Ambassador class

## SPACECRAFT CLASS

Class development project patch (Thomas Marrone).

The ***Ambassador*-class** was a type of spacecraft developed by Starfleet in the early 24th century. It was classified as a scale 5 heavy cruiser when it entered service.

## History

In 2315, Anselm Probert, the lead engineer at Starfleet's San Francisco Fleet Yards, shared a design he had created for a new capital ship. Though the *Excelsior*-class was only a few decades old and was still proving its worth, Probert sought to push the envelope of cruiser capabilities. While many of the elements of his design were impractical at the time, Starfleet Command approved a modified version due to the need for a more versatile cruiser than the *Excelsior*-class and the few *Enterprise*-class vessels still in service.

The lead ship, designated the USS *Ambassador*, began construction at the San Francisco Fleet Yards in 2316. In late 2318 the prototype began initial trials and was formally commissioned mid the next year. Starfleet Command initially placed an order for six space frames, but this was later expanded to a run of fourteen.

### Early service

The USS *Ambassador* and its siblings were assigned to lead cruiser groups along the Federation’s borders and to deep-space exploration missions. Several notable missions, such as the USS *Gandhi*’s first contact with the Zakdorn, were logged by *Ambassador*-class starships.

### The Mark II

The development of isolinear circuitry and advances in warp propulsion systems in the 2320s prompted Starfleet Command to pause the construction of additional *Ambassador*-class vessels past the initial production run. Captain Probert revisited his design and recommended a refit to the class that would bring the cruisers in-line with recent developments. The admiralty approved the adjustments and the USS *Yamaguchi* was picked to first receive them. It entered the Utopia Planitia Fleet Yards in 2329 and spent eight months in drydock before launching the next year as the first of the Mark II, dubbed the *Yamaguchi*-class. It was the first Starfleet class to include isolinear circuitry in its core specifications.

The variant sported several changes and improvements beyond new computers and warp drive units. The *Yamaguchi*-class bore shorter nacelle pylons, its primary hull was situated further back on its neck, and a third shuttlebay was added at the stern. These helped to improve power flow, structural integrity, and overall performance.

### Later service

As border conflicts began with the Cardassian Union, Tzenkethi Coalition, and Tholian Assembly, the *Ambassador*-class was often found on the front lines and at the center of unit formations. Though the cruiser served ably, their complexity and resource cost caused Starfleet Command to instead focus on the production of modular designs, like the *Springfield* and *New Orleans*-classes, and the refit of older starships, like the *Constellation*, *Excelsior*, and *Miranda*-classes.

### The *Niagara*-class

Two of the cruisers, the USS *Niagara* and USS *Princeton*, were scheduled for overhauls in the late 2340s but were instead selected for a refit using elements from the Century Cruiser Project. The intent was to see how well elements of the project could be integrated into older designs when due for maintenance and upgrades. The new *Niagara*-class mounted a triangular nacelle arrangement, which was required to create a proper and safe warp field due to the class not being designed from the ground-up to accommodate Cochrane Warp Dynamics' *Century*-class Circumlinear Warp Drive Units.

Overall, the design proved a failure and no additional Ambassador-class vessels were refitted to *Niagara* specifications. The USS *Niagara* was eventually decommissioned and components were repurposed to speed-up construction of *Freedom*-class vessels. The USS *Princeton* was lost at the Battle of Wolf 359.

### Legacy

Though starships of both the Mark I and Mark II *Ambassador*-class served effectively as deep-space explorers and in patrolling the far reaches of the Federation’s borders, the designs were eventually retired in favor of Starfleet’s next generation of exploration cruiser: the *Galaxy*-class.

Lacking the modularity of many other comparable designs, such as the *Nebula* and *Akira*-classes, and the maneuverability and tactical capabilities of the *Galaxy* and *Sovereign*-classes, the *Ambassador*-class saw little action on the front lines of the Dominion War. Instead, they were often assigned to patrolling borders and defending Federation worlds.

Vessels of the class continued to provide notable service within Starfleet throughout the rest of the century and into the next. In the early 25th century, two subclasses of the *Ambassador*, known as the *Narendra* and *Horatio*-classes, were developed and carried the legacy of the design into the future.

## Technical specifications

### Physical arrangement

The *Ambassador*-class had a length of 478.5 meters, a beam of 283 meters, and draft of 102 meters. It utilized the standard Starfleet design, with a saucer-shaped primary hull, connected to a secondary hull that housed the warp core and connected via pylons to the nacelles. It encompassed 31 decks. The Mark II variant shifted the primary hull and the nacelles slightly aft, which made the *Yamaguchi*-class only a half meter shorter.

### Deck plan

The following was the standard internal layout of *Ambassador*-class vessels.

### Computer systems

Although isolinear circuitry was in development, Starfleet engineers decided to move forward using Daystrom Institute’s M-12 Duotronic V Processor instead of delaying the *Ambassador*-class. The last two vessels of the class, the USS *Niagara* and USS *Princeton*, were constructed with the M-13 Isolinear 1 Processor as it had been completed by 2325.

The design made use of Starfleet’s standard navigation system at the time, the RAV/ISHAK Mod 3 Warp Celestial Guidance system developed by Tlixis Ramab RRB.

### Propulsion systems

In 2315, Leeding Engines released their new advanced circumferential warp drive. The system was a reimagining of the older circumferential drive and offered a higher performance than contemporary linear drive units, but at the cost of increased size and energy needs. Captain Probert had been watching the development of the unit, classified as the ACE-15-LDE-001, and had included it in his design. The *Ambassador*-class carried two of these warp drive units connected to Shuventis Systems’ FC-2 Matter/Antimatter Reaction Assembly.

The class also mounted a single Kloratis *Peacemaker* Subatomic Unified Energy Impulse Unit, located on the aft centerline of the hulls connector. Maneuverability was facilitated through Scarbak Propulsion Systems’ QASR-2 Particle Beam Maneuvering Thrusters and the Trentis III Pulsed Laser Reaction Control System from Orage Ijek.

When vessels were refitted to Mark II specifications, their engines were upgraded to new circumlinear warp drive units. These were developed by Leeding Engines in the mid 2320s from the design created by the Cochrane Institute of Alpha Centauri for the Century Cruiser Project. The CLN-02-LDE-003 units were able to fit within the original *Ambassador* nacelle structure without much modification, although the pylons were adjusted to allow for a better warp field.

### Environmental systems

Life support was provided by the A'Alakon Landiss AL2 Life Support System coupled with the NAG2 Modular Gravity Unit from New Amsterdam Gravitics. The operational standard was a Class M atmosphere, but the system allowed for quarters and laboratories to be adjusted to various atmospheric settings.

### Tactical systems

The *Ambassador*-class carried duranium hull planting over its duranium-tritanium structural members. The shield systems of the class employed the CIDSS-3 Primary Force Field and Deflector Control System connected to 12 Gjermundbu Mod 19j Symmetrical Subspace Graviton Field Grids.

Collimated phaser emitter units were developed by HiBeam Energies in 2315. This new technology allowed for the units to be linked in series to form arrays; a tactical improvement over the turret units used by Starfleet at the time. The *Ambassador*-class mounted 10 of the arrays, classified as Type X by Starfleet, which were strategically located around the starship’s exterior to provide omni-directional and overlapping coverage.

The class also piloted the Mk 75 launch tubes that allowed for burst-fire of projectiles. Due to this new capability, the *Ambassador* design only mounted 2 launchers, one fore and one aft.

### Utility systems

The navigational deflector of the *Ambassador*-class consisted of molybdenum-duranium mesh panels over a tritanium framework. It was powered by 2 graviton polarity generators.

The class had an extensive transporter system, consisting of 6 personnel transporters, 3 cargo transporters, and 10 emergency transporters. Both the personnel and cargo transporters had a range of 40,000 kilometers, while the emergency units were limited to a range of 15,000 kilometers.

### Auxiliary craft systems

The Mark I design included two shuttlebays, one spanning the aft area of decks 3 and 4 of the saucer and another at the stern of the secondary hull over decks 21 and 22. The *Yamaguchi* variant expanded Shuttlebay 2 significantly and added a third shuttlebay below it on decks 24 and 25.

Holodecks, a very new technology in the 2320s, were included in the development of the Mark II refit. Located forward on deck 10, the two holodecks provided additional diplomatic, research, and recreational opportunities for the *Yamaguchi*-class.

### Engineering facilites

Main engineering was located on deck 22, providing direct access to the warp core and other essential ship systems. The chief engineer’s office and two dedicated engineering labs were connected to the main facility.

### Crew support systems

#### Medical facilities

The *Ambassador*-class had two large sickbay wards. The main sickbay, which included an office for the chief medical officer, was rated Class G and was located on deck 8. Two medical laboratories were situated across directly aft of the facility. Sickbay 2 was found on deck 10 and was rated Class C. Additional aid stations were found near key locations, such as main engineering, throughout each starship.

As its name suggests, the *Ambassador*-class was slated for use as a diplomatic platform. The executive conference room on deck 2, the visitor’s quarters on deck 5, and the lecture hall on deck 7 were designed to assist in this purpose. All could be quickly adjusted to accommodate a variety of atmospheric and gravity settings.

## Derivatives

### *Narendra*

   Named for the battle where the USS *Enterprise*-C was destroyed defending a Klingon colony, the *Narendra*-class was originally designed by Captain Anselm Probert in the 2310s. However, the design could not be realized at that time and was modified into what became the *Ambassador*-class. Starfleet engineers rediscovered Probert's original design in 2405 and the Allied Cooperative Starship Development Board modified it to be in line with 25th century technological advances. During the Iconian War the new subclass was put into production and eight of the vessels entered service shortly after the end of that conflict.

### *Horatio*

Employing elements from various designs developed in 2409 and 2410, Starfleet engineers introduced a new update to the *Ambassador*-class in early 2411. The *Horatio*-class was created to fill the need for mid-size cruisers in the Federation.

## Appendices

### Connections

**Project groups:** **Union Station** (*Geneva* • *Concorde* • *Presidio*) • **Century Cruiser** (*Springfield* • *New Orleans* • *Challenger* • *Niagara* • *Freedom II* • *Galaxy* • *Nebula* • *Cheyenne*) • **Multi-Mission explorers** (*Brigid* • *Esquiline* • *Palatine*) • **Deep Shadow** (*Eclipse* • *Phantom* • *Scryer*) • **Miracle Worker** (*Scott* • *Daystrom* • *Tucker* • *Gagarin*) • **Aeronaut** (*Mercury* • *Ajax* • *Icarus* • *Shran*)

**Other named classes:** *Aegian* • *Aerie* • *Akula* • *Atlas* • *California* • *Centaur* • *Challenger* • *Cheyenne* • *Constellation* • *Constitution III* • *Crossfield* • *Curry* • *Daedalus* • *Dauntless* • *Excelsior II* • *Freedom II* • *Gemini* • *Glenn* • *Guardian* • *Inquiry* • *Iwo Jima* • *Jupiter* • *Lexington* • *Niagara* • *Obena* • *Okinawa* • *Parliament* • *Perseus* • *Pioneer* • *Ranger* • *Sagan* • *Solanae* • *Springfield* • *Turing* • *Ulysses*

**Auxiliary craft:** *Aero* • Class C • Class F • *Danube* • *Flyer* • *Gondola* • *Kodai* • *Mollard* • *Peregrine* • *Selenic* • Type 4 • Type 5 • Type 6 (Type 6A • Type 6S) • Type 7 • Type 8 • Type 9 (Type 9A) • Type 10 • Type 11 • Type 14 • Type 17 • Type 19 • *Valkyrie* • *Venture* • *Waverider* • *Yellowstone*

**Leadership:** Commander-in-chief • Joint Chiefs • Chief of Starfleet External Affairs • Chief of Starfleet Operations • Chief of Starfleet Research and Exploration • Chief of Starfleet Tactical

**Agencies:** Operations (Engineering • Judicial • Materiel Supply • Mission Operations • Personnel Management • Records Service • Shipyards Operations • Starbase Operations) • Research & Exploration (Science • Medical) • External Affairs • Tactical (Intelligence • Security • MACO)

**Notable units:** Ktarn Fleet • Task Force 77

**Facilities:** Deep Space K-7 • Deep Space K-13 • Deep Space 9 • Masamichi Array • Starbase 45-Keepsake • Starbase 82-Maat • Starbase 234-Beskerm • Starbase 247-Vershina

**Agencies:** Starfleet • Diplomatic Corps • Department of Temporal Investigations • Federation Security Agency

**Facilities:** 40 Eridani A Starfleet Construction Yards • Antares Ship Yards • Beta Antares Ship Yards • Copernicus Ship Yards • Laikan Starfleet Shipyards • McKinley Station • Memory Project • New Aberdeen Shipyards • Proxima Maintenance Yards • Salazaar Shipyards • San Francisco Fleet Yards • TL-9139 Starfleet Maintenance Yards • Tranquility Base • Utopia Planitia Fleet Yards

### Sources consulted

* Ambassador class article at *Memory Alpha*.
* Ambassador class article at *Memory Beta*.
* Ambassador class article at the *Star Trek Online Wiki*.
* Yamaguchi class article at *Memory Beta*.
* *Star Trek: The Official Starships Collection* issue 46: "U.S.S. *Enterprise* NCC-1701-C."
* *Star Trek: The Official Starships Collection* special issue "U.S.S. *Enterprise* NCC-1701-C."
* Ambassador Class Variants article at *Ex Astris Scientia*.
* *Star Trek: Deep Space Nine Technical Manual*.
* *Star Trek: The Next Generation - Core Game Book* by Last Unicorn Games.
* *Star Trek Roleplaying Game: Starships* by Decipher, Inc.
* *Star Trek Adventures - The Command Division* by Modiphius Entertainment.
* *Ships of the Star Fleet, 190th edition, Volume 1: Cruiser*.
* Ambassador-class article at Bravo Fleet - Star Trek RPG and Community.
* Ambassador-Class Specs article at the *Advanced Starship Design Bureau*, a website for *Star Trek: A Call to Duty*.
* Ambassador Class Starship article at the United Federation Starfleet Wiki.
* Notes on the Ambassador-class post at the Daystrom Institute subreddit.
* Ship in Brief: The Ambassador-class post at the Daystrom Institute subreddit.

### Footnotes

1. ↑ Derived from MSDs created by Alexander Richardson and Joseph Hellar.
2. ↑ *STO* dev blog: "New Support Cruisers Join the Alliance Fleet."