SCHEDULE 2 U.K.Types of accidents and incidents other than any occurring within the Channel Tunnel System which must be notified to the Rail Accident Investigation Branch as soon as reasonably practicable and in any event within three working days of occurrence

5.  The failure of rolling stock on the track caused by— U.K.

(a) the failure of an axle;

(b) the failure of a wheel or tyre, including a tyre loose on its wheel; or

(c) a fire or severe electrical arcing or fusing, whether or not extinguished by a fire-fighting service.