Centuries ago, perhaps a gunner accustomed to firing his cannon became captivated with the idea of getting a second bang—not from his weapon but from the projectile at the target-end of its trajectory. Whatever its genesis, the weapon developed to achieve this goal was the mortar, and the only way devised to get the “second bang” was to use a fused projectile. The firing process was very hazardous and dependent on the experience and skill of the gunner to elevate the weapon, estimate the right amount of propelling charge for the range at hand, trim a fuse to the right length to have it explode on target, and then light the fuse before firing.
So many variables were involved that the mortar really was only good against the likes of massive land targets—stationary fortresses and castles. Warships needed guns capable of greater accuracy with which to fight other ships, with relatively flat trajectories so that they could be aimed more precisely at a target, but for centuries only high-trajectory mortars and howitzers fired exploding projectiles. By the early 19th century, navies were taking mortars to sea for shore bombardment in specially designed ships called bombs.
French artillerist Henri-Joseph Paixhans (pronounced “pay-kahn”) emerged from the Napoleonic wars with a persistent feeling of shame concerning the total defeat of his country’s navy in the late extended conflict. He thought there must be some way to overcome the vast superiority of the Royal Navy. In 1822 Paixhans, knowing that a certain percentage of round shot fired against an enemy ship penetrated far enough to remain embedded in the hull, published a treatise laying out a concept whereby exploding shells could be used against Britain’s “wooden walls.” If embedded shells could be made to explode, the results would be devastating. He began work to develop a fusing system to accomplish this end.
By 1824 the artillery colonel had created a wooden fuse that would be initiated by the cannon’s propelling charge but would not ignite the shell’s explosive charge until some seconds after the projectile’s calculated time of flight. The expected result when the shell was fired from a flat-trajectory gun was that it would strike and lodge itself in a wooden hull and then explode to shatter and enflame the structure.
Two smoothbore muzzle-loading Paixhans guns having been cast, a firing test was arranged using the obsolescent two-decker Pacificateur as a target. The experiment was an unqualified success, with the gunfire reportedly having “broken up the ship.” In 1827 the French navy ordered 50 Paixhans guns, called Canons-obusier of 80, as they could fire solid shot weighing 80 livres (86.5 pounds) and shells weighing 56 livres (60.5 pounds). Powder charges ranged from about 10 to 18 pounds. The guns had 8.65-inch bores, were more than nine feet long, and weighed over 7,900 pounds. Production proceeded slowly into the 1830s. Other countries, especially the United States and Russia, were impressed with the new weapons and set about producing their own.
In 1839 Navy Secretary James Paulding ordered Captain Matthew Perry to conduct gunnery experiments at the Sandy Hook, New York, proving grounds. The tests included Paixhans as well as conventional guns firing at targets from 800- and 1,200-yard distances. These were followed by later tests using the steamer Fulton II. A contract for 8-inch Paixhans guns was let with Cyrus Alger’s South Boston Iron Works in 1841, with the intent of mounting a number of the weapons in each ship-of-the-line and frigate. By August 1842, Alger had delivered 22 of the guns, with 12 having been mounted in the monster Pennsylvania, 4 in the Constitution, and 2 in the Levant. The remaining four were retained in stores. (In the Constitution’s case, a portion of the spirit locker was appropriated to create a magazine for the 152 rounds authorized for the guns.) The Navy placed an order, for 25 10-inch Paixhans guns with the Columbia Foundry in 1842. Some later saw action in shore bombardments during the Mexican War.
But the Paixhans’ “big moment” came in November 1853 in a Black Sea harbor. A war between Russia and Ottoman Turkey was almost two months old at that point, with fighting in the Caucasus and along the Danube. Russian Rear Admiral Pavel Stepanovich Nakhimov was patrolling along the Anatolian coast with a small squadron when he came upon a Turkish man-of-war entering the harbor at Sinope on the 23rd. Investigating, he saw that an enemy squadron was present. Taking station off the port, he sent for reinforcements from Sevastopol. Some had arrived by a week later, and Nakhimov decided to attack before additional Turkish forces appeared.
Placing his six ships-of-the-line, two frigates, and two steamers in two columns, the admiral attacked the anchored Turkish force of seven frigates, three corvettes, and two steamers. Gunfire from the Paixhans on board the Russian ships proved devastating, sinking or running aground all but one agile small steamer, which escaped. The guns then destroyed two shore batteries and every other enemy vessel in the harbor. The Russians suffered about 270 casualties in the battle; the Turks, about 3,000. Later, after the French and British actively intervened in what became known as the Crimean War, the former employed Paixhans-armed floating batteries to smash Russian warships and shore batteries.
The message was clear: Paixhans guns were both the death knell of wooden warships and heralds of a new era of naval warfare. Soon, the French commissioned the first ironclad warship, the Gloire, which was followed 13 months later by HMS Warrior, the world’s first iron-hulled warship. In the United States, Lieutenant John A. B. Dahlgren, a naval ordnance officer, had become well aware of the performance of the Paixhans guns. But he thought that the weapons were inaccurate and deficient in range, and set about designing shell-firing guns that corrected these problems. By the Civil War, he had designed a range of muzzle-loaders, some rifled, with up to 20-inch bores (see “Armaments & Innovations: The Soda-Bottle-Shaped Shell Guns,” June 2013, pp. 10–11). His 9-inch design was the most popular in service, with nearly 1,200 produced by war’s end.
But technology was experiencing something of a golden era and the Paixhans’ day was past. During the postwar period, rifled—usually breech-loading—cannon became more common. More sophisticated mechanical fuses were created. And the advent of the Bessemer process led to ships armored with high-quality steel and naval rifles firing a variety of special-purpose projectiles at targets miles away.