October 15, 2008 > Choppers do the heavy lifting for linemen
Choppers do the heavy lifting for linemen
High above cities and open lands, power lines bring energy to homes and businesses. These high voltage lines, connected by massive towers are lifelines from sometimes from energy sources that are often many miles from the source. Power grids of transmission lines and support towers are vulnerable to the wear and tear of time and weather, sometimes requiring repair in inclement conditions that can be time consuming and dangerous. Power companies are always alert to any solution that can reduce repair time and increase safety for repair personnel. Fixing problems of high voltage electrical connections can be tricky at times. After all, this essential source of power for users can easily move in any direction, even when unintended and deadly.
As power requirements have increased in our highly concentrated and industrialized areas, power lines have increased and the amount of energy required has increased as well. The height and placement of power lines has created significant challenges. In order to safely work on these lines, Pacific Gas and Electric (PG&E) has employed the use of helicopters since 2006 as a transport vehicle for repair personnel. Two factors have driven the increased use of this method: environmental considerations that inhibit access to towers and time saved in comparison to climbing a tower with necessary repair equipment.
Flying from structure to structure is significantly faster and less strenuous than climbing up to an area that needs maintenance, climbing back down, walking or driving to the next structure and repeating the procedure. Under poor weather conditions, access roads may be blocked as well. Senior Transmission Specialist Ken McClure said, "I have spent as much as half a day just walking to a location to climb to the problem." Another example cited by McClure, one of the first done with helicopter assistance, was the routine replacement of 124 parts using a six-man crew. Using traditional work methods, only 24 replacements would have been accomplished in the same amount of time. He noted that the only reason the helicopter-assisted crew stopped at 124 was that they were limited by the number of replacement parts in their inventory.
Helicopter access is used in urban, suburban and rural areas. "The only thing that would stop us from using this technique is excessive wind, limited visibility, where airspace is restricted or where there are schools and homes," said McClure. PG&E personnel are transported to a tower and supported by helicopters as they work by bringing tools and materials to the worksite. Pilots and repair personnel "work hand in hand." The training facility for this unique technique is found in Livermore where repair personnel and helicopters learn to perfect the use of these methods.
The safety record for PG&E "long line workers" is unblemished. McClure noted that of the nine helicopter vendors used by PG&E, only four of them are qualified to work with the "external shipment load program." Pilots go through a vigorous training program to be a part of this program. "We have well maintained equipment and well trained employees, so there is a huge safety factor. For instance, one of the ropes we use has a maximum breaking strength of 17,000 pounds but the helicopter can only take 800 or 900 pounds depending on temperature so we are nowhere near the capacity of the rope. All harnesses and connection points are rated at least 5,000 pounds which, again, far exceeds the capacity of the helicopter."
The Jimmy Webb song, popularized by Glen Campbell, immortalized the Wichita Lineman who drove along, "Lookin' in the sun for another overload." While much of this may be true across the country, PG&E could amend the lyrics to "flyin' along the mainroad fixing another overload. The next time you hear the whirring of helicopter blades near a power line, you may just have a front row seat to watch a few of the over 300 PG&E employees trained to work in this intricate and demanding aerial ballet.