Cost-Effectiveness of Conventionally and Nuclear-Powered Aircraft Carriers
GAO/NSIAD-98-1 -- August 1998

IMPLICATIONS OF AN ALL NUCLEAR-POWERED CARRIER FORCE ON NAVAL PRESENCE IN THE PACIFIC ============================================================ Chapter 4 Homeporting Navy ships overseas enables the United States to maintain a high level of presence with fewer ships because the need for a rotation base to keep forces deployed is smaller. The homeporting of a conventionally powered carrier at Yokosuka, Japan, provides a level of presence that would otherwise require six nuclear-powered carriers homeported in the United States. However, the Navy has been replacing conventionally powered carriers with nuclear-powered carriers. If this trend continues, the Navy will eventually have to either -- establish a nuclear-capable maintenance facility and related infrastructure in Japan to accommodate a nuclear-powered carrier to be homeported there or -- expand the force to include the additional nuclear-powered carriers that would be needed to keep the same level of presence, but with ships deploying from the United States. Alternatively, the Navy could either construct a new conventionally powered carrier or accept a lower level of presence. While it would be several years before the carrier force would have undergone a complete transition to nuclear propulsion, it will also take several years to implement any of the strategies that will allow the United States to maintain a long-term continuous naval carrier presence in the Pacific region. CONVENTIONALLY POWERED CARRIER FORCE STRUCTURE HAS BEEN DECLINING ---------------------------------------------------------- Chapter 4:1 The conventionally powered carrier force has declined from nine carriers in fiscal year 1991 to the current force of four conventionally powered carriers.\1 By fiscal year 2008, current Navy plans project there will be one conventionally powered carrier in the force. Three of the current carriers are in the active force and one is assigned to the reserve force. One of the active carriers, the U.S.S. Independence (CV-62), is homeported at Yokosuka, while two, the U.S.S. Kitty Hawk (CV-63) and the U.S.S. Constellation (CV-64), are periodically deployed overseas.\2 The fourth, the U.S.S. John F. Kennedy (CV-67), is considered an operational reserve carrier. It provides Navy and Marine Corps aviators carrier landing training and qualification, participates in exercises, and can be deployed to fill gaps in overseas presence and help meet crisis response needs. Table 4.1 shows the four carriers now in the force, their last full year of active service, and their age at the end of their estimated service life. Table 4.1 Conventionally Powered Carrier Force-- Last Full Year in Active Service Ship age (in Carrier Year years) ------------------------------------------------------ ------ ------ U.S.S. Independence (CV-62) 1997 39 U.S.S. Kitty Hawk (CV-63) 2007 47 U.S.S. Constellation (CV-64) 2002 41 U.S.S. John F. Kennedy (CV-67) 2017 43-50 ---------------------------------------------------------------------- Source: Navy. As recently as 1994, the U.S.S. Kennedy was scheduled for decommissioning in fiscal year 2011. However, current long-range Navy carrier construction plans indicate it will be decommissioned in fiscal year 2018, thus adding 7 years to its service life. The remaining service life of the Kennedy will depend on several factors, including whether it undergoes extensive major maintenance and modernization, whether it deploys regularly in support of the active force, or whether it is primarily used as a training carrier. Unlike many of the other conventionally powered carriers, the Kennedy did not receive an extensive service life extension overhaul that would have added 15 years of service life. -------------------- \1 There were nine conventionally powered carriers in the Navy's force structure from fiscal year 1981 through fiscal year 1991. \2 The U.S.S. Kitty Hawk (CV-63) is scheduled to replace the U.S.S. Independence (CV-62) in fiscal year 1998 as the permanently forwardly-deployed carrier in Yokosuka. The U.S.S. Independence (CV-62) will be decommissioned. BENEFITS OF HOMEPORTING A CARRIER IN JAPAN ---------------------------------------------------------- Chapter 4:2 A conventionally powered carrier has been permanently forward deployed and homeported in Japan since 1973. This carrier provides full-time presence in the Pacific region without the need for long transit times and can respond to a crisis in the region in a matter of days. Providing continuous forward presence is a clear advantage to having an aircraft carrier and its battle group permanently forward deployed in Japan. Additionally, the government of Japan makes significant contributions for the yen-based costs of maintaining U.S. forces in Japan. The United States and Japan share the cost of basing U.S. forces in Japan through the Special Measures Agreement. Japan also pays for new facilities and improvements the United States uses through the Japanese Facilities Improvement Program. The Program, begun in 1979, is a cost and burden-sharing program funded and administered by the Japanese government. It is not required or protected by any treaty or agreements between the United States and Japan. According to Pacific Command and Pacific Fleet officials, the Program could fund construction of the additional maintenance facilities to permanently homeport a nuclear-powered carrier in Japan. Japan contributes more than 70 percent of the total yen-based cost of stationing U.S. forces there (more than $5 billion in 1995). These contributions include aircraft carrier maintenance and repairs performed by the Japanese work force at the U.S. Naval Ship Repair Facility, Yokosuka. Currently, these facilities have no nuclear repair capability. If the carrier now homeported in Japan were to return to a U.S. homeport, the United States would incur all maintenance costs. For nuclear-related maintenance to be conducted at the U.S. Naval Ship Repair Facility, Yokosuka, several infrastructure improvements would be required and the maintenance would be performed by U.S. shipyard workers at U.S. expense. HOMEPORTING A NUCLEAR-POWERED CARRIER IN JAPAN COULD BE DIFFICULT AND COSTLY ---------------------------------------------------------- Chapter 4:3 Homeporting a nuclear-powered carrier permanently at Yokosuka would require a major base reorganization, including nuclear-propulsion maintenance and support facilities, upgraded utilities, and dredging of the harbor and approach to accommodate a deeper draft ship. It would also require additional family housing and support facilities. Although funds could be obtained through the Japanese Facilities Improvement Program, the approval process could be lengthy. The Department of State noted that the entry into Japanese ports of nuclear-powered vessels remains sensitive in Japan and that there would have to be careful consultations with the Government of Japan should the U.S. Government wish to homeport a nuclear-powered carrier in Japan. FACILITIES AND PORT IMPROVEMENTS -------------------------------------------------------- Chapter 4:3.1 The Navy's requirements for additional facilities to support a nuclear-powered carrier homeported at a base that supports conventionally powered carriers are described in the Navy's March 1995 report entitled Nimitz-Class Aircraft Carrier Homeporting Cost Comparison Between NAS (Naval Air Station) North Island and NSY (Naval Shipyard) Long Beach. Each facility's requirements will differ based on what exists at the facility. The facilities and port improvements being made to accommodate the homeporting of a nuclear-powered carrier at Naval Air Station, North Island in San Diego, which is already capable of homeporting conventionally powered carriers, illustrates what improvements may be needed to expand the maintenance, harbor, and infrastructure capabilities of the conventionally powered carrier homeport in Yokosuka, so that it could accommodate a nuclear-powered carrier. The facilities planned for the nuclear-powered carrier homeport at the North Island Naval Air Station are similar to those at Puget Sound Naval Shipyard. The North Island facilities include an aircraft carrier wharf, a controlled industrial facility, a ship maintenance facility, and a maintenance support facility. Other projects at North Island include the dredging of the harbor channel and a turning basin for the ship. Also, upgraded power would be required at the ship berthing. The controlled industrial facility and ship maintenance facility provide depot-level repair and maintenance of nuclear propulsion plant systems and components. The total area required for these facilities is the equivalent to 4-1/2 football fields. The projects at North Island are estimated by the Navy to cost about $260 million. According to facilities and logistics officials from the Pacific Command, Pacific Fleet, and Navy headquarters, in addition to the nuclear maintenance facilities, other improvements would be needed at Yokosuka to support a homeported nuclear-powered carrier. For example, a larger, stronger pier would be needed to accommodate the larger, heavier nuclear-powered carrier and cranes for pier-side maintenance. Also, upgraded and expanded electrical power supplies would be needed to run the reactor coolant pumps while the ship is berthed. Additional substations would be required for redundancy, and commercial power would also have to be upgraded. Access to controlled pure water would also be required. According to these officials, Nimitz-class aircraft carriers need harbors and pierside-areas dredged to 50 feet or more, compared to a 45-foot depth for conventionally powered carriers. The harbor and pier side at Yokosuka would need to be blasted and dredged, because of the rock bottom, to accommodate a nuclear-powered carrier. Other improvements could include modifications to the drydock and associated equipment. However, the Navy has not conducted a survey to identify specific drydock improvements needed to support a nuclear-powered carrier at Yokosuka. LIMITED SPACE FOR ADDITIONAL FACILITIES -------------------------------------------------------- Chapter 4:3.2 The Navy restricts access to nuclear propulsion system components to U.S. citizens, even though some of the components are the same used in conventionally powered ships. Restrictions on access to nuclear propulsion components require separate facilities for nuclear maintenance and general ship repair. However, according to Pacific Command officials, there is little room at Yokosuka for additional maintenance facilities. Thus, providing additional maintenance facilities would require replacing existing structures; however, Yokosuka's existing conventional carrier maintenance facilities are spread over several buildings throughout the facility. According to Department of State officials, there may be space constraints at Yokosuka that could make the homeporting of nuclear-powered aircraft carriers difficult. The port of Yokosuka is congested. The city of Yokosuka is adjacent to the base, which also limits expansion. FAMILY HOUSING AND OTHER PERSONNEL SUPPORT FACILITIES ALREADY STRESSED -------------------------------------------------------- Chapter 4:3.3 Family and bachelor housing shortages are severe at Yokosuka. According to the Deputy Chief of Staff, Shore Installation Management, U.S. Pacific Fleet, the base needs over 1,200 additional units. The planned homeporting of additional and larger surface combatants at Yokosuka will increase the need for additional housing. For example, homeporting a nuclear-powered carrier could add about 200 families. The housing situation could be further exacerbated with the addition of hundreds of U.S. workers to work on nuclear-related equipment during maintenance periods. The additional personnel would add to the requirement for commissaries and recreation and other support facilities. LENGTHY APPROVAL PROCESS -------------------------------------------------------- Chapter 4:3.4 According to Pacific Command officials, facility improvements at Yokosuka could be funded through the Japanese Facilities Improvement Program. However, obtaining approval is a lengthy process. For example, a family housing project took 10 years to obtain approval and funding. Pacific Command officials estimated it could take between 7 to 15 years to obtain approval for nuclear-powered carrier homeporting facilities improvements. OTHER OVERSEAS HOMEPORTS -------------------------------------------------------- Chapter 4:3.5 The Navy's 1994 Naval Forward Presence Report stated that forward homeporting a nuclear carrier overseas is problematic because of potential host nation opposition as well as the complexity of nuclear-related maintenance that might require the ship to return to the United States for repairs. The report estimated that the establishment of a nuclear-capable maintenance facility at an overseas location would be expensive and politically unacceptable. PROVIDING REGIONAL PRESENCE WITH CARRIERS HOMEPORTED ON THE WEST COAST ---------------------------------------------------------- Chapter 4:4 The Pacific Command's policy requires continuous presence of an aircraft carrier in the Pacific region. The carrier now permanently forward deployed in Japan provides this level of presence. Based on our analysis using the Navy's Force Presence Model and data, we found the single, conventionally powered carrier permanently forward deployed in Japan provides forward presence coverage in the Pacific region that would require six nuclear-powered carriers homeported at West Coast ports of the United States. Reducing regional presence requirements to 75 percent still would require four nuclear-powered carriers in an all nuclear-powered force. The requirement for an increased number of nuclear-powered carriers when based out of the United States is a function of deployment cycle policies and requirements, including a maximum 6-month deployment, the need for post deployment shipyard maintenance, predeployment training and exercises, and the deployment transit distance and speed. (See chs. 1 and 2 for a more complete discussion.) However, the Navy currently does not have the infrastructure to support additional nuclear-powered carriers at West Coast homeports. AGENCY COMMENTS AND OUR EVALUATION ---------------------------------------------------------- Chapter 4:5 DOD partially concurred with the discussion of the difficulties associated with homeporting and maintaining a nuclear-powered carrier in Japan. According to DOD, infrastructure changes would not be as significant as we portray because the non-propulsion plant maintenance would continue to be supported by Ship Repair Facility, Yokosuka. DOD said that if a nuclear-powered carrier was homeported in Japan, maintenance plans could be modified to improve the ability of the ship's force to maintain the propulsion plant, augment the ship's force with "fly-away" teams, and periodically return the ship to the United States for depot-level maintenance and replace it with another carrier. DOD agreed that some changes in base support infrastructure would be required if a nuclear-powered carrier was homeported in Japan. Our discussion of the implications of homeporting a nuclear-powered carrier in Japan was based, in part, on the Navy's current maintenance strategy. We note the Navy has not modified that strategy. Further, we note that significant changes in base support infrastructure would be required to accommodate a nuclear-powered carrier homeported in Japan. We note that the Navy made significant and costly infrastructure changes at North Island Naval Air Station when it decided to homeport a nuclear-powered carrier there. The Department of State noted in its only comment on the draft report that the entry of nuclear-powered vessels into Japanese ports remains sensitive in Japan and there would have to be careful consultations with the government of Japan should the U.S. government wish to homeport a nuclear-powered carrier in Japan.