Since 1960, the blue and gold crews of the Fleet Ballistic Missile Submarine (SSBN) force have conducted more than 3,500 patrols. The original 41 for Freedom served our nation well, and todays 18 Tridents are worthy successors to the early SSBNs. USS Tennessee (SSBN-734) completed the U. S. Navys 3,000th strategic deterrent patrol in April 1992. Recently, USS Michigan (SSBN-727) completed the 500th Trident patrol, and the lead ship of the class, USS Ohio (SSBN-726), recently completed her 50th.
The future of todays SSBN fleet is based on the Nuclear Posture Review (NPR) of 1994. That review determined that 14 Trident II D-5 SSBNs in two oceans would provide the Submarine-Launched Ballistic Missile (SLBM) portion of the deterrent for the future. Once the second Strategic Arms Reduction Treaty (START II) is ratified, the Navy plans to remove the first four Trident submarines from strategic service, two in 2002 and two in 2003, in order to comply with the launcher and warhead-reduction requirements of the treaty.
The remaining four Trident I submarines, based in Bangor and now armed with the Trident C-4 missile, will be backfitted to carry the newer and more capable Trident II D-5 missile, and all 14 will receive refueling overhauls at 20 years of service. The refuelings are currently planned for the Puget Sound Naval Shipyard in Bremerton, Washington, and the Norfolk Naval Shipyard in Norfolk, Virginia. The D-5 backfit conversions are all planned for the Puget Sound Naval Shipyard, and the shore installations at Bangor, Washington, are also being upgraded to support the D-5 missile on the West Coast.
The 14 D-5 SSBN force will continue to patrol in both the Atlantic and Pacific after a rebalancing of fleet assets based on operational considerations. The Tridents will operate for another 20 years after refueling, since those ships hull lives have recently been extended to 42 years: two 20-year operating cycles separated by a two-year refueling overhaul. This unprecedented increase in the hull life of a whole submarine class has been made possible by Tridents unique maintenance plan, which includes the regular replacement and overhaul of key components and an intense 35-day refit period following each patrol.
Although the D-5 missiles were designed with a 20-year lifetime, they are expected to last for 25 to 30 years. With Trident submarine hulls now lasting 42 years, however, there is an obvious mismatch in longevity. The Navys Strategic Systems Program Office (SSPO) is currently studying alternatives to extend the life or replace the existing D-5 missiles using improved technology. This would ensure the survival of the nations at-sea strategic deterrent well into the next century.
Providing 54 percent of the nations strategic warheads on a day-to-day basis, the Navys SSBN fleet requires only three percent of the Navy budget and little more than one percent of Navy personnel. For the United States, this is a bargain price for the most secure and credible part of all Americas deterrent forces.