2. NORTH QUAY
SOUTH QUAY
DUBLIN DOCKLANDS
LOCATION - The Samuel Beckett Bridge links the north-side
and south-side of the city of Dublin over the River Liffey.
To the north is the North Wall Quay and to the South is the
Sir John Rogerson's Quay.
(A quay is a structure built parallel to the bank of a
waterway for use as a landing place).
3. CONCEPT - The Bridge was designed with the aim of being a statement of ambition for
the area, rejuvenating the north and south sides of the river as well as forging a new link
between the affluent south and less affluent north.
It is a landmark, the dramatic shape of the bridge resembles the Irish harp, a symbol for
its secularity.
TIME FOR CONSTRUCTION - May 2007 to December 2009.
DESIGN - The bridge has been designed by Santiago Calatrava who also designed the
James Joyce Bridge which is further upstream.
TYPE OF BRIDGE - The bridge is a cable-stayed, steel box girder structure with a span of The design for the bridge was influenced by
120 metres between north and south quay walls, and is 48 metres high. the Irish harp
SPECIFICATIONS -
•The bridge has four traffic lanes, with cycle tracks and footpaths on either side.
• It is also be capable of opening through an angle of 90 degrees allowing ships to pass
through.
FINANCE - The total cost of the project was estimated at € 60 million, which will also
include a major upgrade of the approach roads.
The project is being funded by the Department of the Environment, Heritage and Local
Government, the Dublin Docklands Development Authority and Dublin City Council.
The Bridge steel superstructure travelled from Rotterdam by
barge following its fabrication.
4. BASIC TYPES OF BRIDGES
CABLE-STAYED CANTILEVER BRIDGE
Beam Bridge These differ from suspension bridges in the following ways:
• There is no single suspender cable
• The suspension cables are attached to the tower(s) and to the deck and
are not vertical
• The deck is attached to the tower(s)
Simple Cantilever Bridge • There may be only a single tower or pylon.
Suspension Bridge
•Used when a large distance, such as a river or estuary, has to be
bridged in a single span.
• Typically two large supporting cables (called ‘suspenders’) are
anchored at each side and fixed to the tops of the towers.
• The rest of the structure is suspended from these two cables. Typical Cable-stayed cantilever bridge
Samuel Beckett bridge
A typical suspension bridge
5. BASICS OF THE CABLE-
STAYED BRIDGE
• A cable-stayed bridge can be
constructed using just one tower.
• The tower is usually placed in
the middle of the river The
weight of one side of the bridge
would balance the weight of the
other side.
• Cables run from the tower to
the road deck.
The Samuel Beckett Bridge
Forces from the cable transferred downwards, to
the support of the bridge.
Cantilever bridge The forces on either side of the support
are still not balanced
The support itself is tilted, and cables are
added on the other side to balance the
Cable pulls up the cantilever forces.
6. •The Samuel Beckett Bridge has a span of 120 metres.
•Its single support is 28 m from the South quay and the bridge can be turned through 90° to facilitate marine traffic.
The Structure of the Samuel Beckett Bridge
•The bridge deck has a box-girder structure which provides rigidity.
•The load is transferred and dissipated (spread) throughout the structure of the bridge deck and into the cable-stays.
•The cable-stays are in tension and the load is transferred to the pylon which in turn transfers the load to the bridge’s foundation, and in
turn to the ground.
•The pylon is in compression.
9. Balance
•In the case of a structure that rotates around a single
support it is desirable to eliminate unbalanced forces.
•This is usually done by adding a suitable counterweight.
The shorter end of the Samuel Beckett Bridge has almost
2500 tonnes of steel, lead and heavy concrete added to it
so that the centre of gravity of the whole structure is
directly above the pivot.
•The bridge is then in equilibrium.
Rotating a Bridge Rotating around one end
A swing bridge rotates horizontally about a vertical axis. A
braking system is required to slow the rate of rotation and
bring the bridge to rest at specified points.
Rotating Balanced Structures
The structure on top is unbalanced.
A balanced structure could be made:
• by moving the axis of rotation to
the centre, or
• by adding a counterweight while
maintaining the same overall
length as shown in the diagram.
The power required to rotate these
structures would be considerably Rotating balanced structures
less– and because they are both balanced there would be
relatively little rotational force on the bridge support.
