Sundial Bridge at Turtle Bay
Are you moving around Redding California and don’t know what time is it? Then have a walk over Sundial Bridge and get your answer.
The Sundial Bridge in Redding is one of only two bridges in the United States designed by world-reowned architect Santiago Calatrava. It is a cantilever spar cable-stayed pedestrian bridge that spans the Sacramento River and forms the world’s largest sundial. The 217 foot pylon of the bridge points due north at a cantilevered angle, allows to serve as the gomon of a mammoth sundial that casts its shadow on a large dial plate on the bridge’s north end. The tip of the shadow moves at a speed of approximately one foot per minute, so the Earth’s rotation can be seen with the naked eye! The bridge is over 700 feet long and crosses the river without touching the water. The deck is surfaced with translucent glass which is illuminated from beneath and glows aquamarine at night. This decking casts decrease shadow on the river below and, along with the fully suspended surface, minimize impact on the delicate salmon spawning grounds in the river.
This type of bridge does not balance the forces by using a symmetrical arrangement of cable forces on each side of its support tower, instead, it uses a cantilever tower, set at a 42-degree angle and loaded by a cable which stays on only one side. This design requires that the spar resist bending and torsional forces and that its foundation resists overturning. While this leads to a less structurally efficient structure, the architectural statement is dramatic. The cable stays are not centered on the walkway but instead divide the bridge into a major and minor path.
The cable for the bridge totals 1,323 meters and was made in England. The dial of the sundial and a small plaza beneath the support tower are decorated with broken white tile from Spain. The bridge’s deck is surfaced with translucent structural glass from Quebec. The steel support structure of the bridge was made in Vancouver and transported in 40-foot (12 meters) sections by truck to Redding.
Project Information :
Architect : Santiago Calatrava
Location : Redding, California, US
Project Year : 2004
- 700 feet long
- 23 feet wide
- 217 feet high (pylon)
Construction Manager : Bob Morrison Jr., S.E./Morrison Structures, Inc.
Inspector : Omni Means
Project Manager : Margaret Zech
General Contractor : Kiewit Pacific Co.
Steel Fabricator : Universal Structural, Inc
Steel Detailers : Tensor Engineering
Erection Engineers : Buckland and Taylor