The only piece of curved glass in Swiss Re's landmark headquarters at 30 St Mary Axe was successfully installed last week. The lens was lifted into place at the apex of the 180 m building from within the dome and placed into position with the assistance of abseilers. Measuring 2.4 m in diameter and weighing 250 kg, the lens is the topmost element of the 24,000 m2 of glass cladding in the building. The tower designed by Foster and Partners with Skanska as lead contractor.