FFG-7: The Concept and Design

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The Oliver Hazard Perry (FFG-7)-class frigates are the first to be built to the “fly-before-buy” concepts developed in the early 1970s. One doesn’t “fly” a ship, of course, but the FFG-7 herself can almost be regarded as a prototype because of the two-year gap between her completion and that of the second ship in the class. This method is in contrast to the “total package pro­curement” used for the Spruance (DD- 963) class of destroyers now under con­struction. With the latter the follow ships have come so quickly after the lead ship that there is little opportu­nity to incorporate lessons learned as the assembly line continues to turn them out.

There’s another important dif­ference as well. The Spruances were in­tended to be built all in the same shipyard, a highly sophisticated facil­ity. Both the yard and the ship design had been developed together by the shipbuilder. In the case of the Oliver Hazard Perry class, we deliberately set out to design a ship that could be built by any yard in the country that is capable of turning out destroyer- type ships. To ensure that this would be possible, the original design was done by a team made up of the Naval Ship Engineering Center, the desig­nated lead yard (Bath Iron Works) and their design subcontractor (Gibbs and Cox), and a potential follow shipbuild­ing company (Todd Shipbuilding Corporation). The Todd Seattle yard has much different capabilities—fewer shipways, smaller cranes—from the one at Bath. It is so obviously dif­ferent that if the ship were designed so that either yard could build it, then virtually anyone could. And we have seen that to be the case now that the construction contracts have gone to those two yards plus Todd Los Angeles. Each has unique facilities, and each is going about construction in a different way.

“Fly-before-buy” is a misnomer in more ways than the obvious. If you truly built a ship and tested her com­pletely before you let a contract for the subsequent ships in the class, the gap would be so large that the technology would be behind you. The follow ships would be obsolete. The gestation period is just too long. It takes four years for us to build one of these ships from contract to delivery, and close to a year to fully test it. We just can’t wait that long. On the other hand, we didn’t want to come along with the second ship only three or four months behind the class leader. The Oliver Hazard Perry was commissioned on 17 December. The first of the ships to be built by Todd Seattle is scheduled for delivery in January 1980.

Without trying to belabor the ad­vantages of “fly-before-buy,” it would be well to add that there is more than just the two-year gap. A major test and evaluation program, including the construction of two land-based test sites, was carried out. In fact, we took all the major component systems and tested them independently before the first ship was finished. The USS Talbot (FFG-4) of the preceding class of guided-missile frigates was used for operational evaluation of the Mk 92 gun-and-missile fire control system and of the Mk 75 76-mm. Oto Melara rapid-fire gun. The long-range SPS-49 air search radar was tested on board the USS Dale (CG-19), and the Mk 13 launcher for Standard and Harpoon missiles has been in service in the fleet for many years.

A prototype plant of the gas turbine propulsion system was built ashore at the Philadelphia division of the Naval Ship Engineering Center. With this land-based test facility, we put the propulsion system through several “cruises,” each as long as 19 days, and we did so long before the ship herself ever went to sea. The full propulsion plant is there, fully manned, and the simulated missions were carried out using the power and speed profile^s that would be expected in actual operating conditions. The only paf^ts of the system missing are the propeller blades. We used actual gas turbines, control systems, reduction gears, and a three-section Navy watch for realism in our tests.

We ran similar trials with the com­bat system at our combat system land-based test site at Islip, New York, where we installed a replica of the shipboard combat information center (CIC) and radar equipment rooms. Fully operational consoles, radars, antennae, and computers were installed in the identical physical con­figuration, including cableways, as on board ship. Only the gun, missile launcher, and sonar were simulated- We “fought” many wars with that system on Long Island before we put it on board the Oliver Hazard Perry', and it was well that we did because the operational evaluation on land re­vealed some significant deficiencies in the ability to coordinate the antisub­marine warfare (ASW) mission. That portion of the combat system was sub­sequently redesigned, rebuilt, and the computer programs redone. It then underwent a second operational evalu­ation at Islip which it passed before the ship put to sea.

All of this testing, of course, took place after the basic ship had been de­signed and contributed to the very successful sea trials just completed. Perhaps, it would be well to backtrack just a bit to examine the fundamental design philosophies behind the class. What is now the FFG-7 started out as ^che patrol frigate (PF-109) in late 1970. There were three main limitations placed on her—cost, displacement, and crew size. Not surprisingly, the *dea was to keep each as low as possi­ble- The ship was the first “design- to-cost” ship, designed with a follow ^sh'p construction cost goal of $45.7 tnillion in 1973 dollars and a threshold of $50 million, built under ^a specific procurement plan that called l°r funding all follow ships from fiscal year 1975 through 1979. In other ^w°^rds, the total class was to be pro­^cured over a period of five fiscal years, at an average cost of less than $50 mil- h°n i_n constant 1973 dollars.

The cost constraint served the very Useful purpose of holding down costs, ^even though sufficient ship quantities '''ere not authorized to support our planned production rate and we didn’t tUeet our goal. The stretching out of the program, along with some ship characteristics changes projected for the later years, has increased projected costs. Consequently, the average cost °f follow ships is now more like $68 uahlion in 1973 dollars. But who ttnows how much they would have keen if we hadn’t been so conscious of costs at every step of the way?

The second major design goal was displacement. Our goal was a fully ioaded ship of 3,400 tons with a threshold of 3,600 tons. We delivered the lead ship a little more than 3,500 tons, which is less, incidentally, than the Knox (FF-1052) class and about the same as the Brooke (FFG-l) class. Obvi- °^Usly, the Oliver Hazard Perry is far smaller than the 7,300-ton Spruance.

The DD-963 was deliberately built with a large amount of room for growth so that new weapon systems could be refitted or added easily. The FFG-7 was deliberately designed to be small and economical. That is why, for example, there is no room for a unit commander and his staff and not even a captain’s sea cabin. (The cap­tain’s cabin is between the bridge and combat information center, making it just as useful as a sea cabin would be.) Nevertheless, there is room to ac­commodate some major modifications which are planned for the ship, in­cluding the forthcoming LAMPS III (light airborne multi-purpose system) helicopters, TACTAS (tactical towed array system) passive towed array so­nar, helicopter recovery and traverse system, fin stabilizers, Vulcan/Phalanx close-in weapon system, and Link 11 tactical data transfer system. That amounts to a lot of planned growth, but we’ve allowed only about 50 tons beyond that. So, once these im­provements are added to the ship, anything additional that is put on will mean that something else has to come off.

The third constraint was in crew ac­commodations. That was easily met by putting in 185 bunks for crew and helicopter detachment, thereby meet­ing our goal. Actually, we did some very careful planning to make sure we could, in fact, operate and maintain a ship with no more than 185 people. We did it largely through savings in watch standers and a high degree of automation in the engineering plant. The main propulsion plant, the elec-

The Oliver Hazard Perry FFGs were designed so they could he built at various yards. FFG-7 is assisted hy tugs off the Bath Iron Works above.

trical plant, and the auxiliaries are all run from one central control station with two or three men on watch. The combat system is run from CIC, and one man can both steer the ship and control her speed from the bridge con­sole. In fact, the ship can operate effi­ciently in Condition III (wartime steaming) with only 22 men on watch. This means we get by with about 65 fewer men than the FFG-l class, but we have as many or more people available for maintenance be­cause of the saving in watch standers.

Logistic support of the ship was a factor kept in mind at every phase of the design. Major systems and com­ponents can be repaired by replacing modules. The modules themselves are then removed and taken to a depot for repair or rework. The modules may be as big as a gas generator, diesel en­gine, or fire pump from the engineer­ing spaces. The ship is designed with access routes so that every major piece of equipment can be removed without major disruption. The hatches all line up under davit heads, and there are soft patches which can be taken off to facilitate removal. The gas turbines, for example, are planned to go out through the exhaust stack on the superstructure. The theory is that the crew will do preventive maintenance. For corrective maintenance on redun­dant, non-mission-essential equip-

ment, it is removed and then repaired or overhauled off the ship. For essen­tial items for which there is no backup capability, the ship carries replace­ment modules or at least the parts necessary to repair them. We think a crew this size will be able to do the job, although we have hedged our bets by developing backup designs to in­stall accommodations for 12, 18, or 30 additional people should the opera­tion of the lead ship over the next year or so indicate a need for them.

The result of all the planning, de­sign, and testing which has gone into the Oliver Hazard Perry class is that the Navy will have what we believe to be a most capable warship for her as­signed mission—open ocean escort of convoys, amphibious task groups, and underway replenishment ships. The

FFG-7 and her forthcoming sisters will serve as excellent complements to the already existing surface combatants of the Spruance and Knox classes. Those two classes are designed primarily for antisubmarine warfare. Where they have large active SQS-26 sonars, the FFG-7 has the small, in-layer SQS-56 to detect targets at closer ranges. Where they have minimal antiair warfare capabilities, the new frigate is excel­lent in that area and in quick reaction missile defense and will be even better when the close-in weapon system is added.

What’s more, the Oliver Hazard Perry class will be much better at ASW as succeeding ships come off ship­builders’ ways. The addition of a passive towed array sonar and the LAMPS 111 helos will make them out­standing ASW ships instead of just very good ones.

In summary, the Oliver Hazard Perry class gives every indication that it will prove to be a most capable ad­dition to the fleet. It is designed to provide the capabilities most in de­mand, in the numbers required by out worldwide sea control mission com­mitments, and at a construction cost and “manning” cost that we can af­ford. The use of “fly-before-buy” has permitted us to avoid the many grow­ing pains normally associated with the lead ship of a class and provides a high level of confidence in the capabilities and reliability of the follow ships now under contract. The lead ship has flown superbly in all her trials. We need have no reluctance about buying more.

The Navy’s Newest Ship: FFG-7

By Commander Stephen J. Duich, U.S. Navy, Commanding Officer, USS Oliver Hazard Perry (FFG-7)