Military


SSN-774 Virginia-class Batch 3 / Block IV / V

Block IV Virginia class

Electric Boat expected [as of late 2007] the RFP for Block IV to be released in 2012 with an award in 2014. Design changes might include new sensors, a new sail design, capabilities for communications at higher speed and greater depth, electric drive, and externally mounted weapons.

Initially the Navy anticipated placing an advanced sail on hulls 5-6 of the VIRGINIA Class. The new sail shape and size might well provide the required volume for advanced future payloads. The Advanced Sail Program for the New SSN (NSSN) program has undergone model testing and later-stage design development. The Advanced Sail was installed on the Large Scale Vehicle (LSV) Kokanee, a self-powered 1/4-scale model of the Seawolf submarine, in late 1999. Changes to the LSV due to the new sail were quantified with a trim verification dive and an inclining experiment. The results indicated all changes to LSV's weight, moment and BG (center of bouyancy minus center of gravity) are exactly as predicted. The first Advanced Sail underway was on 17 November 1999. This underway was designed to compress sail components for final torque of attachment bolts and the installation of coatings over those bolts. The crew also tested sail pressure sensors at various depths. The first acoustic data collection underway for the Advanced Sail Trial was conducted just prior to Thanksgiving. The Advanced Sail will have as much as four times the enclosed volume as its predecessor. The navy is looking at whether to put a large UUV hangar, SOF equipment, or UAV in the Advanced Sail.

According to program officials, in 2007 one design change, the introduction of the advanced sail, was deferred from 2009 until 2014 to allow further design development and risk reduction. Near term funding for this effort was reallocated to take advantage of other cost reduction opportunities. When implemented, this design change will replace the existing sail, the structure that sits atop the main body of the submarine, with one that provides expanded space for sensor systems or equipment for special forces teams. The advanced sail will be constructed of composite materials whose feasibility had already been demonstrated under a separate development program.

DOE's National Nuclear Security Administration [NNSA] is working on a new Transformational Technology Core (TTC) pressurized water reactor that will provide an energy increase to VIRGINIA-class ships with minimal impact to overall ship design. TTC will use advanced reactor core materials to achieve a significant increase to the core energy density - more energy without increasing size, weight, or space - while still at a reasonable cost. Development plans in 2003 called for the delivery of the first TTC core in 2014. Naval Reactors has a limited number of specific long-term performance measures that meaningfully assess progress in achieving program purpose. By 2007 thse goals were to safely steam approximately 2 million miles annually, totaling 150 million miles in nuclear-powered ships in program history by 2015; to provide the reactor plant for the next generation aircraft carrier by 2015; and to deliver the first Transformational Technology Core by 2015. By 2007 DOE had completed 46% of the Transformational Technology Core reactor plant design.

Block V Virginia class

Electric Boat expected [as of late 2007] the RFP for Block V to be released in 2017 with an award in 2019. This timing is a bit puzzling, since it would appear that only four boats would remain in a 30 boat program Design changes might include new sensors, a new sail design, capabilities for communications at higher speed and greater depth, electric drive [first brooded in Bundle 2, once slated for the 2010 timeframe], and externally mounted weapons, if these are not introduced in Block IV.



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