Overhead transmission line work is physically strenuous and exposes workers to an increased risk of musculoskeletal and other injuries. Pole removal is one of the most demanding assignments for transmission crews. The need to remove older transmission poles continues to grow as utilities upgrade their transmission systems. And when Mother Nature throws her hat into the ring, pole crews are put on double-time. This work is some of the most difficult tasks for a pole crew, and the wear and tear on both the crew and the equipment can be costly.

Wrestling Stubborn Poles

Transmission poles provide a greater challenge than distribution poles, because they are larger in diameter, placed deeper in the ground and typically have a more bell-shaped bottom, which increases the mechanical force required to remove the pole from the ground. Concrete or asphalt around the base of the pole also can complicate the removal process. A utility's accounting department would have a hard time placing a dollar figure on the costs associated with the creative methods line crews devise to remove stubborn poles.

In the old days, crews tried creative ways to remove the stubborn poles. There were incidents where crews literally tore the boom off of a digger derrick truck trying to remove a stubborn utility pole. Similarly, extending the outriggers on the truck to gain additional pulling force has resulted in bent booms, broken turret gears and damaged winch lines. Work safety is also compromised when equipment is overstressed or used inappropriately. We seldom see these problems because utility-equipment manufacturers will void the warranty, for example, when a digger derrick truck is used to pull poles.

More conventional ways of removing stubborn poles include digging around the base of the pole with an auger or a backhoe to loosen the larger transmission poles. Although digging may be necessary, crews must call the Diggers Hotline before placing a shovel into the ground. This adds additional costs to the utility and creates time delays.

On stubborn poles, crews have been known to attach a chain to the pole and muscle it out with a backhoe bucket. On occasion, chains have been known to snap and fly past a lineman's head.

Equipment-Use Restrictions

After a few bent booms, broken turret gears and damaged winch lines, most utilities instituted work rules to protect the workers and the equipment. New company guidelines require use of a mechanical device, typically a portable hydraulic pole-puller assembly, when removing utility poles. These rules were implemented much to the dismay of the linemen, especially to the transmission lineman who actually has to manhandle the portable hydraulic unit. His job is to drag the 100-lb hydraulic puller down through the ditch and up to the pole, drag the hydraulic lines off of the truck, chain the puller to the pole, hook up the digger derrick to the pole and attempt to break the pole free with the hydraulic puller, if it doesn't sink down into the mud before the pole is extracted. This whole process could take anywhere from 30 minutes to an hour.

Over the years, We Energies (Milwaukee, Wisconsin) has tested a variety of commercially available pole-pulling devices for field use. The units typically consist of a hydraulic cylinder and base-plate assembly that is coupled to the pole to be removed via a chain that cinches around the pole. These devices serve their purpose to break the pole loose, but are rather cumbersome to operate, and sometimes it becomes a wrestling match to get the pulling device out of the ground once the pole has been removed. In transmission line work, there are also ergonomic issues with carting the heavy puller cylinder and hydraulic hoses back and forth from the digger derrick truck to the pole.

It became painfully obvious to We Energies' pole crews that there was a need for a piece of equipment that could safely not only remove the poles, but also control and lay them down with minimal operator intervention.

Second-Generation Innovation

We Energies' distribution division has been refining a pole puller. This self-contained attachment uses the hydraulic power takeoff of the piece of construction equipment to which it is mounted, such as a skid-steer loader (Transmission & Distribution World, Electric Utility Operations, April 2006). This design showed potential for pulling larger poles. A second-generation larger version of the innovative pole puller, mounted on a backhoe, has now been developed for transmission-line applications.

This past spring, an ice storm at MidAmerica Energy (Waterloo, Iowa) emphasized the need for such a piece of equipment that could safely handle removing a large number of damaged utility poles. The Iowa ice storm snapped off 70-ft and 80-ft poles at the base, taking out many miles of distribution and transmission line wood poles. Crews were challenged to install new poles and restore power to MidAmerica's customers as quickly as possible. To clear the work area, the damaged poles were cut off at the base and removed. This left several miles of old pole butts sticking up out of the ground. From an environmental stewardship standpoint, the prudent thing to do was to remove the preservative-impregnated pole butts, rather than cutting them off below ground line and covering them.

How It Works

The new backhoe-mounted pole-pulling apparatus is ideal for this application, eliminating the setup time for the digger derrick, as well as the time it takes to manually assemble a conventional hydraulic pole puller on-site. A two-man crew consisting of an equipment operator and a spotter can extract a pole in a single stroke of the hydraulic cylinder. This eliminates the time-consuming, multi-step procedure of having to unhook and reattach the conventional hydraulic pole puller to the pole to fully extract the pole butt.

With the construction equipment loader controls in float, the hydraulic cylinder pulling force is applied directly to the ground via the base plate. A set of pole claws grip the pole during the removal process.

Since the pole remains attached to the machine, it can be transported and loaded directly onto a truck or trailer in one operation. The pole is only handled once. This improves crew efficiency, eliminates the ergonomic issues associated with physically handling the roughened pole, and lessens the chance for contact with creosote or other wood preservatives that can cause skin irritation for the lineperson.

Cost Savings

We Energies is constantly looking for innovative ways to maintain reasonable electric rates for customers by controlling costs without compromising safety and reliability. The self-contained puller achieves these goals. Crews report that poles are removed in minutes rather than hours. From a safety standpoint, pole crews are truly letting the equipment do the heavy lifting. And when the wear-and-tear costs to equipment and reduced risks of injuries are taken into consideration, the utility's overall bottom line is greatly improved.

---

Joe Kysely has more than 20 years of experience in the electric power industry, serving as a design engineer for two different high-voltage equipment manufacturers and as an application engineer for We Energies (Milwaukee, Wisconsin). He holds a BSEEE degree from Marquette University and an MEEE degree from Rensselaer Polytechnic University. Kysely is a member of IEEE and is a registered professional engineer in Wisconsin. Joe.Kysely@we-energies.com