An XML database of railway interlocking data is provided which efficiently represent the topology and the logic of interlocking systems. The database has been formalized in a standard format widely used in railways, i.e. RailML. Differently from the other previouly proposed interlocking databases, our approach is able to completely map interlocking systems, removing data redundancy and standardizing its representation. The dataset contains the documentation, the xsd and an example database relative to the Dutch station Santpoort-Noord