In mid-2020 the company "BIEBERBAU Gartenplanung und Gartengestaltung" from Höxter-Fürstenau, inquired about a unit to build a so-called fish ladder in a stream. In order to drain this for the time of the concrete work, a powerful diesel vacuum unit of the type "HC 551/09" was rented with suitable accessories such as pipelines and hoses. Originally, considerably more water had been expected for the project. However, since the stream at a depth of approx. 6 m only had a moderate amount of water, the water could be redistributed by using a Y-piece with a slide valve in such a way that the machine was prevented from running dry.

The HC 551/09 is a powerful diesel vacuum unit for pumping up to 330 m³/h water with solids content of max. Ø 45 mm. The max. delivery head is 21 metres.

The water pump, driven by a sound-insulated diesel engine, and vacuum generators ensure continuous delivery of the water-air mixture. The upstream air separator tank separates the air that has entered the suction line from the water, so that the water pump only delivers water. In addition, safe suction is ensured with this method. The tank volume in the tank frame chassis is sufficient for 24 hours of continuous operation. A dry-running rotary vacuum generator is used for vacuum generation. This does not require lubricants and is therefore very low-maintenance. It delivers up to 105 m³/h and generates a vacuum of max. -0.92 bar.