The use of plate iron in ship construction was not new in 1855. As early as 1822 a commercial steamship, the Aaron Manby, was launched with an iron-plate hull. Design improved rapidly. By 1832, a British merchant ship with an iron hull, the Alburkah, was able to complete an ocean voyage; in 1838, Britain also launched the transatlantic liner Great Britain. The Nemesis, the first iron warship, was put into service for the British East India Company in 1839. Nemesis was used with great success in the First China War (1841-43) on the Canton River, where it joined in the bombardment of Whampoa. The Royal Navy went on to order three shallow-draught iron ships in 1840 for work on the Niger River.
Iron construction had a serious disadvantage when it came to warships, however: iron is brittle and tends to break when hit by shot, unlike wood. As a result, navies were slow to adopt iron or even ironclad vessels (the latter with iron plate protecting a thick wooden hull, in an effort to combine the advantages of both wood and iron). It was the destruction of the Turkish fleet by Russian shells at Sinope in 1853 that renewed interest in providing warships with some sort of armour. When the results of the bombardment of the Kinburn forts by the iron vessels Dévastation, Lave and Tonnante became known, the French Navy again attempted to gain the technological edge over the numerically dominant British Navy. They immediately began converting the French fleet into ironclads by providing a girdle of wrought iron as protection against shells.
The Explosive Shell
The gunnery developments of the Franco-British wars and the War of 1812 had mostly taken the form of improved training for gun crews, rather than changes to the guns themselves. For some time after 1815, the only significant innovation was the introduction of percussion caps to fire guns, introduced in the 1820s, followed by the creation of a British gunnery school in 1829. Improved designs, including experiments in rifling the bores of ship artillery and attempts to create a breech-loading gun, usually had discouraging results. A fundamental difficulty was that most cannon were made of wrought iron, which tended to have weak spots that could cause the gun to explode under high pressure. A particularly notorious example of an experiment that went wrong was the testing of the ‘Peacemaker’ gun aboard the US steam sloop Princeton in February 1844. The gun was fired successfully several times before it burst, killing eight people, including the Secretary of State and the Secretary of the Navy. After the Peacemaker explosion, the US Navy not only turned against further experimentation, but also ordered that naval guns should be fired with only half charges.
While still using essentially the same gun design, however, the adoption of explosive shells for shipboard use had a massive impact on naval warfare. In the early years of the nineteenth century, it was rare for a ship to be sunk in battle. A ship’s great guns most often fired solid shot, which was essentially an anti-personnel rather than anti-ship munition. Even when a shot passed through the hull of a vessel, it made a clean hole that could usually be plugged. So long as enough of her sails and rigging remained in place to allow for manoeuvre and enough crewmen remained to handle the ship, man the guns and repel borders, a warship’s ability to withstand to heavy fire was extraordinary. An extreme example is the British ship Impregnable, which more than lived up to her name in an August 1816 attack on Algiers. By the end of the day, she had suffered 233 large shots in her hull, but was still seaworthy enough to reach Gibraltar for repairs.
This all changed with the explosive shell. Shells had long been employed on land but had seen only limited use at sea, generally aboard bomb ketches for shore bombardment. In the 1820s, however, use of shells became more widespread, despite a general feeling among naval personnel that they were barbarous and cowardly. The explosive shell of the 1820s was fired at low velocity, intended to lodge in the side of a ship rather than going through. Once it was in place, the shell would explode, tearing a large, irregular hole that was hard to patch.
Once again, it was a weaker naval power, France, that took the lead developing the new technology, hoping to offset Britain’s naval superiority. Henri Paixhans developed an effective shell-shooting gun, which had the additional advantage of being lightweight since the shells were fired with only a small charge. These shell guns became part of the regular French armament in 1824. Britain responded with experiments, adopting a gun that could provide an 8in (20cm) shell in 1838.These new weapons were inaccurate and unreliable – but they could destroy a wooden ship in minutes.
The Crimean War, fought from 1854 to 1856 between Russia on one side and a British-French-Turkish alliance on the other, drove home the lessons of this new technology. In the Crimean War, ships and their crews were pushed to the limit of what wooden sailing ships could perform, and often beyond. Military technology was beginning to make them obsolete. The utility of steam and the horror of explosive shells found an international showplace that led to a series of innovations, including the first ironclad ships.
Even before the Crimean War broke out, the Russian Navy demonstrated the military potential of explosive shells in no uncertain terms at the Battle of Sinope in November 1853. European navies had for some time enjoyed a crippling advantage over Ottoman Turkish fleets in terms of ship handling and fire discipline. Sinope moved this naval superiority to a new level. The engagement took place following a storm that forced the Turkish Vice Admiral Osman Pasha, with a squadron of seven frigates, two corvettes and several transports, to take refuge in the Black Sea port of Sinope. Russian Admiral Paul Nakhimov arrived with three line-of-battle ships and several smaller vessels.
Although the Turks were protected by shore batteries, the Russians entered the harbour in heavy mist, a manoeuvre that was possible only because some of the Russian vessels were steam powered. Once there, they opened fire on Osman Pasha’s flotilla. A furious six-hour fight ensued, the Russian ships relying heavily on shells rather than shot. At the end of the day, a single Turkish paddle steamer escaped the carnage. The rest of the Turkish squadron had been sunk, rather than disabled or burned.
Although there were no fleet engagements in the Crimean War, the Allied navy played a key role not just in transporting troops, but also in attacking a number of ports. In 1854, the siege of Sevastopol made a mockery of naval aspirations. The British admiral who commanded a large squadron there was not willing to expose his ships to the fire from the major shore batteries; only the French admiral’s threat to go in alone led the British to take grudging part. In fact, the technology was not up to the challenge. The French were able to move their heavily armed warships into a position from which they could bombard the shore only by lashing steam tugs to their sides – military planners were beginning to expect ships to be able to move against the wind. Yet, even when the Allied fleet began its bombardment, it did little damage; the naval commanders feared the plunging fire of shells from the batteries and stayed at the extreme range of their own guns. On the first day, Allied ships fired 700 gross tons of shot with little effect. The next day, they tried again, and again failed.
At first, matters were the same in the Baltic. An Anglo-French fleet bombarded the Russian naval base at Kronstadt, but it was able to withstand the onslaught. As had been the case for centuries, wooden ships had little protection against the heavy, often heated shot of shore batteries, not to mention shell. The Russian forts at Kinburn on the mouth of the Dnieper were, however, forced to surrender to Allied assault in October 1855.What turned the tide were the three French ‘floating batteries’ – the Dévastation, Lave and Tonnante. These rectangular batteries, with 10cm (4in) of iron plate protecting 43cm (17in) of wood, were dragged into range of the shore batteries. There they set to work destroying the fortresses, suffering hardly any damage themselves in the process. These three vessels were the world’s first ironclads.