The Klingon Raptor was a type of scout ship first encountered by the Vulcans sometime prior to 2151. As such, the vessel was listed in the Vulcan database, however, much of the information on the class remained classified.
The first Earth encounter with a Raptor came in 2151, when the Starfleet ship Enterprise stumbled across the disabled IKS Somraw within the atmosphere of a class 9 gas giant, where it was being crushed by the planet's brutal atmospheric pressure.
With the crew apparently incapacitated, an Enterprise boarding party worked to restore the ship's propulsion systems and regain altitude. Though eventually successful, the boarding party became trapped on the ship, allowing them time to explore the interior of a Klingon vessel – the first Humans to ever do so. (ENT: "Sleeping Dogs", "Judgment")
Schematics for the Raptor-class also appeared in Daniels' 31st century database. (ENT: "Shockwave", "Future Tense") Upon viewing the Raptor, among other Klingon vessel classes, Malcolm Reed noted that there were "schematics on half a dozen different Klingon ships," but was reminded by Jonathan Archer that acquiring information on those ships was not the reason why they were accessing the database. (ENT: "Shockwave")
The outboard plan of the Raptor utilized the same basic avian design that would be further incorporated into a classic and noble warship lineage. It was similar in design lineage as the D5 class battle cruiser and Bird-of-Prey variant.
The Raptor's outer hull was reinforced with a type of coherent molecular alloy made it capable of withstanding atmospheric pressure of 15,000 GSC, or that found in a class 9 gas giant, at an approximate depth of two kilometers. Overall, the Raptor's hull was twice as thick as that of Starfleet's Template:ShipClass. (ENT: "Sleeping Dogs")
The impulse engine was located, like most Klingon starship classes, at the extreme aft section of the main structure. The various components of the propulsion system included a fusion manifold as well as port and starboard fusion injectors. (ENT: "Sleeping Dogs")
Like its D5-class counterpart of the same era, the Raptor was outfitted with standard multi-spectral sensors, which included tactical sensors, and shields. The Raptor-class's tactical systems included a disruptor array and photon torpedo launchers, including one positioned on the ship's dorsal section. The primary weapon array was located on the dorsal section of the ship. (ENT: "Sleeping Dogs")
The main bridge was located in the "head" of the forward section of the vessel. The configuration of the darkened main bridge design of the Raptor-class scout was shared with many contemporary Klingon bridge layouts, including the D5-class and Bird-of-Prey.
Located in the front of the bridge, against the forward bulkhead, was the ship's main viewscreen. Located near the center of the bridge was an access console, separating the viewscreen from the command chair. Directly behind the command chair were two manned consoles, with a corridor access point located to the immediate rear.
Along the port side of the bridge were several stations, each assigned to a specific task, including an engineering console and a tactical console. Additional stations were also located on the starboard side, including a station that displayed structural integrity and helm. (ENT: "Sleeping Dogs")
The word "raptor" means "bird of prey", however, in "The Expanse", the vessels which were referred to as the Bird-of-Prey were of a distinctly different design. It is of note that the original reference to the term "bird of prey" was also mentioned in the dialog from the same episode in which the Raptor appeared.
The Raptor-class was designed and built by Herman Zimmerman's art department, with John Eaves developing the basic shape as a sketch and Doug Drexler refining the sketch into its final form as a CGI model with LightWave 3D.
Several designs were considered when establishing the Raptor. According to Eaves, the designing of the Raptor went through "quite a gamut of shapes." He explained that "originally, it was supposed to be a shuttle, then it got a little bigger as it went on. My thumbnails go from little two-man sized things to four-guy ships, up to the one they chose, which I figure is like a twelve-guy ship. It is lightly based on the Bird-of-Prey, but more on the D-7."
Drexler felt that the Raptor had more of a "PT boat-Civil War ironclad quality to it." He added that "John's sketches suggested a trussed and cabled quality that I was sure to include in the model. Those distinctive touches helped to date it. The coloration is metallic, but suggests the gray tones of Matt Jefferies' original battle cruiser. Japanese submarine rusty-green of later years," which could have also been the color of Verdigris.
After Drexler completed the CGI design, the finished model was sent to Foundation Imaging where it was completed by Pierre Drolet and Rob Bonchune. The length established for the CGI model, as scaled in relation to the other models created for the series, was 145 meters.
"Sleeping Dogs" was the only time that the CGI model of this class would appear on-screen, though it was seen in the title menu of the Star Trek: Enterprise Season Two DVD.