By the early 1950s, generations of ground-combat practitioners had been studying and executing three types of envelopment: seizure of objectives in the enemy’s rear (known as a flanking or single envelopment), pincer double envelopment, and encirclement. The technological refinement of the helicopter added a fourth—vertical envelopment—and fostered a new class of ships.
Following the 1946 Bikini Atoll atomic tests, Marine Corps Commandant General Alexander Vandegrift convened a board that ultimately recommended development of transport helicopters to avoid concentration of troops and material at beachheads. It also called for the formation of an experimental helicopter squadron. In 1948, the Marine Corps published Amphibious Operations—Employment of Helicopters, the first manual for such operations.
The Korean War was the first conflict in which the manual was put in practice, although never in large-scale operations. In 1956, the British used ten helicopters flying from HMS Theseus and six from HMS Ocean to insert 650 marines and 23 tons of supplies in Suez, Egypt. That same year, the U.S. Marine Corps completed the first division-strength training operation using World War II–era escort carriers as jumping-off points. Euphemistically, they were called helicopter carriers, but they were more accurately designated amphibious assault ships, helicopter, or LPHs.
A motley mix of just a dozen ships served the U.S. Navy as helicopter carriers from 1957 to 1998, when much more capable carriers replaced them. Only one class of seven ships, the Iwo Jimas, were purpose-built for their mission, and their hull numbers were not consecutive, with other ship conversions interspersed.
The USS Block Island (ex-CVE-106), a decommissioned World War II–vintage escort carrier, received the designation LPH-1 in 1957. She held that for two years before being redesignated to her CVE number and then scrapped in 1960, without ever having been converted or sailed as an LPH.
The Iwo Jima (LPH-2), the first of the LPHs, built in 1959 from the keel up as an amphibious assault vessel, met the Marine Corps’ need for a vessel large enough to transport, deliver, and support a 1,700-man Marine amphibious unit. The new class could carry approximately 30 aircraft, with the number and type varying by mission. For example, during a NATO exercise in the North Atlantic in 1980, the Iwo Jima embarked a mix of CH-53D Sea Stallions, UH-1N Twin Hueys, AH-1T Super Cobras, two HH-46A Sea Knights, six OV-10A Broncos, and four AV-8A Harriers.
The second ship of the class was the Okinawa (LPH-3), which entered the fleet in 1960, followed by conversions of three World War II–vintage aircraft carriers. The Boxer (ex-CV-21) and Princeton (ex-CV-37) were of the straight-deck Essex class, and the other, the Thetis Bay (ex-CVE-90, ex-CVHA-1), was a former Casablanca-class escort carrier. The Iwo Jima–class Guadalcanal (LPH-7) came next, followed by another Essex conversion, the Valley Forge (ex–CV-45). The final four of the dozen, LPHs 9–12, were each of the Iwo Jima class—respectively, the Guam, Tripoli, New Orleans, and Inchon.
The Iwo Jimas were essentially prototypes for the ships that now populate the so-called Gator Navy, dedicated to amphibious assault. Over nearly four decades of constant operation, the class certified the military value of amphibious operations. Their design was dictated by the need to transport, house, and otherwise accommodate a 1,750-Marine combat force, as well as helicopters to land them.
This requirement put a premium on machinery space, and the ships had but a single screw. But helicopters eliminated the need for catapult and arresting gear trunking and machinery, thus allowing more space for habitability. At the time of their inception, they provided more living space per man than any other amphibious ship. Because of their large sick bays, operating rooms, and 100-bed hospitals, they were often designated as primary casualty receiving ships when operating in a task force.
The Iwo Jima’s history is a fair representation of her sister ships’. Her first assignment was to evacuate and later return non-essential personnel from Johnston Atoll during the 1962 Operation Fishbowl nuclear tests. She then joined a 21-ship squadron that moved from the U.S. West Coast to an area south of Puerto Rico for six weeks during the Cuban Missile Crisis.
Beginning in August 1963, she made the first of six deployments to the western Pacific, where she participated in more than 30 amphibious landings in Vietnam through May 1971. En route to Southeast Asia in April 1965, the ship transported 77 U.S. Army UH-1D helicopters, their equipment, and crews, along with an aviation company of the 101st Airborne Division. Off Vung Tao, South Vietnam, she launched the Army forces before continuing on to Subic Bay, Philippines, to load Marines and their equipment for a landing at Chu Lai on 11 May.
During one of her deployments, in 1967, she became the first and only aircraft carrier (in the larger sense of the term) to bear a white flight deck. The unusual experiment tested two questions: Would the light color maintain cooler temperatures in the electronic, office, and living spaces beneath the flight deck in the steamy Vietnamese environment, and would the reversed colors of light deck and dark markings aid flight operations, especially at night and in inclement weather? Reports at the time indicated that it did indeed help maintain cooler interior temperatures, and the pilots claimed increased visibility. Landing spots stood out clearly and distinctly, and it was easier to orient to the ship when landing at night. The Navy obviously rejected the experiment, but why?
Like four of her sisters (and two of the Essex conversions), the Iwo Jima aided NASA as a primary recovery ship for manned space missions. On 17 April 1970, helicopters of HS-4 recovered the Apollo 13 astronauts and their command module, Odyssey, after their aborted moon landing.
She changed homeports from San Diego, California, to Norfolk, Virginia, in 1972. From there, through 1992, she made a dozen Mediterranean Sea deployments and one to northern Europe. Among her activities were mine clearance in the Suez Canal while fully combat loaded during the October 1973 Yom Kippur War and deployment with Task Force 65 in the Mediterranean.
In 1983, while providing command-and-control and logistic support off the coast of Lebanon for the Multi-National Peacekeeping Force, the LPH provided medical support for Marines wounded in the 23 October bombing of their barracks. In 1990, the Iwo Jima was the first amphibious ship to deploy to the Persian Gulf in Operation Desert Shield and during Operation Desert Storm served as a focal point for successful deceptive maneuvers against the Iraqis. From July to November 1992, the LPH sailed in the Adriatic Sea off the coast of former Yugoslavia, providing search-and-rescue support for United Nations flights during Operation Provide Promise. She was decommissioned the next year.
Throughout its experience with this ship type, the Navy realized the limitations of the LPH and built on its strengths. The subsequent landing helicopter assault (LHA) ships of the Tarawa (LHA-1) class and landing helicopter dock ships of the Wasp (LHD-1) class added a well deck open to the sea at their sterns to internally support landing craft while transporting an additional 300 to 500 Marines.
In the world’s navies, only three officially designated LPHs remain: the Atlântico of the Brazilian Navy (the former British HMS Ocean) and South Korea’s Dokdo and Marado.