Trenches are created through controlled explosions. New York, America (USA, U.S.A.).
Item title reads - Trench digging by dynamite. A little work with tamps, a lot of powder, BANG! - and the job is done. New York, America (USA, U.S.A.).
M/S of hands depressing a plunger. L/S of massive explosion throwing up earth and smoke. M/S as plunger is pulled up and depressed again, causing another huge explosion. L/S of the trench with water running through, and earth at the side.