The US Navy, UK Royal Navy, and UK Royal Air Force sank the decommissioned guided-missile frigate Klakring during a sinking exercise held Sept. 14-25 as part of Exercise Atlantic Thunder 2026 in the North Atlantic, the US Navy told reporters Sept. 28.
The exercise tested live-fire capabilities against a surface target at sea and was intended to foster US-UK interoperability for long-range maritime sinking operations, according to the Navy. The final blow to the Klakring was delivered by an Mk 48 Advanced Capability Torpedo fired from the Virginia-class submarine USS Massachusetts.
US Navy Capt. Kelechi Ndukwe, commander of 6th Fleet’s Task Force 65, said the destroyer USS Paul Ignatius fired an SM-6 missile during the exercise.
“We were testing the surface-to-surface engagement ability at the furthest range that we could,” Ndukwe said. “We were just testing that range.”
Ndukwe did not disclose the exact range tested. The Center for Strategic and International Studies lists the SM-6’s range at nearly 230 miles.
Ndukwe also confirmed that a Royal Navy Wildcat helicopter launched the Sea Venom missile and that the Royal Navy employed its Naval Strike Missile during the exercise.
Before the drill, Naval Surface Warfare Center Carderock and Naval Information Warfare Center Pacific installed sensors aboard the Klakring to collect data from the sinking, which Ndukwe said will be used to “really push the envelope on what we’re able to do with future weapons designs.”
“We started with the longest-range ordinance, which is why we were going with SM-6 first, and then moved into shorter range,” Ndukwe told reporters. “The embedded sensors that were on the frigate will analyze the data and the impact zones and the more the technical aspect over the course of the next few months as all of that data is processed.”
Additional units involved included the Royal Navy frigate HMS Portland, US Navy and Royal Air Force P-8 maritime patrol aircraft, and US Air Force F-15E Strike Eagles.
“Atlantic Thunder demonstrates the unmatched lethality and interoperability of the United States and United Kingdom,” Ndukwe said in a statement. “This sinking exercise not only validated the power behind U.S.-UK offensive weapons but delivers a clear message to adversaries that the U.S. Navy and Royal Navy remain a ready allied force.”
Ndukwe said the data collected from the embedded sensors will be analyzed over the next few months.