The danger of a thunderstorm should not be underestimated. On average, in the Netherlands there are 25 days with thunderstorms each year. It is important to be aware of the dangers of lightning.
During our activities it is important to be alert to a thunderstorm, both during indoor and outdoor activities. The place and the time of a lightning strike can never be determined precisely.
In view of climate change and the increasing number of thunderstorms, identifying safe sheltering sites is not a superfluous action. This can be included as an item in setting up the company emergency response (CER) organization at the construction site itself. In this respect, it is also important to take the potential damage of a lightning strike and how to act into account.
The ‘10-second’ rule is generally used to provide an indication of the distance between you and the lightning strike. Sound travels more slowly than light and the time difference between seeing a lightning flash and hearing the thunder can therefore be used to estimate how far the thunderstorm is away. The number of seconds between seeing the lightning flash and hearing the thunder divided by three provides a rough estimate of the distance in kilometres.
If you hear the thunder within ten seconds, activities must be halted.
What you must do:
Safe locations include:
Material:
Machines:
What you must not do:
If you are not able to reach a safe spot on time, you should act as follows:
The distance of a thunderstorm can be estimated using the following rule of thumb:
Thunderstorms travel fast; distances can be estimated using the following rule of thumb:
Three (3) seconds between the lightning flash and the thunderclap is 1 kilometre!