In the past month, the United States Air Force has sunk three warships – but this wasn’t part of an ongoing military campaign. Rather, the Air Force worked alongside the United States Navy in what is known as a SINKEX, a carefully coordinated exercise that involves a retired vessel that is used as a target.
“SINKEX, short for ‘sink at-sea live-fire training exercises’, is a program run by the United States Navy that arranges for decommissioned Naval warships to be used in live-fire training. This gives Navy personnel the opportunity to use real ammunition on practical targets and apply what they learn to future conflict, practicing gunnery, missile drills, torpedo accuracy, and even special warfare operations,” explained the U.S. Department of Transportation’s Maritime Administration (MARAD).
The most recent SINKEX took place in the Gulf of Mexico, in the waters near Eglin Air Force Base (AFB), where it was actually the Air Force that sent a retired cargo vessel to the bottom – where it will become an artificial reef. In that exercise, the U.S. Air Force employed a QUICKSINK, which employs a guidance kit integrated with a new seeker on an air-launched weapon; in this case, a modified GBU-31 JDAM (Joint Direct Attack Munition) 2,000-pound precision-guided bomb.
Air Force and Navy Working on Anti-Ship Weapons
The Air Force Research Laboratory Munitions Directorate at Eglin AFB in partnership with the Navy has been working to develop anti-ship air-launched weapons as part of the ongoing joint Maritime Weapons Program.
“The development of this technology helps deliver technological superiority to ensure the United States can defend our interests, maintain freedom of action, and seize the initiative over large maritime areas,” explained Col. Matthew Caspers, director of the AFRL Munitions Directorate.
The United States military continues to transition to a great power competition, which comes as China has greatly increased its naval capabilities, and it is seeking new ways to ensure it can retain an edge in naval warfare – especially as there are concerns that Beijing could mount an amphibious assault on Taiwan and other islands in the Indo-Pacific.
“The men and women of the Munitions Directorate consistently find ways to solve our nation’s greatest challenges,” Caspers added. “QUICKSINK is an answer to an urgent need to neutralize maritime threats to freedom around the world. This program is unique in that it can provide capabilities to modify existing and future Department of Defense weapons systems, giving combatant commanders and our national leaders new ways to defend against maritime threats.”
SINKEX From a Spirit in the Sky
It was last month, during the recently concluded Exercise Rim of the Pacific (RIMPAC) two retired U.S. Navy warships were sunk in waters 15,000 feet deep, more than 50 nautical miles off the northern coast of the Hawaiian island of Kauai.
The decommissioned ex-USS Dubuque (LPD-8) – an Austin-class amphibious transport dock – was sunk by U.S. Air Force Lockheed Martin B-2 Spirit bombers; while the amphibious assault ship ex-USS Tarawa (LHD-1) was also sunk by U.S. Navy Boeing F/A-18 Super Hornets armed with the AGM-158C Long Range Anti-Ship Missile (LRASM).
The latter missile was developed by the Defense Advanced Research Projects Agency (DARPA), the research and development agency of the United States Department of Defense, and based on the AGM-148B Joint Air-to-Surface Standoff Missile – Extended Range (JASSM-ER).
“The sinking of the ex-Tarawa included the employment of a Long-Range Anti-Ship Missile (LRASM) from a U.S. Navy F/A-18F Super Hornet. As a precise, stealthy, and survivable cruise missile, LRASM provides multi-service, multi-platform, and multi-mission capabilities for offensive anti-surface warfare,” the U.S. Navy said in a statement announcing the successful SINKEX during RIMPAC 2024. “During the SINKEXs, participating units from Australia, Malaysia, the Netherlands, the Republic of Korea, and the U.S. Air Force, Army and Navy gained proficiency in tactics, targeting and live firing against surface ships at sea.”
The U.S. Navy had been preparing the ex-LHA-1 for use in the SINKEX since at least 2022, while her sister ship, the ex-USS Peleliu (LHA-5) could also be used as a future floating target. The ex-USS Belleau Wood (LHA-3) was sunk in 2006, while five of the seven Iwo Jima-class amphibious assault ships – which preceded the Tarawa class – were also sunk in past RIMPAC SINKEXs. The ex-USS New Orleans was the last one to be sent to the bottom of the Pacific at the 2010 iteration of the exercise, TheWarZone reported.
SINKEX Turn Old Warships Into Floating Targets
Considerable effort is put into the U.S. Navy’s SINKEX. The aforementioned MARAD developed an agreement with the U.S. Navy that requires the safe disposal of retired warships.
It requires that all environmentally hazardous materials be removed from the vessels before they are sunk in accordance with Environmental Protection Agency (EPA) guidelines. This includes the removal of all liquid polychlorinated biphenyls (PCBs) from a ship’s transformers, large capacitors, and small capacitors, while petroleum is drained and then cleaned from the vessel’s tanks, pipes, and reservoirs. In addition, all trash, floatable materials, mercury, and fluorocarbon materials are also removed. Simply put, the ship is about as clean as it likely was at any point during its existence.
“The EPA and Navy have identified and agreed upon those materials to be removed from a vessel prior to any SINKEX exercise,” MARAD further noted “Procedures are also in place to ensure that vessels sink quickly to the ocean floor and remain there permanently without hindering marine navigation in the area. In addition, all sinkings are conducted in water of at least 6,000 feet (1,000 fathoms) and 50 nautical miles from land.”
According to the U.S. Navy, “SINKEXs are conducted only after the area has been surveyed for the presence of people, marine vessels, aircraft, and marine species. SINKEXs are fully compliant with the National Environmental Policy Act, Marine Mammal Protection Act, Endangered Species Act, and a general permit under the Marine Protection, Research, and Sanctuaries Act.”
While all efforts are meant to ensure that a SINKEX is carried out accordingly, it remains a form of training that can’t be easily replicated.
“Sinking exercises give us a chance to sharpen our skills, learn from one another, and get real-world experience,” said U.S. Navy Vice Adm. John Wade, RIMPAC 2024 Combined Task Force Commander. “Using advanced weapons and seeing the professionalism of our teams during these drills shows our commitment to keeping the Indo-Pacific region safe and open.”
