Accordingly, Parliament passed the Electricity (Supply) Act of 1926, which created a Central Electricity Board with the duty of constructing and operating a new transmission system, or grid, connecting the power stations in England, Wales and central Scotland, and adopting a standard frequency of 50 Hz. The grid was to operate at 132,000 volts (132 kV), twice the voltage previously used in the United Kingdom, so it was not surprising that, despite high standards of engineering and design, some operational problems occurred initially.
The most serious problem was the flash-over of the 132 kV overhead line insulators in fog. This flashover—the sparking that occurs around an insulator when subjected to a voltage high enough to overcome its resistance—would cause the line to be switched out, possibly leading to an interruption of the electricity supplied to consumers. In the early 1930s, the fogs in winter were very dense in industrial areas ...
