Ohio-class SSGN-726 Tactical Trident
The Ohio-class cruise missile submarines made headlines when three of America's largest submarines surfaced in Asia-Pacific ports in a US Seventh Fleet show of force. The appearance on 28 June 2010 of the USS Michigan in Pusan, South Korea, the USS Ohio in Subic Bay, in the Philippines, and the USS Florida in the strategic Indian Ocean outpost of Diego Garcia.
The Ohio class cruise missile submarine (SSGN) program entailed the refueling and conversion of the four SSBNs to dedicated cruise missile launch submarines to support the Land-Attack/Strike mission. Each new Multiple All-Up-Round (AUR) Canister (MAC) launchers contain seven Tomahawk land-attack missiles (TLAMs) and fit within the existing Submarine Launched Ballistic Missile (SLBM) vertical launch tubes. Each SSGN accommodates up to 22 MACs, for a total of 154 TLAMs.
The SSGN also supports Special Operations Forces (SOF) missions. Two of the large vertical launch tubes were converted to SOF lockout chambers and the ship will feature dedicated accommodations for SOF personnel and their equipment. The SSGN is capable of hosting the Advanced SEAL Delivery System (ASDS) and Dry Deck Shelter on its upper deck. In the future, the extensive payload capacity of the SSGN may be used to support other offboard systems, including large unmanned and autonomous underwater vehicles, as well as alternate weapons systems.
At an investment of about $400M/ship (not including replacement cores) the Navy acquired a modified Ohio-class submarines capable of carrying 154 Tomahawk missiles as well as Special Forces. SSGNs could operate in otherwise denied areas to provide unique capabilities that would enable other U.S. forces. These capabilities include cruise missiles that can be launched at rapid rates, 66 Special Operations Forces (SOF) personnel, a swimmer lock out shelter, and an Advanced SEAL Delivery System (ASDS). This submarine also retains the multi-mission capability found in SSNs and provide large volumes for future payloads and mission adaptation. These features provide a transformational degree of firepower in a survivable and virtually undetectable platform that can remain on station continuously.
Trident SSGN also provides the CINCs and Battle Group commander a large SOF contingent (4 platoons or 66 SEALs) capable of carrying out a sustained and continuous level of effort of Special Forces missions. Each boat could carry up to 66 SEALs or other commandos, and a minisub currently under development would be affixed to the bow. However, there are not many missions in which such a large force of SEALs would play a significant role.
The Department of Defense and the Navy believe that the SSGN conversion is an example of Military Transformation. Secretary of Defense Rumsfeld illustrates one facet of his efforts to transform America's Armed Forces to include a reexamination of how the US uses the resources it currently has available. The US took an existing platform and remolding it to perform an entirely new mission - one never envisioned by its designers. And by current standards, creating this new capability was relatively easy, inexpensive, and quick.
This new capability adds to the utility and flexibility of the assets the US can deploy. What often is missed in discussions about how the SSGN is deployed is the SSGN benefit to its fellow combatants. Specifically, how an SSGN can support battle group surface ships that are geographically constrained, due to the requirement of maintaining a prescribed number of TLAMs within a given area of operation. Consider that when an SSGN arrives on station, carrying at least 154 missiles, those surface assets would be less restricted in their distribution across the battlespace, offering them the ability to perform other missions.
Employment of Tactical UUVs as a Shallow water surveillance and data collection platform holds promise for future characterization of denied areas. The clandestine nature of missions coupled with the ability to collect data at higher speeds makes the UUV ideally suited for collecting oceanographic information. RADM Sullivan (N77) discussed the idea of launching large UUVs from SSGN and not be limited by the 21 inch torpedo tube diameter. These could include those like the SeaHorse.
The SSGN program represents a relatively low cost way to leverage the highly successful Trident maintenance and training infrastructure and proven two-crew concept to maximize forward-deployed warfighting capability. Having rotating crews allows the ship to be at sea about 70% of the year - an operational status that was (and continues to be) a requirement for the mission of nuclear deterrence. This is not new - the OHIO-class SSBNs were designed to support a high operational status from the beginning.they were tailor-made for this purpose. This ability to remain on station for extended periods fits in neatly with the vision of the SSGN mission, keeping a massive strike capability within range of the conflict for as long as necessary. Complementing its long station-keeping capability, each submarine will deliver fourteen years of deployed presence during its remaining twenty-plus years of life, compared with seven years out of thirty for traditional Navy ships.
It was not initially clear, however, just how long deployments will last. Normal deployment rotations require 3 vessels to keep 1 deployed at all times. The Navy was initially not particularly forthcoming with regards to whether they intend on keeping only one submarine deployed at all times (or if two will be deployed) and whether or not that vessel will be tasked with operations in the Persian Gulf or in other locations. The Submarine Force announced it has achieved another first with all four guided-missile submarines (SSGN) deployed for the first time simultaneously 10 June 2010. Although the West Coast SSGNs, USS Ohio (SSGN 726) and USS Michigan (SSGN 727), and East Coast SSGNs, USS Florida (SSGN 728) and USS Georgia (SSGN 729), have previously been underway at the same time, this milestone marked the first time all four SSGNs have been forward deployed away from their homeports. The submarines deploy for approximately 12 months, with some deployments lasting up to 15 months. While deployed from its homeport, U.S. Navy bases in Diego Garcia and Guam provide ideal locations for crew exchanges and Voyage Repair Periods. Maintenance periods and crew exchanges occur approximately every three months and allow the SSGNs to maintain a continuous presence in the areas of operation for 70 percent of the year.
The SSGN is a Navy "Force Multiplier." A deployed SSGN greatly increases on-station TLAM availability. Combined with the OHIO-class submarine's proven history of high operational availability, the SSGN frees up other Naval Forces for priority tasking, such as anti-submarine warfare, controlling the airspace, and even theater ballistic missile defense. Each SSGN will spend fourteen of its remaining twenty-plus operational years after conversion forward deployed.
The SSGN performs its mission with a much lower level of risk than what would normally be experienced when deploying this level of capability today. The potentially debilitating constraints imposed by vulnerability and support requirements are far less an issue. By definition, the proven OHIO-class platform capitalizes on its existing strengths - endurance and stealth - in maintaining long-term station keeping duty while forward deployed. In addition to having the ability to deploy over 150 tactical missiles, the platform can also be configured to support dedicated accommodations for significant numbers of special operations forces, with their equipment. A possible scenario would involve using missile tubes as air locks for SOF assets to leave the sub and deploy via the Advanced SEAL Delivery System and/or Dry Deck Shelter, also carried by the SSGN. Nuclear power provides station keeping time that is unmatched by conventionally powered warships.
The SSGN payload concept was being developed to take advantage of technologies and hardware that already exist - again, the essence of transformation as defined by Secretary of Defense Rumsfeld. Other payload options were designed to support weapons and sensors that are already in use. These designs are by definition modular, providing a flexible interface between the sea and the ship.
The SSGN does not serve as a simple replacement for existing platforms. A submarine of any kind is not an effective vehicle for showing the flag. Rather, the vision for the Trident SSGN focused on stealth, payload, versatility, and endurance - a vision that does not lend itself to overt power projection.
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