Railway interoperability in Europe is a formidable objective that governments and the EU have been fervently working towards. To ensure interoperability between trains and rail lines, components such as pantographs and catenaries (parallelogram equipment that connects to overhead rail lines for electricity) must also be compatible and function optimally. The EU-funded project 'European optimised pantograph catenary interface' (Europac) gathered major EU railway stakeholders to achieve this interoperability by focusing on preventive maintenance, deterioration and incompatibility issues. The project explored ways to improve the pantograph-catenary and decrease defects, which would enable faster speeds and lessen fluctuations in the contact wire. Studies have shown that significant rail delays emerge from challenges in related equipment, incurring high costs in time and money for the railway sector and society. Europac conducted extensive simulations, track-side monitoring and onboard monitoring to study the challenges. It developed the Europacas software to simulate pantograph-catenary interaction. The software simulates pantographs and catenaries in 3D, considering effects such as wind force, temperature, switches and road bridges. The project also established a track-side monitoring station beside a high-speed line in Germany, with sensors and diagnostic tools to detect and identify defects related to pantographs in motion. An onboard monitoring system that automatically inspects the catenary at high speeds using existing accelerometers and force sensors on the pantograph was also developed. This high-tech equipment, called 'real-time data analyser' (RTDA), analyses the signals in real-time, localising and identifying defects in the catenary system. Overall, the project results are helping refine interoperability specifications and define new ones. They will guide manufacturers in complying with interoperability requirements and reducing development costs. The end result should be increased productivity and economies of scale emerging from interoperability, as well as improved competitiveness in railway transport.