2016 – Applying Mechanical Thinking to Dam Strategy

Tom Reed

Asset management and particularly dam safety management at Snowy Hydro is a continually evolving process and at the heart of the program is our desire maintain the legacy of the Snowy dams and to do everything required to meet our obligations and duty of care. There is a significant shift underway from a schedule-based maintenance to a condition-based maintenance plan. The advantage of this is that the right maintenance is delivered at the right time and resources can be efficiently allocated to the right maintenance.

Condition based maintenance is not driven by a desire to cut maintenance or surveillance spend. A key part to this change is determining the condition of an asset or dam. To achieve this, reliability centred maintenance principles have been applied to dam structures through the use of failure mode effects and critically assessment (FMECA) tool, this differs to a traditional failure mode assessment, as it looks at functional failure of individual structures or equipment rather than partial or catastrophic failure of the dam. The outcome of a FMECA is a detailed maintenance and inspection plan that targets the individual functional failure modes.

One of the outputs of this process is a condition assessment methodology which is used as a trigger for corrective and preventative maintenance activities and a tool for the justification of installing performance measuring instrumentation. Condition assessment is therefore the process where asset performance data is assessed against specific criteria to determine its present state. Currently, comparing condition and performance of multiple dams is reliant on a practitioner’s experience and subjective assessment to determine whether an asset’s condition is fit for service. The condition assessment process; reduces subjective data, provides real-time health assessment, highlights performance issues, continuously identifies and updates priorities and provides justification for capital investment.