The purpose of this leaflet is to ensure the safe operation of wagons intended for traffic with Great Britain, via the Channel Tunnel, resulting from the particular aspects of running safety and loading gauge. This leaflet describes the requirements to be fulfilled when designing wagons destined for traffic with Great Britain. The running safety requirements, including the requirements of additional testing, the specific requirements for operation via the Channel Tunnel and the loading gauges applicable are also defined. In addition, the requirements of the submission file and the two contact addresses, to either one of which the submission may be made, are specified.