20.02.2009 – Screws as big as dumb-bells, heavy equipment at dizzy heights. And on the ground: construction workers riding bikes. A construction site inspection of the E.ON hard coal-fired power station in Datteln.

 

Text: Anne Honisch
Photos: Martin Lässig

»So, what’s your shoe size?« a man wearing glasses, a helmet and an orange safety jacket asks me. The visit to the E.ON construction site in Datteln begins before you even enter the compound – in the safety center. The container seems small and insignificant in comparison to the giant chimneys which tower in the background. 

The impression is misleading as noone is allowed past the container. It is the gateway to the future coal power station and anyone who wishes to enter it receives safety instruction here first. Visitors sit in front of computer screens in the PC room and listen to instructions: »When you walk under cranes, be aware of what is above you«, »When the alarm rings, proceed to the meeting point at the entrance«, »Always wear a safety jacket, helmet and safety shoes while on the construction site.« I have been given some – size 41 – have put them on and am now somewhat heavier. The steel caps and the steel soles protect against treading on nails and against falling objects. 

A test with ten multiple choice questions is made following instruction. Visitors can choose from safety instruction in four languages and for the construction workers there is a more detailed version in ten languages. When we have received instruction and passed the test, a visitor I.D is hung around our necks and we set off.

A Head for Heights 

The streets are wide, a mass of cranes looms ahead of me, the sound of machinery is emitted from the boiler house where a crane swings steel girders from one place to another. Building workers stamp over the gravel or they ride bikes. The coal power station in Datteln covers 60 hectares, why walk the long distances? »Maximum speed 20 km/h« announces a traffic sign. So a bicycle is ideal unless, of course, you have to transport building materials. 

The coal-fired monoblock power station is one of four which E.ON plans to build or is currently building in Europe. The new plant in Datteln will cost the energy provider 1,200 million Euros; Datteln 4 as it is called, will start up in 2011. It is a pilot project in terms of technology, conversion and health & safety. The 1100 megawatts produced will be channeled into public supplies and to the German rail company Deutsche Bahn. In addition, E.ON supplies hot water to the northern Ruhr area which is channeled into the district heating network of North-Rhine Westphalia. 

Health, safety and the environment are not just major concerns for the future power plant but already on the construction site. E.ON have appointed an HSE manager who is responsible for these issues. Security services on the building site are the responsibility of the Dussmann Service branch office, Essen, which also runs security operations at another power station in the area. Thanks to the experience gained there, the service provider provides a growing number of security staff, paramedics, elevator technicians… as construction progresses, more and more Dussmann Service employees are deployed on the site. When construction is completed, there will be 80 in all. Dussmann Service branch manager, Andreas Gutzmann points out: »Security is a very sensitive issue everywhere but during the construction of a power station, requirements are particularly strict. The branch office is very proud to have the opportunity of being part of this gigantic project.« 

When completed, the cooling tower of the power station will stand approximately 180 meters tall. The boiler house has already reached its final height of around 120 meters. Everything on the construction site must adapt to these dimensions, including the building workers. A head for heights. This is a phrase which is often used during the tour. Those working up on the scaffolding wear a safety harness around their hips and are tied securely. The greatest risk is not falling from the scaffolding but hanging too long in the safety harness which restricts the flow of blood. If there is an incident, specially trained paramedics and a rescue crew are always on call – they can abseil to the injured construction worker hanging in his safety harness. 

Swallows Nests are Removed 

It is 5 meters up the aluminum ladder on the top floor to the skylight. The safety shoes make it difficult for unpracticed visitors – what was that about a head for heights? But the climb was worthwhile: From the roof of the stair tower, I have a view of the entire construction site – and of several other power stations in the area. 

Two stair towers frame the future boiler house where scaffolding already stands. Dark red steel columns shoot upwards. Later, the boiler will be hung here – yes, hung. Due to the variations in temperature within the boiler, it expands and contracts. A hanging position allows it to do so.  In the boiler scaffolding, there are hatches. Through an open one, I can see the rungs of a ladder mounted on the interior wall of the scaffolding. In order to save construction workers climbing up and down ladders, there are yellow bridges connecting the scaffolding with the stair tower in which there is an elevator. This enables building workers to take the elevator and access the scaffolding via the bridge. On the corner of the boiler house scaffolding are yellow platforms known as »swallows nests«, on which building work takes place. Like all of the yellow components, they are provisional and will be removed at the end of construction. 

The stair towers are presently the tallest buildings on the site but the cooling tower will overtake them soon – it grows one and a half meters each day until it reaches its final height of 180 meters. On the outer surface of the cooling tower hangs a monster, an octopus wraps its arms tightly around the tower. The octopus is called a climbing formwork, a frame attached to the tower walls. When the walls are cast in concrete, holes are made in which, when the concrete is dry, the climbing formwork is hooked. With the help of a motor, the formwork climbs the wall, meter for meter. The wall is only approximately 23 centimeters thick at its thinnest point and this makes it thinner than egg shell, in relation to the volume. A glance from the top of the cooling tower confirms the comparison.

A Great Deal of Additional Energy 

The conversion rate of the coal power station i.e. the volume of energy produced in relation to the consumption of primary energy, is more than 45 percent. For a land power station, that is world-class efficiency. Using modern technology, E.ON wrings a great deal of additional energy from production. 

One of these technical solutions is round, flat and so big that I can see it lying on the ground from the top of the stairs – a steel wheel, separated into two halves with a dividing wall. When the power plant is put into operation, this wheel will rotate and the gases produced by the burning coal will flow down into the one half. Cold air pours through the other half into the combustion chamber. The gases are cooled during rotation and the cold air is warmed. This saves energy and adds several points to the conversion rate. 

In Datteln, the filtered waste gases are not emitted through a separate chimney but through the cooling tower. This saves constructing an additional chimney and supports the drive in the cooling tower. 

From the other end of the roof, I can see ships carrying black heaps. The future plant is situated next to a canal along which hard coal from all over Europe will be delivered via Rotterdam. On the banks of the canal, a shovel excavator is busy. E.ON is extending the canal and building a parallel port so that several ships can dock simultaneously. Any material that is not delivered by water comes by rail or road from the nearby motorway. A better infrastructure is hardly possible. 

The fundament of the coal mills is already built; this is where coal will be pulverized before being blown into the combustion chamber with a maximum capacity of 360 tons per hour. The by-products, gypsum and fly ash, are useful materials for road construction and in the production of cement which dries faster when it contains ash. 

The old E.ON power plant lies on the other side of the canal. After 40 years of service, it is now outdated. When its successor goes online in 2011, it will continue to run for a short time and then be dismantled. E.ON will make the land available to the town of Datteln and an industrial park is planned. 

The wind whistles past us. It’s windy at the top of the stair tower and it almost blows my helmet off. The aluminum ladder awaits our descent.

Years of Planning Before the Ground-Breaking Ceremony 

Back on solid ground – very solid in fact. In some places the concrete fundament is three meters deep. 

The planning of a power plant takes place many years before the start of construction. The E.ON plant at Datteln is no exception. It was 2002 when the plans first came to the drawing board and the ground-breaking ceremony took place in 2007. Initially, many holes were drilled in the ground to examine it thoroughly: for old bombs and for subterranean damage that might have been caused by the mining which took place on the other side of the canal many decades ago. And to measure the humidity of the earth. As a result, 20 unexploded bombs were found. Pile foundations, three meters deep were set to exclude any future subsidence. 

At the end of the roadway, the control container reappears. Two young men are standing on the other side of the barrier, waiting to be admitted. They have already put on their safety jackets, helmets and safety shoes and successfully completed the instruction test.  

The visitors to the building site are all here for different reasons: college students are interested in the technical processes, building companies in the region are here to advertise their companies and their services, Datteln residents want to see what is going up in their neighborhood. They are all welcome. E.ON has established an information center known as Energy Meeting Point which is situated on the other side of the canal. From its roof terrace, visitors have an excellent view of the construction site. Those who want to have a closer look can take a guided tour – as long as they are willing to divulge their shoe size.

 

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