schwalbe v

[Lorentzen / Nicklaus]

 "'swallow v' [in berga, thuringia] was the largest underground site in the 
 whole german reich. here, up to 1800 concentration camp prisoners from  
 buchenwald, 800 war prisoners and 500 german miners were, under the supervision 
 of the organization todt, building a huge refinery in which fuel oil should be 
 converted to airplane gasoline. in the beginning of april 1945, shortly before 
 its completion, the site had to be closed because of the advancing americans."

                                 (- "der spiegel" 48/00: 96, own translation) 

kfl