The job of a line locator is a lot different than that of a distribution lineman. After being a lineman for 32 years, I found this out last year when I was asked to take over the job of locating and marking our company's underground lines. Line locating was new to me, but I believe my background and experience has helped me greatly in this new position.

Logansport Municipal Utilities (Logansport, Indiana) has more than 20 miles of transmission lines to 10 substations and approximately 200 miles of distribution lines to our business and residential customers. Although it's not a really big system, for the most part, I'm the utility person the Indiana one-call system calls when someone wants to dig around our lines.

Time Underground

I actually don't care much for underground. I'm a lineman. I like to climb, and I like to be able to see what's going on. On an overhead service, when customers call to report that their lights are flickering, I can go out and look for tree limbs rubbing on the wire. But when locating underground cable, everything is harder. For one thing, I can't see the cable. So before I can repair the fault, I have to find the cable. First, I look at the pedestal and the meter riser on the house, and then I look to see if there are any prints or signs of fresh digging, such as someone planting a tree or setting a fence post.

Performing locates takes me a little longer, but I prefer to be right and not gamble with a guess. I have always wanted to do the best job that I could. As a foreman on a crew, I was always fearful of someone getting hurt because of something I had not done or communicated correctly.

Early Locating Experiences

In my early days as a line locator, one assignment in particular made me nervous. I had a locate ticket at a hog-processing plant, which is one of our largest customers. The plant was close to the substation, which meant the fault current on the conductor was close to the source and therefore much higher than normal. Stray current radiating from the line can cause interference on your locator, making it harder to get a precise reading. I remember thinking, “Wow, this isn't your typical 110-V house service.” The cable company was dropping a cable near our 13,800-V single-phase primary, and I felt like I was set up to fail.

Keeping my nerves in check, I used all of my lineman training. I checked the prints, aligned the riser with the pedestal and dropped the box where I thought it was going. I said to myself, “There has to be a better way to locate this.”

Around the time I did that line locate, another line locator in the area told me about a locator training workshop south of Chicago. I signed up and took the class.

Hands-On Training

The week-long workshop covered all the basics of locating. We spent a small portion of the week in the classroom going over the basics of signals and frequencies, and how to read the data, but we spent the majority of the time in the field. With an experienced locator instructing us, we conducted site investigations and practiced different scenarios for assessing a situation in a realistic infrastructure setting.

The training area, located in Manteno, Illinois, is called Planet Underground, because it is an actual abandoned campus of buildings and streets with all the buried utilities built back in the 1950s still in place.

I thought the best part of the experience was that all of the training was done with the locator I use on the job. Logansport owns two Metrotech Model 850 Liner Tracers, so the entire week I used my locator in the class and in the field.

I had been with the utility for many years, but until I took this job, I never had an opportunity to run the locator. Along with the locator box, there were conductor clamps, a ground rod and cables, but even the owner's manual didn't answer all of my questions. The manufacturer gave me a five-minute tour, but I learned from the training workshop that there is more than one way to locate cable.

A Word From the Wise

The instructor, Don Weber, used to work for the gas company and is considered an “old timer” who has “been there, done that.” He preaches, “No shortcuts, double-check the marks and make sure you have done everything you can to make it safe to dig.”

From Weber I learned to respect the locator readings. They may not be 100% accurate, but they are giving you information that you must take into consideration. He also shared many war stories about near misses that have shaped his attention to detail as a line locator.

Weber also believes in learning everything you can about your locator. The Model 850 is really pretty simple to operate. It has push-button depth readings, automatic gain, signal display, gain display, two-stage transmitter power and a feature that indicates left-right visual and audio guidance to target cable. We went over all of its features during the class and practiced using them in the field.

Lessons Learned

Another thing I learned that was very helpful was the difference between the high- and low-output settings on the locator. To locate a cable, you attach the inductive clamp to the cable and transmit a magnetic signal down the cable. To pick up that signal, I always thought the high setting was probably the best, and therefore always located with the transmitter on the high side. I now know that sometimes the low side provides the better reading.

The lower setting gives you a minimum output but, in many cases, enough signal to trace the cable. It is actually designed to minimize “bleed-over” onto adjacent lines. This is a common occurrence on the high-output setting. Bleed-over confuses the device, giving you inaccurate readings. The low setting also helps isolate a single line in a congested area, minimizing “jump off” to an adjacent phone line or cable. The high-output setting actually works best for transmitting for longer distances on a distribution line. It also gives you the ability to push the signal through a fault on the line you are locating.

Lineman Experiences Help

I believe that my experience as a lineman has given me an advantage over some line locators. I can open up transformers and junction enclosures, and I am familiar with everything that's inside. I also have a pretty good idea where the cable is going out of the transformer or enclosure. I have a healthy fear of an energized conductor, whereas some people don't.

Recently, I saw another utility locator using a fancy new locator system with a lot of buttons and screens. He was in his typical routine, going beep, beep, beep and paint, paint, paint. Then he was back in his truck and gone. I was thinking, “My gosh! What if … ?”

I remember hitting a gas line years ago. We had a pole to install between the sidewalk and the street. Usually when my crew would go to do an underground service, everything was marked showing where the cable, phone and gas were supposed to be. I would tell my crew, “That's where it says it is, but let's get our shovels and make sure.” Most of the time our line went underneath the existing lines. Rather than relying on the paint, we normally would dig it up.

On this one incidence, we didn't. We had a 30-ft pole to set 5 ft deep. The gas marks were out in front, which made sense. Instead of digging it up, we decide to auger down behind the marks. About 4 ft down we hit the gas line. It was a 2- or 3-inch main and the gas began blowing. The gas company came and evacuated the houses. The gas just kept blowing. The gas company crew was not happy with us. We said it wasn't intentional, although it could have been serious. That's why I don't cut corners and always try to get it right.

On another incident years ago, I was driving a ground rod on a transmission line. I went in close to the pole thinking there wouldn't be anything there. I ended up driving a ⅝-inch ground rod through a fiber-optic line. It was not a good day for the telecommunications company or me. I learned you dig it up and get a visual locate, just to make sure. I would rather take the time to dig the hole and see it. There's just not much room for mistakes, especially on energized lines.

Tragedies Make You Cautious

Some of my cautious approaches to locating come from tragic experiences other linemen have suffered. A meter man and two linemen I knew were killed on the job. These kinds of tragedies make you very cautious.

I look at my job as a line locator like I did when I was a lineman. You prepare for the worst and expect the best. As a locator, I think the same way. I just always expect the worst and try to prepare for it. The locator we use has three application levels. These days, I use them all.

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Dave Hood has been a lineman at Logansport Municipal Utilities for 32 years and is currently a line locator.