New Attack Submarine

Although the Navy plans to spend $64 billion to acquire 30 new attack submarines during the next 18 years, it has little basis for confidence in the submarine's performance because it lacks an evaluation that reflects current conditions, including a more capable threat from enemy forces, reduced performance of several subsystems, and risks inherent in new development. At this point in the submarine program, the use of modeling tools to identify and correct problems that could affect the submarine's survivability would allow change to be made in development schedules and funding profiles at much lower cost than if problems were identified later. GAO recommends that the Navy conduct survivability modeling to assess the impact that reduced capabilities of various subsystems have on ship survivability when integrated into the overall submarine design. Available research and development funding could be used for this modeling. GAO also recommends that the Defense Department take steps to ensure that the results are used in making fiscal year spending decisions on the program.

GAO noted that: (1) since modeling the NSSN's survivability in 1995, the Navy, because of technical and funding limitations, has modified the design for some subsystems that reduce performance below the optimal levels used to model the 1995 baseline design; (2) other systems also have developmental problems; (3) at the same time, Navy threat assessments have reported that the open ocean antisubmarine warfare threat has improved, resulting in a more capable threat than previously projected; (4) the Navy tester's 1997 assessment report concluded that the NSSN could potentially be operationally effective and suitable, but noted a number of significant changes and risks in the development program; (5) the report also noted several technological advances in the open ocean antisubmarine warfare threat; (5) in addition, the report stated that budgetary pressures resulted in tradeoffs in some of the performance modeled in the NSSN milestone II cost and operational effectiveness analysis and the tester's 1995 early operational assessment; (6) as of November 1997, the Navy program manager planned no additional survivability modeling to test the NSSN with its potential for reduced performance against the improved threat; (7) however, as a result of its 1997 assessment, the Navy tester recommended that the Navy develop a new modeling baseline that reflects the reduced performance of some subsystems and that this new design baseline be evaluated against the increased threat; and (8) without such modeling, the Department of Defense and Navy program officials appear to have little basis for their confidence that the currently designed submarine will perform as expected.

Recommendations

Our recommendations from this work are listed below with a Contact for more information. Status will change from "In process" to "Open," "Closed - implemented," or "Closed - not implemented" based on our follow up work.

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