Before the Ship Went Down: Carderock’s Role in Atlantic Thunder 2026

Before the Ship Went Down: Carderock's Role in Atlantic Thunder 2026

By Alisha Tyer, Naval Surface Warfare Center Carderock Division Public Affairs

Long before the first weapon struck the decommissioned guided-missile frigate ex-USS Klakring (FFG 42) during Atlantic Thunder 2026, engineers from Naval Surface Warfare Center, Carderock Division, were already preparing for what would happen next.

The U.S.-U.K. multi-domain sinking exercise , conducted off the coast of Scotland and led by U.S. 6th Fleet, brought together participating forces for live-fire engagements against the former Navy ship. For Carderock, the exercise offered an opportunity to collect data on real weapons effects while providing technical assessments that helped inform decisions as the live-fire events progressed.

For roughly a year and a half, Carderock engineers worked to prepare Klakring as an instrumented target. They installed sensors, ran cables, prepared power systems and developed ways to collect information remotely. Once the live-fire events began, personnel could not return aboard to inspect the damage, adjust equipment or retrieve what they had installed.

The challenge was not entirely new.

Carderock's involvement in Atlantic Thunder began with the planning of the inaugural exercise in 2022. With nearly two decades having passed since the previous SINKEX off the British coast, the division brought institutional knowledge to help U.S. 6th Fleet plan and execute the event.

Dr. Ken Nahshon, a Carderock senior research engineer who led the division's participation in Atlantic Thunder 2026, and Michael Kipp, a stability subject matter expert and team lead in Carderock's Weights and Stability Branch, played central roles in the earlier effort.

The 2022 exercise also revealed limitations in how engineers could collect data from the target ship. Personnel had to board the vessel to activate generators and other equipment, then allow enough time for the tug and its crew to move clear before the live-fire events began.

By 2026, the process had changed.

Carderock's instrumentation team had developed a battery-powered system that allowed engineers to activate equipment remotely, eliminating the need for personnel to board the ship immediately before live-fire events.

The remote capability was part of a much larger effort to prepare Klakring for Atlantic Thunder 2026, one that required engineers to take their work well beyond Carderock's laboratories.

"You have to go to the ship. The ship's not coming to you," Nahshon said.

Nahshon estimated that Carderock personnel spent about eight weeks aboard Klakring in Philadelphia over approximately 18 months, in addition to developing and testing equipment at Carderock facilities. After the ship arrived in Scotland, the instrumentation and photography teams spent another two weeks conducting final preparations and system testing before Klakring departed for the Ministry of Defence Hebrides range.

Carderock worked closely with Naval Information Warfare Center Pacific and Naval Air Warfare Center Weapons Division at Point Mugu, combining shipboard measurement, networking, imagery and photography capabilities to document the exercise. Other participating organizations, including Naval Air Warfare Center Aircraft Division's Atlantic Targets and Marine Operations and Naval Undersea Warfare Center Division Keyport, also contributed equipment aboard Klakring.

Beyond installing instrumentation, Carderock personnel contributed to exercise planning, providing expertise in weapons effects, ship stability and at-sea operations.

Senior Test Officer Stuart Sachs served as Carderock's SINKEX operations lead, coordinating shipboard work and in-port operations in Philadelphia and Scotland. His responsibilities also included coordinating the installation of emitter systems provided by other participating warfare centers. Establishing a dedicated local coordination role was among the improvements made following Atlantic Thunder 2022.

Nahshon described the scale of Carderock's involvement in Atlantic Thunder 2026 as "literally an order of magnitude more" than in 2022.

Severe weather tested the team's preparations before the first weapon was fired.

Weather delays left Klakring's instrumentation exposed to a full week of severe North Atlantic conditions. Engineers had secured equipment, waterproofed components where possible and incorporated redundant systems to protect the data collection effort. Despite the prolonged exposure and subsequent weapons strikes, the systems performed as designed.

But collecting information was only part of Carderock's role.

Using weapons-effects and stability prediction software, engineers assessed Klakring's condition as the exercise progressed. Hulk status reports summarized their findings, providing the mission director and participating units with updates on the target ship's condition and informing decisions about whether it was ready for subsequent events.

Carderock's expertise and the results generated by its in-house software were integrated directly into the exercise procedures.

"Carderock as a whole was literally written into the procedure," Kipp said.

Carderock develops and maintains stability software used throughout a ship's service life. Before the live-fire events, Kipp's team drew on those tools and its expertise to help determine Klakring's trim and stability conditions for towing, accounting for equipment added aboard the vessel. Once the engagements began, stability specialists worked with weapons-effects engineers to evaluate the ship's changing condition after each weapons strike.

The results also gave engineers a way to compare Carderock's models and simulations against actual weapons effects, identifying gaps and areas for future improvement. The gathered information will help refine tools used to predict weapons effects and ship survivability, supporting the development of more survivable ships and more lethal weapons.

Collecting that information through Atlantic Thunder also allowed Carderock to make use of resources already committed to the exercise, including the target ship, its transportation, weapons and participating platforms. The effort brought Carderock engineers into direct contact with the warfighters who use their research.

"Participating in the SINKEXs, and Atlantic Thunder specifically, gives us a highly cost-effective way to collect data on real weapons effects on real ships," Nahshon said.

For Nahshon, the payoff came after years of planning, development and hands-on preparation for an exercise that would ultimately destroy the ship.

"Seeing things work, be successful and generate critical information for the Fleet and for the warfighter is really exciting and satisfying," Nahshon said.

For Kipp, watching Klakring's final hours carried a different weight.

His group supports Navy ships from design through decommissioning, developing tools and providing training to help Sailors maintain ship stability and safety. Much of that work focuses on keeping ships safely afloat.

"I spend my career trying to keep our ships floating," Kipp said.

At Atlantic Thunder, he helped assess the condition of a ship the Navy intended to sink. It marked a departure from the work defining much of his career, but one that will ultimately help the Fleet better understand weapons effects and improve warfighting capabilities.

"It's hard to help them sink, but there's beauty in it," he said.