The intellectual starting point is Henri-Joseph Paixhans and the destructive potential of explosive shells against wooden ships. The doctrine imagined smaller steam vessels using this firepower to upset larger sailing warships. Ironclads such as HMS Warrior changed the calculation because armour could resist the weapon on which the proposal depended. Jeune École advocates therefore had to search for a different means of making capital ships vulnerable.
Chapter · 6:28-9:19
Explosive shells meet the ironclad
The early doctrine rested on explosive shells and small steam warships, before armour transformed the problem.