I am skipping around the propulsion types because I want to cover sail power in depth. Steam power was developed for shipping back in the early 1800’s. Experiments with steam powered ships were actually conducted back as early as 1704 by Frenchmen Denis Papin. Work continued over the years and the first known steam powered ship was developed in 1774. There is a patent dated 1737 in England for a steam powered ship.

Robert Fulton is credited with the first commercial application of the steam powered ship in 1804. He had seen steam powered boats while in England and France. He was also very aware of earlier steam powered boats from both countries. Fulton only applied the technology to his designs and made it practical. His major contribution was a hull design that allowed the weak steam engines of the time push a boat through the water. It should also be noted that screw, propeller, designs and even paddle wheel designs of the time were not effective.

Steam ships of this time used either coal or wood to power their boilers. Both fuels caused their own dangers and large amounts of weight to the ship. Coal remained the dominate fuel for steam ships until the early part of the 20th century. The United States became interested in the Hawaiian Island because of the need to coal ships in the pacific. Coal was not without its hazards. Coal dust could explode in the coal bunkers and cause catastrophic results, example USS Maine.

Coal bunkers were used as a layer of protection in most ships. The bunkers were placed around machinery spaces as a buffer to damage. It was felt if a coal bunker took a hit it would prevent damage to the engine rooms and allow the ship to maintain watertight integrity. This same design feature was carried over to oil tanks and later fuel tanks on ships. Steam power is still in use on many of today’s ship, although that number is decreasing. Today’s steam powered ships still use fuel to heat water and others use nuclear reactors.

Here is a quick down and dirty explanation for steam power. Most systems are closed double loop type systems. One side is called the steam side while the other is called the wet side, or water side. On the wet side there is a firebox and two sets of heat exchangers. One set is in the fire box while the other is located in the steam generator. The water on this side is under pressure and pumped through the system. The water is heated and circulated through the system. In the steam generator there is another heat exchanger. The hot water on the wet side heats the water on the steam side creating steam. The steam is also under pressure. The high pressure steam is them forced across a turbine and then travels to the condenser. The steam turns back to water and the cycle is repeated.

So, at home take a tea kettle put it on the stove, heat up the water inside, hold a pin wheel over the opening and when the steam hits the pin wheel it spins. That is basically how it works in on a ship, but on a much larger scale.

Steam will continue to be sued to propel ships for many years to come. The only difference in the future will be how to heat the water.