Why Trains Have Wheels with Tires Stored Underneath
When it comes to the design of trains, particularly in certain applications and maintenance contexts, the concept of wheels with tires stored underneath may seem curious. This practice is actually quite rational and necessary in specific situations. In this article, we'll delve into why this is done and explore related aspects of train technology and maintenance.
Introduction to Train Wheels and Tyres
The term “wheels with tyres stored underneath” might be misleading, as trains do indeed have tyres, but they are not stored in the way one might imagine. There are instances, particularly in track repair and maintenance equipment, where wheels with tyres do indeed have a storage function. This is to allow for flexibility in operations and efficient maintenance.
Railway Wheels and Tyres: Past and Present
About 50 years ago, while working in a steel mill, I encountered railway wheels and tyres. They were not just ordinary steel wheels but steel tyres that could be fitted onto the outside of the central part of the wheel through a process of expansion after heating. These tyres were quite heavy, so moving them required a small crane. This method of design allowed for reconfiguration and repair of wheels on-site, providing significant benefits for maintenance.
While the specific method of fitting tyres onto wheels may have evolved over time, the principle remains similar. Modern railway wheels and tyres are still used to ensure the train's stability and safety, and they can be easily replaced or repaired when necessary. The steel construction of these tyres is a testament to the durability and reliability of railway technology.
Subway Trains with Rubber Tyres
Subway trains in major cities like Paris, Montreal, and Mexico present a different scenario. These trains run on rails but primarily carry weight on rubber tyres that travel on a guide way. Although less fuel-efficient, rubber tyres offer several advantages, including a quieter and smoother ride. Personally, I have experienced these systems along with traditional all-steel rail systems, and while there are clear pros and cons, both offer unique value to urban transportation networks.
One of the key benefits of rubber tyres on subway trains is their ability to handle variations in track conditions more gracefully. They can contribute to a more comfortable journey for passengers and reduce wear and tear on the rail system. Moreover, these trains often feature better quietness, which is particularly important in urban environments where noise pollution is a concern.
Track Repair and Maintenance Equipment
In the realm of track repair and maintenance, wheels with tyres that can be lowered and stored offer distinct advantages. This design allows track repair and maintenance equipment to travel beyond the rails, enabling more efficient and versatile operations. Such equipment is equipped with retractable wheels that can be raised and lowered as needed, ensuring that the vehicle can move freely within the work zone.
The flexibility provided by these wheels allows maintenance workers to access areas that would otherwise be inaccessible. This capability is essential in maintaining rail infrastructure, ensuring that tracks are safe and reliable for train operations. The use of such equipment not only enhances operational efficiency but also minimizes disruptions to train schedules.
Conclusion
The concept of wheels with tyres stored underneath in trains serves a specific purpose, especially in the realm of track repair and maintenance. Whether it's the steel tyres for traditional railway wheels or the rubber tyres for subway trains, these designs cater to the unique challenges and requirements of different train systems. Understanding the rationale behind these designs can provide valuable insights into the engineering and maintenance aspects of modern transportation.
For those interested in railway technology and maintenance, exploring these innovations can provide a deeper appreciation for the complexity and precision required in ensuring safe and efficient train operations.