scope:

Earthwork asset criticality applies to soil cuttings, rock cuttings and embankments. Locational criticality applies additionally to Earthwork inspection 5 chains.

Earthwork asset criticality incorporates the direct safety consequence of an Earthwork asset failure prior to any interaction with trains, the potential for the failed Earthwork asset to cause a derailment, and the safety consequence of a resultant derailment.

Purpose

Earthwork asset criticality is an assessment of the potential safety consequences of the failure of an Earthwork asset (soil cutting, rock cutting or embankment) - refer to NR/L2/CIV/086. The assessment assigns an Earthwork Asset Criticality Band (EACB) to a given Earthwork asset, where values range from 1 (least critical) to 5 (most critical).

Locational criticality is a secondary assessment of the potential safety consequence of a derailment at a given location of the rail network. This is independent of any asset properties. The locational criticality assessment assigns a Derailment Criticality Band (DCB) to a given Earthwork asset, where values range from 1 (least critical) to 5 (most critical).

Both Earthwork asset criticality and the locational criticality make use of the enterprise derailment risk model, the Common Consequence Tool (CCT) that is described in appendix A.