French Guiana medium-voltage lines: six photos per support, 1,262 supports in 19 flying days
In 2024 the electricity network operator entrusted us with the drone inspection of four medium-voltage feeders, from Mana to Saint-Georges. Every support had to be photographed accurately enough for a technician to make the diagnosis at the office and prepare targeted renewal works without going back into the field.
Four lots, 128 kilometres
The work was split into four lots: Galion, in Montsinéry-Tonnegrande (397 supports, 35.5 km of line), Mana (246 supports, 26.9 km), Sinnamary – Iracoubo (484 supports, 57.2 km) and the municipality of Saint-Georges (135 supports, 8.8 km). Flights began on 17 September 2024; covering the 1,262 supports took 19 flying days and 67 h 50 in the air.
Six photos per support, give or take one
The method was the operator’s. For each support: two overall views, as the drone approached and as it left, to assess its condition from base to top; four close-ups of the cross-arm assembly, one of them along its axis to reveal any deformation; one view taken from under the cross-arm, camera pointing upwards. Between two supports, sleeves and visible conductor defects were photographed separately. Photos had to reach 20 pixels per centimetre on the cross-arm, be geotagged in x, y and z and time-stamped, and the drone had to stay more than 3 m from each conductor.
The photos covered the supports, cross-arm assemblies, insulators, conductor fixings and attachments, pole-mounted transformers, overhead switches, overhead-to-underground transitions and surge arresters. They had to show corrosion or deformation of the fittings, worn stirrups, broken conductor strands or vegetation too close to the line. Any dangerous situation noticed during a flight, urgent tree trimming, a broken insulator or a decayed pole, had to be reported to the operator by the end of the same day, and any people or number plates in view had to be blurred.
In all, 7,854 photos were taken, an average of 6.2 per support. A point placed on each support produced an overall KML file of the lines, and a tracking table recorded day after day the supports covered, the photos, the flight time and the distance travelled.
The pace
The average came to 18.6 supports per flight hour and 66 per flying day. The best days exceeded 80 supports, with a maximum of 99 on the Mana lot on 26 September. The main constraint was the road: on the lots far from Kourou, the daily round trips ate into acquisition time, and the team now recommends staying on site for this kind of campaign.
On Sentinel Cloud
In March 2026 the Sinnamary lot was loaded into the Sentinel Cloud pylon inspection module: each photo is placed on the map, oriented according to the drone’s heading and attached to its support, with tools to annotate anomalies, rate them on four severity levels and export a PDF report or a table.
