The US Navy has decided to equip its new Constellation-class frigates with fully automatic 57mm Mk 110 naval guns.

The Naval Sea Systems Command Integrated Warfare Systems 3C (NAVSEA IWS) has placed a $26m contract with BAE Systems to equip the vessels with the Mk 110 systems.

As part of the contract, BAE Systems will deliver two Mk 110s for the USS Constellation (FFG 62) and USS Congress (FFG 63), the first and second ship of the Constellation-class of vessels.

The contract also includes engineering support for the naval guns.

BAE Systems weapon systems product line vice-president Brent Butcher said: “The selection of the Mk 110 for the US Navy’s Constellation-class frigates signifies confidence in the gun system and its ability to meet current and future needs in shipboard defence.

“The Mk 110 gun system provides this next-generation frigate with the continued performance that our surface fleet has come to expect from its intermediate calibre guns.”

Internationally known as the Bofors 57 Mk 3, the Mk 110 gun system is a multi-mission, medium-calibre shipboard weapon piece capable of firing up to 220 rounds per minute at air, surface or ground threats.

The gun has an effective range of more than nine nautical miles using BAE Systems’ six-mode programmable, pre-fragmented, and proximity-fused (3P) ammunition.

The MK 110 gun is installed aboard the US Navy’s Littoral Combat Ship and the US Coast Guard’s National Security Cutter ships.

BAE Systems will also deliver a Mk 110 system to the US Coast Guard’s third Argus-class offshore patrol cutter, USCGC Ingham, as part of the latest contract.

Deliveries are slated to begin in 2023.

BAE Systems recently secured a systems engineering and integration support services contract to continue working with the US Navy Strategic Systems Programs (SSP) office. The five-year contract is worth up to $478m.