In 2371, when the prototype USS Defiant was sent into the Gamma Quadrant, she was equipped with at least one of these shuttlepods. Kira Nerys and Odo used the Shuttle 01 to escape a Jem'Hadar attack. Odo piloted the shuttle to the Founders' homeworld in the Omarion Nebula. In a simulation run by the Vorta, Sisko and Bashir believed they had escaped the battle in a similar craft. (DS9: "The Search, Part I", "The Search, Part II")
In the same year, the subspace field coils of the warp drive of Shuttle 01 were used to create a subspace bubble around the Sword of Stars comet fragments as they passed through the Bajoran wormhole. (DS9: "Destiny")
List of type-18 shuttles
- USS Defiant
- Shuttle 01
According to the Star Trek: Deep Space Nine Technical Manual, (page 137) the Defiant carried four of these shuttlepods. In addition to the crew of two, the shuttles could carry up to four passengers. They were armed with phaser weapons, and could be modified to carry other weapon systems. The pods were limited to impulse travel only, but could travel short distances at warp speeds when released from the mothership while it was at warp. This would contradict the fact that in "Destiny" it was clearly established that these ships had full warp drive capability.
According to the Star Trek Fact Files, the warp nacelles were truncated on both sides of the ship, towards the rear of the cockpit. The shuttles were equipped with sensors and subspace communications arrays. There were only two shuttlepods on the Defiant, and only the Defiant-class vessels were equipped with this design of auxiliary craft.
The interior set of the shuttlepod was a reuse of the cockpit of the Federation attack fighter seen in the Star Trek: Deep Space Nine episode "The Maquis, Part II", which in turn was a heavily modified version from its previous use in Star Trek: The Next Generation as the the interior of the type 15 shuttlepod.
According to a comparison chart drawn up by Gary Hutzel and Larry Nemecek, the length of the shuttlepod was 12 feet (3.7 meters).  This was coincidentally the length Rick Sternbach set for the type-15 shuttlepod, the design of which was partly the basis for the type-18 shuttlepod, arguably making it about one quarter to one third too short. The Star Trek: Deep Space Nine Technical Manual states the dimensions as 4.5 × 3.1 × 1.8 meters.
The Type-18 shuttlepod was one of the few models in the Star Trek franchise that did not go through the usual design process, but rather originated as an improvised design. Doug Drexler recalled on his blog, "Among the most mysterious of Starfleet shuttle pods, the miniature built for DS9, and her pocket battleship the Defiant. To the best of my knowledge, this design did not originate in the art department. I spoke with Jim Martin yesterday, and he jogged my memory concerning a plan to wed a surplus boat hull to the TNG shuttlepod. In fact I remember the boat hull in the Marathon Mill quite clearly. This may be the bastard son of that scheme."  Michael Okuda later explained why the model turned out to be the way it became, "If I recall correctly, this shuttle was designed so the TNG shuttlepod could be used as an interior set, even though the exterior was different." 
The design was turned into a physical studio model by Gregory Jein,  who incorporated a nice touch of having the model an articulated side hatch, which could be opened and closed. After its initial three DS9 third season appearances, the shuttlepod model was not called upon to make another appearance until sixth season episode "The Sound of Her Voice". Much to the dismay of effects supervisor Gary Hutzel, it was discovered that the model had been stolen by then, which necessitated Hutzel to have Doug Drexler design a new shuttlepod, now to be conceived as a CGI model. The opportunity was used to give the new upgraded shuttlepod a smoother and more streamlined look for it to become the Chaffee-type shuttlepod.