Underground and Undersea: EU Power Line Between France and Spain
Building the new INELFE power line between France and Spain has taken years to get underway. Dewatering is crucial in the challenging environment, where the line runs entirely underground and three-quarters of the way under the sea. Bessac, the French tunnelling contractor, is relying on Tsurumi drainage pumps, which have proven their worth in similar challenges.
Across the Bay of Biscay
The INELFE (INterconnexion ÉLectrique France-Espagne) project of the two grid operators Red Eléctrica and RTE is a milestone in European energy infrastructure. It is scheduled to allow an improved transfer of electricity between France and Spain to improve security of supply from 2028. This is particularly important for Spain, which has comparatively few connections to the European grid.
The centrepiece of the project, now estimated at 3,1 billion euros, is the construction of a 393-km, four-strand direct current cable. It will run from Cubnezais, north of Bordeaux in France, across the Bay of Biscay to Gatika, near Bilbao in Spain. With a transmission capacity of twice 1000 MW, the project extends the existing link to around 5000 MW. This puts the interconnection capacity on a par with that of France‘s other neighbouring countries.
The submarine cable route was chosen to minimise the impact on the environment, especially as the existing 400 kV overhead lines cannot handle the current flow. The submarine cable is 300 km long. The underground cable sections between the converter stations are 80 km on the French side and 13 km on the Iberian side.
The KTZ415 Pump
BESSAC, a specialist in tunnelling and pipeline construction with 40 years‘ experience and a fleet of over 40 tunnel boring machines, relies mainly on the KTZ415 for dewatering in the three tunnels on the route, but also on other Tsurumi pump models. The performance of these pumps is designed to ensure that water ingress during construction work is pumped out reliably and efficiently.
The KTZ415 is specially designed for use in extreme conditions. With a maximum flow rate of 1980 l/min and a head of up to 55 m, it is in the upper mid-range of the 17-model range. It is one of the manufacturer‘s best-selling pumps and, according to Tsurumi, „has been used in almost every major tunnel project in Europe“. The Tsurumi pumps feature a centrifugal oil distributor with double internal mechanical seal in the oil bath, an encapsulated, hermetically sealed power supply and ultra-hard materials such as silicon carbide – only diamond is harder. As a result, the pumps are safe to run dry. It is also often emphasised that they can be maintained and repaired by the user in the field using standard tools.
Tsurumi Pumps Are Used All Over the World
With 100 years of experience in developing pumps for construction and industrial applications, Tsurumi has established itself as a reliable partner. The company‘s pumps are in use all over the world and have to tackle the most difficult tasks – from dewatering in hard rock tunnels to large construction sites. Tsurumi has a product range that includes over 500 models in Europe alone, with capacities from 30 m3/min to 216 m delivery head. In addition, the company does not manufacture to order but can supply almost the entire range from stock within hours – a factor that can be particularly important in dewatering.
