An operational close call is defined as any unsafe act (formerly termed irregular working) or unsafe condition that in different circumstances could have led to an accident or personal injury or could have resulted in damage to property or equipment. These are occasions where no one was hurt or nothing was damaged, but this is more by chance than by the application of systemic controls.

This measure comprises the number of incidents of operational close calls (OCCs) that introduce significant risk to the railway (categorised as potentially significant and potentially severe) based on an evaluation of their actual or potential consequence.

Operational Close Calls results

OCCs MAA Network-wide36.3822.3123.9217.859.92
Potentially significant33321825116888124
Potentially severe14072596441120

Categories of Operational Close Calls

An OCC involving the work group (e.g. Controller of Site Safety (COSS) or a lookout) which results in incorrect or inadequate implementation of a line blockage, working outside of the protection limits or removal of protection. This includes near misses with staff whilst red zone working (areas where trains are still running), staff being slow to clear the line, or a failure to have a safe system of work in place.

An OCC involving implementation of a possession (i.e. Person In Charge of a Possession (PICOP), Engineering Supervisor, Nominated Person) which results in the incorrect placement of protection, inadequate or incorrect protection arranged, or irregularity in the removal of protection. Isolation placed incorrectly (i.e. outside of possession limits or prior to the possession being taken, trolleys placed outside of possession limits).

Any OCC as a result of an operator (e.g. a signaller or controller) giving permission for protection to be laid with a train not yet having passed the site of work; signalling a train into a possession / line blockage, vehicles or pedestrians trapped between gates at a level crossing or given permission to cross when the line is not clear; failure to caution trains; miscommunication when the signaller is in the lead; two trains in section; train routed into an isolated section, switching incident.

On Track Machine or Plant / Engineering Train / Equipment
Any OCC involving on track plant or engineering trains or involving incorrect use or placement of equipment or materials, for example unauthorised movements within possessions, machines or plant overturning, unsafe operation of machines or plant, equipment or materials fouling the running line, irregularities involving scaffolding on operational infrastructure.


Events categorised as potentially significant or potentially severe are attributed to one of the four categories of OCC. The OCC category with the largest proportion of potentially significant and potentially severe events is protection incidents.

Whilst the number of potentially significant and severe incidents has increased this year, it must be noted that the number of unranked events has decreased by 43%.