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HII Completes The Pressure Hull Of The Future USS Massachusetts (SSN 798)

Huntington Ingalls Industries (HII) announced on 10 August 2022 that its Newport News Shipbuilding division has reached a major milestone in the construction of the Virginia-class submarine Massachusetts (SSN 798).

HII completes the pressure hull of the future USS Massachusetts (SSN 798) - Naval News

Shipbuilders working on Massachusetts recently reached pressure hull complete, meaning that all of the hull sections were joined to form a single, watertight unit. This is the last major construction milestone before the submarine is launched.

Newport News Shipbuilding is one of only two shipyards capable of designing and building nuclear-powered submarines. The advanced capabilities of Virginia-class submarines increase firepower, maneuverability, and stealth.

HII Authenticates Keel of Virginia-Class Attack Submarine Massachusetts - Seapower

This milestone on Massachusetts comes following the delivery of USS Montana (SSN 794) and launch of New Jersey (SSN 796) at Newport News Shipbuilding earlier in 2022, as the shipyard continues to invest in its workforce and facilities to make steady progress on delivering these important assets to the Navy.

Massachusetts is the 25th Virginia-class fast attack submarine.

About Virginia-class Block I II III IV & V SSN

Virginia-class submarine - Wikipedia

Block IV submarines (SSNs 792 to 801) incorporate design changes focused on reduced total ownership cost (RTOC). By making these smaller-scale design changes to increase the component-level lifecycle of the submarine, the U.S. Navy will increase the periodicity between depot maintenance availabilities and increase the number of deployments.

USS Delaware (SSN 791), the last and final of eight Block III Virginia-class submarines, was commissioned in April 2020. Delaware’s keel was laid April 30, 2016, and was christened during a ceremony on Oct. 20, 2018.

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The Block III submarines are fitted with the new Virginia Payload Tubes designed to lower costs and increase missile-firing payload possibilities. The first 10 Block I and Block II Virginia-class submarines have 12 individual 21-inch diameter vertical launch tubes able to fire Tomahawk Land Attack Missiles (TLAMS). The Block III submarines are built with two larger 87-inch diameter tubes able to house six TLAMS each.

Blocks I-III Virginias are planned to undergo four depot maintenance availabilities and conduct 14 deployments. Block IV RTOC efforts are intended to reduce planned availabilities by one to three and increase deployments to 15. The U.S. Navy refers to this as 3:15.

Virginia-Class Submarine Block IV Award Becomes Largest U.S. Navy Shipbuilding Contract | Defense Media Network

Block IV will be followed by the Block V configuration which involves 10 boats and may incorporate the Virginia Payload Module (VPM), which would give guided-missile capability when the SSGNs are retired from service. On 2 December 2019, the U.S. Navy announced an order for nine new Virginia-class submarines – eight Block Vs and one Block IV – for a total contract price of $22 billion with an option for a tenth boat. The Block V subs were confirmed to have an increased length, from 377 ft to 460 ft, and displacement, from 7,800 tons to 10,200 tons.

Submarines in Block IV configuration :

Vermont (SSN 792) – Commissioned 18 April 2020
Oregon (SSN 793) – Delivered to the U.S. Navy Februrary 26, 2022
Montana (SSN 794) – Delivered to the U.S. Navy March 14, 2022
Hyman G. Rickover (SSN 795) – Christened in July 31, 2021
New Jersey (SSN 796) – Launched April 28, 2023
Iowa (SSN 797) – Keel laid August 20, 2019
Massachusetts (SSN 798) – Keel laid December 11, 2020
Idaho (SSN 799) – Keel laid 24 August 24, 2020
Arkansas (SSN 800) – Construction began March 2018
Utah (SSN 801) – Construction began March 2018