Immobilizer 418 cruiser/Legends

Immobilizer 418 cruiser "Never again will the Rebels leave you behind, looking flat-footed and foolish. The Immobilizer will see to that."

- Unnamed Sienar official

The Immobilizer 418 cruiser, also known as the Interdictor-class heavy cruiser, Interdictor-class Star Destroyer, or Interdictor-class medium frigate, was a 600-meter-long cruiser built on the standard Vindicator-class heavy cruiser hull.

Equipped with gravity well projectors designed to pull ships from hyperspace and/or prevent them making the jump to lightspeed, the Interdictor became a valuable addition to the Imperial Navy.

Design and role
Interdictor cruisers, like their Vindicator-class cousins, had the appearance of small Star Destroyers. However, their lines were broken by four large globes housing gravity well projectors, which mimicked a large mass in space and thus restricted hyperspace travel. Nearby vessels were automatically prevented from engaging their hyperdrive, and any ship passing through the area via hyperspace were forced into realspace.

As well as gravity wells, the Sienar design was also equipped with 20 quad laser cannons for short range combat against other ships. The Interdictor's hull was nearly identical to that of the Vindicator-class heavy cruiser and could support several additional weapons depending on mission profile. Enemy fire was absorbed by more than a dozen shield generators.

A variant of the Interdictor design existed, equipped with two large gravity-wells rather than the usual four: a ship of this type appeared in Grand Admiral Thrawn's ambush of Luke Skywalker at Jomark in 9 ABY.

Since they were rare and costly to produce, Imperial tacticians rarely deployed Interdictors in intense combat situations. Typically, they would place them on the edge of a battle area to prevent enemy ships from escaping, or else use them to blockade planets or moons, such as Yavin IV.

Interdictors also took some moments to activate their projectors after arriving from hyperspace, and once activated, the massive simulated mass they created made the ship very cumbersome to maneuver: there was rarely enough time for an entire fleet to make the jump to hyperspace before a newly-arrived Interdictor activated its projectors, but if a fast ship such as a starfighter could avoid enemy tractor beams, it could often escape to the edge of an active gravity well, and then escape.

While the Sienar Immobilizer 418 was the most common design of Interdictor, other ships made use of gravity well projectors, most notably a number of variants of the Imperial-class Star Destroyer. During the Galactic Civil War, ships like Dominator and the command ship used by Darth Vader immediately after the Battle of Yavin mounted large projector globes in the manner of the smaller cruisers.

During the Yuuzhan Vong War, the New Republic launched Mon Mothma and Elegos A'Kla, which carried their interdictor equipment inside a normal Star Destroyer hull. The immense Eclipse-class and Sovereign-class Star Dreadnoughts also carried projectors internally within their massive hulls.

Interdictor technology was not completely limited to the Empire, however. Alliance forces made use of older CC-7700 frigates, and scientists in the Hapes Consortium reverse-engineered the gravity-well projector from captured ships; but rather than building bulky projectors, the Hapans fitted their Battle Dragons with launchers for charges known as pulse-mass mines, which produced much the same effect.

Service history
The Interdictor Cruisers were first manufactured by Sienar Fleet Systems two years before the Battle of Yavin, though these costly cruisers were still only produced in very limited quantities prior to the Battle of Hoth. Producing an entire fleet of such cruisers proved a time-consuming and delicate project and by the time of the Battle of Endor, Sienar Fleet Systems had manufactured only a few Interdictors, which were mainly under the command of Grand Admiral Thrawn in the Outer Rim Territories.

These vessels would not realize their potential until several years after Emperor Palpatine's death, when they became a key component in Thrawn's attempt to defeat the New Republic. The Grand Admiral would deploy such ships to ambush New Republic forces. He once used an Interdictor in conjunction with his flagship, Chimaera, in an attempt to capture Luke Skywalker. However, the Jedi eluded capture, by escaping Chimaera's tractor-beam lock, racing out of range of the gravity-well projector, and making a quick jump into hyperspace.

After Thrawn's defeat, the New Republic confiscated the remaining ships. New Republic technicians redesigned the Interdictor's gravity-well projectors, improving both their range and recharge rate. These new Interdictors, designated Immobilizer 418As, became one of the key components of the New Republic Defense Fleet during the Yuuzhan Vong War. During the Battle of Fondor, the New Republic supplied four Interdictors to the Hapan fleet.

Behind the scenes

 * The Interdictor is almost always shown with its four gravity well generators represented by four complete globes, two on either flank of the hull. One early image of Thrawn's attempt to capture Luke Skywalker at Jomark, however, shows two hemispherical domes protruding along the centerline on the topsides, with two more by inference on the ventral hull.


 * While at odds with most representations, this rendering is as consistent with the original profile view in the Imperial Sourcebook as the more familiar four-globe variant, and another depiction of the same events at Jomark also shows the same distinct type of ship, this time seen from below &mdash; thus strengthening the claim of this type to be a canon variant rather than simply a visual inconsistency.


 * In the game Star Wars: Empire at War, the Immobilizer 418 is designated as a frigate, along with a wide variety of other ships smaller than Star Destroyers.

Appearances

 * Dark Lord: The Rise of Darth Vader
 * Star Wars: Empire at War
 * Star Wars: Rebellion
 * Star Wars: TIE Fighter
 * Star Wars: X-wing vs. TIE Fighter
 * Star Wars: X-wing Alliance
 * Mara Jade: A Night on the Town
 * X-wing: Rogue Squadron
 * X-wing: Wedge's Gamble
 * The Thrawn Trilogy
 * Jedi Knight: Jedi Academy
 * I, Jedi
 * Vector Prime
 * Dark Tide II: Ruin
 * Agents of Chaos II: Jedi Eclipse