The US Navy’s two Ohio-class ballistic missile submarines (SSBN) have demonstrated their replenishment capabilities at sea during a series of joint vertical replenishment (VERTREP) exercises.

The VERTREP exercises were conducted between July and August off the coast of California, US.

It showcased the capabilities of the two submarines, USS Nevada (SSBN 733) and Henry M Jackson (SSBN 730), to perform essential replenishment operations, while continuing their mission at the sea.

As part of the exercise, the submarines operated jointly with the US Marine Corps’ (USMC) CMV-22 Ospreys, US Air Force’s (USAF) C-17 Globemaster III and US Navy’s MH-60R Seahawk helicopters.

Commander, Task Group 114.3 maritime operations director captain Kelly Laing said: “Recently the Pacific SSBN submarine force exercised a VERTREP capability for at-sea SSBNs to prove our resiliency for worldwide operations and to replenish our ships with materials, food and operational gear.

“This allows us to maintain an unpredictable forward presence and continued demonstration of unmatched strength of our strategic forces.”

The VERTREP drills were conducted under the US Strategic Command’s exercises to enhance interoperability of various US military platforms, to further implement the strategic deterrence mission.

It is the latest event in the series of the US submarine force’s efforts to conduct alternative operations, which earlier required a submarine to be pier side to accomplish.

Homeported at Naval Base Kitsap-Bangor, Nevada and Henry M Jackson are two of the eight Ohio-class submarines.

Submarine Group 9 and Task Group 114.3 commander rear admiral Mark Behning said: “Our fundamental mission is to deter a strategic attack, which is an existential threat to the US and our allies.

“Testing our readiness ensures we maintain a safe, secure and reliable strategic deterrent force.”