Ironclad

The ironclad didn't wait for naval architects to dream it up. It waited for blast furnaces to produce cheap iron, steam engines to replace sail, and explosive shells to punch through wooden hulls. By the 1850s, those conditions had converged.

France moved first. In April 1858, Stanislas Dupuy de Lôme laid down La Gloire, launching her in November 1859. She was a wooden hull wrapped in iron plate, but she was enough. Britain's First Lord realized instantly that every unarmored wooden ship in the Royal Navy had become obsolete overnight.

The ironclad exhibits convergent evolution. France launched Gloire in 1859. Britain launched HMS Warrior in December 1860, iron-hulled, longer, faster. America's CSS Virginia and USS Monitor clashed at Hampton Roads in March 1862. Italy, Austria, Russia all built ironclads in the early 1860s.

None coordinated. All arrived at the same solution because the adjacent possible had aligned: industrial iron production, marine steam engines, and explosive shells created conditions where armor became inevitable.

What preceded the ironclad reveals path dependence from the Industrial Revolution. Steam engines emerged for pumping mines in the 1700s, adapted for ships by the 1840s. Iron foundries built to supply steam boilers could also roll armor plate. Screw propellers replaced paddlewheels in the 1840s. The Crimean War (1853-1856) proved explosive shells could shatter wooden hulls.

Without cheap rolled iron, ironclads wait. Without steam propulsion, they're too slow. Without explosive shells, wooden ships remain viable. The ironclad required all three to converge.

The cascade from ironclads transformed naval warfare within a decade. Wooden ships of the line—perfected over centuries, dominating since Trafalgar—became scrap. Palmerston described HMS Warrior among wooden ships as "a black snake among rabbits." Admiralty stopped wooden construction entirely.

By 1906, HMS Dreadnought made every prior battleship obsolete. That lineage traces to the ironclad's founder effect: once one nation armored its fleet, competitors had no choice. Naval procurement became an evolutionary arms race.

Ironclads exhibit competitive exclusion: they didn't coexist with wooden warships, they replaced them. After Hampton Roads, no navy could risk unarmored ships. The U.S. Navy commissioned 60+ monitors during the Civil War. Britain built 11 ironclads in rapid succession.

La Gloire and HMS Warrior never fired a shot in anger. Their power was deterrence, their impact systemic. By 1870, every major navy had transitioned to iron hulls. The wooden ship of the line vanished in a single generation.