In his letter to our USS North Dakota Committee of April 16th announcing the postponement of USS NORTH DAKOTA’s scheduled may 31st commissioning date Rear Admiral David Johnson stated:

NORTH DAKOTA is the first of eight VIRGINIA Class Block III ships. Approximately 20 percent of NORTH DAKOTA was redesigned as part of the VIRGINIA Cost Reduction work done to lower acquisition cost and increase operational flexibility. A significant portion of the redesign encompassed inserting large-diameter vertical payload tubes — VIRGINIA Payload Tubes — into the ship’s bow. The build, test, certify and delivery process used for every new submarine highlighted areas of the VIRGINIA Payload Tube design and certification that needed further work to improve reliability and overall safety of the ship. In parallel with this work, a vendor-supplied component quality issue was discovered that must be corrected before I can certify the ship for sea trials and the Navy can accept delivery.

It is very ill-timed to have both these issues arise during the final stages of NORTH DAKOTA’s construction and preparation for her initial sea trials. The Navy and its shipbuilding partners are committed to ensuring that the design, construction, and certification of the ship’s systems and components meet the exacting standards for NORTH DAKOTA and her VIRGINIA Class sister ships. Unfortunately, that assurance will require more time than the seven weeks remaining before commissioning.

I fully expect NORTH DAKOTA to deliver before her contract delivery date of August 31, 2014 and to set a new benchmark for excellence in what is arguably the gold standard for defense acquisition — the VIRGINIA Class Program. When commissioned, USS NORTH DAKOTA will have no peer, establishing the world-standard for mission effectiveness, lethality, flexibility and affordability. I have no doubt that NORTH DAKOTA will be an enduring source of pride for her namesake state.

Some interesting background is found in this 2008 news release/story about the VIRGINIA Class and the Block III submarines:

The Virginia Class Program: “2 for 4 in 12″

SSN-777 Under Construction

SSN 777 costruction
(click to view full)

The SSN-774 Virginia Class external link submarine was introduced in the 1990s as a Clinton-era reform that was intended to take some of the SSN-21 Seawolf Class’ external link key design and technology advances, and place them in a smaller, less heavily-armed, and less expensive platform. The resulting submarine would have learned some of the Seawolf program’s negative procurement lessons external link, while performing capably in land attack, naval attack, special forces, and shallow water roles. In the end, the Seawolf Class became a technology demonstrator program that was canceled at 3 ships, and the Virginia Class became the naval successor to America’s famed SSN-688 Los Angeles Class.

The Virginia Class program was supposed to reach 2 submarines per year by 2002, removing it from the unusual joint construction approach between General Dynamics Electric Boat and Northrop Grumman Shipbuilding – but that goal has been pushed back to 2012 in progressive planning budgets.

In FY 2005 dollars, SSN-21 submarines cost between $3.1-3.5 billion each. According to Congressional Research Service report #RL32418, and the Navy is working toward a goal of shaving FY05$ 400 million from the cost of each Virginia Class boat, and buying 2 boats in FY2012 for combined cost of $4.0 billion in FY 2005 dollars – a goal referred to as “2 for 4 in 12″. In real dollars subject to inflation, that means about $2.6 billion per sub in 2012, and $2.7 billion in 2013. The Navy believes that moving from the current joint construction arrangement will shave FY05$ 200 million from the cost of each submarine, leaving another FY05$ 200 million (about $220 million) to be saved through ship design and related changes.

Block III: The Changes

SSN Virginia Block-III Bow Mods

Block III bow mods
(click to view full)

The most obvious change is the switch from 12 vertical launch tubes, to 12 missiles in 2 tubes that use technology from the Ohio Class special forces/ strike SSGN program. The Virginia’s hull has a smaller cross-section than the converted ballistic missile SSGNs, so the “6-shooters” will be shorter and a bit wider. [Emphasis provided by me about the changed design] Nevertheless, they will share a great deal of common technology, allowing innovations on either platform to be incorporated into the other submarine class during major maintenance milestones. Net savings are about $8 million to program baseline costs.

The other big change you can see in the above diagram is switching from an air-backed sonar sphere to a water-backed Large Aperture Bow (LAB) array. Eliminating the hundreds of SUBSAFE penetrations that help maintain required pressure in the air-backed sonar sphere will save approximately $11 million per hull, and begins with the FY 2012 boats (SSNs 787-788).

The LAB Array has 2 primary components: the passive array, which will provide improved performance, and a medium-frequency active array. It utilizes transducers from the SSN-21 Seawolf Class that are that are designed to last the life of the hull. This is rather par for the course, as the Virginia Class’ was created in the 1990s to incorporate key elements of the $4 billion Seawolf Class submarine technologies into a cheaper boat.

The SUBSAFE eliminations, plus the life-of-the-hull transducers, will help to reduce the submarines’ life cycle costs as well by removing moving parts that require maintenance, eliminating possible points of failure and repair, and removing the need for transducer replacements in drydock.

The bow redesign is not limited to these changes, however, and includes 25 associated redesign efforts. These are estimated to reduce construction costs by another $20 million per hull beginning with the FY 2012 submarine.

With the $19 million ($11 + 8) from the LAB array and Vertical Payload, and the $20 million from the associated changes, General Dynamics is $39 million toward the $200 million baseline costs goal of “2 for 4 in 12″. While the changes themselves will begin with the FY 2009 ship, the savings are targeted at FY 2012 because of the learning curve required as part of the switch. Recent discussions concerning an earlier shift to 2 submarines per year would result in faster production of the Block III submarines, but would be unlikely to make a huge difference to that learning curve.


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