In the last days before the liberation of the Northern Netherlands, the German forces tried to transport as much useful goods as possible to their homeland.

This was no longer possible by land, since the Canadians had already advanced too far north for that. However, from Leeuwarden through the Van Harinxma Canal (then still the Harlinger Trekvaart) to Harlingen and then across the North Sea to Germany, the road was still open. Shiploads full of essential goods, also for the Dutch population, threatened to disappear with the liberation in sight.

This prompted two members of the Dutch Interior Forces (NBS) from Achlum, the brothers Jan and Rikus de Vries, sons of peat shipper Knilles de Vries, to persuade their father to ship his ship, the 20-metre skûtsje de Dankbaarheid. to give them up. They demolished everything of value, took it to the dredging depot west of Dronrijp and loaded it full of mud there. So full that the portholes of the deckhouse were below the waterline.

They then laid the Gratitude across in front of the swing bridge of the hamlet of Keimpetille (officially: Kingmatille) and opened the windows. Before their eyes the barge sank to the bottom of the canal. The next day a German ship approached, loaded with 5,000 silks of dry bacon, stolen from a cold store in Gieten, Drenthe. It got stuck on the wreck.

The Germans fled and had to leave the precious cargo behind. The bacon was distributed by the NBS to the inhabitants of the surrounding towns, who could enjoy a luxurious liberation meal.

Other ships could not pass it after that either, making this one of the most successfulacts of sabotage in Friesland. Moreover, no German reprisal followed.