Fourteen years ago, Southern California Edison (SCE) linemen maintained lines using bucket trucks and climbing structures. In 1998, however, the utility began exploring the possibility of creating a Human External Cargo (HEC) program to use helicopters for transmission work. Over the years, the utility has invested in equipment, hired and trained qualified team members, and refined its work methods. As a result, the utility is now saving an average of 30% of labor hours per job using HEC methods.
SCE maintains more than 12,000 miles of transmission circuit, provides generation, transmission and distribution, and has a 50,000-sq-mile service territory. The company employs about 18,000 employees, and over the last few years, SCE has worked on training its transmission field linemen on the proper work methods, tools and technologies related to working with a helicopter.
Conducting Field Trials
SCE began its pilot program back in 1998 with a feasibility study involving nonrepresented employees, a single-engine MD 500 helicopter and a man-basket method for air operations. Ten years later, a project charter authorized HEC as a joint partnership. Through benchmarking efforts, the utility was able to identify the best equipment and develop training. Then in May 2009, SCE had a kickoff meeting with a core team including transmission, aircraft operations, the transportation services department, corporate safety representatives and IBEW Local 47.
At that point, SCE was ready to move into field trials in Bakersfield, California. During this phase, the utility had the opportunity to prove concepts and for the line crews to train on the equipment such as the man basket and Yates 390 RTR Tower Harness. Rather than suspending linemen from the helicopter, however, a EC 135 helicopter instead towed nonhuman loads such as Rescue Randy. This gave the helicopter pilot an idea of what it would feel like to have linemen working underneath the helicopter.
The next step was to see what other utilities were doing in terms of helicopter work in the field. SCE turned to Pacific Gas & Electric (PG&E) to observe its work methods. In addition, the utility also worked with drug-enforcement agencies for their ideas on human cargo. SCE also turned to many search and rescue organizations and referred to the Department of the Interior “Helicopter Short-Haul Handbook” for guidance.
The utility moved the trials to Hemet, California, a few months later. For this trial, SCE also used a EC 135 helicopter, Yates harness and man basket. The difference, however, was that the helicopter was transporting the nonhuman loads to the top of the 500-kV horizontal bridge construction tower. In addition, SCE began starting human load trials by lifting the linemen in their harnesses.
Finalizing Work Procedures and Equipment Selection
The utility then began developing and refining its work methods. For example, SCE focused on harness transfer from ground to tower, tower to tower, and ground to ground. The next phase is barehand, which involves the use of a Faraday suit, a Yates Sky Chair for mid-span work and an AirStair-type application from Hydro One. The utility is in the process of filing its barehand variance now. The skychair has been tested under lab conditions and is ready for field trials in the immediate future.
SCE then began researching helicopters and selected the EC 135, which is manufactured by Eurocopter. One of this helicopter's safety features is its redundancy. It is also a twin-engine helicopter capable of flying with one engine operable for fly-away capability in HEC operations. It has a small footprint, which reduces the size of the field-landing locations. With dual-pilot operation for the HEC, a Fenstron tail rotor, and Siren dual hook and release, the helicopter was designed for HEC operations. The lift beam below the helicopter supports the two hooks, which are only 16 inches apart with each holding a lift line to a center ring. Then if the hook fails, the load shifts to the other one for enhanced safety.
SCE selected the short-haul rope from Barry Cordage Ltd. in Montreal, Canada. This rope is custom-made for redundancy and safety. It features dual snap-hook/dual D-ring harness attachments, Dyneema SK75 synthetic fiber, a standard length of 75 ft, and a protective sheath to protect the rope from heat, UV exposure or abrasion. The rope is dedicated for human cargo only, and a 25-lb weight bag is built in on the rope system to make the line more manageable. This rope has two caribiners, so linemen can put a different extension on the base of the line.
The utility opted on the Yates 390 RTR tower harness, which was designed in conjunction with Ropes That Rescue Ltd. This harness meets Federal Aviation Administration (FAA) regulations part 27 and 29 and ANSI/OSHA Z359.01. It is commercially made and acceptable to the helicopter work methods committee. The full-body harness minimizes orthostatic intolerance or suspension trauma and has a 310-lb capacity.
When starting the training program, the FAA attended field training sessions and reviewed the entire program including the manual. SCE is currently operational under Category B but is pursuing Class D certification.
In addition, the corporate and business unit safety group was involved in the training program. The safety group attended the ground school session, validated tests, attended field training sessions and reviewed the manual and the entire HEC program. Both the SCE legal department and the manufacturer of the short-haul rope system reviewed the HEC manual and attended field exercises.
After finalizing the HEC manual, SCE then worked on securing participants for the helicopter work. SCE was losing linemen to the distribution division and was looking for a program to entice linemen to stay in transmission. Those that sign up for the program must stay with it for three years, which leads to increased retention.
The SCE reached an agreement with IBEW Local 47 to allow second-step apprentices and above to volunteer for the HEC team. The transmission personnel were then qualified in SCE's tower rescue training, CPR, basic First Aid, medical requirements, HEC training ground school and field training.
The ground school consisted of two days or 16 hours of training. The instructor-led class required participants to study the HEC manual and watch PowerPoint presentations. They also had to perform hoist and harness exercises with a checklist and take a closed-book written exam.
After a student completes the ground training, he or she spends one day in the field. Six to eight students at a time learn actual helicopter transfer training such as ground to tower, tower to ground, and tower to tower. During the standardized training session, which is led by an instructor, the students get both tandem instructions and solo configurations. At the end of the day, they must successfully complete a pass/fail performance checklist. This checklist shows what areas that they are doing satisfactory work and in which areas they need improvement. If they don't pass the test, then they are put back into training until they have a solid grip on the skills needed for HEC operations.
Back in July 2011, SCE had 203 transmission employees to be trained by the year-end and had already trained 123 people. Those who have been trained earn a SCE HEC hard hat sticker, which provides visual identification of qualified workers at the job site. They also get a HEC certification card, which shows what they have been qualified in.
Assessing Hazards and Mitigating Risks
Now that a select group of SCE's linemen are fully engaged in the HEC program, the utility is implementing risk assessment and mitigation procedures. For example, the company is performing job walks, joint mission planning and job hazard analysis. The utility also has created an Air Ops Risk Mitigation System and has a pilot/dispatch program in place.
In addition, SCE is focusing on improving communications. Right now, the HEC teams use head-to-hand signals as their primary communication, but they also depend on 900-MHz radio communication for all other crew members. The transmission and air operations teams have mandatory joint tailboards to discuss any safety issues relating to lift work.
As part of its risk assessment process, SCE has a job hazard analysis program, which is standard for all external load missions. The dispatch scoring predetermines risk analysis for each work method. Through dispatch briefing, the dispatcher and pilot discuss weather, flight restrictions, risk assessment scores and mission specifics.
The program went operational in 2010, and in the last two years, SCE has used helicopters on projects including the Elsinore 500-kV retorque, the Midway-Vincent 500-kV gunshot conductor repair and spacer/plate replacement, and the Lugo-Vincent 500-kV physical inspection. In addition, SCE also has relied on helicopters on the El Dorado-Lugo 500-kV inspection and the Midway-Vincent 1 and 2 500-kV inspections. In the future, SEC plans to focus on mid-span work and benchmark European transmission maintenance operations.
By using the helicopters, SCE has boosted the morale of the linemen, who are proud of what they're doing. When they step off the helicopter and descend to the tower below, they know that they are helping SCE to efficiently and safely maintain its system to boost reliability.
Dan Carbijal ([email protected]) is the manager of transmission construction methods for Southern California Edison in Rialto, California, and has been with the company since 1980. In this role, he is responsible for vehicle benchmarking, tool design oversight and evaluating work methods. He was part of SCE's engineering and construction crews before he worked in distribution. In 1990, he returned to work in transmission. He then helped to design a prototype man basket for linemen performing helicopter work. In addition, he moved to the training department where he helped in the creation of transmission's hot stick training program. In his current role with transmission construction methods, he is working with air operations and transmission to make the human external cargo program as safe as possible.
Jeff Billingsley ([email protected]) is the manager of transmission asset management for Southern California Edison and has been with the company since 1980. He has worked in construction maintenance and as a groundsman, apprentice, lineman, senior patrolman and construction crew foreman. Billingsley also worked for 12 years in the transmission technical design group. Since 2008, he has been responsible for overseeing the construction, maintenance and inspection of SCE's transmission system.
Barry Cordage Ltd. | www.barry.ca
Eurocopter | www.eurocopterusa.com
Federal Aviation Administration | www.faa.gov
Hydro One | www.hydroone.com
International Brotherhood of Electrical Workers
Pacific Gas & Electric | www.pge.com
Ropes That Rescue Ltd. | www.ropesthatrescue.org
Southern California Edison | www.sce.com
Yates | www.yatesgear.com