Energy for an energy project: Bredenoord ensures water pumps will operate 24/7

Dewatering specialist Hölscher has been awarded a contract to drain the pipe trenches under excavation on the Jutland peninsula and the island of Funen as part of the Baltic Pipe Project. The challenge: at times the groundwater level is higher than the lowest point of the planned excavations. Also, the section under construction is approximately 140 kilometres long and is highly vulnerable to flooding, owing to its proximity to the sea. To keep the pipe trench dry, Hölscher is relying on the continuous operation of its water pumps. Bredenoord has undertaken the task of providing an uninterruptible power supply to the pumps. This way it is possible to lay the gas pipelines without any problems, despite of the challenging conditions.

We need material that is reliable. With Bredenoord I can be certain that the generator sets will run continuously and that the whole process will work smoothly. The dependability of personnel and machines is ensured.

The Baltic Pipe: a 900 kilometre-long gas supply corridor through which Norwegian natural gas will be transported from Denmark to Poland and other neighbouring countries across the Baltic Sea. Among the measures necessary to cope in future with the planned gas throughput is an expansion of the onshore infrastructure in Denmark. New pipelines must be laid. And they must be laid in places where the groundwater level is considerably higher than the pipe trenches. To facilitate installation and welding of pipes measuring 900 to 1,000 millimetres in diameter and 18 metres in length, it is critically important that the excavations are drained and kept dry.

Hölscher and Bredenoord: many years of shared experience in the pipeline business

The energy required for continuous operation of the Hölscher water pumps is being supplied by Bredenoord in the form of 14 gensets in the 70 kVA - 125 kVA power categories and 11 IBC fuel tanks. Units referred to as “automatic sets” have been delivered to provide reliable protection against outages. These consist of a continuously operated genset set and a backup genset which automatically takes over the supply of power in the event of an outage and during maintenance operations. The backup protection so often used in hydraulic engineering projects is being put to use in this case for pipeline, river, railway and road crossings – wherever the risk of flooding is particularly high owing to a higher groundwater level.

High-output water pumps require high-output gensets

Which pumps are selected depends on factors such as the water table, the depth of excavation, inflow permeability and the length of the pumping channels. Where excavations are exceptionally deep or the water pressure is very strong, Hölscher resorts to extra powerful water pumps with a power rating of 11 to 15 kilowatts and an output rating of between 120 and 180 cubic metres per hour. These are operated by preference with Bredenoord’s 70 kVA gensets because the exceptionally powerful engine and its large displacement guarantee that the pumps will come on strong.

Mobile gensets keep pace with the construction progress

Hölscher has drained some 20 kilometres of pipe trench to date and intends to open up another 120 kilometres by the end of the year. It is therefore imperative that the material be adapted in accordance with the progress of construction. Bredenoord responds with flexibility, delivering additional gensets and fuel tanks to meet the developing needs of the job site. Deliveries can be made from Bredenoord’s Danish distribution facility in Vejle within a few hours by means of the company’s own transport fleet. Thanks to their compact, robust construction, Hölscher’s gensets can be relocated independently.