Paragraph 73

The following classes of accident where they are likely to cause an accident to a train or a significant risk of personal injury to any person—

(a)

the failure of a tunnel, bridge, viaduct, culvert, station or other structure or any part of it including the fixed electrical equipment of an electrified relevant transport system;

(b)

any failure in the signalling system which could cause a significant risk to the safe passage of trains other than a failure of a traffic light controlling the movement of vehicles on a road;

(c)

a slip of a cutting or of an embankment;

(d)

flooding of the permanent way;

(e)

the striking of a bridge by a vessel or by a road vehicle or its load; or

(f)

the failure of any other portion of the permanent way or works.