NAVY AIRCRAFT CARRIERS|
Cost-Effectiveness of Conventionally and Nuclear-Powered Aircraft Carriers
GAO/NSIAD-98-1 -- August 1998
COMPARISON OF THE TRANSIT TIME OF CONVENTIONALLY AND NUCLEAR-POWERED CARRIERS RESPONDING TO SELECTED CRISES ========================================================== Appendix IV We examined the movement of carriers that responded to several crisis situations in this decade to compare the transit times of conventionally and nuclear-powered ships. The crises examined were Iraq's invasion of Kuwait in 1990, U.N. operations in Somalia in 1993, threatening Iraqi troop movements toward Kuwait in 1994, and operations in Bosnia in 1995. We also examined the transits of carriers responding to the crisis caused by Iraq's violation of the ıno-fly-zoneş over southern Iraq in October 1997 and actions taken in January 1998 to maintain a two-carrier presence in the Persian Gulf. OPERATIONS DESERT SHIELD/DESERT STORM -------------------------------------------------------- Appendix IV:1 When Iraq invaded Kuwait on August 2, 1990, the nuclear-powered U.S.S. Eisenhower (CVN-69) was in port in Naples, Italy. The carrier traveled about 1,040 nautical miles to Port Said, Egypt, from August 3-7, a period of 5 days, and later moved through the Suez Canal into the Red Sea. The conventional powered U.S.S. Independence (CV-62) was operating near Diego Garcia in the Indian Ocean when the invasion began. The Independence arrived in the Gulf of Oman on August 5th, covering about 2,200 nautical miles in 3 to 4 days. Considering the time taken to travel this distance, the Independence would probably have made the voyage at a sustained speed of between 24 and 32 knots. Table IV.1 summarizes the transit times of six other carriers that sailed from ports in the United States and Japan and participated in Desert Storm. Table IV.1 Steaming Time/Speed of Carriers Deploying to Desert Shield/Storm Depart Arrive Days -------------- --------------- ------------- Net Distan Elaps Underw speed Rema From Date At Date ce ed ay \a rks Carrier ------- ----- -- -------- ----- ------ ----- ------ ----- ---- Midway Yokosuk 10/ Gulf of 11/ 6,495 30 24 11.3 3- (CV- a, 02/ Oman 01/ day 41) Japan 90 90 port visi ts at Subi c Bay and at Sing apor e Saratog Mayport 08/ Red Sea 08/ 5,867 15 14 17.5 Assu a (CV- , Fla. 07/ 22/ mes 60) 90 90 a 1- day dela y to tran sit Suez Cana l San 12/ Strait 01/ 11,666 38 33 14.7 5- Rangers Diego, 08/ of 15/ day (CV- Calif. 90 Hormuz 91 port 61) visi t at Subi c Bay; assu mes no othe r stop s in rout e Norfolk 12/ Red Sea 01/ 5,527 18 17 13.5 Assu America , Va. 28/ 15/ mes (CV- 90 91 a 1- 66) day dela y to tran sit Suez Cana l Red Sea 02/ Persian 02/ 3,450 7 7 21.1 07/ Gulf 14/ 91 91 Norfolk 08/ Red Sea 09/ 5,527 30 27 8.5\b 2- Kennedy , Va. 15/ 14/ day (CV- 90 90 port 67) visi t to Alex andr ia, Egyp t, also assu mes a 1- day dela y to tran sit Suez Cana l Rooseve Norfolk 12/ Red Sea 01/ 5,527 17 16 14.4 Assu lt , Va. 28/ 14/ mes (CVN- 90 91 a 1- 71) day dela y to tran sit Suez Cana l Red Sea 01/ Persian 01/ 3,540 7 7 21.1 14/ Gulf 21/ 91 91 -------------------------------------------------------------------------------- \a Net steaming speed was derived from the total elapsed days minus days spent in port and/or awaiting to transit the Suez Canal, multiplied by 24 (hours), divided into the distance. \b The Kennedy spent about 7 days in the Virginia Capes operating area conducting battle group training and carrier landing qualifications before proceeding eastward. If this time is not counted as days underway toward the Red Sea, then the ship's transit speed was 11.5 knots. Source: Our analysis of Navy data. COMPARISON OF THE VOYAGES OF THE LINCOLN AND THE AMERICA SUPPORTING U.N. OPERATIONS IN SOMALIA (1993) -------------------------------------------------------- Appendix IV:2 The U.S.S. Abraham Lincoln (CVN-72) operating in the Persian Gulf supporting Operation Southern Watch was ordered to move to the coast of Somalia to support U.N. operations on October 7, 1993. The Lincoln moved through the Straits of Hormuz on October 8 and arrived off the coast of Mogadishu, Somalia, 4 days later, on October 12th. We estimate that the Lincoln would have traveled at a sustained speed of 19 knots to cover the approximately 1,800 nautical miles from the Straits of Hormuz to Somalia in 4 days. The Lincoln operated off the coast of Somalia until November 4, 1993. The U.S.S. America (CV-66) was operating in the Adriatic Sea supporting U.N. peacekeeping operations in Bosnia-Herzegovina, when ordered on October 27, 1993, to relieve the Lincoln operating off the coast of Somalia. The America traveled from the Adriatic Sea to the Mediterranean Sea entrance to the Suez Canal, in about 2 days, covering a distance of about 1,040 nautical miles, which equated to a sustained speed of about 22 knots. The America completed the Suez Canal transit on October 30th and reached the coast of Somalia on November 4th. We estimate that if the America traveled about 2,400 nautical miles from the Suez Canal to the coast of Somalia in about 5 days, it could have done so at a sustained speed of about 20 knots. We estimate that the America would have completed the total trip with about 60 percent of its propulsion fuel remaining if no refueling had taken place. COMPARISON OF THE TRANSIT OF THE WASHINGTON IN OCTOBER 1994, AND A TRANSIT OF SIMILAR LENGTH BY AMERICA IN DECEMBER 1995 -------------------------------------------------------- Appendix IV:3 When Iraq moved two divisions of the Republican Guard south of the Euphrates River, toward Kuwait, in early October 1994, the President, faced with the imminent possibility of another Iraqi invasion of Kuwait, directed that U.S. forces be dispatched to the region. This effort was called Operation Vigilant Warrior. Included among those forces was the U.S.S. George Washington (CVN-73), the closest American aircraft carrier to the Middle East, operating in the Adriatic Sea. Two other carriers were also deployed at sea at that time but were much farther away; the U.S.S. America (CV-66) was operating near Haiti, and the U.S.S. Kitty Hawk (CV-63) was operating near Korea. The George Washington battle group was ordered to move to the Persian Gulf on the evening of October 7, 1994, and arrived in the Red Sea on October 10th.\1 The George Washington, with one escort, continued to proceed around the Arabian Peninsula, arriving in the Persian Gulf on October 14th.\2 According to a Center for Naval Analyses study,\3 the George Washington averaged about 25.6 knots, excluding the time spent waiting to transit the Suez Canal and actually transiting the canal. By comparison, the U.S.S. America made a similar voyage, but in the opposite direction, from the Persian Gulf to the Adriatic Sea in December 1995. The America began the voyage on December 2nd, transited the Suez Canal on December 9th, and was in position in the Adriatic Sea on December 11, 1995, in time for the signing of the peace agreement between the fighting Balkan factions. Assuming that this voyage took 8 full steaming days, excluding the time associated with transiting the Suez Canal, the America would have covered the nearly 4,200 nautical miles at a sustained speed of about 22 knots. If the America had steamed at the same sustained speed (26 knots) as the George Washington did during Vigilant Warrior, a speed within its capability, it would have arrived with about 33 percent fuel remaining if there was no refueling during the voyage. With one refueling, the U.S.S. America would have taken about 2 hours longer than the George Washington to cover the same distance but would have arrived with full fuel tanks. -------------------- \1 Once in the Red Sea, attack aircraft from the U.S.S. George Washington, or any other carrier, could have reached targets in southern Iraq with refueling by aerial tankers. Also, on October 10th, Saddam Hussein announced that the Republican Guard divisions would withdraw, and they began to move northward soon afterwards. \2 Several dozen Air Force tactical aircraft arrived in the theater about the same time as did the U.S.S. George Washington. On October 8th, Air Force units at Langley Air Force Base, Virginia, and Pope Air Force Base, North Carolina, were alerted to deploy, but their aircraft were held at their bases pending final basing arrangements with Saudi Arabia. The Langley fighters arrived in Saudi Arabia on October 11th, while the Pope aircraft arrived on October 13th and 15th, after completing approximately 17-hour flights. \3 Exploring Alternative Paths for Future Sea-Based TACAIR Platforms, Report CAB 95-62, July 1995. COMPARISON OF THE TRANSIT OF THE NIMITZ IN OCTOBER 1997, AND A SIMILAR TRANSIT BY THE INDEPENDENCE IN JANUARY/FEBRUARY 1998 -------------------------------------------------------- Appendix IV:4 On October 1, 1997, after Iraqi aircraft had violated the southern ıno-fly-zone,ş the U.S.S. Nimitz (CVN-68) was ordered to proceed to the Persian Gulf at best speed. The carrier had completed a port visit to Hong Kong and was scheduled to visit Singapore before heading for the Persian Gulf. According to the Navy, the Nimitz completed this 5,500 nautical mile transit in 11 days at an average speed of advance of about 21 knots. Our review of transit data indicated the carrier spent about 39 percent of the voyage at 27 knots and above. The carrier's longest sustained steaming period at or above 27 knots was one 9-hour period. The Navy reported that the Nimitz was able to conduct flight operations on 6 of the 11 transit days. The carrier arrived in the Persian Gulf on October 11, 1997. On January 23, 1998, the U.S.S. Independence (CV-62) was ordered to transit from Japan to the Persian Gulf to replace the Nimitz, which was scheduled to return to the U.S. for a scheduled comprehensive refueling overhaul. Our analysis of transit data for the Independence indicated the carrier averaged over 24 knots during the voyage and spent over 70 percent of the time at 27 knots and above. During various parts of the transit, the ship sustained speeds of 27 knots and above for several lengthy periods of time, including 42, 31, and 27 continuous hours. Our review of transit data indicated that aircraft flew on at least 5 days of the transit, the last period ending late in the evening of February 4, 1998, the night before the ship entered the Persian Gulf. The ship slowed down to speeds of 14 knots or less to conduct fuel replenishments and make periodic course and speed changes to conduct flight operations. OPERATIONS OF CARRIERS IN THE PERSIAN GULF WAR =========================================================== Appendix V An October 1995 report on the Naval Nuclear Propulsion Program Classification Review included a discussion of the impact of nuclear propulsion in the Gulf War. The report stated: "During this war the U.S. had unchallenged use of the oceans. Over 85 percent of the war supplies were transported by ocean, halfway around the world. Accomplishing this required complete control of the sea. A few enemy nuclear-powered submarines could have significantly disrupted our supply lines. Nuclear-powered submarines with their covert capability provided platforms for launching cruise missile strikes without concern for detection prior to launch. The nuclear-powered aircraft carriers provided U.S. Commanders with platforms for aircraft strikes that could be located for sustained periods in areas of the Middle East not available by land. If Iraq had obtained access to nuclear propulsion technology and had developed nuclear-powered submarines, it would have significantly impacted the course of the war." Our analysis of carrier operations and support during Operation Desert Storm did not reveal any significant differences between the nuclear-powered carrier U.S.S. Theodore Roosevelt (CVN-71) and five conventionally powered carriers, including the World War II-vintage U.S.S. Midway (CV-41), that could be attributed to nuclear propulsion. Although aircraft from the Roosevelt flew more missions than any other Desert Storm carrier, this was due to several factors independent of the propulsion system, including the distance to targets and the number and mix of aircraft aboard each carrier. When the number of assigned aircraft is considered, the number of sorties generated by each carrier is almost identical. Our analysis also indicated that the Navy supported all six carriers in essentially the same manner. Despite the nuclear carrier's greater jet fuel and ordnance capacity, and its reduced reliance on logistics support, the Roosevelt did not operate for longer intervals between replenishment actions than the conventional carriers. Instead, all of the carriers were replenished at about the same frequency, well before fuel and ordnance reached critical levels.