A railway interlocking system is one example of a critical system, and therefore it must have a high level of reliability in order to avoid problems that may result on the loss of people's lives. However, many railway systems are still specified using historical relay-based diagrams, whose analysis are made by human inspection, which is error prone. This paper constitutes a first step towards using Model Driven Architecture (MDA) in order to specify railway interlocking systems. This work proposes a restructuring methodology starting from relay-based diagrams to produce formalized machine-readable XML models. This is performed by formalizing industrial formalisms and knowledge into a complete Domain Specific Language UML meta-model that is latter used to automatically generate an XSD using Model-to-Text transformation. The conforming XML models may then be understood by different stakeholders and used as input for automated analysis tools.