Such cylinder and piston arrangements are essential to early steam engines as well as modern internal combustion engines.
The first steam engines worked by filling a cylinder with steam, then con-densing it to water. The vacuum created drew the piston into the cylinder. These “atmospheric” engines were useful for pumping out mines and other tasks where their weight was not important. They were far too heavy and bulky to use aboard ships, however. James Watts’s improved steam engine drove the piston in the opposite direction — expanding steam, rather than atmospheric pressure on a vacuum was the driving force. Such engines could be made small enough to power a ship. Their earliest use was to turn a pair of huge side wheels.
Steam gave navies a great strategic advantage. Steam warships no longer depended on weather and could cross the oceans much faster than sailing ships.
“Seizing the weather gauge” (maneuvering into the best location to take advantage of the wind) had long been a favorite tactic of British seamen. It no longer gave any advantage. For that reason, Britain, although it was the home of the first steam engines and it utterly depended on its navy for its primacy in world affairs, tried to retard the development of steam-powered ships. British naval personnel were the most skilled in the world; British shipyards devoted to building sailing men-of-war were the biggest in the world; British technology in preserv-ing food for long journeys, manufacturing the heavy, short-range cannons, called carronades, and everything else needed for wooden, sail-driven warships, led the world. If the world’s navies went to steam, all of that would be worthless.
In 1828, the British admiralty expressed their views on steam-powered warships:
Their lordships feel it is their bounden duty to discourage to the utmost of their ability the employment of steam vessels, as they consider that the introduction of steam is calculated to strike a fatal blow at the naval supremacy of the Empire.
In spite of the size of the British Navy, this policy bore more than a little resemblance to the actions of an earlier British authority figure: King Canute, who tried to tell the tide to reverse itself. The American, Robert Fulton, had built a working steam ship as early as 1807. In 1837, the paddle wheel steamer Sirius crossed the Atlantic in 18 days — breathtaking speed in an era when Atlantic crossings were measured in months.
Although the new method of propulsion had manifest advantages, the world’s navies did not immediately board the steamship. The French started building steam warships in the 1840s, but they did so on a small scale. There were a number of reasons for this slow progress. There was the natural conservatism of sailors and military men, and that the British, owners of the world’s most powerful navy, professed to see little value in the new technology. And, most important, there was the fact that the early steamships could not survive a battle with sailing warships of comparable size. The huge paddle wheels on each side of the vessel were vulnerable to gunfire, and they made it impossible for the ship to carry enough cannons along the side to match the broadsides of a sailing ship. Another drawback was that steamships could not stay at sea nearly indefinitely, as the sailing ships could. They had to be near a supply of coal.
The paddle wheel was the first drawback eliminated. In its place, ship builders used the screw propeller. The new device had to rotate much faster than a paddle wheel, which meant both major changes in gearing and much more efficient engines. John Ericsson, a Swedish engineer, invented both a screw propeller that worked and an engine to drive it. He sold the designs to the U.S.
Navy, and in 1842 the U.S.S. Princeton became the world’s first screw-propelled steamship. Princeton’s engine and drive shaft were located below the waterline for protection, and the ship was able to carry enough guns for a broadside. In 1843, the British steamer Great Britain became the first screw-equipped ship to cross the Atlantic.
The age of steam had arrived. Ship builders were still hedging their bets by equipping their vessels with masts and rigging that could be used if the engine failed, but it was hard to navigate a paddle wheeler using sails alone. Screw propellers made sailing easier, but even the propeller caused interference.
The next major improvement in warships was adding armor (something we’ll look at in the next chapter). Another huge advance in steam engines after the introduction of armor was the steam turbine engine, which used a spinning wheel turned by rapidly expanding steam to propel the vessel. These engines made possible the high-speed torpedo boats that threatened the supremacy of the battleship at the turn of the 19th and 20th centuries. At the British Jubilee Naval Review in 1897, the steam launch Turbinia stole the show as it dashed in and out of the line of battleships at the unheard-of speed of 34 1/2 knots. We’ll have another look at these torpedo boats in Chapter 26 on the “locomotive torpedo.”
Chapter 22
Iron Floats… and Sinks: Armored Ships
In 1592, Toyotomi Hideoshi, the only peasant in Japanese history to make himself supreme ruler of that ancient empire, invaded the neighboring land of Korea. Hideoshi, called “Old Monkey Face,” but not to his face, was a man of immense ambition and the energy to match it, although his esthetic tastes ran more to gold chamber pots than to his country’s exquisite poetry. After Korea, he planned to conquer China and then the Philippines.
He never quite made his first goal (Korea). The biggest reason was a Korean secret weapon and an admiral named Yi Sun Shin.
While the Japanese fleet was unloading at Pusan, several strange-looking objects moved into the harbor. They had no sails. They may have been towed or rowed — accounts differ. All agree, however, that they looked like immense metal turtles. Below their curved iron shells, Yi’s turtle boats had rows of cannons.
That day the turtle boats, designed by Yi himself, sank 60 Japanese ships and stalled Hideoshi’s invasion at its opening.
The Japanese eventually began moving up the peninsula. At that time, the Japanese army had more guns per capita than any other in the world — including anywhere in Europe. Almost all of their guns were matchlock harquebuses; they had few cannons. The Koreans had few handheld guns, but quite a few cannons. And they had allies. Chinese troops flooded into the peninsula. The Japanese were better armed, better trained, and more experienced soldiers, but they couldn’t match the Chinese numbers. Then Yi Sun Shin returned with his turtle boats. In 1598, at Chinhae Bay, Yi and his ironclads sank 200 of the 400 Japanese ships. Yi lost his life in the battle, but he saved his country. The rest of the Japanese fleet fled back to Japan, where they brought news of the disaster to the ailing Hideoshi, who promptly died. The Japanese invasion died with him. Korea was to be free of Japanese troops until 1910.
Fast forward 270 years. Yi Sun Shin and his works have been forgotten everywhere but Korea. In the United States, no one is interested in old tales from exotic places. The country has split into two parts, North versus South, and brothers are fighting brothers. Ships from the North, what is left of the United States, or the “Union,” are blockading ports in the South, or the “Confederacy.”