- Realistic sound technology perfectly recreates railroad acoustics -UIWANG, South Korea – OCTOBER 17 – Korea Railroad Research Institute (KRRI) (President: Dr. Seok-Youn Han) has developed the Train Noise immersive Sound Simulator (TNiSS) technology that reproduces the cabin noise of various trains similarly to reality for the first time in Korea. TNiSS is a technology that realistically reproduces the sound field, which is information about how the actual sound of a train cabin spreads and is heard in space, in a simulator using ambisonic technique, a cutting-edge technology.By accurately reproducing the location and direction of noise sources, it enables analysis of three-dimensional spatial perception and directionality of sound as if you were on board a train traveling on the tracks. ※Related research projects- Project title: Development of Core Technologies for Eco-friendly Railway Technology (KRRI Basic Project)- Research period: Jan. 2023 ~ Dec. 2024 (Subject matter expert: Senior Researcher Ji-Young Hong)The immersive sound simulator verified its sound field reproduction accuracy by studying the running noise of trains in operation or under development in Korea, including subways, high-speed trains, and trams. It has precisely realized the location and directionality of various sounds including announcements, cabin air conditioning noise, door opening and closing noise, and even passenger voices. The system reproduces sound with 99% accuracy in terms of sound pressure levels by playing actual sound fields recorded with a 32-channel Ambisonic microphone through 22 loudspeakers. The system combines 360-degree VR images inside the cabin with a vibration feedback device to provide an immersive experience that utilizes both audio, visual, and tactile senses to make the actual train acoustic environment more vivid.  The developed technology is highly effective in developing various noise reduction technologies by repeatedly reproducing actual running noise.Train testing requires significant costs due to vehicle size. Utilizing a simulator to conduct noise tests under various conditions not only saves time and money, but also verifies the effectiveness of noise reduction in a realistic environment.Furthermore, using it as a virtual demonstration test platform in the early stages of vehicle design to proactively identify and remediate potential noise issues. This enables noise reduction designs that reflect passengers' auditory experience to be implemented before pilot model production.“We will continue our research to develop this technology into an innovative system that can be integrated with acoustic prediction models to predict and evaluate the noise that passengers will experience in the early stages of vehicle design,” said Principal Researcher Ji-Young Hong of KRRI.President Dr. Seok-Youn Han of KRRI said, “This technology is not just a noise reduction technology, but a new paradigm that can scientifically predict and reflect passengers' auditory experience,” adding “We expect it to elevate the domestic transportation noise management to the next level and contribute to providing a better transportation environment.”※References: 1. Train Noise immersive Sound Simulator (TNiSS)Press ContactsYoonju YIKorea Railroad Research Instituteyjyi@krri.re.kr+82 31 460 5189

- Increasing railroad track reliability and reducing maintenance costs - OSONG, South Korea – OCTOBER 16 –Korea Railroad Research Institute (KRRI) (President: Dr. Seok-Youn Han) has installed its newly developed ‘Under Sleeper Pad (USP)’ at the Osong Comprehensive Railway Test Track in North Chungcheong Province, designed to improve the performance of ballasted tracks and reduce maintenance costs. The USP was installed on October 14 over a 10-meter section of the Osong Railway Comprehensive Test Track. Field application tests will be conducted for one year, running from this month until December next year. To accelerate commercialization, KRRI has signed a technology transfer agreement with U1 Platform. The USP is a technology that improves the performance and durability of railroads by attaching special pads to the lower part of the sleeper. It is mainly made of various elastomers such as polyurethane and synthetic rubber. When attached to the bottom of PSC (Prestressed Concrete) sleepers, it increases the contact area with the ballast bed, ensuring a more even distribution of load to the ballast. This process increases track stability, reduces track settlement, and protects the gravel. Additionally, it helps reduce noise and vibration along the track. The developed USP is made of highly durable, non-foaming thermosetting polyurethane and is designed for PSC sleepers used on local and high-speed lines in Korea.  The design considered factors such as allowable rail deflection, which is the permissible range of rail bending under external loads like train weight, and prevention of damage during installation and maintenance. The design optimized the USP's attachment area to cover more than 70% of each sleeper, and its stiffness, adhesion to PSC sleepers, and fatigue performance were rigorously tested and verified.In addition, significant cost efficiency was achieved by simplifying manufacturing and attachment process to enable pad installation during the sleeper production phase. The technology reduces initial ballast settlement by up to 30% and can extend ballast tamping maintenance intervals by more than double, while effectively controlling both overall and localized ballast settlement. Notably, it reduces the occurrence of floating sleepers at rail connections and in areas with varying track stiffness, enhancing overall track quality and driving stability. In Korea, some imported products have been used to reduce noise and vibration on tracks, but they are expensive and difficult to supply materials. The USP developed by the KRRI enables customized production for various railway environments including domestic conventional, high-speed, and urban railways, considering factors such as train passage tonnage and roadbed characteristics. This innovation is expected to offer more efficient solutions for improving ballast track performance. ※ Related research projects- Project title: Development of Technologies for Reducing Waste Generation and Resource Recycling in Railway Facilities (KRRI Basic Project)- Research period: Jan. 2022 ~ Dec. 2024 Principal Researcher Jihwan Kim of KRRI said, “The frequency of ballasted track maintenance has recently increased due to higher train speeds and greater operational demands. Simultaneously, maintenance costs have risen due to higher labor, transportation, and equipment import expenses.” President Dr. Seok-Youn Han of KRRI remarked, “It is a key technology to innovate the performance of existing railway infrastructure and maximize the efficiency of maintenance,” adding that “We will strive to commercialize the USP domestically and expand into overseas markets such as Vietnam and Malaysia.” References: Images of developed under sleeper pad and field test installation     Press Contacts Yoonju YIKorea Railroad Research Instituteyjyi@krri.re.kr+82 31 460 5189