A technical cocktail

Water, electronics and glass are not commonly found together in close proximity, but this year’s Bombay Sapphire Designer Glass grand winner, artist Jaume Plensa, unites them in his Crown Fountain in Chicago.

The fountain is made up of two 50 foot illuminated glass towers covered in falling water, which flows into a large shallow lake between the facing towers.

LED displays behind the glass block walls inside the towers show faces of 1,000 Chicago residents through the water.

At intervals a projected resident’s face spouts water like a gargoyle into the shallow pool. The image then disappears as water cascades down all sides of the towers.

Spanish artist Jaume Plensa's vision presented technical, fabrication and aesthetic challenges for the designers and engineers.

The team, lead by US architects Krueck & Sexton, developed innovative solutions, combining glass blocks, LED display technology and flowing water.

One of the first challenges was to find a manufacturer capable of producing glass blocks thin enough that they would not distort the images produced by the 24 x 49 foot LED displays behind them. The artist had found a European fabricator who could do this, however, the project team wanted to use a more cost-effective US supplier.

With input from the project leaders, L.E. Smith Glass Co. produced 22,000 5 x 10 x 2 inch blocks that resemble glass tiles or bricks. Glass blocks with LEDs behind them are clear, while the rest are textured.

Another challenge was engineering components to withstand Chicago’s cold, windy winters as well as providing interior access for maintenance and repairs.

For the towers a stainless steel T-bar grid was used to absorb the weight of the blocks and inner workings.

About 150 ‘outriggers’ or ‘tiebacks’ were inserted through the video wall to hold the blocks in place as well as absorbing wind pressure. Individual blocks can be removed for cleaning or repair without disrupting the display, although filtered air inside the towers reduces the need for cleaning.

For the ‘gargoyle’ feature, where the faces on the two screens spout water, the team did not want pipes to protrude from the towers. They also didn’t want to remove LEDs in the mouth area because it would have looked like the face had missing teeth. So, the team recessed one LED tile in each tower back about 6 inches and installed 1 inch clear tubing for the water feature.