The Interdictor cruiser is a starship that served a very special purpose in the Imperial Navys fleet. The six hundred-meter-long star cruiser is built on a standard heavy-cruiser hull, but it carries an artificial gravity-well generator and four gravity-well projectors, which act together to simulate the tremendous effects of a stellar body in hyperspace.
When activated, the artificial gravity wells prevent nearby starships from escaping into hyperspace. Any ship already in hyperspace that crosses such a gravity well immediately drops to realspace. Cutting off the escape to hyperspace is critical-with the gravity-well projectors operating, no Rebel starship could thus escape from the empires cruisers and fighters.
Interdictor cruisers, also known as Immobilizer 418 cruisers, were designed by Seinar Fleet Systems, makers of both the TIE fighter and the Skipray blastboat. At first appearing to be a small Star Destroyer, the Interdictor heavy cruiser is recognizable because of the ships four prominent globes; each globe houses a single gravity well projector. Interdictors also have twenty quad laser cannons for short-range combat against other capital ships.
Imperial doctrine called for the Interdictors to be placed on the perimeter of a battle area This gave Interdictor captains a clear view of any battle so the could precisely target the placement of gravity wells to prevent Rebel ships from escaping into hyperspace.
The biggest disadvantage that comes with the Interdictors is that the gravity-well generators can take more than a minute to charge up, giving quick-thinking opponents a chance to jump to hyperspace before the gravity wells can be deployed again.
The Interdictors hull has proved to be of reliable design; it is also favored by the Imperial bureaucracy because of its close resemblance to the Imperial Star Destroyer. Designers have used the hull, which can be fitted with a wide variety of weapons, for several heavy cruiser designs. The hull and ship systems are easily converted for custom mission duties.
Interdictor cruisers figure prominently in Grand Admiral Thrawns tactics. He used them to cut off the escape routes of Rebel starships and nearly captured Luke Skywalker by using an Interdictor to force Lukes X-wing from hyperspace to realspace. Luke escaped both the Interdictor and the Star Destroyer Chimaera by using a desperation move when he reversed his ships acceleration compensators while simultaneously firing a pair of proton torpedoes to throw off the Chimaeras tractor beams. While the maneuver caused significant damage to Lukss hyperdrive, the Star Destroyers tractor beams locked on to the proton torpedoes, giving Luke the precious seconds he needed to make a microjump into hyperspace before the X-wing hyperdrive blew.
Later, Thrawn intended to use an Interdictor above Myrtkr to capture Talon Karrde and his ship, the Wild Karrde. However, Mara Jades sudden burst of intuition save Karrde when she ordered the Wild Karrdes crew to leave the system just before the Interdictor appeared.