New Tool to Combat Brush Fires

Los Angeles County firefighters on Thursday put some weight behind their annual demand that dangerous hillside brush be cleared by May 1. Ten tons, in fact.

Officials rolled out a 14-foot-wide, one-of-a-kind “brush crusher” that can effortlessly create firebreaks on the steepest and most fire-prone slopes of the Santa Monica Mountains.

Resembling a huge, heavy-duty barrel connected by steel cables to a pair of winches on a bulldozer, the crusher mows down thickets of chaparral as it is repeatedly rolled up and down hillsides.

Later, after the flattened chaparral has dried out, firefighters will return and destroy the dead material with a carefully controlled “prescribed burn” that completes a 600-foot-wide firebreak.

Authorities at Thursday’s inaugural run in Malibu said they plan to use the 20,000-pound crusher at “strategic points” in the mountains--along ridgelines that traditionally tend to funnel flames into residential areas during wind-whipped brush fires.

The crusher can clear about 35 acres a day. In contrast, a crew of a dozen workers equipped with chain saws and axes can cover only about an acre, officials said.

On Thursday, the crusher plowed through 10-foot stands of sage and sumac, easily snapping trunks and branches the size of a man’s leg.

Anchored by a 45-ton Fire Department bulldozer, the crusher quickly denuded a swath of Nicholas Ridge, an isolated canyon area two miles north of the intersection of Pacific Coast Highway and Decker Road.

Officials say the ridge is ripe for a brush fire. Thick chaparral there last burned 15 years ago--although surrounding canyons were swept by brush fires in 1978, 1993 and 1998.

The efficiency of the brush clearance drew appreciative nods Thursday from observers from fire departments in Kern, Ventura and Santa Barbara counties as well the city of Los Angeles, the National Park Service and the state’s Division of Forestry.

It put a big grin on the face of the crusher’s inventor, New Zealand forestry worker Lex Norton, who predicted mountain firebreaks can prevent millions of dollars in brush fire damage.

The 54-year-old Norton said he got the idea for what he labeled a “gravity roller” when he was a 16-year-old heavy-equipment operator clearing hillsides in his country for a reforestation project.

“I slid to the bottom of a lot of hills on a bulldozer. I knew there had to be a better way,” he said. After designing a small roller that is now used in New Zealand forestry work, he hit on the idea of using a bigger, heavier one here after visiting the United States during the 1996 brush fire season.

Los Angeles County Fire Chief P. Michael Freeman said his staff spent several years working with Norton on the crusher’s inch-thick steel design. Its $460,000 cost was primarily covered by a Federal Emergency Management Agency grant issued after the 1993 Old Topanga brush fire. Freeman said a licensing agreement will allow the county to receive royalties from other firefighting agencies that buy the crusher--custom-built by a Florida company called Supertrak Corp.

While fire officials were watching the crusher’s efficiency, others at its maiden run were looking at its environmental effects. Most of them gave it high marks in that category, too.

“The root burls are left untouched” and the plants will grow back, said state parks Ranger Frank Padilla Jr. as the roller snapped off the brush at ground level. And mowed-down brush produces less heat than standing brush when it burns, limiting the “glazing” effect that high temperatures have on soil.

Such glazing causes rain runoff and erosion.

Rosi Dagit, a senior conservation biologist with the Resource Conservation District of the Santa Monica Mountains, said the crusher’s 600-foot downhill reach leaves ample vegetation toward the bottom that can help keep eroded material out of canyon streams.

“This looks like the best brush clearance technique used so far,” added David Totheroh, a cabinetmaker who is chairman of the county-sponsored Topanga Citizens Fire Safety Committee and whose family has lived in the Santa Monica Mountains for 75 years.

Officials said firefighters plan to return to Nicholas Ridge on April 11 to burn the 615 acres of flattened brush left behind by the crusher. They predicted it will take about three days to incinerate the chaparral.