“Structure built for viewing purposes.”
Investigations are still ongoing into the March 2009 collapse of the Cologne city archive, though it’s pretty clear that subway tunnel work caused the tragedy. The five-year statute of limitations will expire in only one year. Engineers and the district attorney are now working together to find out how exactly what occurred, including building a fascinating “viewing structure,” 30 meters deep, into the relevant subway support walls and possibly shifting soil layers. Which is good inter alia because the massive stone walls of Cologne’s 800-year-old cathedral, one of the world’s few ships of time, which were strong enough to survive WWII bombing may be being damaged by vibrations from a new subway tunnel that went into operation in December 2012.
Update on 18 Jan 2014: Cologne prosecutors filed charges against ~100 people, including employees of the office responsible for the project, Cologne Transport Services [Kölner Verkehrs-Betriebe, KVB], and of three construction companies and one subcontractor firm, who were working as inspectors, planners, “projecters” and construction workers.
The Kölner Stadt-Anzeiger said the scenario currently favored by prosecutors for causing the collapse of Germany’s most important municipal archive is that there was a hole in the wall of the subway tunnel under construction, through which water continuously got into the tunnel, creating a hole between the tunnel and the historical archive.
Two people died in the collapse. Ultimately, about 95% of the (unique, irreplaceable) historical documents kept in the archive were recovered from the wet sinkhole, Spiegel.de reported, but it is estimated that it will take about forty years to restore them. The Cologne archive had ~30 kilometers of shelves. About 60,000 of the recovered Cologne documents have been distributed to multiple archives in Germany for restoration and digitization.
Update on 24 Feb 2014: Charges have been filed, but it may take years for the trial to start as engineering investigations continue. Spiegel.de said they’re now focussed on “lamella 11” in an underground “huge construction” called a “slotted wall” or “slurry wall” [Schlitzwand]. After a sudden flood of water bursting in from underneath was ruled out by an expert [a so-called hydraulischer Grundbruch], the current scenario is that lamella 11 may have been damaged during final tunneling work, “but although the foreman should have noticed it no notification was made to construction management” because, it is assumed, they wanted to be done. There was serious cost pressure to finish, among other pressures. In this scenario the records documenting the work may also have been manipulated shortly thereafter. Divers are now using the Besichtigungsbauwerk to search for more evidence, presumably contending with even more interesting pressure differentials as Seattlites discovered after the breakdown of our giant tunneling machine in December 2013.
(Beh ZICHH tee goongs BOW verk.)