Like a carefully twisted ribbon or a burnished birthday candle, the new skyscraper would soar into the Chicago skyline, surpassing the nearby Sears Tower as the nation's tallest building -- and leapfrogging a tower backed by Donald Trump as the city's snazziest.

Trump, for one, is not pleased.

Developer Christopher T. Carley will formally unveil the drawings Wednesday for a 115-story spiral designed by Spanish-born architect Santiago Calatrava. From the chiseled plaza to the top of its spire, the hotel and residence would measure 1,458 feet at its rooftop and, with its spire, reach about 2,000 feet. The 1,450-foot Sears Tower extends to just over 1,700 feet when its tallest antenna is included.

What is surely most distinctive about the prospective $500 million building is its twist, achieved by rotating each floor slightly more than 2 degrees from the one below, or 270 degrees in all.

Where some see an architectural signature in the city where Ludwig Mies van der Rohe, Daniel Hudson Burham and Frank Lloyd Wright toiled, Trump said he sees the work of addled minds.

"In this climate, I would not want to build that building. Nor would I want to live in that building," Trump told the Chicago Tribune. "Any bank that would put up money to build a building like that would be insane."

Carley fired back, telling the newspaper, "I wonder where the insanity limit is. It must be just over 1,360 feet."

The figure on Carley's lips happens to be the height of a tower Trump is building along the Chicago River, the project for which he hired Bill Rancic on the first season of "The Apprentice." During the design phase, Trump opted out of the nation's-tallest-building race, saying he was deferring to buyers who feared becoming a terrorist trophy.

It remains uncertain whether Carley can put together the financing and win city approval. Carley is the founder of Fordham Co., a firm based in Chicago that has developed such residential properties as the Pinnacle and the Fordham.

The design is an eye-opener, if only he can get it built, said skyscraper aficionado Ron Klemencic.

"They certainly have something unique to market. I have been very eagerly awaiting the unveiling of the design. I wasn't disappointed," said Klemencic, chairman of the Chicago-based Council on Tall Buildings and Urban Habitat.

As for the threat of terrorism, in the weeks after the September 2001 attacks on the World Trade Center, workers at the Sears Tower worried they might be next after inheriting the title of nation's tallest. Klemencic now wonders if height was less important to the Sept. 11 hijackers than the iconic stature of the twin towers.

A decision about whether the proposed Fordham Spire is built, he said, is "going to be all about the economics."

In a nod to nervousness, a fact sheet distributed by Carley's team promises a "heavily reinforced concrete" core able to withstand high temperatures, and two "independent systems of emergency exits."

Calatrava, describing the design as being based on a sculpture he did early in his career, said he has returned to the idea many times. The Chicago spire would fit in a series of buildings that include projects proposed for New York City; Malmo, Sweden; and Valencia, Spain.

"I find that each new building raises problems that only the next building can solve," said Calatrava, who designed an acclaimed art museum up Lake Michigan in Milwaukee, completed in 2001.

The Fordham building would rise on 2.2 acres at E. North Water Street and Lake Shore Drive, near Lake Michigan. Although so tall, it would have fewer than a million square feet, divided among retail space, a hotel and luxury condominiums. The Sears Tower, built in 1974, contains 4.5 million square feet.

As described in the developer's documents, the twisting effect would be accomplished by building out each floor like a separate box with concave sides. Each box would be rotated slightly farther.

Trump's 92-story tower has no such aspirations. But the cranes and crews are there every day.

"One thing about the Trump tower," said Klemencic, "is it's underway, whereas the Fordham project with Calatrava is still kind of a twinkle in the developer's eye."

An artist's rendering shows the building designed by Spanish architect Santiago Calatrava on a site near Chicago's Lake Michigan waterfront.