At the end of this year, when the traditional miner's greeting of "Glückauf!" will be heard in the mines of Prosper-Haniel in Bottrop and in Ibbenbüren on the edge of the Teutoburg Forest one last time, a chapter of German industrial history will come to an end: that of the coal mining sector. The last two active mines are disappearing, but 150 years of mining tradition leave behind lasting traces in the Ruhr – some traces last forever.
For example, underground where, at up to 1,500 metres depth, the miners dug out the black gold, mine water is building up: rainwater trickles down along the rock strata, is enriched with salts and other minerals and gathers underground. After the termination of coal production, the mine water can rise up to a certain level – with a sufficient separation from the drinking water deposits. Everything above this is pumped above ground so that it cannot mix with groundwater. Drinking water protection has the highest priority in mine water retention. Ruhrkohle AG, as the operator of the German coal mines, has taken on this task. Its parent organisation, the RAG foundation, bears the costs of the perpetual liabilities of mining.
Along with the mine water, underground mining has also changed the topography of the Ruhr. The conurbation between the Ruhr and Emscher is now little more than borrowed land, so-called polder land. The polder measures affect the regulation of surface water in this area. In order to avoid flooded cellars, the region's water boards and RAG operate 1,115 overground pumping stations in North Rhine-Westphalia alone – 24 hours a day, seven days a week.
Almost a fifth of the Ruhr is currently below the water table due to ground subsidence and is only kept effectively artificially dry with permanently running pumps. The pumps installed at depths of 20 metres move an average of 110 million cubic metres of groundwater each year. A quantity of water that could fill Baldeney Lake in Essen almost 15 times.
All pumps, that are distributed throughout the entire region, are to be centrally controlled and monitored in future. From 2019, this will occur via a control room in Herne. The location is the site of the former "Pluto" mine, which extracted coal in Wanne-Eickel until 1976. "What is being created here is something like the brain for dealing with the perpetual liabilities," says Lukas Goretzki, site manager at STEAG Technischer Service (STS). "We are planning and building the energy supply for this brain."
What this means is categorised by Christian Seine, the project manager responsible for the energy supply of the RAG control room: "From Herne we will monitor and control the water drainage, polder systems, water treatment, groundwater purification and all monitoring systems in the Ruhr, Saar and Ibbenbüren." The part for which STEAG has been commissioned is therefore correspondingly important.
The energy supply of the new control room, in which all information will flow together from the middle of next year, is ensured in a so-called transformer house. In the rather nondescript 10 by 24 metre building, there will in future be three transformers for the control room. The entire system is designed in such a way that it is triple secured. "Even if the safeguarding of the regular operation were to fail, there is a third control series that would spring into action," explains Lukas Goretzki. "This is comparable with the emergency power supply to hospitals."
For the 32-year-old industry master in electrical engineering this project presents a major challenge on a daily basis. "We have planned everything from the ground up and in detail, but planning is one thing – and the building site is another," he says. It is for this reason that the master electrical engineer from Essen puts a lot of energy into communication.
"The challenge is that there is also an old control room, which is in operation. There are also many other maintenance groups that are integrated. This all has to be coordinated," explains Lukas Goretzki. "And as we are already putting the new transformer house into operation, step by step, we have to switch everything from old to new. That is like open-heart surgery. And, above all, this means: carefully planning processes, communicating work steps ahead of time and then implementing them on time."
The constant connection to RAG project manager Christian Seine is particularly important in this. "We coordinate every day," explains Lukas Goretzki, who will continue to work with "Pluto" until the end of the year at least. "Then the operation will hopefully be successfully completed and our energy supply for the brain will work."
Images: Marco Stepniak