Tractors versus freighters in Gaarkeuken. Was this a farmer’s protest?

They are cargo ships to say the least: Avalon of 135 meters long and 11.45 meters wide, Elizabeth of 55 meters long, Valinta of 110 meters and Sijtje of 70 meters. But they lie unemployed for hours in front of the Gaarkeuken bridge, powerless against a handful of tractors standing on that bridge and making it impossible for the bridge operators to do their work. And with that the skippers.