Years ago I recall seeing a film produced by CEGB I think where a
fault was deliberately applied to a set of high voltage busbars in a
grid switching station. The bars started to vibrate and under
resonance the amplitude built up until the bars touched and
spectacularly vapourised. An associated film showed an oil filled
transformer exploding when the oil level fell due to simulated leakage
without protection systems.
Try as I might I can't find any references to track these films down
through google.
Anyone out there with any knowledge of them?