Explosive demolitions have a very wide range of military applications, and there are a very wide range of tools available from choices of explosives to choices of detonating systems. When I was serving in the 80s and 90s, the two primary detonating systems were either time fuse or electric blasting caps. Today, “shock tube” initiation is very popular.
Demolitions, especially electrically primed demo, is primarily an Engineer function, though a demolition kit is standard equipment in the Infantry company TO&E, and I was fortunate enough to spend some range time blowing stuff up. Of the two, I greatly preferred non-electric priming, but it was good to have the training on electric systems. And not much has changed since this film was made.