The iconic Samuel Beckett Bridge, built by GRAHAM Hollandia Joint Venture, was opened on 10th December by the Lord Mayor of Dublin, Councillor Emer Costello. The gala ceremony saw the Dublin City Council Mayor drive over the 125m long cable-stayed bridge. The opening was the culmination of 30 months of construction, resulting in the bridge being opened on time.
The €40m Samuel Beckett Bridge is the latest addition to Dublin’s impressive inventory of Liffey bridges. Located in the heart of Dublin’s docklands it provides a valuable new link between the north and south quays in the area. The iconic structure was commissioned by Dublin City Council and designed by the internationally acclaimed artist, architect and engineer Santiago Calatrava.
The concept for the bridge came from Calatrava’s glance at the harp on the back of an Irish coin, leading him to be inspired to design a bridge that reflected the shape of the national emblem. Its curved pylon produces a dramatic shape giving the appearance of a harp lying on its side. The structure is a magnificent paradox of slenderness and strength that embellishes the cityscape, particularly when it is illumi¬nated against the night sky. The cable stay bridge is unique in Ireland as it is capable of rotating through an angle of 90 degrees to accom¬modate occasional maritime traffic.
Alan Bill, Managing Director of John Graham (Dromore) Ltd and GRAHAM Projects Ltd said: “GRAHAM are delighted to be involved in this fascinating project. It gives us an opportunity to further add to our excellent and long established bridge building portfolio, by successfully completing this magnificent Calatrava project on programme and playing a major part in creating a landmark structure in Dublin City centre”.
Dublin City Council Engineer Michael Phillips believes the bridge’s design is something that will impress Dubliners and visitors. “The bridge is a stunning piece of design and engineering. It’s cable-stayed bridge – which gives it a graceful, almost weightless appearance. Its position across the Liffey at Dublin’s maritime gateway sends a confident, forward-looking statement about today’s Dublin”.
Its Origins
The construction of Samuel Beckett Bridge is part of an overall plan to remove through traffic from the City centre. The proposal had been developed, in accordance with central and local government policies, to improve the road network in the inner city east of O’Connell Street.
The bridge is intended to:
• facilitate the regeneration of the north and south docklands;
• provide an important pedestrian and cycle crossing facility;
• accommodate bus priority and a future Luas line across the Liffey;
• facilitate the implementation of the network of environmental traffic cells in Dublin City centre;
• improve traffic circulation, public transport and the pedestrian environment in the City centre.
The design brief for the bridge sought to achieve a landmark structure of unmistakable modernity of unique character.
The Construction Process
The project began with the construction of the reinforced concrete abutments on each quay wall, and the support pier in the River Liffey. A large sheet piled cofferdam was constructed in the river to enable the pier to be built. The main support pier and both abut¬ments at the quay walls rest on piles bored, up to twenty metres deep, creating a firm footing in the limestone rock under the river bed.
The steel bridge superstructure was fabricated off-site and transported fully assembled by barge. Construction began in Rotterdam, Holland in May 2007 and involved the assembly of 8 steel bridge sections to create a 123 metre deck span. A 46 metre high steel curved pylon was fabricated and connected to the deck and 25 forestay and 6 backstay cables were installed to create the main superstructure.
The superstructure, weighing approximately 2,500 tonnes, was trans¬ported to Dublin on a large barge in May 2009. The barge’s journey, from Rotterdam to Dublin, was carefully monitored throughout its 628 mile journey, which took approximately 8 days, during which this remarkable shipment was forced to shelter from high winds.
Once on-site, counter ballast, in the form of heavy weight concrete, was added to sections of the backspan to evenly balance the super¬structure before mounting it on the support pier. The superstructure was suspended above the main pier and engineers used the receding tide to lower it into position. The barge was then removed and the superstructure balanced with its centre of gravity over the support pier. Once in position the final ‘tuning’ ballast, in the form of steel blocks, was installed and the cable-stays were tensioned so that the super¬structure, now weighing 5,700 tonnes, was balanced precisely before it was rotated into its closed position.
A high specification, copper-roofed, control room building was constructed on Sir John Rogerson’s Quay. This is linked, via ducts placed along the river bed, to the bridge’s hydraulic rotational mecha-nism housed in the main support pier.
Pictured above: Dr Santiago Calatrava, Designer of the Bridge with Alan Bill, MD - Construction, GRAHAM and the Project Team.