Train
Overview
A train (열차, 列車) is a mode of railway transport consisting of one or more vehicles designed to run on rails, connected and operated together. Since the advent of the steam locomotive in the 19th century, it has enabled the mass and high-speed movement of people and freight and has served as core infrastructure for industrialization and urbanization. Today, it has evolved into high-speed rail, light rail, and driverless subways that combine electric power and automated driving technology, and is being reevaluated as an eco-friendly means of transport with low carbon emissions.
Main Content
Definitions and Classification
Trains are classified by purpose into passenger trains and freight trains, and by operation type into high-speed trains, conventional trains, metropolitan rail, and urban rail (subway). By power source, there are steam locomotives, diesel locomotives, electric locomotives, and electric multiple units (EMUs). The representative methods are locomotive-hauled trains, in which passenger cars and the locomotive are separate, and distributed traction (dynamic distributed traction), in which power equipment is distributed across multiple cars; recently, most high-speed railways adopt distributed traction. For track gauge (rail spacing), standard gauge of 1,435 mm is the most widely used in the world, and broad gauge and narrow gauge also exist depending on the region.
Development of Power Methods
Early trains were steam locomotives that burned coal to produce steam. In the mid-20th century, diesel-electric locomotives appeared and efficiency improved greatly; thereafter, electric railways receiving power from overhead lines became the standard. Electric power has less noise and exhaust relative to output, making it advantageous for long tunnels and urban sections. Recently, battery trains (BEMU) equipped with lithium-ion batteries and hydrogen fuel cell trains are emerging as alternatives for non-electrified sections.
Structure of the Train
A train consists of the car body, bogies, braking devices, current collection devices (pantographs), and signaling and communication devices. The bogies support the car body and help smooth running on curved sections, while air brakes and regenerative brakes handle deceleration and energy recovery. The signaling system began with the concept of block sections and has developed into today's communication-based train control (CBTC), which became the technological foundation for driverless automatic operation.
Railways of the World and Korea
Globally, Japan's Shinkansen (1964), France's TGV, Germany's ICE, and China's CRH are the leading examples of high-speed rail. Korea opened the era of high-speed rail with the launch of KTX in 2004, and later introduced distributed-traction vehicles such as SRT and KTX-Eum (EMU-260) and KTX-Cheongryong (EMU-320). For urban rail, the GTX (Great Train Express) project is being promoted with Seoul and Busan as centers, shortening commuting times in the capital region.
Latest Trends
In 2024–2025, the railway industry is moving along three axes: decarbonization, automation, and ultra-high-speed. First, commercial operation of battery and hydrogen trains is expanding in Europe and Japan, accelerating the electrification of diesel sections. Second, ETCS Level 3 and CBTC-based driverless automatic operation and AI-based predictive maintenance are being introduced, simultaneously increasing safety and availability. Third, next-generation ultra-high-speed technologies such as hyperloop and maglev trains are in the testing stage, and Korea is also participating in maglev and ultra-high-speed running tests. In addition, railway fares and seat reservation systems for KTX and SRT are being reorganized around apps, and the opening of GTX-A and C lines is changing the transportation landscape of the Seoul metropolitan area. On the logistics side, intermodal transport, automated yards, and digital twin-based schedule optimization are trending toward standardization.
Related Topics
- [[고속철도]]
- [[KTX]]
- [[지하철]]
- [[철도 차량]]
- [[증기기관차]]