How the Steam Locomotive Works! For Everyone:

The firebox is loaded with wood or coal and a fire is started. (Letter A). The fire heats up the tubes in the boiler. (Letter B). The tubes are surrounded by water. The heated water turns into steam and the steam is trapped in the boiler, thus pressure builds up. The pressure goes to the steam dome (Letter C) then down a three-inch pipe to the front of the boiler and is directed into the brass cylinders (Letter D) in the front of the locomotives. Inside the cylinders are a huge piston (shaped kind of like a big plunger) the steam pressure pushes the piston back and forth using an ingenious alternating system. The moving piston is connected to a large iron arm, which is connected to the big driving wheels (Letter E). The big wheels rotate and the locomotive moves.

How the Steam Locomotive Works! For the Railroad Fans:

The Steam Locomotive was developed to move heavy goods on tramways and to replace the use of horses. The principle of the steam engine has remained the same since the early 1800s. They include: 1. Use the energy stored in coal, wood, diesel or other fuel to heat water in a boiler and generate steam that is contained and thus creates pressure. 2. Use the energy now stored in the pressurized steam to drive a piston down a cylinder. 3. Arrange for some valves to admit the pressure and to exhaust. 4. Convert the linear motion of the piston to a rotary motion to drive the wheels. 5. Add some clever bits of mechanics so the process is automatically repeated. Parts of the Locomotive Engines. Boiler and Firebox: The most common design of a boiler is the Tube Boiler. Here the hot flue gasses from the grate are drawn through a series of boiler tubes. These tubes allow for a larger surface area that is relatively easy to heat. The heat is then transferred to the water, which surrounds the tubes. The heated water turns to steam and travels to the top of the boiler and is collected in a steam dome. The steam dome is equipped with a regulator valve the controls the quantity of steam that is delivered to the cylinders. To further improve the performance the steam that travels from the top of the firebox is again heated as it travels the length of the boiler to the pistons and cylinders. To make the fire draw effectively the exhaust steam from the cylinders passes through a pipe below the stack, this arrangement is designed to produce a reduction in pressure. This reduced pressure in the smoke box draws the flue gasses through the boiler tubes, the harder the locomotive is working the more gas is drawn from the fire box thus creating a more efficient engine. Pistons and Cylinders: The pressurized steam coming from the steamdome travels through a three-inch pipe to the front of the firebox down to the cylinders. Here the pressure is converted into mechanical energy and pushes the pistons back and forth. When the piston is a the end of the cylinder the inlet valve opens and allows high pressure steam to enter the cylinder in front of the piston. This high-pressure steam pushes the piston back. The inlet valve then closes and the steam pressure in the cylinder then start over again. After this expansion the steam has given almost all of its energy up to move the piston and the exhaust valve opens; on the return stroke the exhaust steam is forced up the smoke stack's blast pipe. The backwards and forward motion of the pistons are converted into rotary motion by the connecting drive rod that attach on the large drive wheels and work on a rotating cam principle.