When a train
goes through a "signal at danger" (i.e. a red light), the term used by the HMRI
(Her Majesty's Railway Inspectorate) is a "SPAD incident"; Signal Passed at Danger.
The HMRI produces a monthly report of SPAD incidents, catagorised by severity.
Here is the most recent version of the severity table...
0 - Not entered
1 - Overrun 0 to 25 yards, overrun not exceeding overlap, and no damage, injuries or deaths.
2 - Overrun 26 to 200 yards, overrun not exceeding overlap, and no damage, injuries or deaths.
3 - Overrun greater than overlap plus all overruns greater than 200 yards and no damage, injuries or deaths.
4 - Track damage only with no casualties.
5 - Derailment with no collision and no casualties.
6 - Collision (with or without derailment) and no casualties.
7 - Injuries to staff or passengers with no fatalities
8 - Fatalities to staff or passengers.
The term SPAD first came to the attention of the general public after the Paddington Rail Disaster
(October 5, 1999). In this incident, 31 people died and 296 were injured. This was an accident with huge public focus, and inevitebly the question was asked "what caused it?"
This most famous of SPADs has been blamed on many factors. Poor visibility
of the signal, unusual signal design and lack of the new (and expensive) ATP
(Automatic Train Protection) system, which prevents a train from passing a red signal.