At Grigny , trains run at idle speed in the tunnel. Since Thursday morning at 5: 30 pm, officers from the electrical service and amenities ways SNCF suck up water before it will cover the rails and not interrupt traffic.
"This often happens when it rains too. We are there for several days, "said an agent of the SNCF. A heat pump was installed, one already being saturated. Meanwhile, the RER hinder passing through the tunnel. They do not exceed 30 km / h against 100 km / h usually.