Dublin Airport, one of Europe’s fastest-growing connectivity hubs, continues to prepare for the future with the construction of a new visual control tower that, together with a new runway, will help with airspace management and traffic flow.
At nearly 87m high, the visual control tower will be a commanding new addition to the city’s skyline, becoming the country’s tallest occupied structure upon completion.
The tower, a key element in complex high-traffic airports, was designed as a slim, elegant structure offering clear sight lines of both the current and future runways. Arup carried out the civil, structural, mechanical and electrical engineering; and also provided environmental, lighting and façade consultancy services, bringing the project from concept to construction stage.
Salam Al-Sabah, Associate and Chartered Structural Engineer at Arup, commented, “The tower’s dynamic design is an essential element towards achieving the required overall performance. The design solution of this dynamically wind-sensitive structure was achieved through close collaboration of the structural, geotechnical and wind teams working together to attain an elegant solution.”
The new visual control tower will be ready to provide single runway operation during the first half of 2020, transitioning to provide parallel runway operations by 2021, when the new runway becomes operational.
86.9 m high tower
>11,000 tonnesof concrete poured during the tower construction phase
35tonnetuned mass dampers reduce wind induced vibrations
Designing for the needs of air traffic controllers
Visual Air Traffic Control towers are an airport’s central processing hub, a piece of critical safety infrastructure to ensure that aircrafts move seamlessly through an airport. The height of the new tower ensures appropriate visibility of runways, thresholds, manoeuvring areas and stands. The needs of the air traffic controllers were a key consideration during the design, with a view to aiding concentration by ensuring maximum comfort and reducing potential distractions.
Given the height of the tower, minimising wind-induced vibrations was a crucial aspect of the design. Arup engineers carried out a series of wind tunnel tests to determine the specifications for the two tuned mass dampers (TMD). A TMD is a large mass of steel inside the tower designed to absorb vibration energy. It is tuned to vibrate at the same frequency as the structure, reducing the sway of the tower and creating a positive work environment for air traffic controllers.
We have enjoyed the opportunity to cater for the unique challenges of designing such a tall, slender building. Reducing the wind induced vibrations for this important piece of national infrastructure was a vital part of our involvement. ” Sean Barrett Associate | Structures
Early-stage environmental considerations
We also undertook the Environmental Impact Statement (EIS) for the tower, ensuring that the environmental impact was considered from an early stage. The EIS was submitted for planning under the Strategic Infrastructure Act and covered aspects such as visual impact, flora and fauna and policy and planning. Planning was successfully granted by An Bord Pleanála in 2010.
Solving unique design challenges
In order to manage the risks posed by local ground conditions, Arup provided full-time supervision, giving visual confirmation of the rock socket and carrying out verticality and integrity tests. There is a fluvio-glacial channel within the tower’s footprint, with the site also sitting within a zone of variable underlying rock.
Slipform concrete core construction was used for the tower, whereby the concrete is poured in a continuously moving form 24/7. We designed the tower to take into consideration the necessary techniques when constructing high-rise buildings. Over 11,000 tonnes of concrete were poured during the construction of the tower. Slip forming is not a common method of construction in Ireland but is incredibly beneficial for tall buildings.