With Franklin-like frugality and inventiveness, the state will convert the concrete roadbed slabs of the Benjamin Franklin Bridge that opened 62 years ago into an undersea home for lobsters and sea bass.

The 6,000 slabs removed in the $70 million resurfacing of the bridge are being dumped into the Atlantic Ocean to form an artificial reef 5 feet high, the size of five football fields."Ben was for anything innovative. He would have liked this idea - you know, a penny saved is a penny earned," said Bill Lynch, a spokesman for the Delaware River Port Authority, which operates the bridge between Camden and Philadelphia.

"I don't know how much they saved, but I bet it was more than a penny," said Bill Figley of the New Jersey Department of Environmental Protection, who is overseeing the construction of the state's largest artificial reef.

The Port Authority is paying a contractor $1.6 million to barge the slabs out to sea eight miles off Cape May, Lynch said. Bids for landfill disposal of the slabs went as high as $3 million.

"The nice thing is they're actually doing some good," Figley said. "It's going to help out Cape May's fishing industry for the next 20 or 30 years," until sand covers the slabs.

Artificial reefs attract fish and other sea creatures by providing a surface for them to live on and protection against predators, helping to increase marine populations.

For the past five weeks, the contractor has loaded the slabs, each about a foot thick, 6 feet wide and 10 feet long, onto a barge moored under the bridge on the New Jersey side.

Each Saturday, the 250-foot-long barge makes the 18-hour trip down the river, through the Delaware Bay and out to sea, where Figley and his staff are waiting to meet it.

Although it takes five days to load the barge, it only takes about an hour for a front-end loader to dump the slabs into the sea at spots carefully marked by buoys, Figley said. The job is expected to take eight weeks more.

The completed reef will be at least three times the size of several tankers the state has sunk, and will dwarf other reefs made from smaller vessels or old tires, Figley said.

"Other than the Shrewsbury Rocks, we really don't have any natural reefs off New Jersey," he said.

It is difficult to find places to build reefs because commercial fishing operations often oppose dropping debris on the ocean bottom that may get in the way of their nets, Figley said.

The area chosen is about 55 feet deep and falls within a 4.5-square-mile area designated as a reef site in 1935.