Sir, - I refer to the concern expressed by David Reddy (June 8th) about lightning striking the "Spire of Dublin".
The slender, stainless steel monument, 120 meters high, has been designed by Ian Ritchie architects and Arup engineers in accordance with the relevant codes and standards to safely conduct lightning to earth. The spire will be supported in the ground by a circular array of concrete piles which extend down to the bedrock some 14 metres below O'Connell Street. The steel reinforcement within the piles is linked to the spire and has been designed to safely conduct lightning current to earth.
If the spire is struck by lightning, the downward current will follow the easiest path through the foundation steel to earth. This will leave pedestrians standing near or touching the spire unaffected by the lightning. The bronze surround to the monument at pavement level is separately earthed
I trust that this clarifies some of the issues relating to this important civic and structurally complex project. - Yours, etc.,
ANNE GRAHAM, Project Manager, O'Connell Street Integrated Area Plan, Civic Offices, Dublin 8.