The CADS-N-1 (Combined Air Defense System, Naval, first type) Close-In Weapon System is a Russian naval close-range air and surface defense weapon system, designed in the 1990s to address the limitations of the older AK-630 gun system. It consists of a control module, containing computers and radars, and a combat module (up to four per control module) carrying the weapons, a camera and an auxiliary radar. It is a hybrid gun/missile system, made up of an eight-round box launcher for the SA-N-11 Grisom missile, flanked by two six-barreled 30mm gatling guns. The system is probably derived from the 2S6M Tunguska air defense vehicle, and shares many elements with it. It is regarded as the most theoretically capable CIWS of all the currently deployed systems, although the joint German and American RAM is regarded as superior to the SA-N-11.
CADS-N-1 is installed on several classes of warship. In the Russian navy, it is used on the Kuznetsov-class aviation cruiser Admiral Kuznetsov, with two control modules driving a total of eight combat modules. The Kirov-class cruisers Nakhimov and Pyotr Velikhy have six combat modules each, three on each side, with two control modules, and the Neustrashimy class frigates have one control module driving two combat modules. Some of the newer Sovremenny class destroyers and the Udaloy II-class destroyer also use CADS-N-1, with a single control and four combat modules. The Kiev class aviation cruiser Gorshkov was refitted with eight CADS-N-1 mounts and two control modules prior to being transferred to India.