Molybdenum and its applications
Molybdenum containing stainless steel spire graces Dublin
By: C. Houska
A graceful, slender 120-meter (394 ft) high silver spire rises from the center of Dublin. It towers over neighboring buildings and has changed the city’s skyline. The Type 316 stainless steel landmark was completed in late January 2003 and has garnered international attention. Ian Ritchie Architects, London created the design and teamed with Arup’s structural engineers to make it a reality.
The spire is officially called the O’Connell Street Monument. It is three meters (10 ft) in diameter at the base and tapers to only 152 millimeters (6 in) in diameter at the top. The spire is hollow with wall thickness ranging from 35-mm (1.4 in) at the base to 10-mm (0.4 in) at the top.
The Dublin spire rises 120 meters (394 feet) high over the city. Photo: Ian Richie Architects
Ian Ritchie Architects took full advantage of stainless steel’s aesthetic appeal. The highly polished finish sparkles day and night. At night, light shines through 11,884, 15-mm (0.6 in) perforations to illuminate the top 12 meters (39 feet) of the monument.
The project used 126 tonnes of Type 316 stainless steel or about 2.5 tonnes of molybdenum. Type 316 was selected for its superior corrosion resistance in this coastal city. The smooth finish will enhance corrosion resistance and minimize dirt accumulation over time.
The pattern around the base of the Spire has been applied by bead blasting and is based on a core sample of the rock formation at the site. Photo: Ian Richie Architects
Construction required an international effort. The plate was polished in France, rolled into cylinders in Scotland, and trimmed and welded in Ireland. German flanges hold the three sections together, and the damper used to minimize swaying is from Canada.
The top third of the spire is being lifted in place. Photo: Ian Richie Architects
The top of the spire is illuminated at night. Photo: Ian Richie Architects