Modern Transportation Systems and Technologies

AIM: This work describes evidence-based risk assessment methods and threat visualization tools that enable the effective identification of vulnerable areas and emergency prevention planning to improve the technospheric safety of transport infrastructure.

METHODS: The paper uses scenario analysis, spatio-temporal modeling in the FDS and PyroSim environments, the ALARP concept of acceptable risk, and geoinformation technologies (ArcGIS, QGIS) to make digital vulnerability maps. A comparative analysis was conducted using national and international regulations.

RESULTS: We developed a digital threat model for a transport hub, visualized high-risk areas, and proposed an ALARP priority response system. The findings allow to adapt response action to real infrastructure conditions and assess the early intervention performance.

CONCLUSION: The presented integrated approach allows for building a dynamic risk management model for the transport system. Integrating threat visualization into existing monitoring systems facilitates timely response and reduces potential damage from emergencies.

AIM: This work aimed to analyze the feasibility of contactless bearings based on closed high-temperature superconducting (HTS) tape windings. To study the axial load on a bearing in a wide temperature range.

METHODS: The bearing load was measured using an experimental setup based on a strain gauge and a three-dimensional positioning system. The superconductor was cooled using a single-stage cryocooler. The magnetic interaction in the bearing was calculated in the COMSOL Multiphysics simulation environment.

RESULTS: The relationships between the axial force and the axial shift of a superconducting bearing based on closed HTS windings were obtained for temperatures ranging from 40 to 77.4 K and shift amplitudes of 1 to 9 mm. The numerical model was verified using experimental data. Its applicability was proven for closed superconducting currents in HTS tapes. The dynamics of magnetic flux penetration into HTS windings was calculated.

CONCLUSION: Closed HTS windings can be successfully used to manufacture superconducting bearings. Closed HTS windings are most effective in systems where equilibrium shifts exceeding the half-period of the magnetic array are possible. The shift magnitude at which the greatest axial restoring force is achieved increases with temperature.

Designing of intelligent traction substations relies on IT solutions implemented to improve the operational reliability of equipment. One of the ways to improve the reliability of traction substations is to develop condition monitoring systems allowing to detect developing defects and predict the equipment service life. The reliability of traction substations is determined by a number of solutions, including the direct current (DC) power systems with batteries. Today, the residual life of batteries is not determined during maintenance and the condition is assessed during a scheduled maintenance. In addition, the systems that reduce the labor intensity of determining the residual life of batteries are used to increase the reliability of the control current system and traction substations.

AIM: This study aimed to develop a battery model based on the digital twin concept, where the battery's residual life is determined based on the recorded current, voltage, and temperature data with sufficient accuracy for engineering design purposes.

METHODS: The study uses static battery operation observations processed using the experimental design, mathematical statistics, and numerical analysis methods.

RESULTS: We propose a digital twin of a traction substation battery allowing to determine the residual life by monitoring the basic battery performance indicators in various conditions.

CONCLUSION: The findings may be used to develop control and management systems based on a digital battery twin with condition monitoring capabilities implemented in the intelligent traction substations.

AIM: This work aimed to develop a predictive method to analyze the residual life of reinforced concrete overhead line supports integrating predictive modeling in the standards of JSC Russian Railways for the transition from scheduled preventive maintenance to proactive management.

METHODS: The study is based on Order No. 1047r of JSC Russian Railways. A two-tier method is proposed; the first stage involves the support health classification based on the standards; the second stage involves the prediction of limit states based on criteria, such as reinforcement corrosion, concrete strength loss, and crack development, using physical and mechanical modeling.

RESULTS: We developed a two-level method for predicting the residual life and derived formalized calculation formulas for each of the three key criteria (reinforcement corrosion, concrete strength loss, crack development). They allow to measure the time to the limit state of the structure, which provides a reliable basis for support ranking based on the order of taking out of service for repair or replacement.

CONCLUSION: The proposed method provides the basis for integration into predictive maintenance systems and digital infrastructure twins, ensuring the transition to proactive lifecycle management of facilities.

AIM: This work aimed to prove that digital lean management is a tool increasing the cost efficiency of transportation and logistics systems in the context of limited investments and stringent quality requirements to transport services.

METHODS: The study used the lean management principles, digitalization concepts, and systems analysis of transport and logistics processes. The paper uses structured and logical analysis, comparative analysis, generalization of scientific and industry research, and qualitative assessment of the effect of organizational and process changes on the cost efficiency of transportation and logistics.

RESULTS: The study identified industry-specific features of digital lean management in transport and logistics systems and substantiates the feasibility of integrating process and digital management tools. It showed that digital lean management has a synergistic effect, including a higher performance; increased utilization of infrastructure and rolling stock; reduced turnaround time, operating and logistics costs, and higher profitability of transportation and logistics. It was found that digital lean management may be considered a type of intangible improvement of transport infrastructure aimed at increasing the return on existing assets without a significant increase in capital investment.

CONCLUSION: Digital lean management is an effective tool for improving the cost efficiency and sustainability of transport and logistics systems. The findings may be used to develop transport infrastructure improvement and transport and logistics digitalization programmes and substantiate management decisions related to transport system development.