Galvanized Fermoy Toll Plaza built to last over 100 years

“We specified galvanizing from Galco Steel for the first coat because it was going to be exposed to the elements and it needed protection from de-icing salt. The structure is designed to last 120 years, so we needed a long-life solution – that’s why galvanizing was chosen .”
Tim O’Shea, Engineer, FTC

TRAVELLING down the 17½ km motorway that comprises Cork’s brand new Rathcormac/ Fermoy Bypass, two small satellite toll plazas on each side hint at what’s to come. Eventually, the new white and shining toll plaza comes into view on the horizon.

Each one of the six softly curving, visually striking, galvanized arches is made up of an impressive 8.6 tonnes of steel. The 10 metre high arches are painted a gleaming white for maximum visibility so motorists can see the toll plaza in the distance.

The Bypass scheme began in May 2004 and was completed on time in October 2006, marked by the official launch of the new M8.

The Engineers
The NRA (National Roads Authority) provided an outline design based on the Drogheda Bypass to KBR (Kellog Brown Root) who led the overall design on this public-private partnership project. Fehily Timoney & Company (FTC), an Irish environmental engineering and scientific consultancy, provided the tolling infrastructure design.

FTC’s scope for the main toll plaza and two satellite plazas included designing three landmark canopy structures spanning carriageways, a service/ access underpass, an administration building, 14 toll booths, mechanical/electrical utilities, car park, traffic signs and road markings.

The curved metal-clad canopies, designed to provide protection from bad weather and support for toll signage, are suspended from the galvanized tubular steel arches. Access to the toll booths is provided via galvanized steel stairs.

The Fabricators
Thompson Structures, steel fabrication and erection specialists, is a family firm employing 150 staff.

“We specialise in complex structural steel projects. We work out a programme based on the contractor’s requirements for each project.” Feature projects include Dublin’s Millennium Bridge, the Luas Bridge, the East Link Bridge and Roll-on Roll-off Pontoons.

Fabricating the Fermoy arches
Thompson drew up detailed fabrication drawings based on FTC’s design, using Xsteel drawing software. The main steel cords were rolled and placed into a jig to form the shape of the truss. The infill was gas cut to a development template and fitted between the cords, the pieces were welded using Mig welding, all welding was carried out in position, butt welds were ultrasonic tested and passed. Fillet welds were M.P.I. tested, sections were then sent to Galco for Hot Dip Galvanizing and returned for painting. The curved trusses – six on the main plaza and two each on the remote plazas – were made up of four individual pieces bolted together on site.

They had to use ‘positional welding’ for the trusses, where a welder follows the curve of unusually shaped steel. Tested full-strength butt welds enhanced the strength of the tubular steel.

“I’m very happy with Galco. The quality of their product is excellent. If something is exposed to the elements, hot dip galvanizing extends its life. All the better if it can be galvanized, especially if it’s exposed,” says Christy Kelly, Director.