Introducing digital technologies into the structure of Russian railways allows us to apply novel engineering solutions to rolling stock service. Russian Railways OJSC faces a technological challenge of intensifying freight transport through the railway network while maintaining process controllability and ensuring the safety level required. The solution to this problem may lie in automation and robotisation of technological processes using digital twins of infrastructure components. Digitalisation, automation and robotisation are developing into indispensable tools for the desired railway transformation. These activities enable us to increase productivity and improve service quality while allowing for flexibility in passenger and freight transport. The paper presents a case study dealing with development of a robotic system designed to ensure uninterrupted functioning of shunting yards, including automated brake release and uncoupling of railway cars transported as a train onto gravity shunting yards. We consider various design options and engineering solutions concerning the executive group of the robotic system aiming to implement the desired degrees of mobility while servicing non-determinate railway train cars.