 Chain Home could only see targets above 2.5 degrees over the horizon, so these aircraft only became visible at short range.Robert Watson Watt seized several dozen of the CD systems that were in final construction and installed them at CH stations and new locations along the seashore to fill this critical gap in the coverage.CHL remained an important part of the Chain network for the rest of the war, and was retained in the post-war era until it was replaced during the ROTOR upgrades by the AMES Type 80.