NordiConsult recommends that maintenance should derive from prior conditional checks, following with a subsequent assessment. So that companies might achieve better maintenance, we have recommended to the Norwegian distribution companies to strengthen their use of the term “Condition Based Monitoring”.
Among other things, these following tools are used by NordiConsult:
- A hammer to identify/hear rot
- Awl/knife to check for any soft/shell rot
- A Resistograph is able to measure with millimeter accuracy the state of core rot and the extent of rot in a wooden pole.
- The Polux measures the utility pole’s fiber strength and moisture
- NordiConsult’s FieldSolution, contains a checklist of standard controls for plants based upon REN’s (Norwegian standard) recommendations.
- NordiConsult Express is a web based, “real time” maintenance tool able to show a complete and accurate view over deviations and also the true condition to power lines, areas and sectors.
- GPS is used, among other things, to position the utility poles.
- Pictures are made to document special
In addition, this is registered:
- The number of poles in the mast section, the diameter of a pole, the number of power lines, and the line’s diameter in its mast section
- All visible deviations, insulators, traverse, phase lines, forests, any other types of damages to the pole (woodpecker holes, cracks, lightning damages, peeling etc.). All damages are checked against special tables so that one might avoid judgment from the linemen.
- Immediate report: In the field, the inspector receives a message immediately concerning the poles wellbeing. It is then decided if it should be taken out of the operation (the power line), or if it shall continue to be in use. If the pole is deemed unfit, it is labeled with a sign implying that climbing the pole is prohibited.
- Summarized: NordiConsult will determine the pole’s current condition, and will calculate if the pole can safely still be in use, by taking into consideration all of the expected influences of that specific area.
What makes NordiConsult’s methods special in opposed to other competing companies?
- We use experienced linemen who 9 months out of the year, 20 days per month, have as their main assignment to find rot and evaluate wooden utility poles. Approximately 15-20 % of all deviations deal with rot, while the remaining deviations are related to other areas of the plant. It goes without saying that experienced linemen will always evaluate a plant in a respectful and professional manner.
- By using a specialized tool such as the Restistograph one is able acquire specific and precise measurements of the extent of rot in a wooden pole. If we compare the results from a Resistograph and e.g. results from core drilling, the numbers are quite different. Many test projects have shown that core drilling is in fact too imprecise to be used as a reliable reference. Also, we are able to examine probable “rot attacks” up to around 40 cm underground. This is a significant difference between our company and our competitors, since around 70-80 % of all “dangerous” rot is found in the soil (underground).
- After we have completed our inspections, the employer will receive information concerning the residual strength value on all poles inspected. Then he or she will be able to make the following choices:
- Can the pole be replaced?
- Can the pole be fixed?
- How long can the pole function until it becomes critical?