Ajax cup celebration on Amsterdam's Museumplein twice nearly halted over vibrations

The celebration of Ajax winning the Eredivisie cup on the Museumplein in Amsterdam last May was twice nearly halted as the crowd came close to exceeding the vibration protocol - the measures in place to prevent the soil under the square moving and resulting damage to surrounding homes and museums, Het Parool reports. 

During major events on the Museumplein, an eye is kept on the measurements of seismographic equipment in the basement of the Van Gogh Museum. If the meter is in the red, the organizers must immediately intervene in accordance with agreements laid down in the vibration protocol. During the Ajax celebration in May, the meter approached red at two points - both when Abdelhak Nouri's father appeared on stage.

"Twice in a row it was close," Thomas Kuilboer said to Het Parool. He keeps an eye on the measurements on behalf of the Amsterdam municipality. "Fortunately that was it. We would have had to intervene at a third time. Three yellow cards is a red one for the organizers."

These strict precautions have to do with the unique situation on the Museumplein - the marshy soil it is situated on and the important museums that surround it. "It is wetlands," Kuilboer explained. "When the ground starts to move, it knocks against the buildings." To prevent damage to surrounding homes and museums, vibrations caused by events may not exceed 1.2 millimeters per second. "Then action must be taken immediately on stage. At 1.8 millimeters it is over and out."

To quickly calm a crowd down, event organizers use tricks like turning the bass off, showing an advertisement on the screen, or simply stopping the music. These measures are discussed in advance with the event organizer and the police. "The organizers know that they will have to deal with the vibration protocol on the Museumplein. They take that into account. It can be a party, but nobody should call on the public to jump together."