Sienar Fleet Systems already produced an Interdictor, the Immobilizer 418 cruiser based on a 600 m Vindicator-class heavy cruiser (also used for the Enforcer-class picket cruiser). Though it was decently armed for its size, it was a high priority vessel that was generally unable to hold its own in combat, especially if the battle involved Imperial Star Destroyers and comparable vessels.
Kuat Drive Yards decided to produce their own Interdictor offering to rival that of SFS by using an Imperial I-class Star Destroyer hull as a base. To make room for the gravity well projectors, half of the turbolasers and ion cannons, as well as eight of the Phylon Q7 tractor beam projectors found on the original Imperial-class Star Destroyer, had to be removed.. The Interdictor-class Star Destroyer's reduced hangar held four squadrons of TIE fighters. As such the Interdictor did not make an excellent combat destroyer.
The Interdictor-class Star Destroyer did not require additional support when performing patrol and customs duties. Some bold commanders such as Loka Hask even used the ship to pull armed convoys out of hyperspace and destroy them.
Nonetheless, like the Immobilizer, the gravity wells remained a major drain on the ship's main reactor. This had the potential to compromise defenses in heavy combat. For instance, while Loka Hask's Dominator had interdicted and was destroying a Allied Convoy, Rogue Squadron's fighters counter-attacked by hitting Dominator with a salvo of torpedoes. While an Imperial Star Destroyer's shields would have easily held up against such an assault, Dominator's shields partially collapsed and the hull took some damage, prompting its commanders to call off the battle. (Sera also successfully used this tactic on the Immobilizer 418 cruiser Aggregator which caused it to retreat.)
Introduced shortly before the Gi'ru Conflict, the Interdictor Star Destroyer was created by Sienar Fleet Systems as an alternative to the Immobilizer 418 Cruiser. Using the Imperial Star Destroyer hull as a base they sought to compensate for the combat weaknesses apparent in the smaller Immobilizer. Although only produced in limited numbers, the Interdictor was used to great effect by David M. Young during his campaign against the Alliance of Civilizations.