation in case of emergency; the crew would than evacuate to the saucer module, while personnel unable to escape in time could abandon the engineering hull through way of escape pod. (TOS: "The Apple")

Command and control systems

The computer system aboard the Constitution class starship was duotronic based. (TOS: "The Ultimate Computer")

Propulsion systems

Until 2260, the Constitution class was furnished with a lithium-controlled Matter-antimatter reaction assembly, while a dilithium-controlled MARA was installed that year. The vessel's starndard cruising speed was Warp 6 (216c), while its maximum cruising speed was Warp 8 (512c). Maximum warp speed was reached by the USS Enterprise at Warp 14.1 (2803c) due to sabotage to the vessel's warp drive system. (TOS: "That Which Survives")

Following the 2271 refit of the class, the Constitition was equipped with a linear dilithium-controlled MARA, and a pulse dilithium-controlled assembly was installed in 2285 aboard the USS Enterprise. (Star Trek: The Motion Picture)

The Constitution class' impulse drive system was a twin-port fusion reactor engine, capable of 0.25c.

Tactical systems

Originally, the Constitution class starships were equipped with four capacitor-driven medium-power lasers. After 2260, the vessel had two phaser banks and three photon torpedo launchers (furnished with approximately one hundred torpedos) at its disposal. (TOS: "The Cage")

Interior Design

Original configuration bridge.
Refit configuration bridge.
Refit configuration bridge.
Refit configuration bridge (2293).

Main Bridge

Deck 1 was primarily composed of the vessel's Main Bridge, and it was from here that the commanding officer supervised the entire starship's operation. When seated in the command chair, located in the sunken centre section, the commander had visual access to all major personnel station and view screens, facilitating the decision-making process. This room was the nerve centre of the Constitution class starship, and was manned by the top officers of each department.

Navigation and vessel course control were carried out at the helm console, located in the centre of the room. Directly above this station, affixed to the ceiling, was the navigational sensor input system. This device transmitted by laser all input from the ship's main navigational sensor array, and tied directly into the astrogator console beneath it.

Other stations were provided for communications, engineering, weapons control, gravity control, damage control, environmental engineering, sciences 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 centreline, 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.

Only one turbolift serviced the bridge of the original configuration vessels. On the refit Constitutions, the bridge had access to two. (Star Trek: The Motion Picture)

The Starfleet Technical Manual, now considered apocryphal, states that the bridge is rotated 37° port, which would have the turbolift shaft travel down the centerline of the saucer section. No good reason is given as to why the bridge crew is looking in another direction than they're travelling.

Officers' Lounge

Refit configuration officers' lounge.

Located at the stern of Deck 3 aboard the Refit Configuration Constitution class starship was the officers' lounge. Here, four huge view ports afforded a spectacular view of the ship's warp nacelles and space beyond. To the sides, small planet areas holded flora from several worlds and a small pool featured fresh-water tropical fish. Just forward of this section of the lounge were two privacy areas. In each privacy area, a view screen was mounted into the wall, providing a full exterior tour of the vessel. (Star Trek: The Motion Picture)

Officers' Quarters

File:Original Enterprise quarters.jpg

Crew quarters.

Crew quarters were located throughout the saucer section - keeping with Starfleet tradition, Deck 5 housed the senior officers' quarters. These staterooms were quite similar to the V.I.P. units on Deck 4, with only a few differences.

Refit configuration officers' quaters.

The sleeping area holded a single large bed which could double as a sofa during off-duty relaxation. The room's corner circular nook, normally occupied by a dining booth, could be modified at the officer's request.

On the original series, several "different" crew quarters were seen, but always the same set was used, changed by different lighting designs and furniture configuration.

Recreational Facilities

Refit configuration recreation room.

Aboard the original Constitution class starships, there were at least six recreation rooms, which included three dimensional chess and card game tables. Also aboard were a gymnasium, a bowling alley, a threatre, and a chapel. (TOS: "Charlie X", "The Naked Time", "The Conscience of the King")

On the refited Constitution class vessels, recreational facilities were further expanded. One large room in the centre of the starship's saucer section furnished off-duty personnel with a wide variety of recreational games and entertainment.

At the front of the room was an immense, wall-mounted viewing screen. Beneath this was an information display alcove; five small screens exhibited, upon request, a choice of pictorial histories. A raised platform in the centre of the lower level floor featured a diversity of electronic entertainment.

Medical Facilities

On the original Constitution class starships, a Sickbay facility was located on Deck 6, which featured an examination room, a nursery, the Chief Medical Officer's office and a medical lab. Elsewhere on the vessel, another medical lab and a biopsy were located. (TOS: "The Naked Time")

Refit configuration sickbay.

The sickbay set of the pilot episode "Where No Man Has Gone Before" underwent considerably changes following the shooting of the episode for the remainder of the series.

With the class refit of 2271, the Medical Facilities of the Constitution class starship were considerably updated. New micro-diagnostic tables were capable of fully analyzing the humanoid body at the sub-cellular level, offering the physician a total understanding of the patient's status. Another new addition was the medical stasis unit, in which patients whose conditions were considered immediately life-threatening could be placed into suspended animation until the proper cure or surgical procedure could be established. (Star Trek: The Motion Picture)

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.

Refit configuration transporter.

Aboard the refited Constitution class vessels, the transporter operator stood within an enclosed control pod, which had a floor-to-ceiling transparent aluminium 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.

File:Constitution class refit armoury.jpg

Refit configuration staging area.

A door in the standard transporter room wall leaded to a staging area where landing parties prepared for transporter. Four spacesuit lockers line one wall; each containing one suit, providing enough to clothe a standard party of four. A small, locked arms cabinet holded phasers; communicators, tricoders, translators, and outerwear were contained in a separate cabinet on another wall. (Star Trek: The Motion Picture)

Engineering Section

Main Engineering was from where the ship's warp system was controlled. All thrust and power systems were primarily controlled form this site, as were the vessel's life support and gravitional control systems. (TOS: "The Ultimate Computer")

Refit configuration engineering.

During the 2271 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.

Refit configuration engineering.

Deck 15 housed the main engineering room. Located in the centre 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)

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 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 refuelling equipment. Additional space was available for the storage of non-ship shuttlecraft.

Refit configuration landing bay.

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 midlevel 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)

Ships Commissioned

Four Constitutions fly in formation.

Uncertain Ships




Constitution class model.

Matt Jefferies designed the original Constitution class starship for the original series. The image to the right show the almost final version of the first Enterprise. The next design stage was the preparation of scale drawing for model builder Don Loos, incorporating the final changes that would turn this into the Enterprise recognized by millions.

For Star Trek: The Motion Picture, a new Enterprise was designed by Andrew Probert, based upon Mike Minor's concepts for Star Trek: Phase II. Other artists who worked on the refit design were Joe Jennings, Douglas Trumbull, and Harald Michelson.

Interior Design

Officers' lounge elevation sketch.
Officers' lounge concept art.

Andrew Probert was production illustrator for The Motion Picture. A key concern of his was was that the sets built somehow conform to the structure of the starship they are supposed to exist within. Here we see Andrew Probert's development sketches for an officer's lounge in the saucer section's upper dome. Probert's concept art was, however, not used for the movie, and a much cheaper set was constructed for the scene.

File:Mike Minor cargodeck.jpg

Mike Minor concept.

Probert's main contribution for the Enterprise interior came in the form of the vessel's cargo deck, thoughts on which had already been visualized by veteran Mike Minor, before Probert had a chance to address it. Minor worked at the Paramount lot, while Probert was at the Robert Abel special effects facility designing various pieces of space hardware.

Filmed cargo deck scene.
Matte painting.
Andrew Probert matte rendering.
Andrew Probert matte rendering.

The thinking, then at Paramount under production designer Harold Michaelson, was that the cargo bay would be a space 30 feet high that had two walls with twelve holes containing cargo pods. Mike Minor's cargo deck design shows us cargo pods simply stacked or lined up on the deck, leaving a huge open and unused space above. The walkways along the sides were also rather old fashioned looking.

The image to the right shows the plate of the cargo deck scene, filmed from Kirk's perspective as he enters the new Enterprise. What Andrew Probert was required to do was to get a frame of plate film and have it printed at a pre-determined size. Part of this frame, required for the live action elements, would be cut out and pasted to a piece of illustration board. The remaining blank board, intended to be the matte, would then be painted around that piece, blending the two together.

Cargo deck sketch.

Following a discussion with Douglas Trumbull examining the logic of the early cargo deck concepts, this elevation sketch of the Enterprise was drawn by Andrew Probert upon Trumbull's question how the pods would get in and out of the cargo deck. What Probert proposed was that the landing bay and cargo deck be connected, allowing the easy passage of cargo trains.

The idea was that shuttles would normally take off from and land in the landing bay. They then could be lowered to the Hanger Bay level, or lowered another level to shuttle maintenance. A multi-paneled two-story door, between the elevators and cargo bay, has been opened to the sides allowing the transfer of cargo.


Although not considered canon, several sources have produced a long list of Constitution class starships. The main source was Franz Joseph's Star Fleet Technical Manual, which listed over 100 Constitution class ships divided into sub-classes: Constitution, Bonhomme Richard, Achernar and Tikopai. Ships of the class were later expanded by other publications such as Ships of the Starfleet which included the Endeavour, Enterprise and Enterprise (II) sub-classes.


  • Registry numbers: Although the Star Trek Encyclopedia and other references provide complete registry numbers for many Constitution class ships, these numbers are at best conjecture. Many of the Encyclopedia's numbers, especially, were derived from the faulty assumption that the list seen on the wall at Starbase 11 in Court Martial were all Constitutions. Many fans now doubt that claim.
  • Uncertain ships: These ships have been listed in various references as Constitutions, but were never seen on screen as such, and are therefore of uncertain class.
  • "Starship" class: If you read the dedication plaque on the bridge of the original Enterprise, it was actually listed as "Starship Class". The term Constitution class came later, probably from "Space Seed", where one of Scotty's technical manual screens showed a phaser bank diagram for a "Constitution class" starship. Though it was "understood" to have been Constitution Class by both production staff and fans alike, the first time it was actually referred to as such was by Captain Jean-Luc Picard in "The Naked Now".
  • "Enterprise" class: The exact designation of the Constitution refit is a divisive one within Star Trek fandom. Some maintain that the comprehensive nature of the refit of the Constitutions between TOS and the movie era constitutes a new starship class, while others consider the two types maintaining the same profile and hull geometry as keeping the class consistent.
In Star Trek II: The Wrath of Khan, the USS Enterprise simulator at Starfleet Academy refers to the ship as an "Enterprise class" vessel. However, the blueprints that Scotty is seen examining in Star Trek VI: The Undiscovered Country are labeled "Constitution Class (Refit)".
Both designations are supported by behind the scenes material and interviews, Andrew Probert in particular mentioning that the design for the refit was originally designated "Enterprise-class".
The official canon maintains the (Refit) classification as the correct designation.
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