Military


SSN-774 Virginia-class Batch 1 / Block I / II

Batch 1

The Bundle spiral upgrade later gave way to Batches, and Blocks. Batches represented major design changes, while Blocks were multi-year procurement contracts. Not all technology insertions were timed to coincide with Blocks or Batches. The first two Blocks were Batch 1.

Block I Virginia class

The National Defense Authorization Act for Fiscal Years 1998 (Public Law 105-85) authorized the Secretary of the Navy to enter into a contract for procurement of four New Attack Submarines, provided that the prime contractor, which was selected to be General Dynamics, entered into one or more subcontracts with the subcontractor, which is Northrop Grumman, for submarine construction as contemplated in the New Attack Submarine Team Agreement. By mid-2006 Virginia (SSN-774) and Texas (SSN-775) had been delivered, and Electric Boat was focused on delivering Hawaii (SSN-776). Hawaii was built for about 2.3 million fewer hours than the lead ship, USS Virginia. The time span from christening to delivery of Hawaii, the third ship of the class, was less than six months. Newport News was well along on North Carolina (SSN-777), to complete the Block I ships.

Block II Virginia class

SSNs 778-783 are Block II Virginia class submarines. The National Defense Authorization Act for Fiscal Year 2004 (Public Law 108-136) authorized the Secretary of the Navy to enter into a contract for procurement of six New Attack Submarines, provided that the prime contractor, which was selected to be General Dynamics, entered into one or more subcontracts with the subcontractor, which is Northrop Grumman, for submarine construction as contemplated in the New Attack Submarine Team Agreement. The objective was to achieve significant savings on the Block II ships, which would lead us to a $2 billion per-ship cost and ultimately support a two-ship per-year procurement rate.

While SSN-778 New Hampshire is the fifth ship of the Virginia class, the first Block II boat established some significant firsts for the program. It is the first Virginia-class ship to be built in four sections, a noteworthy improvement from the 10 required for the lead ship. This achievement reflects advances in the company's module-handling capabilities, which allow EB to move sections weighing 2,000 tons, up from the previous maximum of just under 1,600 tons. With this increased modular-construction efficiency, EB can ship four essentially complete hull sections to the final assembly facilities in Connecticut and Virginia. Production and process improvements have put New Hampshire on a track to be delivered in 72 months, a year ahead of earlier ships.

The Virginia class submarine program is developing three new technologies for insertion into submarines beginning in 2010. The first of these is a software package containing improved algorithms to monitor and, if necessary, reduce the submarine's electromagnetic signature. This software will be installed in submarines under construction in 2010 and 2011, SSN-781 through SSN-786 [that is, later Block II boats and early Block III boats], as well as all future submarines. Program officials state that after the software is installed, at-sea testing and calibration are required to ensure full functionality. Similar software has been demonstrated in British submarines, but due to alterations and additional testing needed for use with Virginia-class submarines, the software is considered immature.

The other two technologies selected for insertion are integrated to form the Conformal Acoustic Velocity Sensor Wide Aperture Array (CAVES WAA), a sensor designed to replace existing systems and lower the cost of construction while maintaining or improving performance. The two technologies, fiber optic sensors and the integrated panels that contain the sensors and manage their signature, are both immature. Currently rough models of both technologies are being tested in a laboratory environment. If the fiber optic sensors do not develop as expected, a more mature ceramic sensor may be used to preserve cost savings and performance. If both technologies encounter difficulties in development, the program will continue to use the existing systems. While the program office will track the stability of design for these new technologies, it will use metrics other than the engineering drawings.



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