Starting in the late 2260s, a number of engineers were worrying about rising tensions with both the Klingon and the Romulan Empires, and the growing obsolescence of a number of Starfleet ships. Starting in 2268, Starfleet's Corps of Engineers initiated a design program to revitalize the fleet.

The first design that came out of the initiative was a new saucer section with an improved sensor grid and shield grid, and more powerful impulse deck. The bridge was modernized and a number of design flaws in the prior generation of bridge were resolved. The warp engines were redesigned with an improved bussard collector system and improved engine efficiencies, culminating in the FWG-1 engine being delivered in 2270. The issue raised with this, versus the side-project (the Constitution Phase II project), is the power system increases meant that a new engineering deck, intermix chamber, and nacelle pylons would need to be constructed.

Commander Scott of the USS Enterprise eagerly volunteered his ship for the Refit Program, and was placed in charge of the refit of his ship. The saucer was disconnected as the engines were removed, and the hull plating was removed from the engineering and saucer sections separately. The ship was stripped to the spaceframe, which was reinforced and rebuilt with similar proportions, but a new deflector housing, new computer systems, modern aesthetics, and modern defensive systems. After the V'Ger incident, the new systems underwent a proper shakedown, and as its systems proved themselves, the refit program proved its worth and began refitting other ship classes.

The Loknar, Larson, Nelson, Saladin, Anton, Cassard, Pompei, Constitution, Derf, and Valley Forge class ships all underwent upgrades from the 2240s aesthetic and technological generation to the modern 2270s aesthetic and technology. Ships had M-4 computers upgraded to the M-6, engines swapped with the FWG-1 model, FSP shield systems, phasers upgraded to FH-11, which channeled energy through the warp systems to upgrade the power ratings, and FP-4 photon torpedo launchers. Crew quarters were upgraded, crew recreation systems were updated, better botanical decks, officer lounges, sickbay systems, and engineering decks were all added to the ships.

Ship Class Originally Launched Year Refit Launched
Anton 2244 2272
renamed 'Miranda-class'
Cassard 2243 2274
Constitution 2245 2271
renamed 'Enterprise-class'
Derf 2255 2275
Larson 2245 2271
Loknar 2247 2274
Nelson 2245 2274
Pompei 2243 2273
Saladin 2249 2275
renamed 'Sherman-Class' for the USS Sherman
Tyrannis 2249 2274
Valley Forge 2249 2276

Gallery of ShipsEdit

All current vessels of each class (such as the Mk 3 Constitution-Class, and Mk 7 Loknar-Class) were ordered to refit, while all older vessels not yet upgraded would assume the duties of those ships undergoing refit on a rotating basis. Over 200 ships were refit over the next five years at various shipyard around the Federation during this time. As the designs were proven, all existing construction contracts were converted over to the new ship designs, and on a case-by-case basis, all older ships were either refit or scrapped if it proved too costly to refit the ships.

Ship InteriorsEdit

The following shows the ship interiors after completion of the refit project, bringing with it a unified fleet design for a modern age.


The new bridge style fixed a number of issues from the original Constitution-class ship. Originally served by 1 turbolift, then having to shift the bridge a few degrees in the 2259 refit rather than rebuild the turbolift shaft, engineers had made new-built Mark 2 Constitution-class ships with two turbolift shafts (only the original 13 ships had the single-shaft behind the captain), and this was carried through the new ship designs for safety concerns. Crew restraints and bolted chairs for safety in the event of inertial dampening field issues were added, along with a re-evaluated set of crew stations for more efficient ship system management.


Constitution-class refit bridge diagram

The defense and weapons systems were placed in a combined station that was angled away from the viewer so that opposing parties might not see the defensive status of the ship. Some stations were simplified and had their chairs removed, since in actual daily operation, many stations on the bridge were unmanned due to automation or other stations across the ship being used more regularly. Engineering, Science, Communications, and Weapons and Defense remained seated positions, while all other stations were turned more into monitors under regular duty. The streamlined flow made operations on the bridge more efficient and after the shakedown cruise of the Enterprise, these upgrades and changes were made fleet-wide.


The engineering deck of the new Constitution-class ship housed a modern intermix chamber, the first upgrade and vertical chamber in use in the fleet. The original Constitution-class intermix chamber still resembled that of the NX class in its orientation, with the dilithium chamber being accessible from main engineering's main deck, and the rest hidden under the deck plating. This was the source of a number of inefficiencies in actual space operations, and in Mark 2 Constitution-class ships this was changed to a 2-deck arrangement, allowing better engineer access to the entire warp drive.


Engineering deck as of 2271

The final Mark 3 Constitution-class ships had a newer vertical intermix chamber assigned to them, so their refit to the Enterprise sub-class was much easier to accomplish. These vessels also had the dual turbolifts to the bridge, and other design enhancements that made refit a smoother process than with older vessels.


Constitution-class (Mk 3) engineering deck with vertical intermix chamber.


The newer corridors were an improvement in multiple ways. They provided easier access to ship components for engineering personnel, allowed more decentralized computer components so that in the event of a failure of the main computer core, distributed computing components across the ship could handle the load at at least 85% capacity, with a focus on engines, weapons, and life support services. Each segment had an emergency oxygen mask in the event of an environmental issue behind the third segment from the bottom.

Corridor 04a

Modern (as of 2271) corridors with more modular design.