Every time they demolish a building by implosion, all the top experts are called in to use the most hi-tech gadgets & latest explosive charges. Recently it was a sports stadium somewhere as shown on the evening news. The first screen shot was the man pushing the plunger & then cut to the shot of the stadium falling in on itself.
The only thing can come up with is that the mechanical action of the plunger starts a small generator spinning that produces the current needed to set off the charges. But why not just use a battery, or local power?
Isn’t the plunger a romantic image of days gone by? You’d think they could just push a button or something. Heck, why not go back to lighting a mile-long fuse, or a trail of gun powder a la Bugs Bunny.