It is a long and steep climb that “always creates problems in winter because many buses pass through to reach the National Institute of Sports (INS) and the schools in the Cents district,” explained Dan Ferron, an employee of Luxembourg City’s roads department, in conversation with our colleagues from RTL 5minutes.
The problem is that in case of imminent frost risk, the gritter takes too long to reach this black spot in the capital’s road network.
The City of Luxembourg has now found a new solution and “it works”, assures Ferron. The municipality is currently setting up an automatic salting system at the junction of Rue de Trèves and Rue de la Tour Jacob, which links Clausen and Grund to Cents.
The new system is currently being installed and should be operational by February. It was supposed to be installed during the first week of January, but the weather prevented this from happening. Due to rain, the resin that attaches the sprinklers to the pavement was not able to solidify properly. So, while the lower part of the street is already finished, the upper part is still missing.
Several sensors mounted high up and on ground level, as well as a weather station measure both the air and ground temperatures. According to Ferron, “if there is a risk of frost, it is triggered automatically. It can be -10°C without it being triggered. It doesn’t matter as long as it is dry. On the other hand, if the road is wet and the temperature is close to 2°C, it is triggered”.
At that point, more than 40 sprinklers (only on the upper part of the street), very discreetly installed in the middle of the road, “rise a few millimetres under the effect of the pressure and disperse brine to the left and right of the road. And since there is a slope, the tyres of the buses and cars spread the brine”, further summarised the road worker.
To install this automatic salting system, the City of Luxembourg unfroze funds amounting to €104,000.
This is not a first for the capital, as its services have already had ample time to test a similar automatic road-salting system. A respective pilot project has been underway on Montée de la Pétrusse for three years. This steep and paved slope links the Gare district to the Grund district, where the Ministry of Higher Education and Research is located.
The idea “was to see if it is reliable and if it really works. And I can say that it does,” emphasised Ferron. On the Montée de la Pétrusse, the sprinklers are not installed in the paved roadway, but incorporated into the granite curb. A third project is already under consideration and might be implemented on the slope leading to the bridge over the Cents-Hamm station.
In France, the Société des Autoroutes du Nord et de l’Est de la France (SANEF) has been using this system since 2002 to avoid the risk of ice formation on the A4 between Paris and Strasbourg. Several strategic sections of the A4 are equipped with this system. Here, the sprinklers were attached to the side rail.
