Wood Pole Inspection and Testing
Even before OSHA created 29 CFR 1910.269 Appendix D, “Methods of Inspecting and Testing Wood Poles,” it seems likely that pole inspection was a rule of thumb for many field employees. After all, they set poles and repeatedly climbed them to handle upgrades, maintenance, wood rot and decay.
Today, given OSHA regulations and the fact that pole testing and inspections are not difficult to perform, it would also seem likely that workers would adhere to these practices. Unfortunately, some employees don’t inspect a pole at all before climbing. Others believe they can easily comply with regulations by merely rapping a pole several times with a hammer prior to ascending. They have been incorrectly taught by other climbers that it’s sufficient to rap a pole and listen for a hollow sound.
In the last few years, there have been several tragic events due to rotten wood poles falling or otherwise collapsing. The root cause of these events was failure to properly inspect and test the poles prior to climbing or changing tension. It is a disturbing reality to know that skilled and qualified climbers like us would forgo a basic safety procedure such as this one.
Remember that poles should be inspected not only prior to climbing, but also when working out of a manlift device or while using a digger derrick boom. If tension must be changed, consider how it will affect the pole and if the pole will be able to handle the change in tension.
Special attention also should be paid to pole inspection and testing during developmental training. Take advantage of this time to teach employees proper, safe work procedures. Additionally, make them aware of any special circumstances due to a pole’s location. For example, utility workers in Florida must deal with poles set in swamp water. In the Midwest and northern areas of the U.S., poles are planted in frozen ground for several months each year.
Following is the text of 1910.269 Appendix D for use during your next tailgate. While covering this information with your crews, think about your company’s guidance document regarding pole inspection and testing. Does it meet OSHA’s minimum requirements? If not, this may be a good time to meet with the author of the guidance document to discuss necessary changes.
OSHA 1910.269 Appendix D: Methods of Inspecting and Testing Wood Poles
When work is to be performed on a wood pole, it is important to determine the condition of the pole before it is climbed. The weight of the employee, the weight of equipment being installed, and other working stresses (such as the removal or retensioning of conductors) can lead to the failure of a defective pole or one that is not designed to handle the additional stresses. (1) For these reasons, it is essential that an inspection and test of the condition of a wood pole be performed before it is climbed.
Footnote (1): A properly guyed pole in good condition should, at a minimum, be able to handle the weight of an employee climbing it.
If the pole is found to be unsafe to climb or to work from, it must be secured so that it does not fail while an employee is on it. The pole can be secured by a line truck boom, by ropes or guys, or by lashing a new pole alongside it. If a new one is lashed alongside the defective pole, work should be performed from the new one.
II. Inspection of Wood Poles
Wood poles should be inspected by a qualified employee for the following conditions: (2)
Footnote (2): The presence of any of these conditions is an indication that the pole may not be safe to climb or to work from. The employee performing the inspection must be qualified to make a determination as to whether or not it is safe to perform the work without taking additional precautions.
A. General Condition
The pole should be inspected for buckling at the ground line and for an unusual angle with respect to the ground. Buckling and odd angles may indicate that the pole has rotted or is broken.
The pole should be inspected for cracks. Horizontal cracks perpendicular to the grain of the wood may weaken the pole. Vertical ones, although not considered to be a sign of a defective pole, can pose a hazard to the climber, and the employee should keep his or her gaffs away from them while climbing.
Hollow spots and woodpecker holes can reduce the strength of a wood pole.
D. Shell Rot and Decay
Rotting and decay are cutout hazards and are possible indications of the age and internal condition of the pole.
One large knot or several smaller ones at the same height on the pole may be evidence of a weak point on the pole.
F. Depth of Setting
Evidence of the existence of a former ground line substantially above the existing ground level may be an indication that the pole is no longer buried to a sufficient extent.
G. Soil Conditions
Soft, wet or loose soil may not support any changes of stress on the pole.
H. Burn Marks
Burning from transformer failures or conductor faults could damage the pole so that it cannot withstand mechanical stress changes.
III. Testing of Wood Poles
The following tests, which have been taken from 1910.268(n)(3), are recognized as acceptable methods of testing wood poles:
A. Hammer Test
Rap the pole sharply with a hammer weighing about 3 pounds, starting near the ground line and continuing upwards circumferentially around the pole to a height of approximately 6 feet. The hammer will produce a clear sound and rebound sharply when striking sound wood. Decay pockets will be indicated by a dull sound or a less pronounced hammer rebound. Also, prod the pole as near the ground line as possible using a pole prod or a screwdriver with a blade at least 5 inches long. If substantial decay is encountered, the pole is considered unsafe.
B. Rocking Test
Apply a horizontal force to the pole and attempt to rock it back and forth in a direction perpendicular to the line. Caution must be exercised to avoid causing power lines to swing together. The force may be applied either by pushing with a pike pole or pulling with a rope. If the pole cracks during the test, it shall be considered unsafe.
About the Author: Phillip B. McGee, CUSP, is a lead safety professional at Duke Energy. He began his electrical industry career for Florida Power Corp., known today as Duke Energy, in 1979. Over the past 35 years, McGee has progressed from a lineman to a line training specialist to his current position. He has spent the past 10 years working in Duke’s line utility safety organization.