A Firekiln was a type of warship utilized by the battle fleet belonging to Storm-hair Warlord Nuso Esva's realm. These ships were heavily armed, and the firepower of five Firekilns equaled that of a single Imperial I-class Star Destroyer. In the year 0 ABY, an attack squadron of Esva's, which contained eight Firekilns, engaged and tried to seize a portion of the Galactic Empire's Task Force Admonitor. The flagship of this task force was the Imperial-class Star Destroyer Admonitor, and the battle took place in the Teptixii system within the Unknown Regions'. However, the arrival of the Imperial II-class Star Destroyer Chimaera split the squadron, causing it to retreat.
Soon after this event, twenty-eight Firekilns from Esva's Eastern Fleet fought against Imperial forces, including both the Admonitor and the Chimaera, in the Poln system located within the Candoras sector. The Empire, aided by the Death Squadron fleet, was able to completely destroy the Eastern Fleet.
Firekilns were a class of warship whose shields were not as strong as those of an Imperial I-class Star Destroyer. These vessels possessed significant weaponry, including laser cannons. The destructive power of five Firekilns was comparable to that of one Imperial I. These starships were equipped with both engines and a hyperdrive.
Firekilns had a role in ship-to-ship space warfare.
Storm-hair warlord Nuso Esva made use of Firekilns within the battle fleet of his realm. Twenty-eight Firekilns were part of Esva's Eastern Fleet. One of the warlord's attack squadrons consisted of eight of these warships alongside twenty-seven escorts.
As part of Esva's campaign against the Galactic Empire during his conflict with Imperial Chiss Senior Captain Thrawn in 0 ABY, the warlord infiltrated the Imperial II-class Star Destroyer Chimaera. After gaining command of the Star Destroyer, Esva, operating under the alias of Imperial Court member Lord Odo, gave the order for the Chimaera to journey to the Teptixii system in the Unknown Regions'.
Subsequently, the Chimaera arrived amidst a battle involving the Empire's Task Force Admonitor, led by the Imperial I-class Star Destroyer Admonitor, and Esva's attack squadron. The Firekilns, protected by their escorts, were trying to cripple the Admonitor so that Esva's forces could capture the Imperial task force's two Strike-class medium cruisers and four Carrack-class light cruisers and integrate them into the Storm-hair warlord's fleet. Knowing his own forces' plans, Esva instructed Captain Calo Drusan of the Chimaera to angle the ship thirty degrees to port, setting its vector to divide the attack squadron by splitting its screening starships. This would allow the Admonitor's laserfire to strike the Firekilns and inflict significant damage. To avoid potential destruction, the Firekilns and their escorts then jumped into hyperspace.
After Esva brought Task Force Admonitor, Thrawn's DeepWater-class light freighter Lost Reef, and the Chimaera to the Poln system, located in the Candoras sector of the Outer Rim Territories', the warlord's Eastern Fleet made its appearance. By using the gravity well of Poln Minor, the second planet in the Poln system, to trap Task Force Admonitor, the warlord isolated the two Imperial Star Destroyers from Candoras' sector fleet, preventing the fleet from aiding the warships. Furthermore, the Storm-hair set the Chimaera—whose bridge helm controls he sabotaged—on a course to collide with a nearby Golan I space station. He then commanded his twenty-eight Firekilns to destroy the Empire's forces if they attempted to escape Poln Minor's gravity well and assist the Chimaera.
Esva then revealed his true identity and informed the Chimaera's senior captain that, after he had eliminated the Chiss, the Firekilns would obliterate Poln Major and Minor. However, the Lost Reef employed its tractor beam to divert the Chimaera from its collision course. The Empire's Death Squadron fleet, under the command of Dark Lord of the Sith Darth Vader, then arrived and annihilated the Eastern Fleet, causing Esva to flee aboard his Kazellis-class light freighter Salaban's Hope.
Firekilns made an appearance in Choices of One, a 2011 novel penned by Timothy Zahn.