Steam Locomotive Components

The Firebox

• First, the locomotive needs fuels to activate its working parts. This fuel is referred to as the tender. In most traditional steam powered locomotives, coal was used as this catalyst. The coal is burned in the firebox, a square-shaped enclosure located below the boiler. The power or heat of the firebox increases in proportion to its size, so engineers developed larger and larger fireboxes as time progressed. The heat emanating from the firebox causes the water in the boiler to boil.

Steam Box, Cylinders &Pistons

• As the water boils in the aforementioned boiler, it creates steam. This steam is then deposited into a vessel or area called the steam chest, one that generally rests below the cylinders of the steam engine. Once started, the steam exits the steam chest and enters the cylinder, forcing the resident piston down. This causes the wheel to begin moving. With each subsequent stroke of the engine, steam enters, pushes the piston down and excess steam is fed through the exhaust as the piston returns to its position. This, in effect, is what powers the locomotive.

Drivers &Counterweights

• The are a number of parts that facilitate the movement and braking of the train. First off, the driver assembly consists of the wheel itself. So the energy created by the functioning cylinders is distributed to the wheels causing motion. Because of the weight of this overall apparatus, particularly the rotating side rod connections, the entire assembly could become unbalanced. To correct this, the drivers are equipped with counterweights that often appear as crescents. In the 19th century, these counterweights were affixed to the wheels through the use of bolts. By the 20th century they were typically casted.

Cabin &Pilot

• The cabin--or cab--was the space that accommodated the person driving the locomotive. The design specs of the cab depended on the rail line in question, as well as related to the specific era of production. The pilot, also called a cow catcher, was a large wedge-like piece that was fitted onto the front of the locomotive at track level. This was a safety precaution designed to remove anything that got in the way of the oncoming train. Needless to say, a lost cow would not be caught by this device but removed with extreme prejudice.