Defiant-Class Escort


Advanced Technical Specifications for the Defiant-Class Production Vehicle

Accommodation:  40 Officers and Crew

Classification:  Escort [Defensive/Patrol/Reconnaissance]

Funding for Defiant Class Development Project Provided by:  Advanced Starship Design Bureau; United Federation of Planets Defense Council.

Development Project Started:  2366

Production Start Date:  2372

Production End Date:  Still in Production

Current Status:  In Service

Locations of Defiant-Class Construction:

  • Antares Fleet Yard, Antares IV
  • Utopia Planitia Fleet Yard, Mars

Current Starship Identification and Registration Numbers: 

  • N/A

Former Starship Identification and Registration Numbers: 

  •   U.S.S. Pharaoh - NCC-82362




1.0  Defiant-Class Introduction
1.1  Mission Objectives
1.2  Design Statistics
1.3  General Overview
1.4  Construction History

2.0  Command Systems
2.1  Main Bridge

3.0  Tactical Systems
3.1  Pulse Phaser Cannons
3.2  Torpedo Launchers
3.3  Deflector Shields
3.4  The Warhead

4.0  Computer Systems
4.1  Computer Core

5.0  Propulsion Systems
5.1  Warp Propulsion System
5.2  Impulse Propulsion System
5.3  Reaction Control System

6.0  Utilities and Auxiliary Systems
6.1  Navigational Deflector
6.2  Tractor Beam
6.3  Transporter Systems
6.4  Communications

7.0  Science and Remote Sensing Systems
7.1  Sensor Systems
7.2  Tactical Sensors
7.3  Science Labs
7.4  Probes

8.0  Crew Support Systems
8.1  Medical Systems
8.2  Crew Quarters Systems
8.3  The Mess Hall

9.0  Auxiliary Spacecraft Systems
9.1  Shuttlebays
9.2  Shuttlecraft

10.0 Defiant-Class Flight Operations
10.1 Mission Types
10.2 Operating Modes
10.3 Separated Flight Mode
10.4 Landing Mode

11.0 Emergency Operations
11.1 Lifeboats
11.2 Rescue and Evac Operations

Appendix A - Commissioned Starships

Appendix B - Variant Designations

Appendix C - Basic Technical Specifications

Appendix D - Deck Layout

Appendix E - Author's Notes

Appendix F - Credits and Copyright Information




Pursuant to Starfleet Exploration Directives 911.3, Starfleet Defense Directives 114.9 & 154.7, Starfleet Borg Defense Initiative Directive 371.6 and Federation Security Council General Policy, the following objectives have been established for a Defiant-Class Starship:

  1. Ensure Federation security through rapid response to threat forces.

  2. Serve as the first-line of defense in military combat operations and lend support to larger Federation starships.

  3. Provide autonomous capability for full execution of Federation defense policy options in outlying territories and border areas.

  4. Take on the burden of border patrol and threat-response operations from other starship classes currently, and projected to be, in use.

  5. Provide a mobile platform for testing and implementation of mission-specific or new technology, specifically in the areas of covert and tactical operations.

  6. Serve as a platform capable of rapid deployment for special and covert operations deemed necessary by the Federation.



Length: 119.5 meters
Width: 90.3 meters
Height: 25.5 meters
Mass: 355,000 metric tonnes
Cargo capacity: 10,477 metric tonnes

Hull: Ablative armor overlaying a duranium/tritanium composite hull, augmented by synthetic castrodium alloy structural members
Number of Decks: 4



Editor's Note:  History written by Robert Siwiak - based on information found in Star Trek: First Contact,  Star Trek Encyclopedia, Star Trek: The Next Generation Technical Manual, Star Trek: Deep Space 9 Technical Manual, and Star Trek: The Magazine.  Please keep in mind that this is a history developed based on canon information presented in various sources and filled in with logical conjecture.

A Defiant-class starship is a heavily armored, limited-role Starfleet vessel developed at the Antares Fleet Yards in response to the Borg threat to the worlds of the Alpha and Beta Quadrants.  The project was officially begun in 2366 by Starfleet's Advanced Starship Design Bureau (ASDB) under less then ideal conditions, as far as the accepted normal sequence of research, development, testing, and evaluation was concerned.  Fortunately, a number of hardware innovations and design adaptations were already in the inventory and allowed for an acceptable level of reliability versus speed of systems integration and vehicle construction.

Defiant-class vessels are constructed of standard tritanium and duranium alloys and composites. The bridge has been submerged within a larger Deck 1 than was envisioned for the pathfinder vehicle, and the entire vessel has been shortened to four decks plus allowances for crawlways and cable trunks. The notched forward hull has been equipped with a detachable pod consisting of the vehicle's main sensor and navigational deflector, airlock module, and a last-resort matter-antimatter warhead. The warp nacelles have been brought inboard to a minimum safe distance for field EM, and all EPS weapon-power conduits have been truncated to provide a nearly zero lag time between activation signal and beam launch.

All protected internal systems that require access to the vessel exterior are equipped with articulated or jettisonable hull plates, so that most of the familiar structures are hidden from view, including shuttlebay doors, docking ports, lifeboats, impulse vents, and consumables resupply connectors. An integral set of ventral docking clamps and landing pads had been designed into Defiant for possible ditching operations as well as for recoverable planetary landings. No practical demonstration has been attempted, though simulations indicate that if the impulse and reaction control thrusters are fully operational, a successful liftoff to orbital velocity is likely.



The U.S.S. Defiant NX-74205 was the prototype vessel for Starfleet's Defiant-class starships.  It was Starfleet's first true warship and had no provision for families or diplomatic missions, no science labs, no holodecks, or any of the other comforts of home.  It was a heavily armored, stripped-down vessel that was created as a first strike vehicle for use in war, and incorporated the latest in Starfleet weaponry and defensive technology.  As befitted its role, the U.S.S. Defiant was considerably smaller than most Federation starships.  It had a normal operational crew of 40 people, but could accommodate up to 192 in emergencies.  Work on the Defiant project began in 2366 after Starfleet was alerted to the threat of a Borg invasion.  The ship was developed by Starfleet's Advanced Starship Design Bureau (ASDB) at the Antares Fleet Yards and at the Utopia Planitia Fleet Yards on Mars.  It was still in the design stages when the Borg arrived in 2367.  Even though the crew of the U.S.S. Enterprise NCC-1701-D defeated the Borg, Starfleet was sufficiently concerned about the danger of a second invasion attempt to continue work on the project. 

Overall responsibility for the Defiant project rested with Admiral Batelle Toh, though a number of more junior officers were responsible for day-to-day operations.  From 2367 to 2369, Commander Benjamin Sisko, a veteran of the Battle of Wolf 359, worked on the Defiant while he was stationed at the Utopia Planitia Fleet Yards on Mars.  The Defiant project began with the selection of an existing spacecraft design that had just entered the initial systems-level review stage.  No spaceframe had yet been constructed, and the hull shape was undergoing warp field interaction simulations.  The study vehicle, designated NXP-2365WP/T, was being considered as a fast torpedo attack ship for high-warp penetrations of threat defenses.  This Defiant pathfinder would have mounted six torpedo launchers, four in the primary hull and two in the engineering hull, capable of firing photon and quantum torpedoes at speeds up to Warp 9.982.  When the Borg threat drove the redesign of the pathfinder vessel, it was decided to compact the platform with warp nacelles and other structures, which were pulled in closer to the engineering hull, minimizing the sensor cross-sectional area and vulnerable appendages.  It was also deemed necessary to surround the hull with multilayer ablative armor, long considered unworkable for production starships.  In its initial Borg-suppression role, the Defiant class would have produced as few as six custom-built copies.  The mission of the Defiant did not change radically until it was out of the systems integration stage late in 2370 and into final hull reinforcing.  Intelligence-gathering efforts had come upon the Jem'Hadar problem, and in the final year of spaceworthiness testing (2372), the NX-74205 was redirected to Deep Space 9 to become a mobile defensive platform with orders to defend the space station, the wormhole, and Bajor.  Defiant was also tasked with patrol missions in the Bajor Sector and the Gamma Quadrant, engaging threat forces if necessary, as well as special covert assignments ordered by Starfleet Command. 

Early on in its development the Defiant was regarded as a fast torpedo attack ship.  Its designers planned to equip it with six torpedo launchers and a large complement of both photon and quantum torpedoes.  However, as the Defiant project evolved, the ship was given more ambitious mission objectives.  The Defiant's design was something of a departure for Starfleet; the development team took the decision to abandon the traditional Starfleet layout which placed the warp nacelles at the end of twin pylons and moved them in much closer to the main body.  This reduced the size of the Defiant's profile, making the ship a much harder target to hit.  In another important innovation, the designers gave their new ship multilayer ablative hull armor, which could resist repeated weapons fire.  Under the ablative armor, the original hull of the NX-74205 prototype was constructed of a castrodium/neutromium composite.  Due to difficulties inherent to the manufacturing of the exotic alloy neutromium, production-line vessels were chosen to be constructed with a modified duranium/tritanium composite augmented by synthetic castrodium alloy structural members, which makes the hull slightly more dense and less susceptible to impact damage then most other Federation starships.  Considerable effort went into making the Defiant faster and more heavily armed than standard Starfleet vessels.  It was equipped with both warp and impulse engines; by running a plasma conduit through the primary phaser coupling, the designers almost doubled the phaser power, and boosted the efficiency of the warp drive by 30 percent.  Standard cruise speed was warp 7, and safe maximum warp speed was warp 9, though the Defiant was capable of exceeding that limit for short periods of time in an emergency.  Indeed, Defiant's warp core rarely functioned at full capacity, because it was discovered that doing so endangered structural integrity. It wasn�t until extensive field analysis and on-site development, by Commander Benjamin Sisko and Chief Miles O�Brien, had been conducted that the ship�s propulsion and power systems could be run at design specifications.

Once the Defiant prototype had proven itself, Starfleet took the decision to put the Defiant-class into production.  By the end of 2373, there were a significant number of Defiant-class ships in operation, and over the next two years they played a vital role in the Dominion war. 

The U.S.S. Defiant NX-74205 was destroyed by a Breen ship in 2375.  Another Defiant-class ship, the U.S.S. Sao Paulo, was assigned to Deep Space Nine on Stardate 52861.  Given the U.S.S. Defiant's exceptional record under Captain Sisko's command the Chief of Starfleet Operations gave a special dispensation to change the ship's name to Defiant.  On this ship, the shield generators were completely reconfigured so that it would not be affected by the Breen's energy-dampening weapon.  This new Defiant played a distinguished role in the final battle with the Dominion at Cardassia Prime, and remains stationed at DS9.




The bridge layout of a powerful Defiant-class warship is compact, but nonetheless accommodates the familiar engineering, tactical, science, conn, and ops stations.  The main bridge acts as the nerve center for this sleek escort, and the entire module is sunken into a much larger Deck 1 than on most Federation vessels to provide added protection during combat situations.  Access to the bridge is provided by two doorways at the back, located on both port and starboard sides.  Just forward of the starboard entryway is the location of the ship's dedication plaque, as well as an auxiliary computer access panel.  The port side of the bridge houses the Engineering and Tactical I stations while the starboard side features the Science and Tactical II stations.  Because of its nearly exclusive role as a combat vessel, stations aboard Defiant-class vessels are designed with speed in mind.  All of the five main stations on the bridge feature dedicated ODN access lines to the computer core, and can even bypass the core should it be taken offline.  Triple redundant access lines connect the entire bridge to the rest of the ship, and dedicated ODN relays allow for damaged systems to be bypassed and computer lagtime to be decreased.

The center of the bridge features the lone Captain's chair, which is on a raised platform and has a clear view of all the bridge stations, as well as the main viewscreen.  On both sides of the command chair are separate control panels, allowing the occupant access to virtually every system aboard the ship.

Between the command chair and the viewscreen is an integrated flight control and operations panel, capable of performing the joint duties of those stations' larger counterparts on other Federation starships.  Like all of the bridge stations on a Defiant, the Conn has been designed so that the time in between a command being entered in and the action being taken is close to being instant, allowing for the craft to be handled almost like a fighter when under the hands of a skilled pilot. 

The Engineering Station allows for a direct link to the impulse and warp engines, as well as monitoring of the other various systems vital to the operation of the ship.  This single station is capable of mirroring all the readouts and consoles located in Main Engineering, allowing the Chief Engineer or other officer to issue commands from the bridge.

Mirroring the Engineering Station on the port side of the bridge is the Science Station.  Normally occupied by the ship�s Chief Science Officer, the panels and readouts on this station allow direct access to the ship�s sensor systems and science labs.  Capable of taking high resolution scans of both natural and artificial phenomena, this station plays a vital role during reconnaissance missions.

Flanking both sides of the viewscreen are two Tactical Stations, which have primary access to the ship�s powerful pulse phaser canons, torpedo launchers and various other special ordinance packages.  Working closely with Conn, the officers stationed at these consoles are responsible for firing the various weapons aboard Defiant-class vessels during combat operations.  The purpose of the Tactical II Station is to lighten the load on its sister station, particularly in battle.  During normal cruise modes, this station can be reconfigured for other operating modes.

The aft portion of the bridge varies from starship to starship, but two popular models have come into use for the arrangements available.  Earlier versions of the Defiant make use of a multipurpose mission-planning table, which acts as an informal conference table for the bridge officers.  This table is capable of displaying various mission relevant information in a variety of forms, including a holographic projection just above the table�s surface.

The second available arrangement involves a two-man console that is situated just behind the Captain�s chair.  Like all other bridge consoles, with the exception of the Conn, this station can be reconfigured to suit the operator stationed on it.  Because of the limited space aboard Defiant-class vessels, the primary stations are designed to fill a variety of roles depending on the current situation or mission profile.  Available console arrangements preprogrammed into all the bridge stations include:

  • Communications
  • Operations (Dedicated)
  • Tactical
  • Science
  • Environmental
  • Damage Control
  • Engineering

While a flexible LCARS program allows for any variety of console reconfigurations, the above-mentioned presets are the most common chosen by bridge officers.  Should a situation warrant it, these stations can be configured to act as a secondary station, such as Tactical II or Science II.  It is the discretion of the ship�s Commanding Officer as to how to allocate bridge space.




A total of four pulse phaser cannon assemblies are located in forward-facing locations onboard Defiant-class vessels.  The cannons are located above and below the nacelle root attachments on the main body on both port and starboard sides of the ship.  Due to the ship�s extreme maneuverability, yard engineers deemed it unnecessary to mount aft-facing cannons onboard vessels of this class.  Computer simulations also indicated an unacceptable loss in phaser power performance due to increased strains on the power systems from the proposed aft-mounted cannons.

The development of the pulse phaser cannon applies a number of lessons learned at the Starfleet Tokyo R&D facility, where large, nearly flawless emitter crystals had been grown in ground-based microgravity chambers.  The new crystals, combined with rapid-discharge EPS capacitance banks and high-speed beam-focusing coils, allowed the phaser discharge to be stored temporarily (up to 2.1 nanoseconds) within the coils and then released as a layered pulse structured something like an onion and is able to land a target contact that is more difficult to disperse than a standard phaser beam.  Four pulse phasers are located above and below the nacelle root attachments on the main body.

Pulse phaser cannons store up their charge between 1.7 and 2.1 nanoseconds, resulting in an energy pulse more powerful then standard Type-X phaser emitters.  Rapid fire of multiple bursts is accomplished through a direct EPS shunt from the warp reactor.  If situations warrant, power can be routed from the impulse engines through a secondary plasma tap.  For maximum effectiveness, all four cannons fire several bursts at the same time, resulting in a large amount of energy impacting a relatively small location.  This tactic has been proven to pierce the shields of threat vessels without having to collapse the entire grid.  Maximum energy output of a pulse phaser cannon is classified as of this date.

Pulse Phaser Range: Maximum effective range is 150,000 kilometers.



Earlier production line Defiant-class vessels have a total of four torpedo launchers, two forward and two aft.  During the Dominion War, it was found that Defiant-class starships were better suited to engage in hostile encounters with their phaser cannons, and the awesome number of torpedo launchers only served to use up the relatively small stockpile that the ship could handle.  As a result, the second and current production line of Defiants makes use of a total of three torpedo launchers, using a location underneath the bridge originally intended for tactical systems for a third shuttlebay.  

On both variants, the aft launchers can be found just behind the aft landing struts and Shuttlebays 1 and 2.  The first production line vessel's two launchers were located in the space between the warp engine housing and the detachable Warhead.  The Defiant (UPRTD) retains the aft torpedo launchers and replaces the other two launchers with additional tactical and scientific sensor packages.  The removal of the stockpile space and older targeting systems allowed for the addition of a third shuttlebay in this variant.  The new single forward-facing launcher is located just below the main deflector at the fore of the ship in a location originally used for a variable-setting beam emitter.

Along with the Sovereign-class, Defiant-class vessels are the only starships in the fleet normally outfitted with the Mark Q-II Quantum Torpedoes.  But like all Starfleet ships, the launchers onboard a Defiant are capable of firing standard photon torpedoes as well. 

Payload: The uprated design is capable of carrying a maximum of 64 torpedoes, while the original design had a standard load-out of 96.

Range: Maximum effective range is 3,000,000 kilometers.



Being of a relatively new and unique design compared to other ships in Starfleet�s inventory, it is somewhat surprising that the Defiant-class line of ships makes use of standard graviton polarity source generators, the design of which has not changed much in the past 70 years.  Off the shelf generators used in Galaxy-class starships were heavily modified by the original yard engineers at Utopia Planitia to closer pack the twelve 32 MW sources found in each generator, allowing for an additional four sources to be added.  Designed in response to the oncoming Borg threat in the 2270�s, all ships of this class make use of automatically rotating shield nutations. 

A Defiant makes use of a total of four shield generators located throughout the vehicle space frame.  The forward-most generator is located along the vehicle centerline within the Warhead section, and is responsible for keeping it shielded in the event that it must separate from the ship.  Two additional generators are located further within the hull from the warp nacelles, port and starboard, while the final generator is located on the centerline just above the main impulse engines and forward of the deuterium storage tanks on Deck 1. 

Standard flight operations require that at least two generators be operational at any given moment.  To simplify field manipulation, it is desired for two corresponding units to be online, meaning that the forward and aft units should be used in sync, or the port and starboard units.  During high-impulse and warp flight, the generators are kept at their minimum output to deflect stray particles in the interstellar medium from impacting the ship and degrading the hull.  Should conditions warrant, one generator is capable of protecting the entire space frame.  At high levels of alert, all generators are brought online and create a multilayered graviton field around the ship.  In combat situations, the field is typically within several meters of the hull, creating an oval shape.  If required, the field can be extended outward to protect another vessel or object at the sacrifice of some protection.



With the addition of the warhead component aboard the Defiant-class, yet another radical departure has been made from Starfleet's standard policy concerning tactical operations.  Designed as a single-use last-ditch explosive component, usage of the warhead weighs as heavily upon a ship's commanding officer as the possible order to initiate self-destruct. 

Housed at the forward-most portion of the ship, the warhead contains the ship's main navigational deflector, forward torpedo launcher and magazine, forward airlocks, and dedicated impulse engines for independent powered flight.  Access to this area is provided by two walkways on Decks 2 and 3 where miniaturized versions of the standard airlock provided sealable entry between the main vehicle and the warhead.  Interior movement within the pod is provided by two ladders that run between decks.  A dedicated control room is located on Deck 2 and allows for both user operated and automatic control of the Warhead.

Typically used when the vessel is totally disabled, it should be noted that once the warhead is launched it cannot be reattached to its parent craft without the assistance of a space station equipped to handle small starships.  Once the order is given, the Warhead section is detached from the parent spaceframe by means of four explosive bolts that serve to provide the initial forward momentum for the pod to leave the ship before engaging its own engines.  EPS power distribution lines and ODN hard lines between the two craft are designed to break apart at key points during the separation, and the EPS flow is cut off upstream to prevent spill-off.  Once free from its parent, the warhead is capable of achieving .8 c and automatically arms all remaining torpedoes present in the launcher storage area.  Computer projections indicate that the entire warhead vehicle will be destroyed in the resulting collision between it and its target.  Due to space restrictions, no escape pods are present in the warhead section, meaning any crewmembers aboard tending to the vehicle will perish in the resulting explosion.  Feasibility of using the warhead as an escape vessel during imminent parent vessel destruction is currently under consideration at the time of this writing.

Without its main deflector dish, the Defiant-class vessel is unable to engage at high warp.  However, the three remaining defensive shield generators, under computer simulations, have been shown to be able to sufficiently shield the vessel at low warp speeds in the event of an escape after the warhead has been separated.  These generators are also capable of shielding the ship after the forward generator is lost once the warhead separates.




Twin isolinear processing cores are situation just aft of the bridge on Decks 2 and 3.  The total computer core possesses 675 banks of chromopolymer processing and storage sheets, for a total capacity of 246.97 megaquads.  The system is normally powered by an EPS shunt from the aft impulse reactors, but can be powered by a smaller regulated EPS conduit from the warp core.  Cooling of the isolinear systems is accomplished by a regenerative liquid nitrogen loop, which incorporates a delayed-venting heat storage block for stealth activities.  The typical mission requirements for the main computer involve only 45 percent of the processing and storage capacity; the other 55 percent is reserved for intelligence-gathering or tactical operations, or taking over for a damaged core.  Defiant-class vessels can operate on a single core and can even retain some critical data from a damaged area through compression and scattered storage methods.

A network of 48 quadritronic optical subprocessors is distributed throughout the volume of the vehicle spaceframe.  The main bridge has a total of 18 dedicated and shared subprocessors, which permit operations even in the event of main computer core failure.

In addition to its obvious defensive capabilities, the Defiant-class was also designed to perform fast-paced reconnaissance missions.  In stealth mode, the EM output of the vessel blends in with the natural emissions of the surrounding space while sensors attempt to scan the area with the highest detail.  This raw information is dumped into the computer core, and after returning to friendly space, the twin computer cores are easily removed from the ship through hull plates just behind Shuttlebay 3 on Deck 3.  This is done so that a fresh core can be swapped in, and the ship can return to its reconnaissance operations while the data from its previous mission is analyzed from the safety of Federation space.




The warp core is located in the aft engineering section and spans the top three decks vertically.  The matter-antimatter reaction assembly (M/ARA) is embedded within Deck 3, with the surrounding systems balcony above, on Deck 2.  The core is constructed from a central translucent aluminum and duranium reactor with dilithium articulation frame, four-lobed magnetic constriction segment columns, and matter and antimatter injectors.  Plasma transfer conduits exit the core on Deck 3 and extend laterally to the nacelles and the warp plasma injectors.  The nacelles incorporate an experimental in-line impulse system, which accepts matter intake and heating within the nacelles and exhausts the heated gases through a space-time driver assembly in the nacelle aft cap.  Antideuterium is stored in a series of standard Starfleet antimatter pods on Deck 3, forward of the warp core. 

The warp field coils, unlike most Federation ships, are located within the main hull as opposed to outboard nacelles.  The basic structure of the nacelles is similar to that of the remainder of the starship, however, the entire length of the nacelle housing is augmented with longitudinal stiffeners composed of cobalt cortenide to protect against high levels of warp-induced stress.  Throughout the nacelle housing are triply redundant conduits for Structural Integrity Field (SIF) and Internal Dampening Field (IDF) systems.  Each nacelle contains a pair of four warp field coils, making Defiant-class vessels have a total of 16. 

The Class-7 warp reactor is extremely powerful for a ship of this size, and as such, Defiant-class vessels put out a warp signature equivalent to much larger starships.  Advances in variable warp field geometry ensures that all ships of this class will not cause harmful subspace damage.  The standard maximum warp speed of the a Defiant is Warp 9.5, however, a speed of Warp 9.982 can be reached if power from the pulse phaser capacitors is used, thus taking that system offline for at least six hours as it recharges.  All regulation warp engine controls and procedures apply to Defiant-class vessels. 

In the event of a possible warp core breach, the main M/ARA is not designed to be ejected like on larger starships.  Instead, a series of four circular plasma exhaust vents on both the port and starboard sides of the ship are used to vent out the highly volatile warp plasma before it has a chance to breach the containment vessel.  Deuterium and antideuterium reactants are cut off up stream from the reaction chamber and the core is brought to a cold shutdown.  The only portion of the M/ARA that is capable of being ejected is the antimatter storage pods, located on Deck 3.  In the event of containment loss, twin hull loading plates are ejected from the underside of the ship and the pods follow shortly after.  Total replacement of the M/ARA can be accomplished during a major overhaul at a Starfleet Drydock or Fleet Yard facility and requires the removal of various hull segments not normally accessible during normal operation modes.

Type: Class-7 Matter-Antimatter Reaction Assembly (M/ARA).

Normal Cruising Speed: Warp 7

Maximum Speed: Warp 9.982 for 12 hours



The primary impulse system consists of three pairs of redundant fusion reactors, space-time driver coils, and vectored exhaust directors.  The exhaust products may be held temporarily in the impulse nozzle cowling, to minimize the ship's ion or EM signature, or they can be vented through electroporous plates along the trailing surface of the cowling.  All three main impulse engines are located on both Decks 2 and 3.  An experimental in-line impulse system further augments the standard engines, allowing for fuel conservation (See Chapter 4.1).

Standard operational procedures limit impulse speeds to .25c (Full Impulse) due to time dilation problems that occur once an object travels close to the speed of light.  Each individual engine is capable of propelling the ship to a speed of .75c.  Together, a speed of .994c (Maximum Impulse) can be reached but is only used during extreme circumstances due to relativistic time displacement accompanying objects traveling close to the speed of light.

A pair of smaller impulse engines are located on Deck 3 and provide propulsion and power to the Warhead section during separated flight mode. 



The Reaction Control System (RCS) thrusters are adapted from thruster packages from Galaxy- and Ambassador-class vessels.  A total of eight thruster groups are installed; two are placed in the forward hull, four in the mid-hull, and two in the aft cowling.  Deuterium is supplied by the primary tankage on Deck 2 and immediate-use tanks within thruster packages. 

Output: Each thruster quad is capable of producing 4.2 million Newtons of exhaust.




Defiant-class starships have a forward-facing twin-deflector system located on Deck-4 in the Warhead.  Situated on both sides of the forward torpedo launcher on the uprated version, the main deflector also houses key elements of the long-range sensor system.  Like most features on ships of this class, the deflector is reinforced with multiple tritanium struts, but its internal design is characteristic of most Starfleet deflector systems.  Each dish is composed of several molybdenum/duranium mesh panels over a tritanium framework.  Should one system become severally damaged, the other deflector can compensate by adjusting the ship's deflector field.  It should be noted, however, that at speeds exceeding Warp 5 one deflector is unable to sufficiently clear the ship's path and may result in impacts with micrometeoroids and stray interstellar particles since the deflector field is unable to compensate for the added subspace distortion. 



Type:  Multiphase subspace graviton beam, used for direct manipulation of objects from a submicron to a macroscopic level at any relative bearing to the starship. Each emitter is directly mounted to the primary members of the ship's framework, to lessen the effects of isopiestic subspace shearing, potential inertial imbalance, and mechanical stress.

Output:  Each tractor beam emitter is built around three multiphase 15 MW graviton polarity sources, feeding two 475 millicochrane subspace field amplifiers. Phase accuracy is within 1.3 arc-seconds per microsecond, which gives superior interference pattern control. Each emitter can gain extra power from the SIF by means of molybdenum-jacketed waveguides. The subspace fields generated around the beam (when the beam is used) can envelop objects up to 920 meters, lowering the local gravitational constant of the universe for the region inside the field and making the object much easier to manipulate.

Range:  Effective tractor beam range varies with payload mass and desired delta-v. Assuming a nominal 15 m/sec-squared delta-v, the multiphase tractor emitters can be used with a payload approaching 116,380,000,000 metric tons at less than 2,000 meters. Conversely, the same delta-v can be imparted to an object massing about one metric ton at ranges approaching 30,000 kilometers.



Defiant-class vessels normally carry one primary and one backup transporter on Deck 1.  The modular unit includes a 45 percent scaled version of the standard pattern buffer tank and molecular imaging scanners found on larger starships.  The transporter is powered by an impulse system EPS tap and is EM-shielded with a multilayer duranium jacket.  The hull-transporter emitter pads are armored with electroporous plating, which requires the computer to maintain tighter control over the ACB in terms of look angle in dwell time on both beam-up and beam-down targets.

  • Number of Systems: 3

  • Personnel Transporters: 2

  • Cargo Transporters: 1



All standard RF and subspace communications systems are installed, with additional capacity for narrow-beam and encrypted signal transmission and reception.  Stealth com is possible through modulated impulse exhaust streams and navigational deflector beams.  A set of three primary and three backup subspace distress beacons is provided for emergency use.

  • Standard Communications Range: 42,000 - 100,000 kilometers

  • Standard Data Transmission Speed: 18.5 kiloquads per second

  • Subspace Communications Speed: Warp 9.9997




Ships of this class are equipped to perform highly detailed scientific missions, especially those concerned with defensive operations.  While not outfitted for extended scanning and analysis tasks, the suite of onboard systems is well suited for 82 percent of the standard astophysical, biological, and planetological sweeps and accompanying data reduction.  A load out of ten mixed class-1, -3, and -5 probes is normally provided at nearby starbase layovers and can be supplemented with class-9 and -9 quantum or photon torpedo-derived probes. 

The external long- and short-range sensors are adapted from standard sensor pallets and set behind selectively EM-opaque hull plating.  In most battle situations, the sensor clusters can retreat into reinforced wells until action levels have been reduced and then brought into closer contact with the hull plates.  All sensor inputs are recorded and analyzed within the computer core and displayed at the science panels on the bridge, or on PADDs, tricorders, or other displays around the ship.  Most sensor systems have been optimized for reconnaissance and spacecraft combat maneuvers.

Long range and navigation sensors are located behind the main deflector dish, to avoid sensor "ghosts" and other detrimental effects consistent with main deflector dish millicochrane static field output.



A suite of dedicated tactical sensors is located in triangular packages between the warp nacelles and Warhead section.  Originally, torpedo launchers were located in this position but field testing aboard the U.S.S. Defiant and information recovered from the sensor logs in the escape pods of the U.S.S. Valiant indicated that dedicated tactical sensors would prove more effective in long term battles, allowing for the pulse phaser cannons to more accurately lock onto threat vessels.



Two dedicated Medical/Science labs are located just behind the Warhead on Deck 2.  (See Chapter 8.1)


7.4 PROBES    

A probe is a device that contains a number of general purpose or mission specific sensors and can be launched from a starship for closer examination of objects in space.  Starfleet makes use of a total nine different classes of probes, which vary in sensor types, power, and performance ratings.  The spacecraft frame of a probe consists of molded duranium-tritanium and pressure-bonded lufium boronate, with sensor windows of triple layered transparent aluminum.  The standard equipment of all nine types of probes are instruments to detect and analyze all normal EM and subspace bands, organic and inorganic chemical compounds, atmospheric constituents, and mechanical force properties.  All nine types are capable of surviving a powered atmospheric entry, but only three are special designed for aerial maneuvering and soft landing. 

Due to restrictions in space aboard Defiant-class ships, only three probe types are carried aboard.  Starfleet regulations require the presence of at least one type of ejectable buoy capable of acting as an emergency beacon in the event of hazardous events that may result in the destruction of the spacecraft.  Three Class VI, one in each torpedo launcher's storage area, are onboard Defiants for this reason.  Two additional probe types, the Class VIII and Class IX, are also in place due to the relative ease with which a standard photon or quantum torpedo casing can be converted. 

7.5.6 Class VI Comm Relay/Emergency Beacon:
Range: 4.3 x 10^10 kilometers
Delta-v limit: 0.8c
Powerplant: Microfusion engine with high-output MHD power tap
Sensors: Standard pallet
Telemetry/Comm: 9,270 channel RF and subspace transceiver operating at 350 megawatts peak radiated power. 360 degree omni antenna coverage, 0.0001 arc-second high-gain antenna pointing resolution.
Additional data: Extended deuterium supply for transceiver power generation and planetary orbit plane changes
7.5.8 Class VIII Medium-Range Multimission Warp Probe:
Range: 1.2 x 10^2 light-years
Delta-v limit: Warp 9
Powerplant: Matter/antimatter warp field sustainer engine; duration of 6.5 hours at warp 9; MHD power supply tap for sensors and subspace transceiver
Sensors: Standard pallet plus mission-specific modules
Telemetry: 4,550 channels at 300 megawatts.
Additional data: Applications vary from galactic particles and fields research to early-warning reconnaissance missions
7.5.9 Class IX Long-Range Multimission Warp Probe:
Range: 7.6 x 10^2 light-years
Delta-v limit: Warp 9
Powerplant: Matter/antimatter warp field sustainer engine; duration of 12 hours at warp 9; extended fuel supply for warp 8 maximum flight duration of 14 days
Sensors: Standard pallet plus mission-specific modules
Telemetry: 6,500 channels at 230 megawatts.
Additional data: Limited payload capacity; isolinear memory storage of 3,400 kiloquads; fifty-channel transponder echo. Typical application is emergency-log/message capsule on homing trajectory to nearest starbase or known Starfleet vessel position



The main sickbay is located on Deck 2 between the mess hall and science labs.  Containing four biobeds, this room serves as the primary crew support facility during emergency situations.  The room is equipped with limited surgical facilities and is primarily intended to stabilize patients until they can be delivered to a nearby friendly starbase medical facility.  Six stasis pods are located just across the main corridor from the sickbay facilities, allowing for patients to be stabilized in the event that their ailment cannot be cured aboard the ship. 

In its limited role as a reconnaissance starship, the Defiant-class is equipped with two dedicated science/medical labs for field testing and investigations.  These rooms mirror their counterparts on larger Federation starships by making use of scaled down devices that would commonly be found on those ships.



The primary crew-support systems include twenty-two main cabins and ten contingency cabins, each equipped with a minimum of two bunks.  These cabins can be outfitted with as many as six bunks, allowing for a potential total crew of 192.  Each cabin is equipped with one replicator port and one standard computer terminal.  Overall, crew quarters aboard Defiant-class vessels are the most spartan when compared to other ships in the fleet.  Obviously, due to the nature of the ship's missions and the lack of facilities, families are not allowed onboard. 

A normal class-M environment is maintained throughout the vessel, but can be adapted in three of the crew living quarters for life-forms from class-H, -K, or -L worlds.  All atmospheric conditions, heating, and humidity are controllable by deck and by section.  All storable gases and fluids, as well as transfer and manipulation hardware, are distributed among all four decks and engineering spaces.

With emphasis towards the tactical systems being the foremost priority in the vessel designers' minds, crewmembers must be prepared to share their quarters with at least one other crewmate during normal times of operation.  Only the ship's Captain is given his own room on Deck 1, which doubles as an informal Ready Room.



Ships of the Defiant-class lack any sort of recreational facilities, and the only place for informal gathering is the two mess hall areas located on the port side of Deck 2.  Like all the equipment and materials aboard the ship, the mess hall was spartan and compact.  At the head of the room were three open slots that served as dispensers for the replicators.  A counter extends from the underside and is used for the placement of trays, mugs and eating utensils.  Seating inside the mess hall is provided by four metallic tables arranged in a semicircle at the wider end of the room.  These tables are approximately one meter square, and each has four stools connected to its legs.  In addition, the mess hall doubles as a makeshift meeting area that could be used to conduct crew briefings and mission profiles.  A tall screen panel located on one of the walls can be used as a visual aid to display tactical graphics. 




The current version of the Defiant-class vessel is equipped with one main shuttlebay and two auxiliary bays that double as exterior access hatches for Cargo Bays 1 and 4.

Shuttlebay 3 is a recent addition that has now become standard on the Uprated version of the Defiant, and houses a single Type-10 Shuttlecraft and the facilities to maintain it.  This two-story bay is located on Decks 2 and 3 directly beneath the main bridge in an area originally intended to house future weapons stores and computer upgrades. Two horizontal sliding hatches on the ventral side of the ship allow access to space while a ceiling-mounted tractor beam holds the shuttle in position for launch as the doors open.  The Deck 2 portion of the bay features a flight control booth that serves as the nerve center for shuttle operations.  This room also controls the doors of the other shuttlebays as well as having direct control of the main tractor emitters should a damaged shuttle need to be towed in.  Force field emitters throughout the bay ensure that atmospheric integrity will not be lost, even when the bay doors are open.

Shuttlebays 1 and 2 are located on Decks 3 and 4 and are each capable of housing two Type-18 Shuttlepods that, like the Type-10, were specifically designed for the Defiant before being put to use elsewhere in the fleet.  The Deck 3 portion serves as the main bay and contains an interior door that connects to a Work Bee storage area, as well as access to nearby cargo bays located throughout the deck.  The back of the bay contains an area for servicing the Shuttlepods and Work Bees, and a connecting elevator lowers the craft to the Deck 4 portion.  The lower portion contains the elevator mechanism, as well as the exterior doors for the bay, which are mounted facing the center of the ship.  These Shuttlebays also act as an exterior platform from which to conduct repair operations.




Type:  Medium short-range sublight shuttle.
Accommodation:  Two; pilot and system manager.
Power Plant:  Two 800 millicochrane impulse driver engines, four RCS thrusters, four sarium krellide storage cells.
Dimensions:  Length, 4.5 m; beam, 3.1 m; height 1.8 m.
Mass:  1.12 metric tones.
Performance:  Maximum delta-v, 16,750 m/sec.
Armament:  Three Type-V phaser emitters.

Developed in the mid-2360s, the Type-18 Shuttlepod is somewhat of a departure from the traditional layout for ships of its size.  In response to the growing threat of conflicts with various galactic powers bordering or near to the Federation, this shuttlepod was designed to handle more vigorous assignments that still fell into the short-range roles of a shuttlepods.  Even with her parent vessel under attack, the Type-18 was designed to function in battle situations and could even be used as an escape vehicle should the need arise.  Lacking a warp core, the pod is a poor choice for travel beyond several million kilometers.  Ships of this type are seeing limited deployment on various border patrol and defensive starship classes, including the Defiant-, Sabre-, and Steamrunner-class.



Type:  Heavy long-range warp shuttle.
Accommodation:  Two flight crew, two passengers.
Power Plant:  One 250 cochrane warp engine, two 800 millicochrane impulse engines, four RCS thrusters.
Dimensions:  Length, 9.64 m; beam, 5.82 m; height 3.35 m.
Mass:  19.73 metric tones.
Performance:  Warp 5.
Armament:  Three Type-V phaser emitters, two micro-torpedo launchers, jamming devices.

Developed specifically for the Defiant-class starship project, the Type-10 Personnel Shuttle is the largest departure from the traditional role of an auxiliary craft that Starfleet has made in the past century.  Short of a dedicated fighter craft, the Type-10 is one of the most powerful auxiliary ships, with only the bulkier Type-11 being more heavily equipped.  Nonetheless, the shuttle sports increased hull armor and the addition of micro-torpedo launchers, as well as a suite of tactical jamming devices.  A larger warp coil assembly, as well as torpedo stores, makes the Type-10 much more heavier then other shuttles.  Elements from the Defiant-class project that were incorporated into the shuttle include armored bussard collectors, as well as a complex plasma venting system for use during possible warp core breech situations.  This bulky craft is equipped with a powerful navigation deflector that allows it to travel at high-warp, and a complex sensor system makes this shuttle suitable for reconnaissance work.  Able to hold its own in battle situations, the Type-10 is seeing limited deployment on Defiant-class starships, as well as border patrol vessels and combat-ready ships.


9.2.3 WORK BEE

Type:  Utility craft.
Accommodation:  One operator.
Power Plant:  One microfusion reactor, four RCS thrusters.
Dimensions:  Length, 4.11 m; beam, 1.92 m; height 1.90 m.
Mass:  1.68 metric tones.
Performance:  Maximum delta-v, 4,000 m/sec.
Armament:  None

The Work Bee is a capable stand-alone craft used for inspection of spaceborne hardware, repairs, assembly, and other activates requiring remote manipulators.  The fully pressurized craft has changed little in design during the past 150 years, although periodic updates to the internal systems are done routinely.  Onboard fuel cells and microfusion generators can keep the craft operational for 76.4 hours, and the life-support systems can provide breathable air, drinking water and cooling for the pilot for as long as fifteen hours.  If the pilot is wearing a pressure suit or SEWG, the craft allows for the operator to exit while conducting operations.  Entrance and exit is provided by the forward window, which lifts vertically to allow the pilot to come and go.

A pair of robotic manipulator arms is folded beneath the main housing, and allows for work to be done through pilot-operated controls.  In addition, the Work Bee is capable of handling a cargo attachment that makes it ideal for transferring cargo around large Starbase and spaceborne construction facilities.  The cargo attachment features additional microfusion engines for supporting the increased mass.




It should be of little surprise that the Defiant-class is a spaceframe designed primarily for tactical and defensive operations, and thus, its primary mission types are rather one-sided when compared to most other ships that serve in the Federation fleet.  While this may appear to be short-sided of the Defiant, recent evidence suggests that continued hostilities between the Federation and threat forces means that tactical mission types will never be in short supply.

The following are the primary mission types for the Defiant-class vessel:

  • Tactical and Defensive Operations:  Typical missions include protection of Federation assets in the form of colonies and space stations from anticipated threat forces.
  • Patrol and Interdiction:  Typical missions include the patrol of established neutral zones, shipping lanes and recognized regions of dispute and/or conflict.
  • Reconnaissance:  Typical missions include scouting of areas deemed worthy of note by Starfleet Intelligence.
  • Emergency/Search and Rescue:  Typical missions include answering standard Federation emergency beacons, extraction of Federation or Non-Federation citizens in distress, retrieval of Federation or Non-Federation spacecraft in distress, small-scale planetary evacuation - medium or large scale planetary evacuation is not feasible.
  • Secondary Scientific Investigations:  In some cases, a Defiant is found to be the most suitable platform from which to perform certain scientific applications.  They include experiments and research that requires increased shielding to observe certain phenomena, or a weapons platform from which to test new technologies.

The listed mission types are by no means the only operations that Defiant-class vessels are capable of performing.  Even after the initial testing of the NX-74205 pathfinder vessel, Starfleet continues to run projections on possible mission types.



The normal flight and mission operations of the Defiant-class starship are conducted in accordance with a variety of Starfleet standard operating rules, determined by the current operational state of the starship.  These operational states are determined by the Commanding Officer, although in certain specific cases, the Computer can automatically adjust to a higher alert status.

The major operating modes are:

  • Cruise Mode:  The normal operating condition of the ship.
  • Yellow Alert:  Designates a ship wide state of increased preparedness for possible crisis situations.
  • Red Alert:  Designates an actual state of emergency in which the ship or crew is endangered, immediately impending emergencies, or combat situations.
  • Blue Alert:  Designates a state in which the starship is preparing to land on the surface of a planetary body.
  • Separated Flight Mode:  Used during periods when the Warhead is separated from the ship.
  • External Support Mode:  State of reduced activity that exists when a ship is docked at a starbase or other support facility.
  • Reduced Power Mode:  This protocol is invoked in case of a major failure in spacecraft power generation, in case of critical fuel shortage, or in the event that a tactical situation requires severe curtailment of onboard power generation.

During all modes of operation, the ship runs on four six-hour shifts designated Alpha, Beta, Gamma and Delta. 



See Section 3.4.



In extreme circumstances, a Defiant is capable of landing on a planetary surface by making use of four retractable struts built into Deck 4.  Originally designed to allow a ship to set down in a large landing bay within a starbase. actually field testing has shown that with all its engines in working order, a Defiant is capable of reaching escape velocity on planets with a mass less then 1.2 Earths.  Any planetary bodies with a higher gravity will result in the starship being unable to escape its gravity well.  With all available power routed to both the SIF and IDF, the ship is capable of making a controlled landing, preferable on a flat and stable surface.  Automated computer algorithms have been preprogrammed to allow greater ease of control for the flight control officer.

Taking off from a planetary body requires much more effort then landing.  All secondary and most primary systems must be taken offline to provide further power to the impulse engines and RCS thrusters.  The already overrated engines of the Defiant-class require that the ship be launched in a near-vertical manner.  SIF, IDF and gravity systems are brought to full enable while all other systems, including life support, are taken offline for the duration of the launch.  Seeing as the process typically takes only a few minutes, there is sufficient breathable air still in the system during the entire process. 




Aside from the escape options provided by the onboard shuttlepods, the principal survival craft is the Starfleet lifeboat, or escape pod.  The current lifeboat is sized to include two main types, a six-person and an eight-person version.  Defiant-class vessels carry twenty-six of the six-person types, which measure 3.6 meters tall and 3.5 meters across the hexagonal faces.  Each lifeboat contains enough consumable and recycling capabilities to keep the crew alive for eight months, longer with multiple lifeboats connected in standard "gaggle mode."  All are equipped with navigational processors and impulse microthrusters, plus emergency subspace communication systems.  These units have been specially modified for low-observability and minimal EM signatures due to the general wartime conditions.



Rescue and evacuation operations generally fall into two categories, rescue and evacuation to the ship, and evacuation from the ship.  The former will generally involve transport from another ship or planetary surface.  The latter will generally involve removal of the ship's company to another ship, a planetary surface, or into space.

Rescue Scenarios

Due to the nature of the Defiant, its ability to perform in evacuations is hindered by the limited amount of space onboard, as well as the small number of transporters available.  With the cargo transporter reconfigured for quantum resolution transport, the Defiant is capable of beaming aboard 175 persons per hour.  Typically, this is deemed an acceptable beam up speed since the Defiant is only capable of evacuating 150 persons from a ship/station/planet in need.  The Type-10 shuttlecraft onboard is also capable of assisting in evacuations, however, the shuttlepods are ill-equipped to render such need.

Abandon-Ship Scenarios

As the Dominion War had indicated, it is quite conceivable that a starship may be lost in battle or due to other unforeseen circumstances.  While Starfleet general policy dictates that all efforts must be made to save a starship, situations sometimes warrant the total evacuation of a ship.  As stated before, Defiant-class vessels are capable of transporting 175 persons in one hour.  Unlike most Federation starships, Defiants lack dedicated emergency transport systems.  Instead, they rely heavily on escape pods to evacuate the ship.  In addition, all four shuttlepods and the Type-10 shuttlecraft are brought to full operation and are capable of carrying personnel from the ship.  After the computer has acknowledged that all personnel have cleared the ship, it begins to lock out all major command functions so that information cannot be stolen from the ship should a hostile vessel board a Defiant before a salvage team can make it to the site.  Automated distress beacons are launched shortly after.  At the time of this writing, computer simulations suggest that the Warhead section could be used as an escape vehicle if that portion of the ship isn't severely damaged.



The following starships have been commissioned by the Federation:

  • U.S.S. Defiant NX-74205 - Destroyed in Breen confrontation.
  • U.S.S. Valiant NCC-74210 - Destroyed in Jem'Hadar confrontation.
  • U.S.S. Sao Paulo NCC-75633 - Renamed U.S.S. Defiant NX-74205
  • U.S.S. Pharaoh NCC-82362



AES - Armored Escort Starship
AESU - Armored Escort Starship Uprated




Officers and Crew:  40
Evacuation Limit:  150


Overall Length:  119.5 meters
Overall Draft:   90.3 meters
Overall Beam:  25.5 meters


Maximum Velocity Warp:  9.982 (12 hours maximum)


Standard - 4 Pulse Phaser Cannons, 2 forward torpedo launchers, 2 aft torpedo launchers
Uprated -  4 Pulse Phaser Cannons, 1 forward torpedo launcher, 2 aft torpedo launchers


Shuttlecraft (Standard)

  • 4 Type-18 Shuttlepods

  • 2 Work Bees

Shuttlecraft (Uprated)

  • 4 Type-18 Shuttlepods

  • 2 Work Bees

  • 1 Type-10 Shuttlecraft


  • Two personnel

  • One cargo



Deck Layout for Uprated Variant:

Deck 1:  Main Bridge, Captain�s Ready Room, Transporter Room 1, Pulse Phaser Cannons (2), Upper Main Engineering, Plasma Exhaust Vents, Upper Sensor Array, Officer and Crew Quarters, Deuterium Storage

Deck 2:  Lower Main Engineering, Main Impulse Engines, Computer Core, Targeting Sensors, Mess Hall, Warp Coils, Med/Science Lab, Sickbay, Transporter Room 2, Officer and Crew Quarters, Warhead Control Room

Deck 3:  Main Impulse Engines, Warhead Impulse Engines, Shuttlebay 1-2, Shuttlebay 3, Antimatter Storage, Cargo Bay 1-4, Airlocks (2), Aft Torpedo Magazine, Warp Coils, Shuttle and Work Bee Maintenance

Deck 4:  Landing Struts, Navigational Deflector, Pulse Phaser Cannons (2), Forward and Aft Torpedo Magazines, Aft Torpedo Launchers (2), Forward Torpedo Launcher (1), Lower Senor Array, Shuttlebay 1-2 Exterior Doors and Elevator System, Main Tractor Emitter



From the Desk of Robert Siwiak:

This is the one point in this entire page where you'll find that, for the first time, I've stepped out of the Star Trek universe and back into our own 21st Century mindset.  The information presented on this page is a result of hours and hours worth of researching, more researching and then a rigorous and intensive process of compiling the best information from canon sources, and making an attempt to fill in the blanks.  For the purposes of ST:ACTD, these are the specs for the Defiant-class vessel, like them or not.  Now to address some of the problems found in compiling this information, followed by a brief explanation as to why a certain path was taken in these specs.

Defiant History:  Why does it seem that the history of the Defiant has just been cut and pasted from many sources?  Because it is, all of them being considered canon or semi-canon sources.  The history of the starship classes that we create are made to coincide with what is seen on screen, and it is not or duty to rewrite what has already been established without just cause.  The history of the Defiant has already been written by a handful of people, all of which are either staff members involved with the production of Deep Space Nine or under authorization from Paramount to do so.  There are not many places left in the ship's history to allow for useful writing that would benefit the readers of these specifications without dipping too deep into the realm of fiction. 

Hull:  While Star Trek: The Magazine lists the original Defiant's hull as being constructed with a castrodium/neutromium composite, none of us on the team has any recollection of a DS9 episode stating this.  Our main concern is that neutromium has a very similar spelling to neutonium.  The latter happens to be the same substance that the TOS Planet Killer was made of, while the former is what I believe the cargo door to Dominion Headquarters in DS9's "What You Leave Behind" was constructed of.  Nonetheless, it isn't mentioned anywhere else, which leaves us to believe it is some sort of exotic substance.  Still, to cover our butts, Steve suggested that we say the original NX-74205 hull had what the ST: Magazine said, and all production line ships are of a more standard type.

Size of the Defiant:  This is perhaps one of the most widely debated topics when it comes to this starship.  As it turns out, backstage information tells us that this ship was designed with no real size in mind, which is why you'll find no identifying marks on the studio model in terms of windows and airlocks; things that would give away the true size of the ship.  The DS9 Tech Manual states that the ship is 170.68 meters in length, but onscreen evidence shows the ship to be more around 120 meters in length.  The master systems display seen in engineering and throughout the ship was designed with a 120 meter length in mind and in addition, the sizes of the living quarters, sickbay, mess hall and various other studio sets further support the 120 meter design.  The two foldout schematics of the Defiant at the back of the DS9 TM also are made around a 120 meter model as well.  The purest canon is considered to be the actual onscreen evidence, and therefore, I assume that the Defiant is 120 meters in conjunction with that evidence.  The relatively recent publishing of the "Starship Spotter" also supports this size.

Decks:  While Worf was heard saying that there was once a plasma leak on a so-called "Deck 5," onscreen evidence and Master Systems Displays (MSD) point towards a 4 deck Defiant.  The only support for a Decks 5 and 6 is the appearance of several portholes at the back underside of the Defiant model, but we do not know for sure if these are windows or possibly something else.  Because we see more references to a 4 Deck version of the ship as opposed to a 5 deck, I've concluded that the ship only has 4.

Torpedo Launchers:  Throughout DS9 we've always seen the Defiant launch torpedoes from the targeting weapons sensor pods near the front of the ship.  The DS9 TM and MSD like to tell us that the forward torpedo launcher is located just beneath the main deflector at the front of the ship.  This seems to make sense with the Warhead module, which is said to be able to detach from the Defiant and act like a mobile torpedo.  If the torpedo launcher were located in the front, then the torpedo magazines for the forward launcher would add to the Warhead's destructive power.  MSDs show that the ship has two aft torpedo launchers, which makes sense even if the DS9 TM says there's a total of 2 launchers on the ship.  It also says the Galaxy-class has two launchers, but we know for a fact that a third launcher is located in the saucer section as stated in the TNG TM.  You'll notice that the torpedo launcher anomaly is discussed in these specs, and appropriate cover-ups and explanations are included for the two variants.  For the purposes of ST:ACTD, all Defiant-class ships are of the later design, meaning there's only a total of 3 torpedo launchers.  Think that it's a little premature to call this new version the UPRTD one?  Well, it needs to be called something... and Production Run 2 Variant didn't sound so good.

Phantom Phaser Arrays:  Several times we saw Defiant-class ships fire a standard phaser beam blast from the upper area of the ship, close to the Main Bridge.  While on the model we can see two strip-like objects on the upper hull, the phaser blasts seen onscreen are not anywhere near those pseudo-emitters.  It was a rare occasion to see a blast from that area, so we're assuming that those ships were perhaps outfitted with a special test module to see if it was feasible to mount standard phaser strips on the Defiant.

Probes:  Obviously, the Defiant is simply too small to allow for it to be equipped with all the known types of probes listed in the Star Trek: The Next Generation Technical Manual.  Since the ship already carries a number of photon and quantum torpedoes, the Class VIII and Class IX are the only known types that make use of the same casings.  Switching out a warhead with a sensor package takes only a few minutes, and saves a lot of space; especially when the components for the sensor package can be replicated, while the warhead and warp sustainer coils cannot.

Cloaking Device:  Only the original Defiant, which was destroyed in battle, carried a Romulan Cloaking Device onboard.  This was on loan from the Romulan government, and treaty stipulations still apply for all other starships.  Bottom line, no other Federation starships can legally use a cloaking device until we hear onscreen that revisions have been made to the Treaty of Algeron.

Warp Core Ejection Systems:  So far, I've yet to see a hatch on the underside or topside of the ship that suggests the warp core can be ejected.  However, we do see that the ship has eight plasma exhaust vents on the dorsal side, suggesting a possible new technique in avoiding a core breech.  The ventral side of the ship does show a hatch in the exact place of the antimatter pods, suggesting that they can be ejected.  The dual computer core also has a hatch on the underside of the ship.

EMH/Holodeck:  It's reasonable to assume that Defiant-class vessels have been equipped with the latest version of the EMH series.  However, we know for a fact that the ship has no holodecks or holosuites. Holographic emitters have been embedded throughout the immediate sickbay area, but do not spill off into the surrounding science labs or corridors.

Bridge Stations:  This became somewhat of a problem because of the accepted number of positions on all ST:ACTD ships and stations.  The bridge allows no seating for a Counselor or Executive Officer and the Operations position has little function if the forward console controls both Conn and Ops.  That said, I've decided to put in that all of these stations can be reconfigured depending on who is sitting there, and ultimately, that is being left up to the ship's Commanding Officer and Starship Manager.  For secondary positions (SO, TO, EO, MO), there is no room to mount additional seating on the bridge, and therefore they must either stand at the various control panels mounted on the walls around the bridge or find themselves another location on the ship to perform their duties, such as Engineering, Sickbay, the Science Lab, etc.

Robert Siwiak, November 28, 2001 - January 28, 2002





  1. Star Trek:  Deep Space Nine Technical Manual

  2. Star Trek:  The Next Generation Technical Manual

  3. Star Trek:  The Magazine, Issue 6 October 1999

  4. Star Trek:  Starship Spotter

  5. Ex Astris Scientia -

  6. Maximum Defiant -


Copyright 2001 - Star Trek : A Call to Duty. Use of these specifications is restricted to the Star Trek: A Call to Duty (ST:ACTD) Technical Specifications domain at and may only be reproduced with the express permission of the ST:ACTD on sites that clearly serve to provide information on ST:ACTD, its various ships and stations, or other related topics. Editing the contents of the information present on this page or reformatting the way in which it is presented is not permitted without the direct permission of ST:ACTD.  Wherever possible, published sources were consulted to add to the wealth of knowledge in this document, and in some cases, this text was reproduced here.  Sources used are properly cited in the "Credits and Copyright Information" appendix.  No copyright infringement is intended.


Copyright 2001 - Star Trek : A Call To Duty, all rights reserved (herein referred to as the 'ST:ACTD').  STAR TREK and related marks, symbols, and materials are trademarks of Paramount Pictures Corporation.  Unless noted otherwise, all material on this website, including but not limited to images, audio, and text material (collectively the "Material"), is protected by copyright owned or controlled by the ST:ACTD, unless otherwise indicated.  UNAUTHORIZED COPYING, REPRODUCTION, REPUBLISHING, UPLOADING, DOWNLOADING, POSTING, TRANSMITTING OR DUPLICATING OF ANY OF THE MATERIAL WITHOUT EXPRESS PERMISSION IS PROHIBITED.