The Evolution of Transportation
People and things have always had the need to move or be moved from one place to another. People have always looked for more comfortable or quicker ways to travel. Transportation is a way people and things move from one place to another. Different environments require different methods of transportation.
People have invented machines, called vehicles or crafts, to travel. Some vehicles travel on the ground, like a train. Some vehicles travel on top of the water, like a jet ski. Some even help people to travel under the water, like a submarine. People use other types of crafts to travel in the air. A hot air balloon is an interesting way to travel through the sky.
Crafts such as rockets can help people to travel into space. Over the centuries, inventors designed machines or improved ways of traveling to move people faster and faster.
Ships and Boats
One of the earliest ways to transport people and things was by traveling in the water. Boats are small crafts generally used for a special purpose like fishing. Ships are larger crafts that might use sails or an engine to propel them through the water. They may travel on rivers, lakes, or oceans.
Boats With Paddles
People use flat wooden boards called paddles to row small boats. An oar is another name for a paddle. A raft is a simple boat with a flat bottom. We can make a raft using tree trunks or logs. Sometimes, flat pieces of wood called planks are bound together to make a raft. Some rafts are made of rubber or a plastic called vinyl. These rafts are often inflatable.
Early Native Americans made canoes out of tree trunks. They hollowed out the trunk and used a paddle to move from place to place. Today, an artificial substance, made by man, called fiberglass is a popular material for building a canoe.
A kayak is a sleeker version of a canoe with one or two small holes. The holes are where people sit. A rider may attach a watertight skin or enclosure to prevent water from getting in the boat. The boat can turn all the way over without sinking. Some people compete in kayak races. The Olympics have had a kayak event since 1936.
Boats With Sails or Motors
Other boats and ships use different types of power. A sailboat uses pieces of canvas or other fabrics called sails, which are filled by the wind fills and pushes the boat forward.
Ancient Egyptians used sailboats to move the stones for the Great Pyramids from Aswan to Giza. Pilgrims traveled from England on a large sailboat called the Mayflower to reach America in 1620.
A motorboat uses an electric motor and propellers. Propellers are turning metal blades that help the vessel to move through the water. A speedboat is a small, but very fast motorboat. Speedboats pull water skiers, help the Coast Guard or marine patrol on rescue missions, or might even compete in a race.
Larger Boats and Ships
Most large ships are made of metals like iron or steel. They use giant propellers powered by engines to move through the water. A steamboat is a large boat with paddles. A steam-powered engine turns the paddles to move the boat.
The biggest ships are tankers and aircraft carriers. Oil tankers can carry millions of barrels of oil inside huge cargo areas. Designers built tankers to travel long distances and other than oil, they may transport water, chemicals, or liquefied natural gas.
Aircraft carriers are long, flat warships designed to act as a floating airbase. Planes take off and land on the runways on the top of the ship.
A submarine is a metal ship that can travel underwater. A submarine can be small enough to carry one or two people and remain underwater for a few hours. They can also be very large, have a crew of over eighty people and remain underwater for a few months.
A train is a vehicle that runs on tracks, or rails. Passenger trains may have many compartments for people to travel from one place to another. Freight trains carry cargo, or things. Different cars transport different types of items.
Refrigerator cars transport food. Container cars need a crane to lift cargo in or out of the car. Tanker cars transport different types of liquids.
People sometimes use the term light rail to talk about trains that run on city streets. A trolley, also called a streetcar, is one type of light rail transportation. The first streetcars were pulled by horses or even people. Modern streetcars usually get their power from electricity. Electricity makes things run.
A subway is a light rail system of cars. A subway runs on the street and in underground tunnels. Many large cities have a network of subway tunnels.
Big trains have wheels that run on railroad tracks. They travel long distances between cities and towns. The first car on a train is the locomotive. The locomotive powers the train. The first trains used steams engines. Today, most trains get power from using gasoline or electricity. High-speed rail trains are electric trains that run faster than a regular train, sometimes called a bullet train. These high speed rail systems also transport people in Germany, Korea, and Spain. The first countries to build and use the bullet train are the countries of France and Japan.
The monorail is another type of train. Most monorail systems run on a single rail. Some monorails are suspended. The train cars actually hang from the track.
People drive and are passengers in motor vehicles in most places of the world. Motor vehicles have wheels and a motor. They can be driven on many different land surfaces. Cars, buses, and trucks allow people and things to travel to certain places. They can travel where boats and trains cannot go.
Cars are vehicles used by people to get from one place to another. Combustion engines are often the power source for cars. This type of engine burns gasoline or diesel fuel to run. Some people are concerned that combustion engines are contributing to pollution in the air.
Inventors are developing other types of power systems to make cars run. Electric cars have electric motors that run on batteries. Some cars use hydrogen to provide power. A hybrid car uses a combustion engine and battery power to make the car work.
Cars vary in their size. A limousine is a long car, which has space for many passengers and has a chauffeur to drive the vehicle. A micro-car, also called a bubble car, is very popular in countries outside of the United States. Auto makers designed the microcar to use less gas. It is also economical because a small amount of material is necessary to build the car.
Some people like to drive a sports car. The fastest cars are race cars. Some cars have special features, like convertible, which have a fabric or hard top that folds back.
Buses are bigger than cars. A bus has a long body with several rows of seats or benches for passengers. Buses usually operate on a schedule. A passenger bus can carry people long distances. They travel between different cities and towns. A tour bus carries tourists or people on vacation. Some people charter, or rent, a bus for special purposes.
Vehicle engineers designed trucks to carry materials of all kinds. Pickup trucks are a bit bigger than cars. They have a flat bed behind the passenger compartment. They can carry many things in the flat bed. Large trucks transport different kinds of heavier materials or equipment. They carry things to places where trains and boats cannot travel. An 18-wheeler is a very big truck. It has 18 separate wheels.
Hot Air Balloons, Blimps and Dirigibles
Aircraft are vehicles or machines that let people travel through the air. The first type of air transportation was the hot air balloon. It is the oldest successful human carrying technology for flight. It floats using a large bag of silk or nylon filled with heated air. People travel in a wicker basket called a gondola, that hangs underneath.
A blimp or dirigible is like a balloon. The gas helium fills up the balloon to help it float. It has a motor to push it forward. This type of craft was very popular before 1940.
As technology for airplanes improved, people stopped using blimps to travel. Today, advertisers use blimps to market their products. Some companies offer sightseeing tours in a blimp.
Airplanes, Gliders, Helicopters
An airplane is an aircraft that flies using wings and an engine. The Wright brothers receive credit for the invention of the first airplane in 1903. Airplanes can be small and carry only one or two people. Commercial airplanes can be large and carry many passengers a long distance in a short amount of time. A motor makes the propellers turn. Most larger airplanes have jet engines. This type of engine has many turning blades inside. They move air much faster than ordinary propellers.
Jet airplanes use turbines to make them move faster. The military uses supersonic aircraft, such as fighters or bombers, to move quickly with a great amount of power. A fighter jet is a small military airplane that can go very fast. The Concorde is one of the only supersonic planes used as a commercial airplane. It carried passengers from Europe to America in less than half the time it took for a regular airplane to fly the same distance. The Concorde was very expensive to fly. Due to rising costs, the Concorde was retired from use. The last Concorde flight was on October 24, 2003.
A helicopter is an aircraft with a large propeller on top. It can rise into the air, or take off, straight up. A helicopter can take off without using a runway.
A glider has a similar shape to an airplane. It uses only the wind for power. The military may use gliders to deliver troops. Gliders are very quiet because they don’t have an engine. Some people participate in glider competitions.
A rocket is a vehicle that travels into the air at a very high speed. It burns fuel to make thrust. Thrust pushes, or propels, the rocket upward. A rocket engine ejects the thrust out of the bottom of the rocket. A lot of energy is required to propel a rocket into space. Energy is necessary to make things happen. Astronauts and cosmonauts are people who travel into space using rockets. Rockets also transport the satellites into their destination orbit. Satellites study the Earth and other objects in the universe.
Rocket Design and Travel
Multiple sections or stages make up the design of most rockets. Each stage contains its own fuel supply and rocket engine.
When its fuel is used up, a rocket is released. This lightens the weight of the rocket. It allows it to travel faster. A rocket needs to travel at least 17,700 miles per hour, (28,500 kilometers) to make it out of the atmosphere into space, which is the so-called “escape velocity”. The part of the rocket that actually reaches space is often called a spacecraft.
Some rockets get extra thrust from booster rockets. The scientists usually attach the boosters to the side of the main rocket. The space shuttle is both a rocket and an airplane. It releases two booster rockets. As the rocket uses up its fuel, it will also release an external fuel tank. The space shuttle lands like an airplane when it returns to Earth.