The Fleet Rehabilitation and Modernization (FRAM) program of the United States Navy extended the lives of World War II-era destroyers by shifting their mission from a surface attack role to that of a submarine hunter. The FRAM program also covered cruisers, aircraft carriers, submarines, amphibious ships, and auxiliaries. The United States Coast Guard also used this term in the 1980s for the modernization of its Hamilton-class cutters.
The program was started by Admiral Arleigh Burke as a response to estimates that the Soviets would have a force of about 300 modern fast-attack submarines by 1957. The US Navy was unable to produce enough destroyer escorts (frigates after 1975) and other anti-submarine warfare-capable ships to counter this threat, given other priorities such as new anti-aircraft warfare-capable frigates (cruisers after 1975) and aircraft carriers, so Burke instead looked for ways to modify the existing World War II-era destroyer fleet, which was rapidly becoming outdated anyway.
Burke oversaw preparation of a report to the House and Senate Appropriations Committees entitled "The Aging Fleet." The idea that became FRAM was only one of six recommendations of a special committee to address the poor material conditions of ships built during World War II. Those recommendations were, in order of preference:
A comparable programme for the Royal Navy had provided modifications to 33 British War Emergency Programme destroyers, which were converted during 1949-1956 into 23 Type 15 first-rate anti-submarine frigates and 10 Type 16 limited conversions, pending the construction of new-build Type 12 and Type 14 frigates.
Among the destroyers, Gearing and Allen M. Sumner classes would take precedence over the Fletcher and Benson classes. Destroyer conversions relied on experience with Fletcher-class destroyers modernized for transfer to Spain and Germany in 1957. The first two destroyers began FRAM in Boston, Massachusetts and Long Beach, California shipyards in March 1959.
In Navy slang, the modified destroyers were called "FRAM cans", "can" being a contraction of "tin can", the slang term for a destroyer or destroyer escort.
In order to provide the ships with a credible anti-submarine weapon, the FRAM I upgrade for the Gearings centered on the addition of AN/SQS-23 sonar and two new weapon systems, the ASROC rocket-assisted torpedo launcher with a range of 1-5 miles (not in FRAM II upgrades), and the DASH antisubmarine helicopter with a range of up to 22 miles (35 km). Both were armed with the new Mark 44 torpedo, which was also carried in torpedo tubes on the ships. ASROC could also launch a nuclear depth charge.
There were three different sets of FRAM upgrades. During refitting in the early 1950s, FRAM I Fletcher-class destroyers gave up No. 2, 3 and 4 5-inch/38 caliber gun mounts. A trainable Mark 15 Hedgehog mount took the place of No. 2 gun, connected to a new, enlarged sonar suite. All topside 21-inch (533 mm) torpedo tubes were removed and replaced with two tubes mounted in the after deckhouse. One twin 3-inch/50 caliber gun mount was placed aft, atop the after deckhouse. There were variations such as Boyd, which had the 5-inch/38 mounts 3 and 4 removed in exchange for two twin 3-inch/50 caliber gun mounts above the after deckhouse connected to a computer controlled aft director. FRAM II changes saw the replacement of the Hedgehog mount with a Mark 108 Weapon Alpha ASW rocket launcher, the addition of two new triple Mark 32 torpedo tubes for the 12.75-inch (324 mm) Mk.44 torpedo and the removal of the 3 in guns for the DASH hangar and flight deck. The only Fletcher-class destroyers to receive the FRAM II upgrade were Radford, Jenkins and Nicholas.
Ships from the Gearing class were completely torn down and rebuilt from the hull up, including new engines, a much larger combat information center, and new sonar and radar systems. The 21-inch torpedo tubes between the funnels were removed, and the 8-round ASROC launcher (FRAM I only) placed there instead. All 3-inch/50 cal gun mounts were removed, and the after superstructure was used for the DASH's hangar and flight deck, with two new triple Mark 32 torpedo tubes for the 12.75-inch Mk.44 torpedo placed just behind the rear funnel. This modernization was designed to extend the life of the destroyer by at least eight years. Eventually, all but four Gearings received FRAM I or FRAM II conversions.
Ships in the Allen M. Summner class received only armament modifications under FRAM II, and not all ships of the class received the FRAM upgrades. Although the rear deck was also converted as a flight deck for DASH, the new 12.75-inch triple torpedo tubes were placed where the older 21-inch ones had been, and ASROC was not installed. Typically, all three 5-inch/38 twin mounts were retained. Additionally, two new 21-inch torpedo tubes for the Mark 37 ASW homing torpedo and variable depth sonar (VDS) were added. The converted Allen M. Sumners were designed for another five years of service . Sixteen Gearings were also converted under FRAM II. These included six radar picket destroyers (DDRs) and six escort destroyers (DDEs) that retained their specialized equipment (radar or trainable Hedgehog), as well as four former DDRs that were converted to near-twins of the Allen M. Sumner-class FRAM II destroyers. No Gearing FRAM IIs received ASROC. The retained DDRs kept all six 5-inch guns, and photographs show their DASH hangar was smaller than on other ships, plus the landing pad had no markings, so they may not have received DASH.
All classes came in for FRAM II refits starting about 1959, being rotated out of service in order to keep as many ships at sea as possible. The upgrades were complete by 1965, and most of the ships involved continued to serve actively until the late 1960s.
A total of 94 Gearings and 33 Allen M. Sumners received FRAM modifications 1960-1965. Many of the ships provided significant gunfire support in the Vietnam War. DASH was withdrawn from ASW service beginning in 1969 due to poor reliability. Lacking ASROC, the Allen M. Sumners were left without a standoff ASW capability, and were decommissioned 1970-1973, with most being transferred to foreign navies. The Gearings lasted somewhat longer in US service, with most decommissioned and transferred to foreign navies 1973-1980. The FRAM destroyers were replaced as ASW ships by the Knox-class frigates (destroyer escorts prior to 1975), which were commissioned 1969-1974, and the Spruance-class destroyers, which were commissioned 1975-1983. Both of the replacement classes had the same ASW armament as a Gearing FRAM I destroyer, with the addition of more and faster ASROC reloads, improved sonar, and a piloted helicopter, typically the Kaman SH-2 Seasprite. Some ships of both the Allen M. Sumner (from 1965) and Gearing classes (from 1973) served in the Naval Reserve Force (NRF), remaining in commission with a partial active crew to provide training for Naval reservists. The last FRAM destroyer in US naval service was William C. Lawe, a Gearing FRAM I, decommissioned and stricken 1 October 1983 and expended as a target 14 July 1999.
The Essex-class aircraft carriers modified for ASW service received the SCB-144 upgrade in 1960-1964 as part of the FRAM II program. They received a bow-mounted AN/SQS-23 sonar, as well as improved displays in the Combat Information Center.