The US Navy has commissioned the 24th Virginia-class nuclear powered attack submarine (SSN), the USS Iowa (SSN 797), into service at a ceremony at Naval Submarine Base New London, on the east coast of the United States.
According to a 4 April 2025 release from the US Navy, the USS Iowa is the fifth naval vessel named for the state, which includes the famed World War 2-era battleship that also saw service in the Korean and Vietnam wars.
The submarine was built under a unique teaming agreement between General Dynamics Electric Boat and HII-Newport News Shipbuilding; both companies build sections of each submarine and then alternate deliveries. SSN 797 is the 13th Virginia-class submarine delivered by GDEB.
The USS Iowa’s keel was laid in August 2019, with the SSN subsequently christened in June 2023.
Each Virginia-class submarine is 7,800-tons and 377 feet (ft) in length, has a beam of 34ft, and can operate at more than 25 knots submerged. The boat’s reactor will not need to be refuelled through its expected 25–30-year service life.
A total of ten Virginia-class SSNs are either in production or undergoing testing after being launched. A further nine boats are publicly announced as being planned for acquisition.
US Navy submarines: SSNs in service
The US Navy has three classes of SSNs in service. The Los Angeles-class (SSN 688) submarines have been the backbone of the submarine force for the last 40 years, with 23 still commissioned. They are equipped with 12 Vertical Launch System (VLS) tubes for firing Tomahawk cruise missiles.
The Navy also has three Seawolf-class submarines. The first of the class, USS Seawolf (SSN 21) was commissioned July 1997.
Instead of VLS, the Seawolf class has eight torpedo tubes and can hold up to 50 weapons in its torpedo room. The third boat of the class, USS Jimmy Carter (SSN 23), has a 100ft hull extension called the multi-mission platform to accommodate advanced technology used in carrying out classified research.
Of the Virginia class, 24 have been commissioned, replacing the Los Angeles class as they retire from service.
The US Navy states that the Virginia class has several upgrades to improve combat capabilities, particular in littoral operations. The class has special features to support special forces, including a reconfigurable torpedo room to accommodate SOF personnel and equipment for prolonged deployments, as well as future off-board payloads.
In Virginia-class SSNs, traditional periscopes have been supplanted by two photonics masts that host visible and infrared digital cameras atop telescoping arms.
Block-by-block: Virginia class upgrades
As part of the Virginia-class’ Block III contract, the US Navy redesigned 20% of the boat to reduce acquisition costs. Most of the changes are found in the bow to replace the air-backed sonar sphere with a water-backed Large Aperture Bow array. This reduces acquisition and life-cycle costs while providing enhanced passive detection capabilities, the US Navy states.
The new bow also replaces the 12 individual Vertical Launch System (VLS) tubes with two large diameter 87-inch Virginia Payload Tubes (VPTs), each capable of launching six Tomahawk cruise missiles using Multiple All-up Round Canisters already employed on guided missile submarines (SSGNs).
The next major change in the Virginia class will be the incorporation of the Virginia Payload Module (VPM), starting with the second Block V ship, SSN 803, currently under construction. The VPM incorporates four additional large diameter payload tubes in a new hull section located amidships.
Each VPM payload tube is capable of carrying seven Tomahawk cruise missiles adding 28 missiles per VPM. The VPM returns the ability to host dry deck shelters for SOF operations and allows the US Navy to host additional advanced payloads via multiple ocean interfaces.
Block V hulls include the ten ships procured from 2019 through 2023 (SSNs 802-811), with two other boats planned (SSN 812 and SSN 813. Two additional future blocks, Blocks VI and VII, will leverage Block V modifications and future changes. Currently planned Block VI Virginia class include SSN 814, 815, and 816, respectively the future USS Potomac, USS Norfolk, and USS Brooklyn.
