In this paper we describe the design of a knowledge-based condition analyzer that performs on-board intelligent fault classification. The system is designed to be deployed as a prototype on E414 locomotives, a series of downgraded highspeed vehicles that are currently employed in standard passenger service. Our goal is to satisfy the requirements of a development scenario in the Integrail project for a condition analyzer that leverages an ontology-based description of some critical E414 subsystems in order to classify faults considering mission and safety related aspects. (6 pages)