The Virginia class, also known as the SSN-774 class, is a class of nuclear-powered fast attack submarines (hull classification symbol SSN) in service with the United States Navy. The submarines are designed for a broad spectrum of open-ocean and littoral missions. They were conceived as a less expensive alternative to the Seawolf-class attack submarines, designed during the Cold War era, and they are planned to replace the older of the Los Angeles-class submarine, many of which have already been decommissioned. The class was developed under the codename Centurion, renamed to NSSN (New SSN) later on. The “Centurion Study” was initiated in February 1991. Virginia-class submarines will be acquired through 2043, and are expected to remain in service past 2060. Based on recent updates to the designs, some of the Virginia-class submarines are expected to still be in service in 2070.
Design of NSSN Virginia Class submarines
The engineering teams and design and build teams at Electric Boat in partnership with the Naval Sea Systems Command, NAVSEA, of the US Navy have used extensive CAD/CAE simulation systems to optimise the design of the submarine.
The hull size is length 377ft by beam 34ft and the displacement is 7,300t dived, which is smaller than the more expensive Seawolf attack submarine with displacement 9,137t dived.
The hull structure contains structurally integrated enclosures, which accommodate standard 19in and 24in width equipment for ease of installation, repair and upgrade of the submarine’s systems.
The submarine is fitted with modular isolated deck structures, for example the submarine’s command centre will be installed as one single unit resting on cushioned mounting points. The submarine’s control suite is equipped with computer touch screens.
The submarine’s steering and diving control is via a four-button, two-axis joystick.
The noise level of the Virginia is equal to that of the US Navy Seawolf, SSN 21, with a lower acoustic signature than the Russian Improved Akula Class and fourth-generation attack submarines. To achieve this low acoustic signature, the Virginia incorporates newly designed anechoic coatings, isolated deck structures and a new design of propulsor.
Goodrich is supplying high-frequency sail array acoustic windows and composite sonar domes.
The command and control systems module (CCSM) has been developed by a team led by Lockheed Martin Naval Electronics & Surveillance Systems – Undersea Systems (NE&SS-US) of Manassas, Virginia. It will integrate all of the vessel’s systems – sensors, countermeasure technology, navigation and weapon control and will be based on open system architecture (OSA) with Q-70 colour common display consoles.
Weapon control is provided by Raytheon with a derivative of the CCS mk2 combat system, the AN/BYG-1 combat control system, which is also being fitted to the Australian Collins Class submarines.
AN/BYG-1 combat control system
The Virginia has two mast-mounted Raytheon submarine high data rate (sub HDR) multiband satellite communications systems that allow simultaneous communication at super high frequency (SHF) and extremely high frequency (EHF).
The submarine is equipped with 12 vertical missile launch tubes and four 533mm torpedo tubes. The vertical launching system has the capacity to launch 16 Tomahawk submarine-launched cruise missiles (SLCM) in a single salvo. There is capacity for up to 26 mk48 ADCAP mod 6 heavyweight torpedoes and sub harpoon anti-ship missiles to be fired from the 21in torpedo tubes. Mk60 CAPTOR mines may also be fitted.
Virginia Payload module will increase cruise missiles on Virginia Submarines by 76%
The US Navy plans to build one of the two Virginia-class boats procured in FY2019, and all Virginia class boats procured in FY2020 and subsequent years, with an additional mid-body section, called the Virginia Payload Module (VPM). The VPM, reportedly about 70 feet in length (earlier design concepts for the VPM were reportedly about 94 feet in length), contains four large diameter, vertical launch tubes that would be used to store and fire additional Tomahawk cruise missiles or other payloads, such as large-diameter unmanned underwater vehicles (UUVs).
The four additional launch tubes in the VPM could carry a total of 28 additional Tomahawk cruise missiles (7 per tube), which would increase the total number of torpedo-sized weapons (such as Tomahawks) carried by the Virginia class design from about 37 to about 65—an increase of about 76%. The Navy wants to start building Virginia-class boats with the VPM in FY2019. Building Virginia-class boats with the VPM would compensate for a sharp loss in submarine force weapon-carrying capacity that will occur with the retirement in FY2026-FY2028 of the Navy’s four Ohio-class cruise missile/special operations forces support submarines (SSGNs).
Tomahawk launcher assembly
BAE to increase Virginia-class submarine launch tube production: Here
Tomahawk Cruise MissileHarpoon Cruise Missile
The Navy Just Got A SUPER Explosive New Toy [VIDEO]: Here
Navy Prototypes More Lethal New High-Tech Mk 48 Heavyweight Torpedo
The earlier version, the Mk 48 Mod 6, has been operational since 1997 – and the more recent Mod 7 has been in service since 2006.
Lockheed has been working on upgrades to the Mk 48 torpedo Mod 6 and Mod 7 – which consists of adjustments to the guidance control box, broadband sonar acoustic receiver and amplifier components.
Tom Jarbeau, Director and General Manager of Targets, Torpedoes and Sensors, Lockheed Martin, told Scout Warrior in an interview that Lockheed is now delivering 20-upgrade kits per month to the Navy.
Part of the effort, which involves a five-year deal between the Navy and Lockheed, includes upgrading existing Mod 6 torpedoes to Mod 7 as well as buying brand new Mod 7 guidance control sections.
The new Mod 7 is also resistant to advanced enemy countermeasures.
Modifications to the weapon improves the acoustic receiver, replaces the guidance-and-control hardware with updated technology, increases memory, and improves processor throughput to handle the expanded software demands required to improve torpedo performance against evolving threats, according to Navy information on the weapon.
The Mod also provides a significant reduction in torpedo radiated-noise signatures, a Navy statement said.
Alongside Lockheed’s work to upgrade the guidance technology on the torpedo, the Navy is also preparing to release a Request for Proposal, or RFP, to industry for a completion to build new Mk 48s.
Upgrades to the guidance control section in includes the integration of a system called Common Broadband Advanced Sonar System, or CBASS – electronics to go into the nose of the weapon as part of the guidance section, Jarbeau explained.
“This provides streamlined targeting and allows the torpedo to transmit and receive over a wider frequency band,” Jarbeau said.
Jarvo added that the new technology involves adjustments to the electronic circuitry in order to make the acoustic signals that are received from the system that allow the torpedo to better operate in its undersea environment. Source scout.com
Mk 48 Mod 7 CBASS submarine torpedoes
The CBASS broadband sonar makes the torpedo more effective against emerging submarine classes in the harshest of acoustic environments, Lockheed Martin officials say. The Mark 48 Mod 7 CBASS torpedo uses modern commercial-off-the-shelf (COTS) technologies in an open-architecture computing environment, and can be improved with regular hardware and software upgrades.
(Edit: HD) Mk 48 Mod 7 CBASS schematic, the US Navy’s current heavyweight torpedo. Sonar transducer in front followed by the electronics, warhead, fuel tank, and engine. @imgur.com
The Mark 48 Mod 7 torpedo is standard armament for the Navy’s fleet of Los Angeles-, Virginia-, and Seawolf-class fast attack submarines, as well as Ohio-class ballistic-missile and cruise-missile submarines.
Mk 48 Mod 7 CBASS schematic, the US Navy’s current heavyweight torpedo. Sonar transducer in front followed by the electronics, warhead, fuel tank, and engine. @imgur.com
The Lockheed Martin Corp. Mission Systems and Training segment in Washington is building the Mark 48 Mod 7 CBASS heavyweight torpedo with advanced common broadband advanced sonar system for expanded operational capabilities for shallow waters along coastlines and inside harbors, as well as in the deep-water open ocean.
The CBASS torpedo also has the ability of multiband operation with active and passive homing; advanced counter-countermeasure capabilities; effectiveness against low-Doppler shallow submarines, fast deep diving submarines, and high-performance surface ships; autonomous fire-and-forget operation or wire-guide capability to enable post-launch monitoring and updates via the submarine combat system; and running Otto Fuel II as the propellant.
Detail: CBASS fuel tank containing Otto II fuel (wire reel on the right). @imgur.com
The Mark 48 Mod 7 CBASS torpedo can transmit and receive over a wide frequency band and use broadband signal processing techniques to improve the torpedo’s search, acquisition, and attack, Lockheed Martin officials say. Source militaryaerospace.com
Primary Function: submarine-launched heavyweight torpedo
Manufacturer: Mod.1: Gould, Inc. / Honeywell ADCAP: Hughes Aircraft (now Raytheon)
Power Plant: swash-plate piston engine; pump jet (Otto fuel II)
Diameter: 21 inches (533 mm)
Length: 19 feet (5,79 m)
Weight: 3434 lb (1558 kg), original // 3695 lb (1676 kg), ADCAP
Range: > 25 NM (46 km)
Depth: > 1200 feet (365 m), officially // 800 meters (2620 feet), estimated
Speed: > 30 knots (56 km/h), officially // 55 knots (102 km/h), estimated
Warhead: 650 lb (295 kg)
In Service: 1971 – present (Mod 1) // 1988 – present (ADCAP)
Users: US Navy, Royal Australian Navy, Royal Canadian Navy, Royal Netherlands Navy, Brazilian Navy Data seaforces.org
An integral lock-out / lock-in chamber is incorporated into the hull for special operations. The chamber can host a mini-submarine, such as Northrop Grumman’s Oceanic and Naval Systems advanced SEAL delivery system (ASDS), to deliver special warfare forces such as navy sea air land (SEAL) teams or Marine reconnaissance units for counter-terrorism or localised conflict operations.
Virginia is fitted with the AN/WLY-1 acoustic countermeasures system being developed by Northrop Grumman, which provides range and bearing data, along with the mast-mounted AN/BLQ-10 electronic support measures (ESM) system from Lockheed Martin Integrated Systems.
AN/BLQ-10 provides full spectrum radar processing, automatic threat warning and situation assessment.
The Virginia Class sonar suite includes bow-mounted active and passive array, wide aperture passive array on flank, high-frequency active arrays on keel and fin, TB 16 towed array and the Lockheed Martin TB-29A thinline towed array, with the AN/BQQ-10(V4) sonar processing system. A Sperry Marine AN/BPS-16(V)4 navigation radar, operating at I-band, is fitted.
Lockheed Martin TB-29A thinline towed array
The submarines have two Kollmorgen AN/BVS-1 photonic masts, rather than optical periscopes. Sensors mounted on the non-hull-penetrating photonic mast include LLTV (low-light TV), thermal imager and laser rangefinder. The mast is the Universal Modular Mast developed by Kollmorgen and its Italian subsidiary, Calzoni.
The Boeing LMRS long-term mine reconnaissance system will be deployed on the Virginia Class. LMRS includes two 6m autonomous unmanned underwater vehicles, an 18m robotic recovery arm and support electronics.
LMRS includes two 6m autonomous unmanned underwater vehicles
Northrop Grumman Electronic Systems is supplying the lightweight, wide-aperture array (LWWAA) system based on fibre-optic arrays, instead of traditional ceramic hydrophone sensors.
LWWAA is a passive ASW sonar system which consists of three large array panels mounted on either side of the submarine’s hull.
Lockheed Martin provided acoustic rapid commercial off-the-shelf insertion (A-RCI) hardware for the sonar system upgrade. The $25.1m contract was awarded in August 2009 and deliveries were completed in 2012.
In January 2011, an $84m contract was awarded to Lockheed Martin for submarine sonar upgrades.
The main propulsion units are the GE pressure water reactor S9G, designed to last as long the submarine, two turbine engines with one shaft and a United Defense pump jet propulser, providing 29.84MW. The speed is over 25kt dived.
Updated Dec 03, 2016
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