Siemens Brothers (later taken over by Associated Electrical Industries, who renamed each section accordingly e.g. AEI Telecoms) had set up an electronic switching lab at Blackheath. This lab was headed by John Flood, who had been a founder member of Tommy Flowers' electronic switching team at Dollis Hill. In the Siemens team was an engineer called Jim Warman. It was his trunking ideas (sectionalisation, serial trunking, line scanning, route choice, repeat attempt etc.), which were to be central to the development of the British TXE exchanges.