In anticipation of the communications requirements of the 1992 Olympic Games, Barcelona was facing an explosion of transmission masts on the Tibidabo mountainside. Sensing the environmental impact this would have, Mayor Pasqual Maragall decided that the communications and broadcasting infrastructure for the entire region should be coordinated. He convinced the three primary players - national and Catalan television and Telefonica - to build a shared telecommunications tower. The competition brief posed the problem as a balancing act between operational requirements and the desire for a technological symbol. The solution reinvents the telecommunications tower from first principles.
A conventional reinforced-concrete tower would have required a shaft with a 25-metre-diameter base in order to achieve the 288-metre height required. Following an analysis of precedents, including suspension bridges and shipbuilding techniques, an entirely new structural concept emerged: a hybrid concrete and steel-braced tube, with a base diameter of only 4.5 metres, which minimises the towers impact on the mountainside. In order to meet a construction programme of just twenty-four months the construction of shaft, mast and equipment decks was overlapped. As the shaft was poured, the steel-framed decks and public viewing platform were assembled on the ground ready to be jacked, inch by inch, into position.
In a final flourish, the steel radio mast was telescoped inside the hollow shaft.
The equipment decks are suspended from the shaft by three primary trusses and braced by Kevlar cables, which are transparent to broadcasting signals. Equipment is installed or removed by lift, and a crane at the top of the mast hoists antennae into place. Inherent flexibility ensures that the tower is able to respond to a rapidly evolving telecommunications future.
“The tower is basically an exercise in minimalism, as different from the ‘chimney’ towers of the 1960s as is the electronic world of the 1990s from the age of black and white television and room-size computers.”Kenneth Powell, Blueprint extra 6, 1992
“The form of the tower is a revolutionary response to its site and function. But more importantly it is perceived as a three-dimensional sculpture. In that sense it has become a popular and enduring symbol for the cit of Barcelona.” Norman Foster
“The tower visually links the ancient heart of the city and its far flung suburbs, and the mastery of advanced construction technique that it displays seems appropriate in the symbolic pivot of a community determined to approach the future with optimism.”John Pink, The Architectural Review, August 1992
Construction start: 1990
Area: 5 800 m²
Height: 288 m
Client: Torre de Collserola SA
Structural Engineer: Arup
Quantity Surveyor: Davis Langdon