The children swarmed onto the new rubber-tire swings, ignoring the drizzle and the wet ground as they moved in wheelchairs and walkers toward the newest equipment at the H.W. Wheatley Early Childhood Center playground.

But the adults gathered for Thursday's dedication in Capitol Heights couldn't stop looking at the wood chips.

Four years of research and about $200,000 went into developing these chips, special wood particles that will mesh to form a rubberlike surface, safe enough for a playground and smooth enough to handle a wheelchair.

As schools across the country work to make their playgrounds comply with the Americans With Disabilities Act, the innovative chips put in place in Prince George's County could provide a model for an affordable and accessible solution.

"This is a big deal because wood chips are very cheap for a playground surface," said Theodore Laufenberg, chief researcher on the project. "A wood-chip surface is about $2,000, compared to a rubber surface, which is about $30,000."

This was such a big deal to Laufenberg that he flew in from the federal Forest Services' Forest Products Laboratory in Wisconsin to be part of the ribbon-cutting.

President Bush declared last week National Forest Products Week and, in observance, researchers and educators gathered Thursday to dedicate the playground at the Wheatley center, where about 10 percent of the 600 children use wheelchairs or walkers.

"For our children, having access is a beautiful thing," said Pamela Hoffler-Riddick, Region III executive director for the county school system. "We are the first school in the Washington area and along the East Coast to have use of a playground like this."

Principal Linda Wiskochil of the Wheatley center was so happy about the playground that she baked for the guests. "Having a barrier-free playground allows children in walkers or who have trouble with access to get to equipment they normally couldn't get to."

In addition to the wood-chip surface and the tire swings, the playground will soon have a slide and other equipment designed to let disabled children play alongside their non-disabled peers.

Four-year-old Aaron Harrison rolled over to the swings and scooted on. "We can swing fast," said Aaron, who along with other children sang songs, presented oversized thank-you cards and cheered the scientists in attendance.

"This is one of the best things, to see our research put into a product that someone can use. You live your whole life as a researcher to deliver something," said Ann M. Bartuska, deputy chief of research and development at the Forest Service.