Sounding and Visually Inspecting a Pole
When a lineworker has to climb a pole, one of the determinants of whether that can be done safely is the integrity of that pole.
The lineworker has control over the elements of their own ability and their equipment, but if these two elements are at a high level and the pole is weak, they are at risk.
The inspection of a pole is a mix of art and science.
The science is what a person learns about decay, impact damages, loading and how it all fits together to determine the strength versus load ratio of the pole. These are things that can be measured.
The art is what a person perceives about that particular pole, which is like no other pole on the system, which may influence its strength. These are such things as a large number of knots in a small area, the twisting or checking of a pole, the fact that a pole is bent over time due to strain and any other number of factors. These are things that are unique to that pole and are not easily quantified and good judgement must come into play.
A lineworker wears a lot of hats and adding extensive training as a pole inspector and asking them to carry extra tools with them is not likely. However, there are some tools that they already carry that will keep them safe
The First Tool: A good set of eyes. After 18 years of pole inspection, I play a game of trying to determine if a pole has extensive decay before I get close to it. I look at it from a distance. From a distance, I can see things like woodpecker holes and lightning damage more easily than if I am only looking at the pole when I am underneath it performing the sounding step. I can see better if a pole is leaning and its taper from a distance.
When I get up closer to the pole, I generally follow a circle about the height of the pole all the way around so that I can keep that perspective of distance before I get up close. Up close to the pole, I examine the base of the pole. Are there indicators of decay? Some indicators of decay that can be visually detected are:
Green Stain: This is an early sign that the pole has very little resistance to decay. This is green coloring near the ground line where little microscopic plants have begun to grow on the pole. They themselves are not damaging, but they are a sign of things to come.
Fruiting Bodies: This is a huge red flag! If you see any kind of fungi that has horizontal dimensions growing on the pole, it is likely a very bad reject and should not be climbed.
Carpenter Ants: If the check is full of sawdust, they have been at work!
Mechanical Damage: Many times, there is more than meets the eye with machinery hits, be it impact damage or mower damage. At least 5 times a year, I come across a pole that initially seems fine, but when the grass is moved at the groundline, the pole has been sawed anywhere from ¼ to ½ way through by someone pulling something along the base of the pole, usually barbed wire. It is very subtle if someone is in a hurry.
Woodpecker holes: Woodpeckers are nature’s little pole inspectors. There is a loose relationship between woodpecker holes and a decayed pole, aside from the obvious woodpecker damage. The other issue to remember is that there are holes and there are nests. A nest may carve out a pole to a 1” shell and extend many feet. One will certainly see a nest on the way up and stop at that point.
The Second Tool: A hammer! A pole should be sounded 30-40 hits, concentrating the strikes near the groundline, but extending as high as one can reach also. The strikes near groundline should be 6 inches apart and cover the bottom two feet of the pole extensively. The higher strikes should be a foot apart and circle the pole.
Different species sound differently and hardware, even the presence of a groundwire, changes the resonance. The worst of the worst will be easily detected, but there will always be some sleepers that keep their decay low and present a challenge. These are the ones to discover through diligent sounding of the base of the pole.
The two tools mentioned are not suitable for finding subtle decay, but a proper visual inspection and sounding will reveal the worst poles and prevent an accident.
Joel Rovang RAM Utilities
A combination of green stain and mechanical damage.