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Wouda Pumping Station

Moving Water with Steam

Close to one third of the Netherlands is below sea level. Originally, the Dutch used windmills to keep their feet dry, but in the middle of the 19th century steam-powered pumping stations took over; for example Cruquius (1849), now a museum, used to empty the Haarlemmermeer polder. During the last century, many of them were converted to diesel operation, and nowadays most stations are powered by electric engines. One of the last steam pumping stations built is the Wouda Pumping Station (1920) in Lemmer, which is the largest ever constructed and the only one still in use, although in cases of heavy rain only. It has a capacity of 4,000 m³ per minute, allowing for the discharge of some six million m³ of water per day.

The engine room is virtually identical to what it was when it opened a century ago. Eight centrifugal pumps are powered by four tandem compound steam engines, which have a combined capacity of 2,520 h.p. The only significant change to the pumping station was made in the boiler room, with the replacement of the eight original boilers with four larger-capacity Scotch boilers in 1955, and their subsequent conversion from coal to fuel-oil firing twelve years later. On average, the station comes into action only once every two years, but in addition it is brought to steam twice a year for training purposes. The Wouda Pumping Station is open to visitors Tuesday through Sunday from February to December, as well as on Mondays in July & August.

Reader comments

Jelle

Under normal conditions, the province of Friesland is drained through three sluices in Engwierum, Harlingen & Zoutkamp. When the water level reaches 6 cm over its target (NAP –52 cm), i.e. the water rises above 46 cm below the Amsterdam ordnance datum, the Hooglandgemaal (1967) in Stavoren is switched on. In case its four electric-powered pumps with an overall capacity of 7,340 m³ per minute cannot stop the water level from increasing to NAP –41 cm, the Woudagemaal gears into action as well.

Hilda

Normally the pumps operate at a speed of 90 revolutions per second, moving 65 m³ of water, in which case two boilers are in use. To expand the capacity to 72 m³ per second, the speed of the pumps needs to be increased to 105 revolutions, which requires the assistance of a third boiler. The fourth is used as a fall-back, but it takes six hours to heat up a boiler from cold.

Johan

The capacity of a centrifugal pump depends not only on its impeller diameter & rotation speed, but also on the head, which is the height above the inlet that the pump needs to lift the water. At 6,300 rpm & a head of 100 cm, Wouda Pumping Station’s flow rate is 72 m³/s, but when the head is just 30 cm, its flow rate is 78 m³/s. So when the water level in the inlet goes up, the head goes down, and the pump’s capacity increases.

Martin

Another place to see steam live in action is at the Dutch Steam Engine Museum in Medemblik, in the former pumping station Vier Noorder Koggen (1869), where engines are under steam around a hundred days a year. It’s a 30-minute walk from the station of the Hoorn–Medemblik steam tram to the museum.