Trident 1C4

Trident I C4 was the first Trident submarine-launched ballistic missile and replaced Poseidon on selected U.S. ballistic-missile submarines while also arming early Ohio-class SSBNs. Strategic Systems Programs describes C4 as a three-stage, solid-propellant, inertially guided SLBM with much greater range than Poseidon. It was a transitional but important step between Poseidon C3 and the later Trident II D5.

C4 used solid propulsion, inertial guidance, and multiple reentry bodies to give SSBNs longer patrol-area flexibility than earlier missiles. Its range allowed submarines to cover target sets from safer patrol zones, improving survivability of the sea-based nuclear deterrent. It should be classified as an SLBM rather than a land-based ICBM, even if the database category uses ICBM.

Operationally, Trident I C4 served the U.S. sea-based nuclear deterrent from the late Cold War until final retirement as Ohio-class submarines converted to D5 or SSGN roles. Its importance lies in increasing SSBN patrol flexibility and maintaining deterrence continuity during the transition to the larger, more capable Trident II missile.