Boyne bridge adds to areas historical legacy
Published 16/05/2003 | 00:11
STANDING more than 300 feet above the River Boyne, Droghedas record-breaking cable stay bridge will undoubtedly be a valued modern day structure complementing centuries of local history that surround it.
Once opened, motorists passing over the bridge will look east to Drogheda’s other record breaking bridge, the 150-year-old Boyne aqueduct.
The town is now flanked on both sides by the products of past and present engineering supremacy.
The suspension bridge, valued at ?33m, is the culmination of three years of construction work, 17,500 cubic metres of concrete, 2,360 tonnes of steel, 56 separate protected suspension cables and thousands of man hours.
Workers from a variety of countries including Ireland, England, Wales, Spain and Italy made the project truly European while the thousands of assorted materials came from countries across the globe.
The symmetric cable stay structure is the largest of its kind in the country and has been hailed as a substantial architectural achievement.
Having begun in May 2000, the bridge is due to open this June to accept four lanes of traffic along its 350 metre span as Drogheda’s by-pass re-routes thousands of vehicles between Dublin and Belfast.
At night it will be illuminated with 150 and 250 watt lamps projecting a strong blue light up the cable stays and main inverted Y structure.
A fine white line of fibre optics will illuminate the entire length of the bridge.
Its lighting designers, English based-company Lightmatters, were responsible for lighting Rotterdam’s famous Erasmus Bridge and Dublin’s Millennium footbridge.
This fantastic spectacle, sitting impressively above the sprawling natural habitat of the Boyne Valley, is expected to initially attract hundreds of sight seers eager to catch a glimpse of this impressive monument to modern day architecture.
Climbing the new Boyne bridge is no easy task. Some 550 steps line the bare interior walls of the structure. Approximately 16 ladders, each at 6 metres in height, combine to make up about a 20 minute vertical climb.
These ladders were constantly tackled by construction workers as the bridge was slowly pieced together. However, while they may have become accustomed to the steep and tiring climb, the roof’s impressive panoramic views of Drogheda and its surrounding environs will never fail to leave an impression.
The project, under the auspices of Meath County Council, is a joint venture between Irish construction giants SIAC and the English Cleveland Bridge Company that have erected similarly imposing suspension bridges throughout the world.
Its design was chosen with regard to the protection of the area’s natural environment. Its decking was carefully extended out across the river with stringent efforts made to respect and protect the delicate wildlife habitat below.
Naturally, constructing such a monumental feat of engineering was not going to come without its problems.
Designers and construction workers alike were forced to combat a series of problems along the way including uneven land heights on either side of the river, environmental sensitivity, in particular the reed beds and Yellow Island, while large foundations could not be put down in Drogheda’s historical Battle of the Boyne site.
With its situation high above the river, cross winds, potentially dangerous to high-sided vehicles, were also an important element of the bridge’s design. With this in mind the engineers provided transparent wind-shielding which protect but allow impressive views on both sides of the bridge.
During its lengthy construction strict safety procedures were implemented. All workers and visitors to the bridge must undergo safety de-briefing and strict rules govern the site. An inflatable launch awaits in the river below in case of emergencies.
Although it will only initially cater for two lanes of traffic in either direction, engineers have also taken into account increasing national traffic figures and the capacity is there to widen the surface for a total of six lanes when required.
The deck is a made of a revolutionary composite steel and concrete. As steel, exposed to the elements, requires regular repainting the structure is enclosed by glass-reinforced plastic.
Although the ongoing tolls issue has continued to provoke controversy in Drogheda, engineers on the bridge feel that this remarkable achievement is at least value for money. While tolling may be contentious, it is the opinion of many of the bridge’s staff that commuters are set to benefit immensely from the time efficiency and comfort of the newly constructed by-pass.
There can be no doubt that Drogheda’s rich and impressive architectural legacy has been strengthened by this new structure. Not just a visual attribute, the Boyne cable stay bridge is a reminder of the town’s infrastructural strength, vibrancy and future economic stability.