Vermont Electric Power Co.'s (VELCO, Rutland, Vermont) right-of-way team used to depend on our crew's years of experience to estimate tree heights. With a new laser-measurement device, however, we now perform accurate measurements with the touch of a few buttons. This accuracy increases the reliability of our lines by decreasing the risk of line failure due to downed trees.

Our three-man crew uses the TruPulse 360, a reflectorless laser rangefinder manufactured by Laser Technology Inc. (LTI; Centennial, Colorado) to identify “danger trees.” If these trees fell over, they could come in contact with our transmission lines and jeopardize electric system reliability.

We identify danger trees when we inventory a quarter of VELCO's system. Inventories are conducted annually to determine the next year's treatment plan. By increasing the accuracy of field measurements, we increase efficiency, improve safety, maintain reliability, better conserve forest habitat and improve discussion quality with our neighboring land owners.

Multiple Benefits

The $1500 laser rangefinder paid for itself in the first two weeks of field use. VELCO's vegetation management crew, which is responsible for inventorying all the trees that may affect a line, often errs on the side of caution when it comes to cutting down trees. If we estimate a tree is tall enough to affect a line, it will often be cut down. By using the device, we no longer cut down trees whose heights do not pose a danger to VELCO's transmission lines.

In addition to its economical benefits, the device comes in handy when meeting with landowners. We can demonstrate through accurate measurements which trees have the potential to impact a line. This gives the landowners a better understanding of necessary tree clearing on their property.

In case a landowner questions why we are cutting down a tree, we can measure the height of that tree and instantly provide assurance to the landowner.

Learning Curve

The TruPulse 360 can measure the distance to the center, top and base of a tree. The device then does all the math calculations to give the exact tree height. Within a day in the field, VELCO's crew was up to speed and using the device with no problems.

Three members of the vegetation management team are currently using this device, but VELCO may purchase another unit for the line or substation crews. With the device, our linemen can capture accurate height and distance measurements for utility poles. According to LTI, the device combines an integrated compass, inclinometer and distance laser that allows users to shoot from any angle. As a result, users can collect the data quickly and easily, even in mountainous terrain, wetlands or snowfields.

Full Potential

In the future, our vegetation management crew plans to use the device to its fullest capability. Right now the crew performs inventory on handheld computers out in the field. The device's Bluetooth capability makes it so we no longer need to input the measurements into the computer; instead, the device will record these measurements as we take them.

We have mainly used the TruPulse 360 to determine tree heights, but have begun using the tool to measure the distance from trees to conductors to ensure we are meeting required clearances.

The TruPulse 360 has increased vegetation management accuracy and reliability, and improved VELCO crews' efficiency. We now better identify and are no longer cutting down non-danger trees. The days of getting down on the ground and pulling a tape measure through low-growing brush are officially over.

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Jeff Disorda is the supervisor of right-of-way management for Vermont Electric Power Co. (VELCO) in Rutland, Vermont. He has been with the utility for four years. jdisorda@velco.com