{
  "technology":
  [
    [ "Schall-tanks-1", "Schall-tank-1" ],
    [ "Schall-tanks-2", "Schall-tank-2" ],
    [ "Schall-tanks-3", "Schall-tank-3" ],
    [ "Schall-concrete-walls", "Schall-concrete-wall" ]
  ]
}