Day 80/365 of Steel – Torre de Collserola

The Torre de Collserola telecommunications complex entered into service on June 27, 1992.

Torre de Collserola is located on the Tibidabo hill in the Serra de Collserola, in Barcelona. It was designed by Sir Norman Foster and by the Spanish civil engineers Julio Martínez Calzón and Manuel Julià Vilardell. This emblematic tower was built in 1991 for the 1992 Summer Olympics. It features a pod for floor space like many towers but uses guy wires for lateral support like a mast. Mainly used as a TV and radio transmitter, this futuristic design provides the highest viewpoint over the city. The top antenna reaches 288m and the top of the pod, which has thirteen floors, reaches 152 m.

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 program 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 steel 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. 

About the Author:

Bruno Dursin – Managing Director at Believe in Steel. Bruno has more than 30 years of experience in promoting steel & steel solutions. His clients benefit from his extensive network within the building industry.

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