Base creates world-class tensile fabric entrance to Heathrow Terminal 5
“Heathrow Terminal 5 was a wonderful experience, not only providing Base with an opportunity to establish ourselves as a leading UK tensile fabric sub-contractor, but also to demonstrate the high quality results that can be achieved with complex and challenging landmark projects.”
Mark Smith, Director, Base Structures
The Team
Andy Dearman, Architect, Pascall and Watson Architects
Paul Yates, Laing O’Rourke
Mark Randerson, SH Structures
Mark Smith, Project Manager, Base Structures
Duncan Baird, Site Supervisor, Base Structures
Project highlights
• Terminal 5 is the newest terminal in the world’s busiest airport
• The client, BAA, is part of one of the largest transport companies in the world
• Over 4000sqm of tensile fabric
• Dramatic bespoke lighting scheme
• PTFE coated glass cloth – high translucency, excellent fire rating, superior strength
The background
The Terminal 5 complex at Heathrow Airport is one of the most successful and iconic airport terminals in the United Kingdom, serving the busiest airport in the world. The terminal is exclusively used as the global hub of British Airways, handling 30 million passengers a year and includes the largest free-standing structure in the United Kingdom, able to fit nearly fifty football pitches across it’s five floors. To be able to handle such an enormous volume of passengers efficiently, the state-of-the-art check-in hall boasts the largest baggage handling system in the world with around 18km of conveyor belts and over one hundred shops and restaurants. The complex building program was the largest construction project in Europe and included three terminal buildings, 60 aircraft stands, control tower, railway and underground train extensions, a 4,000 space multi-storey car park and a 600 bed hotel.
The brief
Base Structures were commissioned to design, manufacture and install the departures tensile canopy scheme, one that would provide a truly stunning entrance to the new terminal. As one of the first areas of Terminal 5 encountered by passengers, it was absolutely essential that we created a world class structure that made an exceptional first impression.
The solution
The project consisted of over 4000sqm of PTFE tensile fabric canopies that extended the whole length of the set down lanes at the terminal entrance. Additional canopies in the package included the car park entrance structures that reflected the main scheme. The eye-catching design utilises several series of a twisted hypar arrangement tensioned on an architectural steel frame, the sweeping undulations of fabric serving not only as shelter for passengers underneath but also as an outstanding architectural flourish to the terminal building.
A major contribution to Base Structures winning this tender was by partnering with a well respected steel fabricator from the beginning of the project. As the value of the steel exceeded the fabric content a more competitive price was achieved by having the steel fabricator as the lead contractor.
Specialist Skills
PTFE fabric was chosen instead of PVC to bring a number of benefits including increased translucency, higher strength, improved fire rating and a lower susceptibility to dirt. Being far more difficult to manufacture and install than PVC however required specialist skills to ensure the longevity of the structure was not compromised; poorly manufactured and installed PTFE will quickly fail. The accuracy and quality of the design, manufacture and installation are critical to the success of this material; when all these disciplines combine successfully PTFE has an exceptional life span as a tensile fabric.
A Bright Idea
The high translucency of PTFE was exploited as much as possible; during the day a high level of natural light transmission allows bright, diffused natural lighting to filter through the canopies from above, whilst at night bespoke lighting illuminates the canopies from underneath, transforming them into an entirely new visual form. Base Structures worked closely with Light Bureau who helped to design and supply the functional and feature lighting, entrusting us to install the equipment on site. Up-lighting onto the canopies from below created a high level of indirect, diffused illumination thrown onto the walkways underneath. The lighting scheme design cleverly utilises the form and shape of the canopies to ensure an even distribution of light onto the walkways to predefined LUX levels. Compact street light luminaires were also specially designed to be concealed into the end of each boom arm that supports the tensile fabric, discretely lighting up the roadway.
Careful Co-ordination
As well as supply and fit of the fabric membrane Base were also responsible for installing the steelwork, fitting steel cladding to the lighting arms, installing bespoke lighting equipment and co-ordinating all works on site. Our installation team were working on-site continuously for eighteen months, finally culminating in a seventeen man team for the last six months to ensure we could bring the project in on time.
The installation went smoothly across the board but the PTFE canopy did create it’s own technical difficulties to be overcome; because it cannot be folded or creased whole sections of canopy had to be hoisted up using massive 22 meter wide Spreader Beams lifted by a 100 tonne crane. Using such specialist machinery ensured that the final quality of the fabric canopy was not compromised. The principal challenge on this project proved to be the site operations, working under overall direction of Laing O’Rourke required careful coordination of deliveries and notifications to ensure a smooth work flow and minimal delays. This project also brought in a huge improvement to health and safety regulations; being the largest building site in Europe meant a raising of the bar in standards that has continued to develop further through to the London 2012 Games building works, when the standards have been raised once more.
The results
The execution of the manufacture and installation reflected the high quality of the design and the expectations for the gateway to be the country’s new showcase terminal. The project was completed in plenty of time for the official opening of Terminal 5 by the Queen on 14th March 2008, finally opening to the public on 27th March 2008.