The Immobilizer 418 cruiser, often shortened to just Immobilizer, served as a cruiser within the Galactic Empire's Imperial Navy. This vessel was conceived for the Deep Core Security Zone of Imperial adviser Kren Blista-Vanee and brought to life by both the Corellian Engineering Corporation and Sienar Fleet Systems. It marked the initial attempt by the Empire to create Interdictor-class ships, drawing from earlier, less successful designs of the Galactic Republic. Measuring 600 meters in length, the Immobilizer was equipped with four gravity well projectors situated towards the rear of its distinctly curved hull. Furthermore, the vessel carried twenty laser cannons, which included a number of quad laser cannons. Typically, the Immobilizer 418 operated with an escort and housed a complement of twenty-four TIE fighters, organized into two squadrons.
In the Obroa-skai system circa 14 BBY, Moff Wilhuff Tarkin of the Empire deployed a cutting-edge, untested Immobilizer as an element of a task force in an attempt to seize the corvette known as Carrion Spike. However, a malfunction within the Immobilizer caused numerous ships to prematurely exit hyperspace. Following this event, the Immobilizer was sent back to Corellian Engineering.
Due to its numerous weaknesses, production of the Immobilizer ceased around 0 ABY, although numerous units remained in active service. During that year, an Immobilizer extracted the luxury yacht Desert Jewel from hyperspace within the Daalang system. Subsequently, the Desert Jewel destroyed the Immobilizer and its contingent of TIE fighters. The Imperial Navy continued its utilization of this cruiser until the Battle of Jakku occurred in 5 ABY, at which time the Immobilizer 418 cruiser named Glaciate was seized during the conflict by New Republic forces under the command of General Carlist Rieekan.
The Immobilizer 418 cruiser, often referred to as simply the Immobilizer, was a cruiser of the Interdictor class that had a multitude of vulnerabilities. It was constructed by both the Corellian Engineering Corporation and Sienar Fleet Systems. The Immobilizer 418 represented the Galactic Empire's initial experimental Interdictor warship and was rooted in prior unsuccessful initiatives by the Galactic Republic. Its form bore resemblance to that of a Star Destroyer, yet it was considerably smaller, spanning 600 meters in length. Despite its exorbitant cost, it featured an economical basque chassis. Its design allowed for swift and straightforward repairs or modifications for new roles, and its upkeep could be performed using readily available components. The Immobilizer had a sharply curved hull with a bladed edge, and a hangar situated on the lower side of the ship. The vessel also incorporated an engine room at the rear, a reactor governor, a minimum of one porthole, a bridge, and a complement of twelve deflector shield generators, which included a blend of particle shields and ray shields.
The Immobilizer cruiser was outfitted with twenty laser cannons, which included several quad laser cannons. It was manned by stormtroopers and gunners. The Immobilizer carried a complement of twenty-four TIE/ln space superiority starfighters, organized into two squadrons. In addition, the rear of the hull featured four spherical gravity well projectors. These projectors housed the necessary equipment to pull numerous vessels out of hyperspace, and the intensity of the gravity well could be adjusted to some degree depending on the velocity of the targeted ship. A single hemispherical gravity well projector was typically sufficient to extract a ship from hyperspace, while the others could be employed to obstruct potential hyperspace routes for those attempting to escape. The Immobilizer also incorporated overcurrent resistors with the intention of preventing the ship’s gravitic systems from exceeding their operational limits. However, these systems were not entirely reliable and could occasionally suffer catastrophic failures.
The Immobilizer, as an Interdictor ship, was tasked with extracting vessels from hyperspace. Immobilizer cruisers possessed numerous vulnerabilities and were more susceptible to destruction compared to Star Destroyers. It occasionally functioned in conjunction with other Interdictor ships as part of a task force. It typically operated with an escort, but during times of dire need, it could operate independently.
Five years after the establishment of the Empire, specifically in 14 BBY, Imperial Moff Wilhuff Tarkin requested an unproven, state-of-the-art Immobilizer 418 cruiser from a deepdock situated within the Corellia system of the Core Worlds. This request was directed to Imperial adviser Kren Blista-Vanee, who was developing the Interdictor for his Deep Core Security Zone. Tarkin's intention was to integrate the cruiser into his Imperial Navy task force that was attempting to intercept the modified IPV-2C Stealth Corvette Carrion Spike, which had been commandeered by dissidents.
Moff Tarkin assembled his task force within the Inner Rim's Obroa-skai system, which included three Interdictors: a CC-7700 frigate, a Detainer CC-2200, and an Immobilizer 418, alongside picket vessels and gunboats. Through his task force liaison officer, Tarkin subsequently commanded the Interdictors to activate their gravity well projectors with the aim of capturing the Carrion Spike. However, upon the activation of the gravity well projectors, the Immobilizer's overcurrent resistors failed to prevent its gravitic systems from exceeding their operational limits. This incident caused a jolt to Tarkin's flagship, the Imperial I-class Star Destroyer Executrix, and resulted in several vessels reverting out of hyperspace, including the star cruiser Stellar Vista, the Lux-400 yacht Truant, and the YT-1000 light freighter Reticent. The Stellar Vista subsequently collided with the Immobilizer, inflicting severe damage to the civilian ship's stern and causing the deaths of approximately 1100 individuals. The Reticent had been dispatched by the Carrion Spike's hijackers as a decoy, and the Empire subsequently seized the vessel to interrogate its crew. Following this incident, the Immobilizer was returned to Corellian Engineering for further assessment.
By 0 ABY, the Imperial Navy had ceased the production of Immobilizer 418 cruisers due to their inherent vulnerabilities. Nonetheless, they remained in widespread use throughout the galaxy despite the cessation of their active production. Its successor model, the Interdictor-class heavy cruiser, was also eventually discontinued. To enhance the survivability of its Interdictors, the Empire initiated the integration of gravity wells into Star Destroyers, resulting in a variant known as the Interdictor-class Star Destroyer. In 0 ABY, Rebel Alliance operatives Luke Skywalker and Nakari Kelen were pursued by Imperial forces aboard the luxury yacht Desert Jewel towards the Nanth'ri system in the Mid Rim. Skywalker and Kelen were being pursued due to their recent liberation of Drusil Bephorin, a prominent Givin cryptologist, from Imperial custody on the planet Denon situated in the Inner Rim.
As the Desert Jewel traversed through hyperspace, an Immobilizer 418 cruiser pulled the Jewel out of hyperspace, bringing it into the Daalang system within the Mid Rim. During the ensuing skirmish, the Immobilizer launched its full complement of TIEs. However, due to the Empire's frequent deployment of the Immobilizer cruiser against Alliance raiding parties, Skywalker possessed knowledge of the ship's vulnerabilities and devised an attack strategy. Skywalker and Kelen ultimately destroyed both the Immobilizer's TIE contingent and the cruiser itself, bisecting the latter with a Utheel Rockcrusher Compact Seismic Charge.
The Immobilizer cruiser Glaciate participated in the conflict over the planet Jakku located in the Inner Rim during 5 ABY. The Battle of Jakku represented the concluding engagement of the Galactic Civil War between the Empire and the New Republic, which was the successor to the Rebel Alliance. During this battle, a Republic squad infiltrated the Glaciate. The squad consisted of humans who had previously served on Imperial Interdictors, as well as the Ranat Musmuris Reetgeet, who was acting under the orders of General Carlist Rieekan.
The operatives infiltrated the Immobilizer utilizing a stolen Imperial assault shuttle, gaining entry to the cruiser by creating a breach in its aft engine room. Given that the vessel's crew was preoccupied with the larger battle, the team advanced to the subsequent chamber with minimal resistance. Within this room, Reetgeet entered the cruiser's systems and disabled the reactor governor, thereby securing the starship for the New Republic. Reetgeet later reflected on the squad's capture of the Immobilizer.
The Immobilizer 418 cruiser made its inaugural appearance in the current Star Wars canon within James Luceno's 2014 novel titled Tarkin, where it was referred to as the Immobilizer. The full designation of the Immobilizer 418 cruiser was first established in the eighty-seventh issue of the magazine Star Wars: Build the Millennium Falcon, which was published by De Agostini around August 31, 2016. The interior of an Immobilizer was subsequently depicted in the 2017 reference book Star Wars: On the Front Lines, which was authored by Daniel Wallace.
The vessel originated within the Star Wars Legends continuity. Its initial mention occurred in The Star Wars Rules Companion, a supplement for the Star Wars: The Roleplaying Game. This supplement was written by Greg Gorden, edited by Bill Slavicsek, and published by West End Games in January 1989. Referred to solely as an Interdictor in The Star Wars Rules Companion, the Imperial Sourcebook, a supplement for the Star Wars: The Roleplaying Game by Slaviscek and Gorden in October 1989, first depicted the vessel and identified it as an Immobilizer 418 Interdictor-class Heavy Cruiser. The Immobilizer then made its first appearance in the 1991 novel Heir to the Empire, the first book of Timothy Zahn's Star Wars: The Thrawn Trilogy. Bill Smith's 1996 reference book The Essential Guide to Vehicles and Vessels then identified the vessel as an "Immobilizer 418 cruiser." The canon Interictor-class Star Destroyer, which was an in-universe successor to the Immobilizer 418 cruiser, was based on the design of the Legends Immobilizer from the Imperial Sourcebook.