They wore silk bustiers and leather boots, carried parasols and copper, space-age pistols, showed off thigh-high stockings and brass mono-goggles, and cheered wildly as crazy contraptions raced — sometimes careened — down old railroad tracks.

The steampunk-themed Handcar Regatta festival again took over Railroad Square on Sunday. It drew thousands of people into the historic West End neighborhood, coloring it in a sort of turn-of-the-century-inspired irreverence.

"It's a dreamed-of future from the past that doesn't exist," said Rain Thibaudeaux, 54, of San Francisco, trying to capture the essence of steampunk.

"It's kind of Victorian with a modern aspect. It's weird," said Luke Mott, 11, of Santa Rosa.

Whatever it is, it was an event anchored by its racing machines, 26 muscle-powered inventions that seemed both cobbled together from scavenged materials and works of mad-eyed mechanical genius.

What was the name of that low-slung sled-like affair with a silvery tortoise head and reddish shell?

"You'll have to ask the engineer," said Adam Burns, 38, a Healdsburg tattoo artist, who painted it.

But the engineer, a large man in overalls, stepped away and disappeared into the crowd, estimated at about 12,000 by Ty Jones, the event's co-founder.

The handcar's tortoise shell was fiberglass; the ribs, insulation foam; the rivets — about 150 of them — peppermint candies covered with fiberglass and painted to resemble metal.

"I just wanted it to look like a submarine, Jules Verne-inspired," said Burns, whose handlebar mustache was curled to pin-sharp points.

Irony attended, too.

The crowds around the old railroad station were almost certainly the kind of scene dear to the imagination of commuter train officials who envision the area as a rail-centered hub of transit, residential and commercial life.

But the 4-year-old regatta's future at its current location is uncertain.

Sonoma-Marin Area Rail Transit District authorities have said that next year the event may be displaced as work on the tracks starts. Railroad Square is the terminus of the rail agency's initial planned route, from Santa Rosa to San Rafael.

SMART officials, though, have also said they want to try and find a way to allow the festival to go on while the rail line moves into construction.

And on Sunday, Jones, 49, sounded a positive note, saying the event's value is being recognized.

"I think people are starting to understand the cultural and economic importance of the event," he said, adding that over its lifetime, the event has generated $225,000 in spending, mostly in Santa Rosa.

Spectators flitted from booths selling preserved lemons to stands offering freshly butchered sausages, from cherry pies to Vietnamese spices.

And a weary 11-year-old, Akshay Pagre, leaned against a wall.

"I just sold all of my 260 hot dogs," said one half of the namesake for the Akshay and Rohan's Super Hot Dogs food stand.

Later, he said, he would watch the races and "look forward to some failures."

His brother Rohan, 10, laughed. "Those are fun," he said. "When parts break off."

On the tracks, the six-seater Bindelstiff Express — picture mining cart meets racing bikes with beer can holders —had all its parts in place as its crew readied it for a race.

The machine belonged to the Black Butte Center for Railroad Culture, in Weed. A driver, a 29-year-old Oakland woman who went by the name Miss Max, warmed up by doing dips on the handlebars.