The Kammhuber Line consisted of three layers of zones of about 32 km long (north–south) and 20 km wide (east–west). In each zone there were two German night fighter aircraft receiving ground-directed guidance from their own Himmelbett controller within each zone. While the Himmelbett control center could only handle two fighters, this was adequate for dealing with the RAF Bomber Command tactic of sending its night time bombers individually, with each bomber plotting its own route to the target, to avoid flak concentrations.