On a recent Thursday morning, the Workshop School in West Philadelphia was a symphony of drills and saws and welding torches.

Amid the whirring stood two tandem bicycles welded together and topped — or in the process of being topped-with a massive wooden cut-out of a brain.

This contraption may not be the most outlandish entrant in this year's Kensington Kinetic Sculpture Derby and Arts Festival, but it may take top prize for societal benefit.

For one day every year, the streets of Philadelphia's Kensington neighborhood host a parade of pedal-powered devices topped with outlandish decorations. The Kinetic Sculpture Derby is a chance for local artists and makers to strut their creative stuff. And this year some high school students are entering the fray.

Thanks to a $4,000 grant from the Philadelphia Federal Credit Union, a derby sponsor, freshmen from the Workshop School will pilot two machines of their own design and making during the Saturday festivities.

Over the past six weeks, Workshop School students have been planning, building, failing, and rebuilding as they rush to have their devices ready. The test will come Saturday as they navigate the parade route and eventually encounter the famous mud pit that all must attempt to trespass at the end.

"It kind of removes me from the teaching role — like I'm grading you," said teacher Jared Lauterbach (better known around here as Mr. L). "It's like life grades them. Does the bike work? How cool does it look? What response, what feedback are they getting from people about their work?"

The Workshop School belongs to a network of small, experimental schools within the School District of Philadelphia. The school grew out of an automotive program at West Philadelphia High School and steers students toward long-term, hands-on projects.

It's not the kind of education that keeps kids in their seats, and ninth-grader Treasure Jackson didn't think it was quite her speed when she arrived in the fall.

"When I first got here I was like I don't want to do this hands-on stuff because I like getting my nails done, as you can see," Jackson said, flashing a set of pink-and-silver fingernails.

She's since learned how to change a tire and her perspective.

"When I had to get dirty for a grade, I was like, this is so much fun," she said.

Jackson built paper-mache tools to decorate one of the sculptures. She's also responsible for interviewing students as the project unfolds and documenting the journey.

And there's been plenty to document.

Several students learned how to weld as part of the project and found their initial efforts wanting. During a test ride, two bicycles that were supposed to remain attached split apart almost immediately, according to Lauterbach.

The team realized their design wasn't solid enough, and attached more metal beams to create a more durable connection between the wayward bikes.

That's the kind of challenge freshman Wendell Redmon craved when he applied to the Workshop School, which accepts students from across the city.

Redmon's goal is to be an automotive engineer. He got the inspiration from his dad, who works on cars part-time.

Redmon's goal is to eventually run his own repair shop.

"To impress my dad," he said.

The Workshop School won't be the only Philly school represented at Saturday's festivities. Teams from the Charter High School of Architecture and Design and H.A. Brown Elementary School will also participate, according to the festival website.

The action starts at noon on the corner of Trenton Avenue and E. Norris Street.