Purpose: To improve the reliability of the contact network operation and reduce operational costs through the detection of the icing of the contact wire, a thermophysical method is proposed. This method is based on the monitoring the thermal effect associated with the phase transition of water from solid to liquid. Methods: The approach involves analyzing the thermophysical parameters of the «ice-water» phase transition. A specialized module is installed on the contact wire, equipped with two temperature sensors and two electric heaters positioned at a distance from one another, functioning in asynchronous mode. The measurement technique entails calculating the temperature difference between the two spaced-apart sections of the contact wire and subsequently analyzing the duration of the phase transition to determine the thickness of the ice. The paper presents a description of the design features and operational principles of a specialized module. It also describes a method for measuring ice thickness based on the analysis of thermal characteristics. A mathematical model is presented, as well as a comparative analysis of the effectiveness of the proposed solution compared to traditional methods of ice control. Results: It has been confirmed that a characteristic temperature «plateau» is formed in the presence of ice, with a zero temperature difference, allowing for accurate detection of ice and quantification of its thickness. This method, based on thermal analysis, is insensitive to symmetric external disturbances such as wind and precipitation but highly sensitive to even a thin layer of ice. Practical significance: The study confirms the feasibility of timely and accurate detection of ice and its thickness on the contact wire, with the data being transmitted to the control system. This solution has the potential to be applied in the modernization of existing de-icing systems and the design of new sections of the contact network.