What will be done with the old 520 Bridge pontoons?

What will be done with the old 520 Bridge pontoons? »Play Video
SEATTLE -- There's currently 31 million pounds of material holding up the 520 Bridge, and there are a range of ideas for what should be done with that material when the new bridge opens.

Conventional wisdom says the state will make some kind of pier or dock, or else crush the concrete and re-use it, but one woman tapped into some creative minds and now she has some other ideas.

The massive pontoons were put in place more than 50 years ago to make the bridge float. New pontoons have floated into Lake Washington for the new bridge, but Washington State University architectural student Sara Strouse has a soft spot in her heart for the old structure.

"There's 33 floating pontoons," she said. "They each weigh 9.5 million pounds about."

When the new bridge opens, something will have to be done with those old pontoons, and that's a question Strouse has spent some time pondering.

Her idea was to seek out other ideas. She did that by getting a few sponsors and some prize money and putting together an international competition.

The ideas soon came pouring in. Seventy-three concepts from 18 countries, and some of those are now being shown at the American Institute of Architects.

Imagine a center for the creation of tidal power, or a floating snowflake or a big floating farm on the lake. Other ideas take an apocalyptic turn, like turning the structures into floating boats for human survival in case of a flood of biblical proportions.

The ideas bridged the gap between the practical and the absurd.

"Then they span all the way to cemeteries, and there was even a space elevator," Strouse said. "'A space elevator. Somebody created a dock for a space elevator."

The winner has already been chosen, but Strouse won't say which idea won.

"I can't, but if you want to know you can come tomorrow to the Seattle Design Festival event at 5:30 p.m., and you can hear the winner announced."

Somewhere, somebody is wondering if $3,000 is enough to build an elevator to space.

The judges were a team of architects and artists, and the winning idea will be delivered to KGM, which is the construction company that will ultimately decide what do do with those pontoon.