Pylons of Cádiz

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Cádiz Pylon

The Pylons of Cádiz, also known as the Towers of Cádiz, are two tall pylons supporting two 132 kV three-phase AC powerlines crossing the bay of Cádiz, Spain, from a large substation at Puerto Real to the Térmica substation situated on the peninsula upon which the city of Cádiz stands. (To be more precise, the Puerto Real pylon stands in the Matagorda quarter near the commercial wharves, and the Cádiz pylon is near Fort Puntales and the Puntales Naval Station.)

The pylons of Cádiz, averaging 158 metres in height, handle two electrical circuits. They were conceived and designed by the Italian engineer, Alberto Toscano, and they are of a very unconventional construction.

Towers of Cádiz, 2006

Each is a hollow mast resembling a truncated cone (or frustum). The frustum tapers from a base 20.7 metres in diameter to a crown six metres in diameter. The towers rest on reinforced concrete plinths, and they are crowned by transverse members (or crosspieces), rhomboid in profile, that hold the insulators and maintain the high tension of the lines suspended between them. The towers are assembled from galvanized steel components that form, using vertical, horizontal, and diagonal members, a network (or graticule) of rhombuses enclosed within rectangles. Inside the steel framework, a helical staircase ascends to the top crosspiece.

The overall effect is as aethetically pleasing as it is functional. In this respect, the towers bear a superficial resemblance to the Eiffel Tower in Paris.

This unconventional mode of construction was chosen because Spanish steel mills were unable to produce massive steel carriers at the time, and importing such carriers was impossible because of the Francisco Franco regime.

The construction was carried out under the supervision and direction of Remo Scalla, a close friend of Alberto Toscana. The same team of Toscana, the designer, and Scalla, the builder, also joined forces in building the structures supporting the lines that span the Strait of Messina, between Calabria, on the mainland of Italy, and the island of Sicily. The Cádiz project started during the latter part of 1957 and concluded in 1960. Upon completion, the towers were acquired by the Spanish National Institute of Industry.

Hyperboloid pylons of similar design by V. G. Shukhov can be seen on the Oka River near Nizhniy Novgorod, Russia.

[edit] Images

Towers of Cádiz, 1958	Towers of Cádiz, 1959	Towers of Cádiz, 1960	Towers of Cádiz, 1960, Fort Puntales
Tower elevator	Inside view	Inside view	Construction
Tending the lines	Line work	Remo Scalla, center	Making and tending lines
A true "high-wire act"	Inaugural party	Inaugural party	Matagorda site with Fort Puntales in the background
Close-up of the Fort Puntales tower, 2001	Puntales tower site, from the city of Cádiz	Towers of Cádiz, 2006	Drawing of Cádiz pylon, demonstrating its structure