Eiffel Tower: how do illuminations and headlights work?

It's no secret that the Eiffel Tower can be seen from afar, including at night, and not only thanks to its size.

Which Parisian and which visitor to the capital has not one evening taken the time to wait for a fixed time to contemplate its sparkle, with precise timing?

Who has never seen the light of its headlights pierce the sky of Paris, and beyond?

But how does it all work?

On the occasion of its special morning on Wednesday September 16 from the 1st floor of the Tower, Europe 1 wanted to understand the mechanism of the lights of the Iron Lady.

>> Six months after the start of the COVID-19 crisis, Europe 1 is gaining height and focusing on the next four months which will be decisive for France: economic and ecological recovery, tourism but also the fight against epidemic.

Matthieu Belliard, accompanied by his columnists and editorial writers from the resort, is offering a special morning session this Wednesday from the Eiffel Tower, a major French and global tourism hub and symbol of the country's attractiveness, to better decipher and understand what is happening draw.

Smart flicker

Every evening after dark, the Eiffel Tower puts on its golden dress and lights up for five minutes every hour, until 1 a.m. (when the last sparkle lasts 10 minutes).

And she is never wrong: you will never see the Iron Lady shining by day, nor her 20,000 bulbs waking up before or after the hour.

How to explain such precision?

"The Tower is equipped with sensors which measure the brightness. As soon as it drops sufficiently, this will automatically start the process", explains Yann, technician at the Eiffel Tower.

Once nightfall is registered by the sensors, the system will program the illumination at the next fixed time, thanks to a sprawling 40 km device of light garlands and other power cables.

As for the "themed" illuminations, like the one in blue-white-red following the victory of the French football team at the 2018 World Cup, they are decided by the Paris city hall, and ask each time complex technical means (and rarely revealed to the public).

For some behind the scenes of the Iron Lady's 130th anniversary illuminations, see for example the video below:

The Eiffel Tower has been sparkling since December 31, 1999 at midnight, but it has been lit (the "golden dress") since 1985. "The 336 orange-yellow projectors integrated into the structure have two functions: they underline the fine structure of the tower Eiffel and ensure the safety of the night operation of the Tower ", completes the site of SETE, the operating company of the Iron Lady.

According to estimates, the Eiffel Tower would consume the electricity equivalent of a village or a very small town, a balance however reduced by 40% since 2004. According to SETE, the 20,000 LED bulbs intended for flickering would only represent " "0.4% of the monument's annual electricity consumption, ie the consumption of a 30m2 studio occupied by two people.

And for several decades, it has tried to reduce its footprint on the planet, multiplying measures: installation of two wind turbines, solar panels, heat pumps, rainwater recovery, etc.

One lighthouse, two beams, four projectors

The Eiffel Tower emits not one, but two light beams, which come together to illuminate the Parisian sky over a range of 80 kilometers.

In total, the "lighthouse" is made up of four motorized projectors (two for each beam), installed at its top and controlled by a microcomputer using specific software and a programmable controller which manage their movements.

"Rotating 90 °, they are synchronized to form a double cross beam rotating 360 °", details the site of the Eiffel Tower.

This system, made up of 6,000 watt lamps, also dates from the year 2000. But the Eiffel Tower was already lighting up the sky in 1899!

Gustave Eiffel had rail projectors installed at the top, to illuminate the monuments of Paris and celebrate the Universal Exhibition.

In the 1950s, the lighthouse even emitted up to 300 kilometers, serving as lairs for planes.

It had been replaced in 1970 by simple red lights… until the year 2000, therefore.

She welcomes us tomorrow for an exceptional morning from 5 a.m. to 9 a.m.

@LaTourEiffel, behind the scenes, it's a world of metal and colors, as well as a unique industrial heritage # Europe1SurLaTourEiffelpic.twitter.com / BVVlZ1UWG9

- Europe 1 (@ Europe1) September 15, 2020