- The work was completed ahead of schedule and involved some thirty technicians specialised in working at heights and in the use of specialised machinery.
- Now in service, the new cable was specially manufactured for these towers and is made of an alloy that is resistant to the stresses exerted by the distance between the two towers and the inclement weather in the area.
- A total of 14,928 metres of cabling were replaced with a total investment of €700,000.
Earlier today, Endesa completed the electrical connection of the new cabling for the Cadiz Bay towers after replacing 14,928 metres of old cabling that had been in service for 40 years but is now reaching the end of its useful life.
Now in service, the new cable was specially manufactured for these two unique towers in the industrial engineering panorama and is made of a special alloy created by the company Trefinasa from Navarre. The steel-core alloy was designed to withstand the strain of the 1.6 kilometre distance between the two towers at a height of 150 metres. These parameters combined with the local climate mean that they have a useful life of 40 years, which makes their replacement a real challenge.
Part of the old wiring is already being analysed by a team of experts, as the information extracted from it will not only be of use to Endesa in another 40 years' time when the conductors have to be replaced, but will also serve as a study in engineering universities where these towers, their construction and their operation are still an example.
“Fresh energy now runs through the Cadiz Bay towers via these new cables, constituting a record replacement time by a 30-person team that included Endesa workers and engineers, together with AMETEL, a company with international experience that assisted in executing the work”, explained Jose Manuel Revuelta, managing director of Redes de Endesa, which delivered a presentation on the completion of the works today, He concluded by saying that “this project is an example of the application of the latest technology and innovation in the distribution network that we are implementing throughout our electricity infrastructure to provide a more resilient network adapted to today's needs”.
Executed work
The Cadiz Bay towers are linked by two 132 kV circuits, each comprising three cables spanning 2,488 metres, which is why the work was divided into two phases: one for each circuit, so that while the three cables on one circuit were being replaced, the other continued operating, thus guaranteeing the Cadiz electricity supply.
Specialised machinery was used to undertake this work, which began on 2 November, and placed on the gantries of each tower, a concrete structure that not only maintains the tension of the cables, but also connects them to the substation from which they are supplied with energy.
The heavy machinery used was a brake or braking machine and the coils of the new cables that were placed in the Cadiz Free Trade Zone, where the Pórtico San José gantry is located. The pulling motor or winch was installed on the opposite side at the Pórtico Cabezuela gantry in Puerto Real to collect the old cable. The two machines located on either side of the bay were secured by 8.5 tonne anchors capable of withstanding the tension exerted by the cables.
At a height of 150 metres, the technicians removed the insulator chains to place the pulleys through which first the guide cable and then the new cable passed. This was precisely the moment of greatest tension as it was designed to the millimetre and executed at a height of 150 metres. During this phase, maritime traffic was suspended for safety reasons.
Once the new cable was laid, the insulators and dampers were reinstalled to overcome the vibrations caused by the intense winds in the area. These elements were also manufactured in Spain. The glass insulators are manufactured by the Segovian company Saint Gobain La Granja, while the dampers come from the Navarrese company Saprem.
Information dossier with more details at this link
About Endesa
Endesa is the largest electricity company in Spain and the second largest in Portugal. The company is also the second largest gas operator in the Spanish market. Endesa operates an end-to-end generation, distribution and marketing business. Through Endesa X it also offers value-added services aimed at the electrification of energy use in homes, companies, industries and Public Administrations. In addition, it has created a new line of business. Endesa X Way is fully dedicated to electric mobility. Endesa is firmly committed to the United Nations SDGs and strongly supports the development of renewable energies through Enel Green Power España, the digitalisation of grids through e-distribución, and Corporate Social Responsibility (CSR). The Endesa Foundation is also active in CSR-related matters. Our workforce numbers around 9,260 employees. Endesa is a division of Enel, the largest electricity group in Europe.