In all of these cases the service was confined to specialists that were trained to use the equipment. After the war German police in the British zone of occupation first used disused tank telephony equipment to run the first radio patrol cars. Later radio telephony was introduced on a large scale in German tanks during the Second World War. At the same time, radio telephony was introduced on passenger airplanes for air traffic security. In Europe, radio telephony was first used on the first-class passenger trains between Berlin and Hamburg in 1926. While travelling across the country, he would stop at a cordless phones with answering machine place where telephone lines were accessible and using a pair of long electric wires he could connect to the national telephone network. In 1910 Lars Magnus Ericsson installed a telephone in his car, although this was not a radio telephone. During the early 1940s, Motorola developed a backpacked two-way radio, the Walkie-Talkie and later developed a large hand-held two-way radio for the US military.