Primarily remembered for designing the first iron-clad warship, Ericsson wasborn in the Värmland region of Sweden and displayed an early talent forscience and mathematics. As an adolescent he worked as a draftsman on the Swedish Göta Canal project and later served as a land surveyor in the Swedish Army.
Ericsson went to London, England, in 1826 to pursue a career in engineering.During the next thirteen years, he developed an interest in propulsion systems, making several improvements to steam engine design, experimenting with theuse of compressed air for power, and working on a device he termed the caloric engine. In 1829, Ericsson and John Braithwaite designed and built a locomotive which they entered in the Rainhill Trials, a competition to find the best new locomotive design. The competition was won George Stephenson's famous locomotive, the Rocket. Ericsson later turned his attentions to naval engineering. His innovations in ship design include placing the engines below the waterline and replacing the commonly used paddle wheel with a screw propeller. These design modifications considerably reduced the vulnerability of ship propulsion systems to damage from hostile fire. In 1837 a ship incorporating these design elements, the Francis B. Ogden, was successfully launched.
In 1839 Robert Field Stockton, a captain in the U.S. Navy, brought Ericsson to the United States to build the engines and propulsion system for the U.S.S.Princeton, the first propeller-driven, steam-powered, iron-hulled warship. During an 1844 demonstration attended by President John Tyler, one of the Princeton's guns exploded, killing the U.S. secretary of the Navy and several others. No blame, however, was attached to any of the designers. Ericsson became a naturalized U.S. citizen in 1848.
During the Civil War, Ericsson presented the United States government with adesign for a new type of heavily armored warship. Built in 1861 and launchedin January of the following year, Ericsson's vessel, dubbed the Monitor, was the first completely iron-clad warship. Driven by a steam-powered screw propeller, the Monitor had a low box-like shape, 172-feet long, andwas armored with five inches of iron plate on the sides and one inch on the deck. The Monitor's two eleven-inch guns were enclosed in a deck-mounted turret covered with eight inches of iron plate and rotated by steam power.Soon after the Monitor was launched, Confederate forces salvaged a ship called the Merrimack(also known as the Virginia) and coveredit with iron railroad track.
On March 8, 1862 the Merrimack sailed into the harbor at the mouth ofthe James River in Virginia and used its ten guns to sink two wooden-hulled Union warships. While the Merrimack attacked a third ship on the following day, the Monitor arrived on the scene. The two iron-clad vessels exchanged numerous rounds in a heated battle. When the Merrimack scoreda direct hit on the pilothouse of the Monitor, the captain of the Union vessel was blinded by flying iron fragments and let his ship wander into shallow water. The crew of the Merrimack concluded that they had won and returned to their home base leaking water and low on ammunition. The Merrimack's success in sinking wooden ships served as a propaganda victory for the Confederacy, but most commentators either interpret the battle betweenthe two iron-clad ships as a victory for the Monitor or find the results inconclusive. Never particularly seaworthy, the Monitor sank during a storm in December 1862 with a loss of sixteen lives.
Ericsson went on to design and build other monitor-type vessels for the U.S.government. He also experimented with torpedoes and investigated uses for solar energy. After his death in 1889, Ericsson's body was returned to his native land at the request of the Swedish government. Monitors of Civil-War era design were used by various navies until the early part of the twentieth century, last serving as submarine tenders during World War I before being scrapped. Monitor-class vessels of modern design have been used by the United States,the Soviet Union, Britain, and Romania as river gunboats and landing craft.
Few seem to know that Ericsson was a true mechanical genius who, as a very young boy, constructed models of machines he had never seen and that had only been described to him. In one instance, despite never having seen a windmill,he correctly sketched the mechanism that connected the windmill crank with the power lever. Once Ericsson's prodigious talents were brought to the attention of the president of the Gotha ship canal project, the twelve year old boywas made a member of the canal surveying team and was soon directing the workof some 600 soldier/laborers. So respected was the twelve year old that thearmy assigned one soldier to do nothing but carry a stool for the young engineer to stand upon while he used the tall surveying instruments.