Sinking decommissioned warships: Inside RIMPAC 2023's grand maneuvers

One way to test the effectiveness of anti-ship weapons is by using them against real warships. During this year's RIMPAC exercises, the Americans sank two of their own decommissioned large ships: USS Dubuque and USS Tarawa.

RIMPAC (Rim of the Pacific) is a large international maritime exercise held in the Pacific, organized by the United States since 1971. This year, for the exercises planned from June 26 to August 1, the Americans invited as many as 29 other countries.

The maneuvers involve 40 ships, 150 aircraft, and more than 25,000 soldiers from around the world. Part of the maneuvers includes SINKEX exercises, during which real weapons are used to attack real—although decommissioned—warships.

This year's exercises featured the new LRASM anti-ship missiles. Among others, maritime targets were attacked by F/A-18F Super Hornet carrier-based aircraft and B-2 Spirit strategic bombers.

Two decommissioned ships, USS Dubuque (LPD 8) and USS Tarawa (LHA 1), were the targets. Before sinking, both ships were prepared according to the Environmental Protection Agency (EPA) guidelines to minimize potential pollution in the exercise area. Removing fuel, ammunition, and flammable substances from the ships' interiors also made them harder targets to sink.

American regulations allow ships to be sunk provided that the wreck settles at a depth of at least 6,000 feet (over 1,800 meters) and is at least 50 miles (about 80 kilometers) from the shore.

The ships sunk during the exercises were notable for their size. The USS Tarawa (Tarawa class) was a large amphibious ship with a length of 820 feet (250 meters) and a displacement of 39,000 tons. It featured a flight deck and hangar capable of handling 35 helicopters and eight vertical/short takeoff and landing aircraft.

The ship could transport up to 1,800 Marine Corps soldiers and equipment. A well deck facilitated amphibious operations—hovercraft, amphibious vehicles, and various types of landing craft could depart directly from the ship's interior. Five ships of this type were built.

The USS Dubuque (Austin class) displaced 17,000 tons and could transport 840 Marine Corps soldiers. It also had a good deck and a flight deck and was equipped to handle up to six large helicopters. A total of 12 ships of this type served in the US fleet.