Hundreds cheered and clapped when USS Klakring slid into the blue water of the Kennebec estuary. For many at last month's launching the ship represented steady employment.

For the shipbuilder, Bath Iron Works, Klakring became the 15th guided missile frigate to be launched since the prototype, USS Oliver Hazard Perry, hit the water in 1977. Eight are still to be constructed before Bath converts from frigate production to what the company hopes will be an ambitious chunk of the U.S. Navy's sophisticated Aegis cruiser program.

Meanwhile, Bath keeps popping out frigates to the rhythm of the descriptive phrase "ahead of schedule and under budget." The 11th frigate, USS Aubrey Fitch, is to be delivered to the Navy Oct. 9, behind a dais that is to support Vice President Bush, among others, and Bath says it, too, will qualify for that testimonial.

"The Fitch will bring the total number of production weeks saved for the taxpayer to 142," Bath spokesman James McGregor says.

No one is providing dollar amounts because Bath's biggest customer, the Navy, doesn't want such numbers open to scrutiny. But before Bath stopped counting, the company was cutting production budgets an average of about $7 million per ship. To the skeptic who might ask if the budgets were too high to begin with, Bath officers say they won the frigate contracts because they bid low enough.

When Beverly Bohen of Napa, Calif., broke a champagne bottle across the bow of USS Klakring in honor of her uncle, World War II hero Thomas Klakring, on Sept. 21, she helped continue a tradition of productivity that Bath Iron Works people say began in the early days of the English colonies. Colonists built the first European ship in North America at Popham Beach, five miles from Bath on the Atlantic Coast. And it was a Bath built yacht that J. P. Morgan was referring to when he said, "if you want to know how much it costs you can't afford it."

John F. Sullivan chief executive officer and chairman of Bath, attributes the company's productivity to modular planning and Yankee pride. Planning takes shape in "pre-outfitting" the 16 modules of a frigate on dry land before they are welded together to form a ship. Pride becomes part of the process in the energy and craftsmanship for which New Englanders are known, he says, referring to the Navy dictum, "Bath-built is best-built."

"Large manufacturers in New York or Philadelphia or even Seattle-Boeing devote such a small part of their overall efforts to shipbuilding that they don't get people's attention. Here people have made fortunes in shipbuilding back to the time of the sailing ships so they have a lot of pride. We're saying 'it's you, the people, who are making it work.' We're not saying 'what a great management team,' " says Sullivan, who was credited with making Bath profitable after being installed by the company's parent, Congoleum Corp., in 1975.

Frigate production has been most visible this year. Klakring was the fifth launched at Bath in 1982 and another is expected in December. BIW, Maine's largest private employer, says its employment has risen from 5,500 to nearly 8,000 since April. The company is anxious to finish the FFGs and get on with the cruisers, which are expected to increase employment even more.

In May, the company announced it had been designated as the second source for the high-technology cruisers supporting RCA's battle-directing AEGIS systems. This so far has resulted in the award to BIW of a $300 million contract to build a single Ticonderoga-class cruiser by 1988.