By 1937, the first three stations were ready and the associated system was put to the test. The results were encouraging and an immediate order by the government to commission an additional 17 stations was given, resulting in a chain of fixed radar towers along the East and South coasts of England. By the start of the Second World War, 19 were ready for the Battle of Britain and, by the end of the war, over 50 had been built. The Germans were aware of the construction of Chain Home but were not sure of its purpose. They tested their theories with a flight of the Zeppelin LZ 130 but concluded the stations were a new long-range naval communications system.