Spare a thought for the humble neon aircraft obstruction beacon. As seen on many a tall building, mast or crane the 12mm diameter coiled neon tube is not much larger than a modern domestic CFL bulb (compact fluorescent light) but thankfully produces enough light to warn off planes from some considerable distance.
Many of these bulbs were originally produced in the Oldham Claudgen factory in Wembley during the 1980's and early 1990's. Using a process known as electric bending, clear glass tubing was placed inside a metal braided sheath, which in turn was heated by passing an electrical current through it. Once the correct glass temperature was reached, the glass being maliable enough to bend, the whole thing was quickly wound onto a spiral former, where it would be annealed over a short period of time before being removed to be electroded and pumped.
The tubes were electroded using large shelled electrodes (120m/A plus) and neon resevoirs were added to enable the tubes to be run on a higher milliampage for a longer period of time.
Sadly now being replaced by the LED, this one war repaired by myself a while ago, a thing of beauty, now rarely seen.
