Multinational effort needed to put it in its place

The creation of the Spire of Dublin was a multinational operation, with contributions by France, Germany, Canada, the UK and, of course, Ireland.

Most of the 126 tonnes of stainless steel were milled and polished in France, rolled into "tapering half-cylinders" in Scotland, and trimmed and welded into spire sections by Radley Engineering in Dungarvan, Co Waterford.

The flanges connecting the sections came from Germany, while the two-tonne "damper" that minimises the spire's sway is Canadian in origin.

At 120 metres, the spire is seven times the height of the nearby GPO, but at its widest the diameter is a mere three metres, tapering to six inches at the top.

The cone is hollow, with the thickness of the steel plate also narrowing as it climbs, from 35 mm at the base to 10 mm at the apex.

The light diffusing from the top 12 metres of the structure will do so through 11,884 perforations, each 15 mm in diameter.

Erection required nine concrete foundation piles and 204 bolts. The design of the spire, by Ian Ritchie Architects, was British, as was the firm which erected the monument, GDW Engineering.

The cranage was Irish, provided by Monaghan and Dublin firm McNally's. With a lifting capacity of 1,000 tonnes and a 180 metre jib length, the main crane used on the project is currently the largest operating in Europe.

According to a company spokesman, its applications in Ireland are "few and far between", but it has recently worked on fitting out an oil rig in Harland and Woolf Belfast, and its next job will be on a wind farm in Sligo.

Two smaller "slave" cranes also operated on the O'Connell Street site.

Crowned by a red aircraft-warning light, the top of the spire is designed to sway in the wind by up to 1.5 metres. Below the luminous tip, the structure is designed to reflect the changing light of the sky and requires minimum maintenance.

Transporting elements of the Spire was a precarious business given the length, width, height and weight of the sections. Special permits were required from seven local authorities along the route from Co Waterford to O'Connell Street. The heaviest section weighed 42 tonnes.