Wood Pole Inspection & Life Extension

 

Proper maintenance of wood utility poles helps add many years to the safe, reliable service life to your pole plant, thereby reducing unnecessary or premature replacement costs.

Osmose pole inspection programs allow you to better manage the critical factors that determine pole performance – strength, load, and cost.

 

The keys to a successful pole inspection program are:

  • Identifying decay and measuring defects 
  • Estimating the pole’s remaining strength to determine pass/fail - Inaccurate strength calculations can be costly.  A false fail can lead to unnecessary spending on restoration or replacement, while a false pass can create risk that may lead to pole failures and costly damage and repairs.  Osmose technicians use StrengthCalc® software which models the cross section of decaying poles in relation to the transverse loads.  StrengthCalc accounts for both the severity and location of the decay with respect to conductors and equipment.  StrengthCalc determines precise section modulus to provide the percent remaining strength for weakened poles.
  • Applying effective remedial treatments to extend the safe, reliable service-life of the pole.  Remedial treatment is the key to getting the most out of your investment.  The use of remedial treatments will earn dividends via extended pole life and improved plant resiliency.  

Osmose can help you optimize your life-extension investments by matching your program objectives with an appropriate inspection method.

Inspection Methods & Accuracy 

 

Sound & Selective Bore

Sound & Selective BorePoles are "sounded" with a hammer to detect internal decay. Poles that show signs of internal decay (based on the sound test) are bored to determine the location and extent of the decay.  

Level of accuracy for identifying rejects: 15%

 

 

 

Sound & Bore

Sound & BorePoles are both "sounded" with a hammer to detect internal decay and bored to determine the location and extent of the decay.   

Level of accuracy for identifying rejects: 10 - 35%

 

 

 

 

Sound & Bore with Partial Excavation & Selective Treatment

Sound & Bore with Partial Excavation & Selective TreatmentPoles are "sounded" with a hammer to detect internal decay and bored to determine the location and extent of decay. Poles that show signs of internal or external decay are fully excavated to a depth of 18" to determine the extent of decay at the groundline. Decayed wood is removed and a preservative paste is applied to protect the remaining sound wood.   

Level of accuracy for identifying rejects: 55 - 85%

 

 

Comprehensive Life Extension
Industry Best Practice

Comprehensive Life ExtensionThis program includes sound, bore, 18" excavation, remedial treatment. Poles are "sounded" with a hammer to detect internal decay and bored to determine the location and extent of decay. Each pole is fully excavated to a depth of 18" to determine the extent of decay at the groundline. Decayed wood is removed and a preservative paste is applied to protect the remaining sound wood.   

Level of accuracy for identifying rejects: 98%

Ohio Electric Cooperative & Sonic Inspection

Case Study
Ohio Electric Cooperative & Sonic Inspection

 

Osmose inspected 36 poles on Ohio Electric Cooperative's distribution system that were previously inspected by a company utilizing their sonic inspection device. As a result, Osmose mitigated the replacement of six poles the original inspection company rejected, and reduced risk on the pole plant by accurately rejecting six poles missed by the original inspection company.

Program Benefits Limitations Pole Life Extended

Sound & Selective Bore
Recommended Cycle:
Every 2 years

% of Total Rejects Located: <40%

Locates obvious rejects quickly with a minimal investment.

  • Leaves a considerable number of undetected rejects (along with liability and risk)
  • 2-year inspection cycles are recommended
  • Reject rates remain high in future cycles
  • 100% O&M (no life-extension means no opportunity to capitalize a portion of the expense)
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Sound & Bore
Recommended Cycle:
Every 2 - 4 years

% of Total Rejects Located: 50% - 60%

Locates obvious rejects quickly with a minimal investment.

  • Leaves a considerable number of undetected rejects (along with liability and risk)
  • 2 to 4-year inspection cycles are recommended
  • Reject rates remain high in future cycles
  • 100% O&M (no life-extension means no opportunity to capitalize a portion of the expense)
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Sound & Bore with Partial Excavation & Selective Treatment
Recommended Cycle:
Every 4 - 6 years

% of Total Rejects Located: 70% - 90%

  • Improved inspection accuracy (because a below grade portion of pole is exposed and inspected)
  • Investment will earn some dividends via extended service of life of treated poles
  • Inspection cycle can be extended to 4-6 years
  • Though inspection accuracy is improved, it is not "best practice" and leaves 10%-30% of rejects unidentified.
  • Reject rates will be higher on future cycles than those obtainable with a full excavate program
Only for those "select" poles that receive treatment

Comprehensive Inspection
Recommended Cycle:
Every 8 - 12 years

% of Total Rejects Located: 98%

  • Most accurate inspection - locates 98% of rejects
  • Investment will earn dividends via extended pole life and improved plant resiliency
  • Because asset life is extended, owners may choose to capitalize all or a portion of the expense
  • Inspection cycle can be extended to 8-12 years
  • Increased initial investment
  • May take longer to inspect entire system
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Contact your local Osmose professional.