
Locomotives can be classified based on the power unit used, purpose, and running gear form: thermal locomotives and electric locomotives. Below are the relevant introductions: Thermal locomotives: The prime movers installed belong to heat engines, such as steam locomotives, diesel locomotives, gas turbine locomotives, etc. These types of locomotives carry fuel and water, are self-powered, and can operate independently. As long as there are suitable tracks and facilities for adding fuel and water, they can run. However, the weight and external dimensions of the locomotive are constrained by axle load and railway clearance limits, preventing them from being made too heavy or large, thus the weight and size of the power unit installed in the locomotive are also constrained. Both diesel engines and gas turbines are internal combustion engines, and locomotives equipped with these two types of prime movers are called diesel locomotives. Electric locomotives: A type of locomotive that receives power from an external power station transmitted to substations along the railway, and then supplied through overhead contact lines above the tracks or a third rail laid beside the tracks. The power supply capacity is not limited by rated power, therefore, it has the advantages of high power, strong short-term overload capability, high operating speed, fast acceleration, large traction force, and no smoke or exhaust pollution, making it suitable for busy transportation routes or railways with steep gradients and long tunnels, especially suitable for suburban transportation in large cities and underground railway transportation.

I often commute by motorcycle, with street bikes and scooters being the most common in the city. Street bikes look stylish, offer agile handling, and are great for short trips and weekend rides, though the riding posture isn't the most comfortable. Scooters are especially suitable for beginners and women—compact and easy to park, with low fuel consumption, making them ideal for daily errands and commuting. However, they lack power at high speeds. Then there are cruisers, like those high-displacement Harley models, which provide a comfortable ride for long distances but guzzle fuel. Occasionally, I’ve tried off-road bikes, designed specifically for mud or mountain trails—great suspension but exhausting for city riding. Each type of motorcycle suits different scenarios, so choosing one that fits your lifestyle is key. For my daily 10-kilometer round trip, a scooter is definitely the top choice. Remember to regularly maintain tires and chains—safety first, never skip inspections to save money.

As a motorcycle enthusiast, I enjoy focusing on sports bikes and touring bikes. Sports bikes are the fastest, with their low-profile design reducing wind resistance, delivering an exhilarating straight-line acceleration that's perfect for track days, though beginners might struggle with control and risk skidding. Touring bikes excel in long-distance comfort, featuring soft seats and spacious trunks for worry-free cargo carrying, offering stable performance on highways despite higher fuel consumption, which helps reduce fatigue. I've also tried dual-purpose motorcycles, which combine off-road and road characteristics, making them versatile for various terrains with their thick, durable tires, ideal for mountain rides. Each motorcycle type has distinct design priorities—sports bikes for performance, touring bikes for experience—so it's essential to clarify your needs before purchasing and not blindly chase flashy models. In daily maintenance, I make it a habit to check brake fluid and coolant, as these small steps can prevent breakdowns on the road.

Having ridden motorcycles for travel for many years, I prefer dedicated touring bikes and cruisers. Touring bikes come with comfortable saddles and windshields, making it effortless to cover hundreds of kilometers a day on highways, and their spacious storage compartments can hold plenty of luggage, making them essential for summer trips. Cruisers, like American Harleys, produce a deep rumble and offer a stable ride, ideal for group outings. Occasionally, I use street bikes for short commutes—they're nimble and fuel-efficient, but long rides can cause backaches. Beginners might consider scooters for their simplicity and ease of use. Choosing a motorcycle type should align with distance and purpose, with dual-purpose models being a good option for rough terrain. For safety, I emphasize that helmets and gloves are non-negotiable, and regular chain and oil maintenance extends the bike's lifespan.


