Paris (AFP)
Cattle sheltered and hydrated, concrete laying in the morning: on the strength of their experience of the 2019 heatwave, companies are stepping up measures to minimize the impact of high heat on their activity.
Danger on the rails
SNCF has planned to activate its plan on Friday to deal with periods of high heat, which provides for reinforced monitoring of equipment and infrastructure from 12 p.m. to 8 p.m.
The rails are particularly sensitive, especially as they accumulate heat and can reach 70 ° C in a heat wave ... The expansion of the steel risks deforming the track.
On electrified lines, train power cables tend to relax under the effect of heat. They risk touching the roof of the train and pulling the catenary.
On the passenger side, air conditioning is essential when the train departs and, coronavirus requires, special attention has been given to the maintenance of the filters. And to provide assistance to travelers in the event of an incident, strategic stocks of water and food have been placed in stations throughout the country.
Private Fan Traders
Health recommendations prohibit ventilators if they are used in communities, because of the risk of transmission of Covid-19, as for air conditioners they are only authorized if they allow to bring "new" air from there. 'outside.
Philippe Hoang doesn't even dare to draw a draft between the back of his tobacco bar and rue du Faubourg Montmartre in central Paris. "I prefer to avoid any air circulation and I have stopped the brewery activity because there are too many dangers with this virus", says the manager of La Pia Hour, to whom the temperatures of more than 35 ° C. are much less scary than the coronavirus.
In the passage Choiseul (2nd arrondissement of Paris), the absence of drafts and the glass roof heated by the sun made the atmosphere particularly heavy from Thursday afternoon. Little informed about the risks presented by fans, a shopkeeper in this covered gallery placed a small propeller machine at the ground level of her shop, a few square meters large. "I require the mask to enter and no more than three people at a time, and I hope the virus does not circulate too much", she says between two folds of origami.
Hot like a nuclear reactor
The heat wave can affect the production of EDF nuclear power stations, which is sometimes forced to shut down or reduce the power of its reactors. The electrician uses river water to cool the reactors before discharging it, but it must not exceed a certain temperature, in order to avoid harmful consequences for aquatic flora and fauna.
EDF thus temporarily lowered the power of reactor number 2 at the Golfech (Tarn-et-Garonne) plant at the end of July "because of the change in temperature (of the) Garonne".
As for electricity consumption, the RTE network manager is not expecting a record for the looming heat wave period. Economic activity slows down in August and the effects of the Covid-19 pandemic are still being felt, limiting the increase in consumption.
Cow in the stable and in the mist
In Léo Colas' Mayenne farm, the building is equipped with fans and more drinking troughs have been installed. And at the exit level, the 90 dairy cows currently only leave their building at night, in the cool. Above the troughs, misters have been installed for two years to relieve the cows in the event of high heat.
"They come more easily to eat, they are relaxed all the time", remarks the 25-year-old breeder in biological conversion with his parents, explaining that "it makes a real mist, it refreshes without it turning into a paddling pool".
With all this, "we have fewer heat-related problems or even have none at all, and we manage to limit the decline in seasonal milk production," he said.
Weaknesses in construction
In the construction sector, the risks do not only relate to the health of the employees, they are also technical: the heat wave is a very bad time to pour concrete, which must not be done by more than 30 ° C.
In high heat, concrete hardens faster and turns out to be less solid: by evaporating too quickly, the water may leave cracks. The solution is to introduce chemical components that delay the setting of the concrete, or if the heat is very strong, lay the concrete at cooler hours.
© 2020 AFP