It could have been worse, said the families and institutions that call the picturesque 17th-century weavers' houses on the Vijzelgracht in Amsterdam home when they saw the devastation in Cologne on March 3. On that day, the building that houses the historical archive in the German city disappeared into a 30-meter deep hole. The collapse left two people dead and much of the archive's irreplaceable collection destroyed.
At least no one was injured when the historical houses on Amsterdam's Vijzelgracht subsided last summer, and all their belongings are safely in storage. But it will be years, if ever, before they can safely return to their homes.
Both in Cologne and Amsterdam, the construction of an underground metro line beneath a densely populated area is widely blamed for the disasters that occurred, and there are more similarities between the line in Germany's fourth largest city and the one under construction beneath Amsterdam's historic heart.
"Visiting Cologne was like looking in the mirror," Jeanine van Pinxteren, an Amsterdam city council member for the environmentalist green party GroenLinks, says. She was part of a delegation of Dutch representatives who visited the German city two-and-a-half years ago. "We were told things were going excellently there," Van Pinxteren recalls.
However, excellent is not a word anyone in Amsterdam would use to refer to the progress on the North-South metro line being built there.
Even before the incidents on the Vijzelgracht, the metro project was plagued by seemingly endless delays and budget overruns. A new executive for transportation, Hans Gerson, had to be appointed this week to take charge of what many consider a flat-out fiasco and a millstone around Amsterdam's neck. His predecessor, Tjeerd Herrema, resigned in February after admitting that the metro line could end up costing 65 percent more than was budgeted in 2002.
Tunnel Digging Has Yet to Start
The city government has been struggling with the construction of Amsterdam's fourth metro line for over a decade. Plans to connect the north of Amsterdam to the rest of the city and, eventually, Schiphol airport, some 15 kilometers to the south, had been in the making for decades before the city council finally approved an €800 million (1.8 billion guilders at the time) budget in 1996. The city didn't start the tender for the North-South line until 2002, and by then it was expected to cost €1.4 billion and destined to be up and running by 2011.
Seven years later, the digging of the seven-kilometer-long tunnel has yet to begin. Instead, people walking and driving around Amsterdam have to navigate the construction pits for the various future metro stations. Those may only be a minor nuisance for tourists, but they have become a disaster for some living on the Vijzelgracht. Twice last year a leak in the concrete wall of the underground station being built there allowed water and sand to flow into the construction pit, damaging the foundations of adjacent buildings. Neighboring houses subsided by up to 23 centimeters and have since been declared unfit for habitation.
Ad van Zwieten, whose family has owned one of the monumental buildings on the Vijzelgracht for over a century, was at home when the first subsidence occurred on June 19. "We heard a pang, pang and another pang and with each sound a new crack in the wall appeared," he told NRC Handelsblad at the time. Van Zwieten and his neighbours have not been allowed to return to their homes and have been told that it will be at least four years, if ever, before they can.
Just up the busy Vijzelgracht is the Amsterdam city archive, which was recently renovated. Like the archive in Cologne, it is located very close to the new underground metro line. Is there reason to fear for its safety? "A little, yes," Jan Maertens, a Belgian professor of civil engineering specialized in underground construction, told NRC Handelsblad right after the accident in Germany. Maertens is an adviser to both the German and the Dutch metro projects and sees several similarities.
To limit the risk of further damage, several landmark buildings on the route -- including the luxury Bijenkorf department store and a branch of the Madame Tussauds wax museum -- have been structurally reinforced, but there is no way to test if these measures will be enough to suffice if new soil shifts occur.
Parallels Between Amsterdam and Cologne
Both Amsterdam and Cologne are located on river banks and are built on sedimentary soil. Both metro lines will run from north to south, cutting through the historical hearts of the cities. The German company Züblin is involved in the construction in Germany and will also drill the tunnels in Amsterdam.
Yet the situation is not entirely the same. The soil in Cologne consists of sand and gravel, known for its supporting power, and buildings there stand on short, concrete poles. Amsterdam, on the other hand, relies on clay, sand and layers of peat, and houses are built on long, wooden poles.
"The similarity is the sand," Maertens says. "When something goes wrong a lot of soil can flow away," he explains, causing immediate subsidences. The shift of sand and underground water seems to be what caused the collapse of structures on the Vijzelgracht in Amsterdam and, with even more disastrous effects, at the historical archive in Cologne.
The Vijzelgracht incidents last summer meant another great setback for the construction of the troublesome metro line. Work on the Vijzelgracht station has come to a halt after the incidents. After a steady rise of the estimated costs of the metro line over the years, the repairs and subsequent delays have added hundreds of millions of euros to the budget, which now stands at €2.4 billion.
The digging of the actual tunnel has been postponed, again, because the work cannot begin until all the underground stations have been finished. It now seems realistic that work on the most ambitious part of the construction project, the tunnel, will not begin until 2010. The idea of extending the line beyond the World Trade Center to the airport isn't mentioned anymore these days, either.
The Vijzelgracht incidents have had political fallout as well. In an attempt to take back control over the project, an independent investigation led by Cees Veerman, a former Dutch agricultural minister, will now review the options for the future of the metro. In theory, Veerman could even propose to cancel the whole North-South line project.