FFG-7 OLIVER HAZARD PERRY-class
The Navy is retiring all frigates in FY 2015. The Perry class FFG forms a capable undersea warfare [USW] platform with the LAMPS-III helicopter onboard. The Mk 13 Mod 4 missile launcher provides secondary anti-air capability. Ships of this class are often referred to as "FFG-7" (pronounced FIG-7) after the lead ship, U.S.S. Oliver Hazard Perry (FFG-7). These ships were originally conceived as a low-cost convoy escort (hence the original "PF" hull number for the prototype). They are particularly well suited to be a convoy escort and are Link 11 capable. As older first-line destroyers and frigates were retired without replacement, however, the FFG 7 class has been integrated into the fleet, and numerous updates have been applied to permit it to cope with modern combat conditions. As a result, the fully equipped units displace nearly 500 tons more than the designed displacement, and crews have been greatly enlarged. The soundness of the design has permitted the expansion, and the ships have proven remarkably sturdy.
These ships have a full load displacement of that ranges from 3,658 tons to 4,100 tons, are either 445 or 453 feet in overall length, have a 45 foot beam and a draft of 22 feet. Construction materials include a steel hull with an aluminum superstructure. They are powered by a single shaft driven by 2 LM2500 gas turbines. Their maximum sustained speed is about 29 knots and the have a 4,200 nautical mile range at 20 knots. The ships active complement is about 15 officers and 179 enlisted personnel.
Frigates fulfill a Protection of Shipping (POS) mission as Anti-Submarine Warfare (ASW) combatants for amphibious expeditionary forces, underway replenishment groups and merchant convoys. PERRY-class frigates are primarily Undersea Warfare ships intended to provide open-ocean escort of amphibious ships and convoys in low to moderate threat environments in a global war with the Soviet Union. They could also provide limited defense against anti-ship missiles extant in the 70's and 80's. The ships are equiped to escort and protect carrier battle groups, amphibious landing groups, underway replenishment groups and convoys. They can also conduct independent operations to perform such tasks as counterdrug surveillance, maritime interception operations, and exercises with other nations. The addition of NTDS, LAMPS helicopters, and the Tactical Towed Array System (TACTAS) has given these ships a combat capability far beyond the class program expectations of the mid-1970's, and has made the ships an integral and valued asset in virtually any war-at-sea scenario and particularly well suited for operation in the littoral.
Detailed design of the FFG-7, then known as the Patrol Frigate, began in May 1973. The $94.4 million lead-ship construction contract was awarded in October 1973 to Bath Iron Works Corp., Bath, Maine. Construction began in March 1975, and the lead ship was delivered in November 1977. In February 1976, the Navy awarded contracts to Bath Iron Works and to two Todd Shipyard Corporation yard in Los Angeles and the other in Seattle for construction of 11 follow-on ships. Additional contracts were awarded to these yards.
The 1973 estimate for a total program of 5O ships was $3.2 billion, with an average unit cost of $63.8 million. The Department of Defense estimated at September 30, 1978, that the cost of a 52-ship FFG-7 program would be $10.1 billion, an average cost per ship of $194 million. Two primary factors causing this increase were the addition of equipment that was not included in the original cost estimate such as a towed sonar, fin stabilizers and electronics equipment and much higher than anticipated shipbuilding costs.
From the inception of the FFG-7 program, the Navy recognized a need for a large number of these frigates to replace World War II destroyers retiring from the fleet. In order to meet this numerical requirement, stringent design controls were placed on the size and cost of the FFG-7. Keeping down size and cost naturally led to some sacrifices in operational effectiveness, most of which appeared to be good management decisions. There were several areas where cost constraints may unduly effect operational effectiveness. Four matters are (1) the selection of the short-range AN/SQS-56 hull-mounted sonar, (2) the decision to include only minimal space, weight, and stability margins for modernizing the ship, (3) operation and maintenance of the ship, and (4) ship survivability.
Modernization potential is the ability of a warship to accept new equipment to avoid obsolescence. The long life of warships (25 or more years) and relatively short life of systems installed on the ships (7 to 10 years) made modernization potential important. Over its lifetime, a warship will usually have mucn of its original equipment replaced by new, more capable systems. From the outset of the program, space, weight, and stability margins for growth in the FFG-7 were minimized. The low margins were linked to the Navy's determination to restrain the size and cost of the ship. As a result, the FFG-7, unlike most new warships, was unable to accommodate any new equipment beyond what was planned, unless compensating removals were. The two areas of particular concern were the reductions in (1) the service life weight margin, and (2) the future growth margin.
The service life weight margin allows for weiqht increases occurinq during the life of the ship. Normally, the margin for a ship this size would be about 150 tons. The margin in the FFG-7, however, was only 50 tons, or 100 tons less than normal. The future growth weight margin is established to allow for unknown, but anticipated future modifications and new equipment approved by the Chief of Naval Operations. This margin is intended to make new ships more adaptable to changing requirements, the increasing threat, and changes in technology. In the FFG-7, there was no margin for unplanned future ship characteristic changes which require additional space or increases in the ship's weight.
In addition to the tight weight margins, opportunities for future qrowth were even further constrained by very limited space on the ship. These space limitations could make some necessary future improvements impractical if compensating equipment removals cannot be made. This, in turn, could affect the capability of the ship to perform its mission against an increasing enemy threat.
These limited opportunities for future ship modifications were a serious matter because major modernizations are almost always required in order to naintain an effective ship. Historically these modernizations have usually required space, weight, and stability reservations. The absence of weight and Space margins for fitting new equipment beyond those already planned meant added risk that needed mid-life modernizations to keep the ships abreast of an increasing threat throughout their life will prove impractical.
The retirement of the ocean escorts of the Claud Jones, Courtney, and Dealy classes from the active fleet when they were only 15 to 20 years old are examples of ships with limited growth potential. Not only did the Navy fail to get a full measure of active service from these ships, but while active they contributed less in terms of effectiveness than less cost-constrained designs would have.
The class had only a limited capacity for further growth. Despite this, the FFG-7 class is a robust platform, capable of withstanding considerable damage. This "toughness" was aptly demonstrated when USS Samuel B. Roberts struck a mine and USS Stark was hit by two Exocet cruise missiles. In both cases the ships survived, were repaired and have returned to the fleet.
Two ships of this class suffered heavy damage while patrolling in the Persian Gulf. On 17 May 1987, two Iraqi fired Exocet SSMs hit the U.S.S. Stark (FFG-31), one of which detonated near berthing spaces resulting in heavy loss of life. On 14 April 1988 the U.S.S. Samuel B. Roberts (FFG-58) struck a mine which detonated an estimated 250 pounds of TNT. The explosion heavily damaged propulsion systems and blew a nine-foot hole under the keel. In both attacks, the ships suffered intense fires aggravated by the all aluminum construction of the superstructure. Nevertheless, exceptional damage control efforts carried out by their crews kept both ships on the surface and enabled them to reach friendly ports in the Persian Gulf. The Stark returned to the United States on her own power and underwent repairs. The Roberts was transported to the United States on the Dutch-flag heavy-lift ship, Mighty Servant 2.
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