This three-part series looks at some of the key instruments of war, their history, the milestones of modern weaponry and the technological leaps performed by innovative engineers and inventors that saved the day but ultimately changed the face of warfare forever. From the cruise missile and the tank to the machine gun the series unpacks the technological shifts that created these machines. From propulsion mechanisms to guidance systems the series reveals how the tank got its track how a submarine fires a missile and how to build a fully automatic gun.