Analysis of rolling stock coupling designs and technologies for the implementation of international railway operations between Ukraine and the European Union

The purpose of this study is to analyze the existing and prospective coupling device designs and technologies for their application in organizing international railway operations between Ukraine and the European Union. The research identifies the main technical barriers associated with domestic rolling stock and explores optimal pathways for integrating Ukrainian rolling stock into the European transport system. The study also considers the possibility of adapting EU-member-state wagons for operation within the railway network of JSC “Ukrzaliznytsia”. An analysis of regulatory and technical documentation was conducted, including DSTU, UIC, and EN standards, as well as regulatory documents of the Council for Rail Transport, which define the requirements for coupling devices and rolling stock. A comparative review was conducted, followed by a detailed investigation and analysis of the design, operating conditions, and structural features of various types of couplers: SA-3 automatic couplers, screw couplings, universal systems, and digital automatic coupling systems (DAC). The research employs a systematic approach, providing a comprehensive assessment of operational performance, safety levels, and the economic feasibility of deploying each of the examined coupling technologies. The object of the study comprises the designs and performance characteristics of railway rolling stock coupling devices and the technologies governing their use in international railway operations on both 1520 mm and 1435 mm gauge networks. The results obtained based on a systematic analysis of regulatory documents for rolling stock operating on 1520 mm and 1435 mm gauge networks, as well as the design features and engineering solutions of coupling systems. They also include the identification of key directions for the development and implementation of modern coupling technologies for international railway operations involving both freight wagons and passenger rolling stock. The analysis considers the specific operational conditions at border crossing points and stations, as well as the local operational and environmental constraints that affect rolling stock operations. A comprehensive assessment of the compatibility between SA-3 automatic couplers and screw coupling systems under international transport conditions between Ukraine and EU member states has been performed. Contemporary technologies enabling the adaptation of rolling stock for joint operation on 1520 mm and 1435 mm gauge networks have been systematized, including adapter devices, variable-gauge systems, and combined coupling configurations. A model for the phased integration of the Ukrainian automatic coupling system into European standards has been developed, utilizing transitional technical solutions. The results of the research can be applied to the development of technical regulations for rolling stock modernization, wagon and train handling technologies, and engineering solutions for designing wagons and locomotives intended for interoperable operation on both 1520 mm and 1435 mm gauge systems. The proposed recommendations will help reduce dwell times at border crossing points by eliminating the need for coupling device replacement. Additionally, they will help reduce operating costs and increase the efficiency of logistics processes for wagons equipped with screw coupling systems by automating train formation procedures, while enhancing operational safety. The findings of this study may be useful for infrastructure projects aimed at integrating the Ukrainian railway network into the European transport system.