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An airport requires excellent water drainage especially when it is situated 3 metres below sea level. Rainwater needs to be quickly removedwhilst separating it from environmentally harmful products like de-icing liquids.
Amsterdam Schiphol Airport in the Netherlands is constantly being expanded and drained. A particular feature of the areais that it is 3 meters below sea level. With the skill of the Dutch indraining polders, this land was wrung from the sea around 1850. Draining the land today means different challenges need to be met: de-icingliquids used in the winter are separated from the rainwater and drained off separately for environmental protection reasons.
On the 19th of September 1916, more than 90 years ago, air traffic operations were initiated here. This makes Amsterdam's airport the oldest airportin the world still in operation at its original location. The name ofthe municipality bordering the airport, Haarlemmermeer, is a reminderof the large lake that used to be there. The word Schiphol means "ShipHell" and is derived from the fact that ships often sank in the Haarlemmermeer during storms. Whether in a ship or an airplane, dangers abound under extreme weather conditions.
To guarantee safe air traffic operations, the rainwater accumulated must be quickly, directly, andcompletely collected and drained off. To do this, channels must be installed on the surface whose gratings need to meet the architectural demands as well as provide the stability necessary for heavy loads. ForSchiphol, load class F 900 was necessary for installation lengths of2m and nominal widths of up to DN 500.
F 900 is the highest of 6 categories and is used "where particularly high wheel loads will be expected, such as on airport operating surfaces" as per DIN EN 1433. The operational safety required according to DIN is achieved by bolting thegrating and channel together 8 times per meter. The 4mm thick solid steel edge angle provides additional stability, serves as corrosion protection, and provides sufficient lateral holding force when connectedlaterally to the surface layer.
Amsterdam Airport Schiphol receivedthe "Europe's Best Airport" award from the Airports Council International ACI in the year 2007 in the category of airports with more than 25 million passengers per year. One criterion in the assessment was environmental protection.
In case of an accident, the airport plannersrequired shut-off devices securely fastened to the body of the channel that could be used to utilize the backup volume of the channel to trap liquids. To guarantee permanent operation, a trapezoid spindle madeof V2A stainless steel was inserted in a sleeve made of gun metal. Itcan be opened and closed mechanically and permits the de-icing liquids sprayed on the airplanes on cold winter days to be separated in thechannel system and then drained off separately.
Certain surfaces on the airfield where materials hazardous to the groundwater are handled were equipped with different channels with special sealing joints. In this case, the sealing material adheres to both sides of the joint and is fully elastic along the entire length of the joint. Expansion due to temperature variations and minor settling can therefore be compensated for, and the channel will not leak. The expansion joints can beviewed from above, which makes inspection and maintenance easier.
The number of passengers at Schiphol Airport increased by 4.3% in the years from 2004 to 2006 while the total air freight tonnage increased in the same period by 5.3%, and there is no end to the growth in sight.In the year 2006, more than 440,000 flight movements were registered.A seventh runway is already being considered, but there are problemswith noise protection for downtown Amsterdam, which is only 15 km away, and the surrounding communities. For more than 20 years, a utopian plan has existed to relocate the entire airport to an island in the North Sea about 30 km from the Dutch coast. The project is still considered to be too expensive today and remains an option for the future.
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