David Gerstein has been a fixture in the Israeli art circuit for decades, but his career just scaled new heights - literally. The artist, best known for his colorful pop aesthetic, recently unveiled his most expensive, largest-scale work to date: a $1.2 million sculpture called "Momentum" that measures 18 meters high, weighs 44 tons and sits at the core of Singapore's central business district. "'Momentum' is something optimistic, something dynamic that reaches the sky," said Gerstein, 64. "The idea behind the sculpture is to strive for excellence. That's very important in Singaporean society." With this concept in mind, Gerstein created a giant spiral that becomes increasingly narrow the higher it swirls; attached to it are 175 human figures, one of which sits atop the piece and holds a disc that revolves like a weather vane. And to reflect Singapore's multicultural society, Gerstein painted half of the figures red and decorated the other half using his bold palette of almost every color imaginable. "That's my attitude toward art," said Gerstein. "It shouldn't be heavy, it shouldn't be depressing, it should bring light into the area, and be vivid and alive and reflect happiness on its surroundings." No stranger to public art, Gerstein's works can be seen all across Israel, not to mention in London and Korea. But he said the Singapore project (commissioned by One Raffles Quay, one of the country's largest real estate developers) offered him an unprecedented opportunity: to work on a scale and with funding greater than he could have imagined. "In the beginning, I was thinking it would be about 10 meters," said Gerstein, noting that original budget was around $600,000. But once the project was approved by Singaporean authorities and by O.R.Q., Gerstein said "let's do something really outstanding. They not only agreed to make it bigger, but they gave a much bigger budget for it." Despite these advantages, 'Momentum' also presented Gerstein with a logistical nightmare. The spiral was built in Singapore with the help of a small local staff, but the figures, which were cut in Israel, had to be shipped and welded to the base under canvas shrouds at night. Gerstein and his staff worked for several months in this tightly controlled, secretive environment because O.R.Q. wanted to reveal the work over 10 days, leading up to New Year's Day. To Gerstein's dismay, however, the unusual working conditions led to some unexpected results. "I thought of dispersing the figures randomly," he said, "but when 'Momentum' was unveiled, I realized this randomness created certain patterns. The artwork is alive. In many cases, you do something spontaneously, and then you look back and say, 'Gee, it's not what I thought when I made it, but it's very interesting.'" The sculpture's real coup, though, is the ease with which it makes 44 tons of metal look like paper. "The structure is very strong and yet it looks like a house of cards," Gerstein said. Little did he know that the proceeds from this house of cards would help subsidize a real home for his art: a brand-new two-floor gallery at 99 Ben Yehuda Street in Tel Aviv that opened Feb. 1 and that, starting next month, will also exhibit other artists. "The sky's the limit," said Gerstein, who is currently at work on a handful of new public art projects in Israel and abroad. "Two years ago, 18 meters looked huge to me. Now, my horizons are extended."