Structure masts support large PTFE sails

Span Systems Inc. | Manchester, N.H., United States

The project, which won an Outstanding Achievement Award in the architectural structures category of the 2008 International Achievement Awards, consists of two large porte cocheres, one at each major entrance to the new facility, the Twin River Entertainment Complex, Lincoln, R.I. Both structures have three large masts supporting a pair of large PTFE fabric sails, and each entrance has six sails. The concept sounded simple, with three requirements: have large sails at the two main entrances to provide high impact way-finding; mimic the sails used as the state of Rhode Island’s logo (one of the owners of the facility) and be striking, modern and light. The client’s requirements, combined with the potential of very high wind and snow loads, made for a unique design challenge. These sails achieve a billowed form through a system of outer frames, curved ribs for shape, and bracing to connect sails to the mast and roof. The challenges were huge. All the steel was curved, making the “fish-mouth” connections of this size difficult to execute. The quality of the steel finishing and the fabric fixed edge needed to be perfect. The masts are topped with nautical beacons and the sails are up-lit from the roof providing “way-finding” day and night.