With the launching of HMS Warrior in 1860, naval gunners faced a problem: how to pierce the iron hulls of the new warships. Developments from the small arms field helped provide a solution: percussion firing, rifled gun barrels, breech-loading and cordite. Now, massive guns with less recoil and greater accuracy became a reality.
The ideological conflict between the USSR and the West, after the explosion at Hiroshima & Nagasaki, over the next 40 years, remained as a stand-off, never reaching the point of outright war. 'Real' fighting was confined to localized wars where the interests of East & west clashed, such as those in Korea and Vietnam. This 'Cold War' governed arms development during that period.
The mine is the weapon to which the enemy must come. It represents a cool, calculating kind of warfare, one of strategy & waiting. There are no immediate results.
The first torpedoes bore little resemblance to later more familiar designs. Made of elm wood, with copper-lined core of explosive, they had no propulsion of their own. Some were attached to a protruding spar extending like a knight's lance from the bow of the attacking vessel. Others were towed behind the stern on wither side. Both types were detonated by electric wire. The breakthrough came in 1866 when Robert Whitehead, an English engineer working near Trieste in Italy, invented the first self-propelled torpedo.
Until the 1870's, gunpowder was virtually the only practical explosives available. More powerful substances were in existence - in 1847 Ascanio Sobrero of Italy had developed nitroglycerine, and Christian Schonbein of Switzerland had produced guncotton (nitrocellulose) - but at the time these were far too unstable to use in guns and shells. From the 1870s, guncotton, which retained its explosive capacity when wet, was used in mines and torpedoes, but it was only when cordite was introduced into naval service in 1893 that gunpowder was replaced as the main propellant.