The design and function of train wheels are critical to the safe and efficient operation of trains. Unlike most vehicles, trains don't use tires. Instead, they rely on specially designed wheels that interact directly with iron tracks. This article explores the reasons behind this unique feature and explains how train wheels operate.
Guiding Function of Train Wheels
The first wheels of a train serve a guiding purpose. The term "rail" is actually short for "iron guiding track." On the inner side of each train wheel, there is a raised part called a flange. Since each train has two wheels per axle, there are two flanges that fit snugly on the inner sides of the rails, ensuring the train stays on track.
Why Trains Don't Use Tires
There are two primary reasons why trains don't use tires:
Track Compatibility: Train tracks are made of iron, and iron wheels create a perfect bond with these tracks. This bond is crucial for supporting the heavy loads trains carry. The interaction between the iron wheels and iron tracks solves the issue of load-bearing, something that rubber tires would struggle to manage.
Fixed Routes: Unlike cars, trains travel on fixed routes. When a train goes around a curve, it can't rely on tire friction to provide the necessary grip. Instead, the unique shape of train wheels, specifically the flanges, provides the support needed to keep the train stable while turning. Tires simply wouldn't offer the same level of support.
Direction Control
Another reason trains don't use tires is that they don't need steering wheels. A train's direction is primarily controlled by a dispatch center. The train follows the tracks and is powered by diesel or electricity, which eliminates the need for tires. If trains had tires, they would add unnecessary weight without providing any real advantage.
How Trains Navigate Turns
Train wheels are embedded within the tracks, and as the tracks curve, the wheels adjust their position accordingly, allowing the train to turn. This design eliminates the need for tires to provide extra support during the turning process.
Conclusion
The absence of tires in train design is not just a matter of tradition but a necessity dictated by the unique demands of rail transport. The iron wheels and tracks, along with the guiding flanges, ensure that trains can carry heavy loads safely and efficiently while navigating the curves of their fixed routes.
