In 2016, a sleek new walkway was added to Geneva’s iconic 140 metre high jet of water, known as the Jet d’eau, Bill Harby met the team and got a look at the machinery that makes it all happen.
Viewing Geneva’s famous landmark, the Jet d’eau, up close is now a breeze for all, including the disabled. A new wooden walkway out to it opened last June. The award-winning bridge pictured below was designed by Ingeni.
Jet d’eau walkway – Source: Facebook Ingeni
Before the new walkway was added, those hoping to get close to the nozzle, which shoots a mixture of water and air as high as 140 metres, had to walk on a narrow cement jetty built in 1891, with no wheelchair access.
The new wood plank walkway – 3.8 metres wide and 200 metres long – has no steps, so now even those in wheelchairs can get within a few metres of the nozzle, for dramatic views and a chance to get a shower if the wind changes!
It pumps out 500 litres of water per second. The video below shows drone footage of the jet in action.
A new LED (light emitting diode) system replaces the old lights, saving energy and allowing the fountain to be lit in a variety of colours at night.
The famous Swiss landmark first spouted its watery plume on this site in 1891, but its history goes back to 1886, when the rapidly expanding city opened a nearby hydraulic pumping station on the Rhone river to serve local artisans. Much of the water was used to power factory machines. At the end of each workday, when the machines were shut down, excess pressure built up in the system, so a valve was needed to release it. This valve created Geneva’s first aquatic plume, a 30-metre high fountain of water.
Some visionary saw the crowd-pleasing potential of such a jet and, in 1891, the city built a new fountain at its present site. It rose to a maximum height of 90 metres.
That fountain used city drinking water until 1951 when a completely new, more powerful pumping system began taking water directly from the lake. Combined with a new nozzle, the jet could now push water up to a maximum of 140 meters.
“The exact height depends on the wind,” says Gérard Luyet, who oversees the Jet d’eau for SIG (Services Industriels de Genève), the Canton of Geneva’s energy agency. “When there is a slight wind, the water at the top of the jet is pushed to the side, so it goes higher. If there is no wind, the water falls back down on the rising water, so the fountain cannot go so high.”
The nozzle – Photo – @ Bill Harby
The fountain begins at its nozzle, which is just 10 cm. in diameter. It shoots 500 litres of water per second at a speed of 200 km per hour. At any given moment, 7,000 litres (7 metric tonnes) of water are in the air.
At the nozzle, the water is mixed with air to form countless bubbles, turning the fountain white, making it visible for many kilometres.
The fountain is propelled by dual motors and pumps housed in a water-tight compartment mostly below the waterline.
Inside the pump house – Photo – @ Bill Harby
The fountain is operated each day by a team of five volunteers, each one a retired SIG employee. If the operator sees that the wind is too strong or the temperature is dropping too low, he can shut off the fountain instantly.
Samuel Chanson at work in the control room – Photo – @ Bill Harby
The budget for running the Jet d’eau is CHF 800,000 per year. The tours (in French or English), last 30 to 45 minutes, and are open to any group of 10 to 12 people. Mandatory booking can be made online.
The tour includes the pumping station. Visitors descend via a short ladder into a small circular room where the giant motors (named Salève and Jura, after the mountain ranges on either side of Geneva) and pumps do their work – switched off during the tour, which takes place only when the fountain is not operating. The room is spotless, and includes a display of the huge old wrenches that were once used to maintain earlier machines.
After the tour, when the jet once again shoots high into the sky, visitors can stand near its base and contemplate this feat of engineering and imagination as the mist drifts down around them.
Jet d’eau Hours of Operation
- From 1 January to 4 March 2018 – 10 a.m. to 4 p.m.
- From 5 March to 29 April 2018 – Monday to Thursday : from 10 a.m to sunset and Friday to Sunday : from 10 a.m to 10:30 p.m (with lighting)
- From 30 April to 9 September 2018 – From 9 a.m. to 11.15 p.m.
- From 10 September to 28 October 2018 – Monday to Thursday : from 10:00 a.m to sunset and Friday to Sunday : from 10 a.m to 10:30 p.m (with lighting)
- From 29 October to 14 November 2018 – Shutdown of the Jet d’Eau for maintenance work
- From 15 November to 3 March 2019 – 10 a.m. to 4 p.m.
By Bill Harby
More on this:
SIG’s website (in English)
More information (in French)
The video below summarises the jet’s history (in French) – Take a 5 minute French test now
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