Dr. N. Subramanian, Consulting Engineer, Gaithersburg, MD, USA

Arcelormittal Orbit
Figure 1: The ArcelorMittal Orbit
The ArcelorMittal Orbit is a 115 m high sculpture and observation tower constructed in the Olympic Park in Stratford, London (Fig. 1). The steel sculpture is Britain's largest piece of public art, and is intended to be a permanent, lasting legacy of London's hosting of the 2012 Summer Olympics, assisting in the post-Olympics regeneration of the Stratford area. Located in between the Olympic Stadium and the Aquatics Centre, it will allow visitors to view the whole Olympic Park from two observation platforms. Designed by one of the world's leading artists, Mr. Anish Kapoor and one of the world's leading structural designers, Mr Cecil Balmond, the Orbit is the tallest sculpture in the UK - twice the height of Nelson's Column (Fig. 2).

The Orbit has two observation floors, a 455-step spiral staircase, a lift and restaurant. At ground level, visitors are greeted by a massive steel horn which hangs overhead. The uppermost observation floor is flanked by two concave mirrors which disorientate the visitor before they get to see the skyline beyond. Visitors will be able to go up the 35-storey structure in a lift. At 114.5, the Orbit gives panoramic views across London's skyline of up to 20 miles. After their visit is over, visitors have the option to descend via the 455 steps that were designed to make the visitors feel as if they were orbiting around the structure. The exterior of the structure is outfitted with 250 colored spotlights. Each can be individually controlled to produce a stunning digital combination of static and animated effects including a 15 minute moving light show every evening after the Games.

Creation of unusual structure

The design was the winning entry to a competition launched by Mr Boris Johnson, the Mayor of London. He wanted to create "something extra" to celebrate London Olympics 2012, which would "arouse the curiosity and wonder of Londoners and visitors." Designers were asked for ideas for an "Olympic tower" at least 100 m high, and Orbit was the unanimous choice from proposals considered by a nine-person advisory panel. From the initial sketch, it has grown into a looping lattice form. The lattice evolved from the need to build the vision and make the concept constructible. Kapoor and Balmond's idea was to 'challenge the idea of tower', so initially it was just a vertical form. It is stabilized by points crossing in space on a tripod base. Daniel Bosia of Arup engineered the overall form.

heights of iconic sculptures
Figure 2: Comparison of heights of iconic sculptures (Source: http://www.e-architect.co.uk)
M/s Ushida Findlay Architects (UFA) was appointed by Arup to realize the architectural elements of the ArcelorMittal Orbit. They are responsible for turning one of the world's tallest sculptures into a 'habitable building'. UFA's most visible contribution to the tower is the emergency stair design. In the initial concept drawings, the external helical stair was purely functional in form, expressing the flights and landings through a transparent enclosure. UFA explored the idea of creating a more sculptural form for the stair, designing a sinuous curve that articulates the visitor journey from the observation deck to ground level. The stair's expanded stainless steel mesh creates a 3-dimensional pattern that changes in opacity depending on the viewing angle and the density of the apertures, which become more open in the upper section of the panels.

Structure of Orbit

The structure of Orbit consists of the following three parts (see Fig. 1):
  • The central tower, which houses the elevators and stairs and supports the observation deck.
  • The open lattice of red steel that surrounds the trunk (Fig.3).
  • The external helical stair
fiberglass composite construction
Figure 3: (a) Concept and (b) actual structure of looping steel lattice around the central tower (van Velzen, 2012)
The central tower has a base diameter of 37 m, reduced to 5 m near the top, and widening again to 9.6 m, just under the observation deck. The trunk is supported and stabilized by the looping lattice tube, which gives a structural character of a tripod to the entire construction. (van Velzen, 2012). Further structural integrity is given to the construction by octagonal steel rings that surround the tube and trunk, spaced at 4 m and cross-joined pairwise by sixteen diagonally mounted steel connectors (van Velzen, 2012).

A special part of the construction is the canopy, the conic shape that hangs off the bottom of the trunk. Originally, it was planned as a fiberglass composite construction. Consideration of cost resulted in the use of steel for this section also. Centraalstaal International, Netherlands was approached as a special consultant for the design of the steel cone and came up with a design for a cone built out of 117 individually shaped steel panels with a total surface area of 586 m2 and weighing 84 tonnes (van Velzen, 2012).

Creators of the ArcelorMittal Orbit

Anish Kapoor

Chicago Millennium Park
Anish Kapoor And Cloud Gate in Chicago’s Millennium Park
One of the world's leading artists, Turner Prize winning Anish Kapoor was born in Bombay, India and studied in London, where he is now based. He is well- known for his use of rich pigment and imposing, yet popular works, such as Marsyas, which filled the Tate's Turbine Hall as part of the Unilever Series, Cloud Gate in Chicago's Millennium Park (popularly known as 'The Bean') and his recent record breaking show at the Royal Academy, the most successful exhibition ever presented by a contemporary artist in London.

Cecil Balmond

Sydney Opera House
Cecil Balmond, a Sri Lankan is a British designer, artist, architect, writer and one of the world's leading structural designers. He has taught at Harvard and Yale and currently holds the Paul Philippe Cret Chair at Penn Design as Professor of Architecture where he is also the founding director of the Non Linear Systems Organization, a material and structural research unit. He was also deputy chairman at Arup (Arup are behind landmark buildings such as the Sydney Opera House, Beijing's Water Cube and the Beijing Olympic Stadium). He is known for his innovative work on some of the greatest contemporary buildings in the world, such as the CCTV building in Beijing, as well as many Serpentine Gallery Pavilion commissions.

sustainable material

Using steel as a sustainable material

Construction of the ArcelorMittal Orbit took 18 months and required 560 m of tubular steel to form the sculpture's lattice superstructure. A four-man team assembled it together, comprising two steel erectors, a crane operator and a site foreman. All of the junctions between the big red bits of steelwork are wild, with unpredictable shapes and members coming in all directions. The result is a bold statement of public art. It is important to note that the tower is both permanent and sustainable, with close to 60% of the 2,000 tonnes of steel used, coming from recycled sources (harnessed from every continent where ArcelorMittal has operations). This tower cum sculpture underlines steel's status as the world's most recyclable material. Steel was chosen for the Orbit because of its unique properties including strength, modular structure, and advantages of weight, speed of construction, and recyclability.

Some Highlights about ArcelorMittal Orbit
  • Tallest sculpture in the U.K.
  • Standing at 115 m, it is 22 m taller than the Statue of Liberty in New York.
  • If the loops around it are flattened out and the tower is made vertical, it will be taller than Eiffel tower in Paris.
  • Provides unparalleled views of the entire 250 acres of the Olympic Park and London's skyline from a special viewing platform.
  • Over 35,000 bolts and 19,000 liters of red paint were used in its construction.
  • Designed by Artist Anish Kapoor and Cecil Balmond
  • Architects : M/s Ushida Findlay Architects
  • ArcelorMittal donated $ 30.7 million and 2000 tons of steel to create it.

Public Opinion about the Orbit

Cecil Balmond said that he and Anish were conscious from the beginning that the ArcelorMittal Orbit would be a lasting legacy to the city and so they wanted to stretch the language of the icon as far they could go. The Orbit is a hybrid, a network of art and structure, and its dynamic is the non-linear. You read into it multiple narratives in space." Towers are almost always symmetrical," he continued, saying the Orbit's twisted loops were "the refusal of a singular image". Kapoor and Balmond believe that Orbit represents a radical advance in the architectural field of combining sculpture and structural engineering, and that it combines both stability, and instability in a work that visitors can engage with and experience via an incorporated spiral walkway.

The design of the Orbit has split opinions since its inception at a chance meeting between London Mayor Boris Johnson and steel magnate Lakshmi Mittal in a cloakroom at the 2009 World Economic Forum in Davos. Critics have described the orbit as "the Eiffel Tower after a nuclear attack" and "a catastrophic collision between two cranes." Oliver Wainwright, from Building Design magazine branded it "a contorted mass of entrails". He objected the way it towers over the stadium, saying that the 2,000-tonne structure compared unfavourably to the lightweight construction of the venues in the Olympic park.

Funding

ArcelorMittal, the sponsor of the tower and the Olympics, is a leading steel manufacturer and provided the material for the sculpture.

It provided £19.2m towards the cost of building the Orbit, with the remaining £3.1m was funded by London Development Agency.

The tower is expected to attract 1 million visitors per year to Stratford's Olympic Park, when it reopens as the Queen Elizabeth Olympic Park after the Games. During the Games, the ticket price is fixed as £15 for adults and £7 for children.

Olympics Tower

About ArcelorMittal

ArcelorMittal is the world's leading steel and mining company. Guided by a philosophy to produce safe, sustainable steel, it is the leading supplier of quality steel products in all major markets including automotive, construction, household appliances and packaging. ArcelorMittal operates in 60 countries and employs about 260,000 people worldwide. Mr. Lakshmi Niwas Mittal (born on 15th June 1950), is the Chairman & CEO of ArcelorMittal and was ranked the sixth richest person in the world by Forbes in 2011. In 2009, ArcelorMittal had revenues of $65.1 billion and crude steel production of 73.2 million tonnes, representing approximately 8 per cent of world steel output.

Future

Eiffel Tower was built as a temporary structure and erected in 1889 as the entrance arch to the 1889 World's Fair. Although, Eiffel Tower was hated by most Parisians and the design was criticized by many at that time, it has now become a global and cultural icon of Paris. One of the most recognizable structures in the world, this tower is the tallest structure in Paris and the most-visited paid monument in the world (7.1 million people ascended it in 2011). Similarly, will the Orbit be acclaimed as the cultural icon of London? Only time can provide the answer!

References:

  1. http://www.london.gov.uk/priorities/art-culture/culture-2012/arcelormittal-orbit
  2. Meinhold, B., "Anish Kapoor's Recycled Steel ArcelorMittal Orbit Tower Provides Views of London's Olympic Park", Inhabitat - Sustainable Design Innovation, 26th July 2012. (http://inhabitat.com/anish-kapoors-recycled-steel-arcelormittal-orbit-tower-now-complete-in-london/arcelormittal-orbit-anish-kapoor-1/?extend=1 Accessed Aug. 1st 2012)
  3. http://www.anishkapoor.com/
  4. http://www.arcelormittalorbit.com/orbits-journey/perspectives/cecil-balmond
  5. http://en.wikipedia.org/wiki/ArcelorMittal_Orbit
  6. Oh, S., Cool Olympic Tower, Modern Steel Construction, Vol.52, No. 8, Aug. 2012, pp. 38-39.
  7. van Velzen, T., Rood icoon (Red icon), (in Dutch). De Ingenieur, Vol. 124, No.10/11, June. 2012, pp. 25-27.
  8. http://en.wikipedia.org/wiki/ArcelorMittal_Orbit