The Aerial Tuning Inductor (the Rugby Coil)
The Aerial Tuning Inductor (ATI) was enormous. It consisted of five coils, each of eight turns of cable. These were 17ft diameter and mounted on wooden formers, each consisting of six arms made from American Whitewood. They were known a ‘spiders’ because they looked like a spider’s web. The coils were supported on large wooden beams that were mounted 15ft above the concrete floor.
The coils were made by WT Henley’s Telegraph Works Co. Ltd., at their Gravesend factory. The spiders were made complete and part of the factory wall had to be dismantled to get them out and onto the lorry for transportation to Rugby.