11A2R1 naval coilgun battery (Earth-5875)

11A2R1 naval coilgun batteries are a massive coilgun mounted on the hull of many UNSC ships.

History
The Phoenix-class colony ship UNSC Spirit of Fire was equipped with ten 11A2R1 naval coilgun batteries in 2520. The weapons were used trough the First Contact War, particularly by Punic-class supercarriers. In 2531, they were manned by the UNSC Spirit of Fire to supply orbital support for its ground troops.

At the Battle of Etran Harborage, the cannons were used by the Spirit of Fire to destroy a CPV-class heavy destroyer and numerous Type-25 Spirits in order to buy time for SPARTAN-II Red Team and a team of UNSC Marines to fend the borders of the ship.