Client

RTE

Name of OHTL

Avranches - Launay - FRANCE

Voltage of OHTL

90kV

Partners

Ingedia Bep topographical survey

Duration of assignment

01.2007 - 04.2008

Value of service

450 k€


The aim of the project was the design of a new 90kV double circuit Overhead Transmission Line between Avranches and Launay substations. The tower spotting has been carried out by HECLA, integrating all environmental constraints listed in the Environmental Impact Study (EIA). To do so, HECLA used a .xyz file generated from a LIDAR survey of the corridor and Orthophotos. Optimization of the tower spotting has been made thanks to the modeling of the OHL with the OHTL calculation software PLS-Cadd (POWERLINE SYSTEM Inc.).

The line route and tower locations have been adjusted following the numerous meetings with landowners and farmers, the main stake in this kind of project being acceptability by third parties, as well as the technical and financial optimization for the Transmission System Operator.

The OHTL was mainly made of tubular steel structures and some latticed steel structures, coming from normalized RTE catalogs, including two aerial - underground towers. Conductors used were ASTER 366 (AAAC) and earth wire was THYM 107 (OPGW). All topographical survey, administrative authorizations and landowner agreements have been carried out by our partner INGEDIA BEP.

Key figures:
54 towers (including 49 tubular steel poles and 5 latticed steel structures), 14 km long, double circuit, 405 Tons