Overhead Line Work, Then and Now
Overhead line work requires much planning beforehand and total attention when it is being performed. Recently I’ve had several requests to discuss this kind of work, so I’m going to take you back to the days when I was a lineman and, later, a crew supervisor to aid in this discussion of overhead jobs.
When I first became a lineman in 1972, I was hired as a helper on a line crew. The job was trial by fire in those days. There was so much material to learn, but there wasn’t much in the way of training schools back then – almost all of my training was of the on-the-job variety. Lineworkers would put a “newbie” in a bucket, raise the bucket, and then have the new guy put their hands on 4 kV and 7.2 kV, for example. If you were that newbie, you also might have been made a winch truck operator long before you became an apprentice. And if you did not like the feeling of energized conductors in your hands, you were usually directed to the meter shop or another department. Lineworkers during that time found out quickly who might not make it in this kind of work. By the time I became an apprentice lineman – after attending a two-week apprentice school – I was being moved from apprentice to bottom journeyman about half the time, especially on callouts and trouble work. Many of the lineworkers at that time did not want to work nights or weekends.
It was July 1972 when I became a journeyman lineman in Jonesboro, Georgia. I stayed on the line crew there for a few months before going back to my hometown of Macon, Georgia, where I worked on Smokie Smarr’s line crew. Smokie was a tough, hardworking foreman who pushed us hard, too. The only reason I went back to Macon was because other people preferred not to work on that crew. I didn’t mind. The crew hardly did anything other than reconductor, cut in gang switches and change out junction poles. Essentially, a lineworker on that crew knew how to do those things, learned quickly or was moved to another crew. I was led to believe that if a lineworker can set up and complete a large three-phase reconductoring project, they had proven their worth and were a true lineworker.
A Method to the Madness
So, how was a large reconductoring job planned in the 1970s? There was a method to the madness then as there should be today. The first step, of course, was putting together locates and a major materials list, plus doing any needed tree trimming. Then, industry and company plans took over.
During my time in the industry, I have seen leaning poles and framed new ones next to them. Does that work? It does, although I’m not sure it is the safest or most practical method. I was always taught to set every pole to be changed and transferred, to use wood arms and layout arms to get old distribution out of the way to provide a safe corridor to pull in new conductor. I was also taught to frame new construction to the National Electrical Safety Code and company specifications. This may require customer outages if a three-pot bank or a UD riser pole needs to be changed out. It just depends on what is involved or paralleling the bank to keep it hot during transfer.
When a pole has been transferred, roller blocks should be installed and pilot lines should be secured to the bottom of the pole, high enough off the ground to prevent them from being tampered with. If the new conductor to be pulled in is much larger than the existing conductor, additional poles may need to be added. When pulling in 750-795 ACSR or AAAS, the span lengths should be kept to around 250 feet to mitigate excessive wind or ice loading of new wire. If one is available, a four-spool pilot line should be used to pull in ropes prior to the day that conductor is to be installed. If the pilot lines are used and a single bull line is pulled out, the project will take longer.
Down guys are another interesting topic. A fellow named Jim Swift once made the statement to me that “if you can’t guy it, don’t pull it.” Inadequate or incorrect guying of distribution causes leaning and unstable poles. Down guys should be installed at primary locations and neutral shackles of 4/0 or larger conductor. Nothing looks worse than a pole with a “belly” in it because conductor was pulled unsupported. Also, TV and telephone can wreck a pole in a heartbeat. I have seen contractors pull in larger cables and pull the down guys when the cables are in. Please, if you cannot do better than that, do not try.
New Conductor Installation
The day the new conductor is installed is a busy day. If pilot line isn’t used, the pulling of the hard line or bull rope will take longer. Once all the lines are in, pulling of the new conductor can begin. A spotter should follow the becket and swivel as the pull proceeds. If there are a lot of angles or suspension poles on a pull, the blocks must be set up correctly or there could be a hang-up, causing damage or even an outage.
Once the new conductor is in place, a dynamometer should be used to sag to the ruling span. Determine just how tight to pull, allowing for cold and wind, or you will pay later. There was a time – and at least a few people learned the hard way – when some workers would eyeball the sag and install too tightly on a hot day. When cold weather arrives, wire contracts, and I have seen a 4-inch curved washer pull all the way through a 45-foot Class 3 pole. It’s ugly. On a 60-degree day with 750 ACSR conductor and span lengths around 250 feet, approximately 1,000 pounds on the dynamometer should be sufficient and safe. It will vary a little. The tendency is to add 10% to the total weight to make it look better. Just avoid the old “get all you can and four clicks more” to keep it tight. Also, if you have major elevation changes on a 5,000-foot pull, you may want to consider sagging at each end. Going up hills tends to change sag from one end to the other. It depends on the location of the hill to the dead-ends.
After the initial sag has been completed, it should ideally sit for 24 hours to ensure equal sag and any settling in long spans. New conductor should be grounded on each end as the tying in proceeds. Also, remember, if you are in a corridor with other transmission lines, there will be induced voltages and differences of potential, even on grounded lines. Refer to Notes 1 and 2 to OSHA 29 CFR 1910.269(q)(2)(iv).
When new conductor has been tied in and visibly checked, it can then be energized, and the transfer of load from old to new conductor can begin. Paralleling all the load from old to new allows the customer to never have an outage. In my day, we always said that if the customer did not look out the door and see us working, they should never know we were there.
There are many other details that go into a job this size. It takes years of experience to be safe and successful while doing this type of work. What I’ve shared here is just a glimpse of the past methods I personally learned from great linemen like Ed Lunsford and great foremen like John Lane. I would not trade anything for those experiences with those people.
About the Author: Danny Raines, CUSP, safety consultant, distribution and transmission, retired from Georgia Power after 40 years of service and opened Raines Utility Safety Solutions LLC, providing compliance training, risk assessments and safety observation programs. He also is an affiliate instructor at Georgia Tech Research Center OSHA Outreach in Atlanta.