UGM-96 Trident I

The UGM-96 Trident I, or Trident C4, was an American submarine-launched ballistic missile (SLBM), built by Lockheed Martin Space Systems in Sunnyvale, California. First deployed in 1979, the Trident I replaced the Poseidon missile. It was retired in 2005, having been replaced by the Trident II.

The missile was a three-stage, solid-fuelled system, capable of carrying up to eight W76 warheads in the Mark 4 RB.

The first eight Ohio-class submarines were armed with Trident I missiles. Twelve James Madison-class submarine- and Benjamin Franklin-class submarines were also retrofitted with Trident I missiles, which replaced older Poseidon missiles.

In 1980, the Royal Navy requested Trident I missiles under the Polaris Sales Agreement. In 1982, the agreement was changed to supply Trident II instead.