Ballistic Missile Submarines (SSBNs)
The Navy's ballistic missile submarines, often referred to as "boomers," serve as an undetectable launch platform for intercontinental missiles. They are designed specifically for stealth and the precise delivery of nuclear warheads.
Each of the 14 Ohio-class SSBNs can carry up to 24 submarine-launched ballistic missiles (SLBMs) with multiple, independently-targeted warheads. However, under the New Strategic Arms Limitation Treaty, each submarine will have four of its missile tubes permanently deactivated in the coming years. The SSBN's strategic weapon is the Trident II D5 missile, which provides increased range and accuracy over the now out-of-service Trident I C4 missile.
SSBNs are specifically designed for extended deterrent patrols. To decrease the amount of time required for replenishment and maintenance, Ohio-class submarines have three large-diameter logistics hatches that allow sailors to rapidly transfer supply pallets, equipment replacement modules and machinery components, thereby increasing their operational availability.
The Ohio-class design allows the submarines to operate for 15 or more years between major overhauls. On average, the submarines spend 77 days at sea followed by 35 days in-port for maintenance. Each SSBN has two crews, Blue and Gold, which alternate manning the submarines and taking them on patrol. This maximizes the SSBN's strategic availability, reduces the number of submarines required to meet strategic requirements, and allows for proper crew training, readiness, and morale.
From U.S. Navy Fact File