Electrified railways are an important symbol of modern railway transportation and a significant manifestation of the modernization of national transportation infrastructure. In July 1975, the electrification project of Baocheng Railway was completed, and the first electrified railway in New China was born, marking the beginning of China's railway modernization. Half a century has passed, from the meticulous sketching on blueprints to the multidimensional presentation of digital twin technology; From manual wire laying by workers to automated operation by intelligent robots... With the support of digital technology, China's railways have entered a new development track, and electrified "steel dragons" are "flying close to the ground" on the land of China. As of the end of 2024, the total operating mileage of railways in China has reached 162000 kilometers, including over 120000 kilometers of electrified railways, with an electrification rate of 75.8%. What is the 'digital code' behind the speeding electrified railway? The key to the development of modern railways lies in the construction of the 'four electricity' system, which promotes intelligence through simplification. ”Lu Chunfang, academician of the CAE Member and president of the China Railway Society, analyzed that the "four electricity" composed of communication, signal, electricity and electric traction power supply is the power source and nerve center of high-speed railway. And technical standards are its important support. For many years, China Railway Electrification Bureau Group Co., Ltd. (hereinafter referred to as "China Railway Electrification Bureau") has been continuously tackling key issues in core areas such as traction power supply, contact network systems, and intelligent equipment. It has built a series of key technology systems with completely independent intellectual property rights and is rapidly advancing towards intelligent construction. The railway overhead contact system is the core power supply facility of electrified railways. Previously, China's railway overhead contact system used multiple standards from Germany, France, Japan, and other countries, with diverse and varied types. In 2015, China Railway Group Co., Ltd. initiated a project, with China Railway Design Group Co., Ltd. as the main sponsor and China Railway Electrification Bureau as the main participant in the development. The new simplified overhead contact system emerged. Simplification refers to the "simple and unified standardization" of contact network components and installation, achieving the goal of unifying technical parameters, simplifying equipment structure forms, reducing component types, and improving the service performance of key components. Compared with traditional structures, the simplified catenary arm components reduce the number by 39%, thread pairs by 57%, and fastening torque types by 50%. The stability of product manufacturing and the integration of components are comprehensively improved, which can meet the operational requirements of high-speed railway power supply systems. Simplification provides a unified interface standard for intelligent construction equipment and a compatible foundation for automation equipment. Under the continuous research and development of technical personnel from China Railway Electrification Bureau, equipment such as automatic positioning and measuring instruments for contact network tunnels with completely independent intellectual property rights have been successfully developed, reaching the international advanced level. The contact wire suspension column is a key component in the electrified railway contact wire system, and one of its functions is to ensure stable contact between the contact wire in the tunnel and the pantograph. In the past, traditional total stations were used for positioning when installing contact wire suspension poles, which consumed a lot of manpower and had significant measurement errors, affecting the quality of power supply in the later stage. The automatic positioning and measurement instrument for contact network tunnels has solved this problem. It uses laser sensors to measure the distance between the instrument and the object being measured in real time, and then processes and uploads the collected data to mobile terminals, achieving digital circuit integration and automated measurement and calculation functions. During the construction of the Qingbaijiang to Huangshengguan section of the Chuanqing Railway, this equipment demonstrated its capabilities. Zhang Suihong, Chief Engineer of the Zhenhuang section project of the Chuanqing Railway of Xi'an Electrification Engineering Co., Ltd. of China Railway Electrification Bureau Group, told reporters that the automatic positioning and measuring instrument for the contact network tunnel has effectively improved the construction efficiency and installation accuracy of the contact network. Currently, China's electrified railways are moving towards higher speeds, and higher requirements have been put forward for the technical standard system of the "four electric" system to enhance adaptability in all scenarios. Lin Yunzhi, Chief Engineer of China Railway Electrification Bureau, said that the bureau is conducting systematic research on high-speed traction power supply systems, continuously promoting the application of intelligent construction technologies such as intelligent equipment, digital technology, and data platforms, and making every effort to create a new benchmark for intelligent high-speed railways and a new benchmark for high-speed railways in the world. In fact, the transition of electrified railways from mechanization to intelligence is not only reflected in the improvement of speed, but also in their strong adaptability to complex environments. Under various extreme natural conditions such as high cold, high temperature, high humidity, and high altitude, China's standard electrified railway has achieved a calm response. The Lalin Railway is the highest electrified railway in the world, running through snowy plateaus with a maximum altitude of 3650 meters. China Railway Electrification Bureau has carried out a series of technological innovations, including the research and development of high-altitude adaptation equipment, intelligent remote control systems, etc., to achieve safe and stable operation of the Lalin Railway in complex high-altitude environments. The traction substations along the entire railway line are equipped with unmanned and remote control systems. Workers from Xining, 2300 kilometers away, can complete their work tasks with just a few clicks of their fingers. From the Guinan High speed Railway in mountainous areas, to the Geku Railway in the Gobi Desert, and then to the Lanxin High speed Railway in Dafengsha, China's electrified railways, empowered by digital technology, are forming the ability to cover all terrains, climates, and scenarios, continuously accumulating experience in the construction of electrified railways in complex environments. After the intelligent operation and maintenance upgrade ensures the electrification of railways, operation and maintenance become a key factor in their efficient operation. Including the "four electricity" system, the operation and maintenance of the entire profession and road section require a large amount of manpower. To enhance the effectiveness of railway operation and maintenance, China Railway Electrification Bureau has built a multi-disciplinary integrated intelligent operation and maintenance big data platform, which utilizes new means such as big data, 5G, cloud computing, drones, image recognition systems, and intelligent equipment to significantly improve the ability of railway safety operation and maintenance guarantee. Lin Yunzhi told reporters that compared to previous operation and maintenance models, the smart operation and maintenance big data platform has "four 20%" advantages, namely, reducing operation and maintenance costs by 20% for traction power supply equipment management, reducing traction power supply equipment failure rate by 20%, extending equipment overhaul period by 20%, and extending the service life of contact network components by 20%. From the perspective of high-speed rail power supply maintenance, the detection and monitoring of the suspension status of the overhead contact system is the most critical and direct link. Its detection image data intuitively displays contact network defects and is a powerful assistant in eliminating defects and safety hazards. The high-speed railway 4C visual intelligent analysis system developed by China Railway Electrification Bureau adopts a multi technology fusion method of intelligent recognition, industrial algorithms, knowledge graphs, etc., to achieve the function of quickly obtaining effective information in massive data, effectively improving the safety level of high-speed railway operation. Previously, the detection of hidden dangers in high-speed rail contact networks often required inspection engineers with 6-8 years of experience to analyze and judge over 1 million collected photos annually with the naked eye. With the intelligent analysis system, the detection of faults and hidden dangers in high-speed rail contact networks has changed to a "smart recognition+manual review" form, achieving high-precision and efficient detection of more than 1300 hidden dangers and defects such as loose and missing contact network components. Compared with traditional detection methods, the number of hidden dangers discovered has increased by 10 times, and the analysis efficiency has increased by more than 20 times. The auxiliary monitoring system of railway traction substations has also brought changes to the unmanned inspection of railway operation and maintenance. In the past, in addition to the comprehensive automation system, China's railway traction substations were also equipped with video surveillance, security, access control, environmental control, fire alarm, fire monitoring, online monitoring and other systems. However, these systems did not fully realize information sharing, interactive linkage, and backend visual operation management, and could not meet the needs of unmanned development. ”Lin Yunzhi said. Now, the auxiliary monitoring system of traction substations is based on machine vision recognition technology in complex scenarios, integrating subsystem data such as video inspection, safety prevention, environmental monitoring, fire alarm, power lighting control, and online monitoring to achieve intelligent inspection and operation and maintenance decision support. The system has been put into use in multiple projects, safely and efficiently completing tasks such as monitoring and inspecting the operational status of equipment within the facility. Over the past 50 years, China's electrified railways have not only accelerated the smooth flow of people and goods, but also become an accelerator for the country's modernization development. Generation after generation of electrification builders continue to strive, using their wisdom and sweat to paint a railway network that spans across the land of China, promoting China's railways towards intelligence and intelligence. (New Society)