Cedar Flourishes in the Palm Springs of Utah

They call St. George, Utah, the green oasis in the desert, located within the northern end of the Mojave Desert and the Southeast corner of Utah. With hot summers and mild winters, St. George is also known as a winter haven for tourists and an oasis of relaxation for its 55,000 residents. Population growth has averaged 7.5 percent with some years as high as 15 percent.

Substantial switching capability provides flexibility in the system.

In hot, dry climates such as Utah's, poles are susceptible to checking. On a cedar pole, the check occurs partially in the naturally durable heartwood, making the pole less prone to rotting and more appropriate for Utah's dry climate.

Founded by Brigham Young in 1861, St. George has provided municipal power since 1909 when electricity came from a small hydro generation system powered by water from the open ditch of the Cottonwood Canal at the base of the Pine Valley Mountain.

In 1916, due to operation problems the City of St. George sold its franchise to a private businessman and became known as Dixie Power Company. In 1941, after 25 years of private ownership, the City of St. George again resumed control over its energy future to become what it is today.

Over the course of varying ownerships, cedar has always been the mainstay of the transmission system with 98 percent of the wood poles being butt treated cedar.

The City of St. George utility covers 50 square miles with 18,724 meter hook-ups.

A distribution line supported by cedar poles along a palm tree lined residential street.

The oldest cedar poles currently in the system date back to the early 1960s. Major new cedar lines include the completion of the loop around the system in 1989. Other new lines built in 1996 have 69kV distribution overhead and double secondary circuits underbuild.

A 69kV line looping around St. George has substantial switching capability and provides flexibility in the system. Some of the key transmission lines have double circuit secondary distribution.

The municipality is no longer dependent on one power source, but is now served by a variety of power sources. This includes the Glen Canyon Dam about 200 miles east of St. George, Hunter Power Plant in Colorado and the San Juan station near Farmington, New Mexico. The latter two are coal fired, and St. George's own diesel generation is also in high demand, peaking at 108 megawatts. Two 138kV lines deliver power to St. George's grid.

While the Virgin River, which flows North through the valley, has some generating capacity, St. George does not utilize this power. This wild river could not be tamed by the early pioneers.

St. George continues to grow at an astonishing rate. With growth comes the demand for more power. Future power supply depends on the building of more transmission lines supported by cedar.

When it comes to repair and maintenance training, a number of utilities are providing a range of choices for pro-spective linemen.

Many utilities use their own staff to train employees. However, a wide selection of programs is available. These include Avo International Training Institute of Dallas, TX; Western Electric Power Institute of Portland, OR; Electrical Industry Training Institute of Surrey, BC; and T2G Training Technical Group in Canton, OH. There are also courses available through the National Rural Electric Cooperative Association.

Computer training can benefit both new and experienced linemen.

Their content includes the physical and chemical aspects of working with wood poles. These subjects are becoming increasingly available in computer format.

Merchant recognizes the necessity of hands-on training for students, and requires certain parameters be met. Among these is the subject, "Poles and Towers," which encompasses any work with poles such as loading and hauling, training, inspecting and treating.

Training can also be conducted via intranet. Intranet training is more feasible for utilities that cover a larger geographic area. "By using satellite up-links and the Internet," says Dan Oslé of General Physics Corporation, "the classroom is no longer confined to a specific geographic location." This method becomes more cost-effective bringing the overall program budget down while still providing quality training.

General Physics Corporation views computer based training as reducing the budget; however, students don't receive hands-on experience through this method. Oslé says that most companies still rely on instructors or self-paced lesson guides with demonstrations and laboratory sessions. "This method allows students to learn and apply the knowledge needed to perform their job tasks," says Oslé.

Vivid Concepts, based in Richland, WA, focuses on interactive training for its students. Two different CD-Roms are available; Electrical Worker Training .269 contains materials that replaces classroom preparation for hands-on training, and the Instant OSHA Plus for Electrical Utilities covers basic safety awareness training. These CDs are useful for both new employee training and refresher courses, as well as topic presentations for company meetings.

Linemen and journeymen also need to update their knowledge. Concerning regulatory compliance, many linemen know the OSHA standards, often better than their teachers do. Yet OSHA requires that they refresh their knowledge of safety annually. "The linemen don't want to hear the same stuff over and over," says Vivid Concepts' founding President Steve Halliday. "Consequently, they're less attentive in a information review session." The CD program allows students to bypass topics they are already familiar with, but later answering questions for credit.

Being able to select presentations saves time as well. Demonstrating knowledge, students can go through presentations more quickly, usually in about two hours.

Halliday admits, "Human instructors are motivating and inspiring. It's hard for a computer to match this level." But an advantage is the fact that a computer program consistently provides thorough material while saving precious time.

It is still important to accompany computer-based training with hands-on experience. Computer programs take students through the academic portion and assumes that students will then go through the same material in the field to prove they have learned the information and can apply it to real-life situations.

Wood Pole Coalition Technical Bulletin Indicates Wood Poles Have a Higher Capacity Than Steel Poles

NP-C1 DESIGN

Under the National Electric Safety Code (NESC) Standards wood poles have a significantly higher "Working Load" than thin walled steel poles for a given pole class when designing line construction to Grade C. This grade of construction is commonly used for distribution lines.

Under Grade B construction, which is commonly used for transmission lines, the overload factor for wood poles is 4.0 and the overload factor for steel poles is 2.5. Therefore the steel pole manufacturers produce their poles with an ultimate strength of 2.5/4.0 or 62.5% of the same class wood pole. This makes the steel pole's working load equivalent to the wood pole's only under Grade B Construction. For other grades of construction the different types of poles must be evaluated to determine their working loads.

To achieve equivalency under Grade C standards, thin walled steel poles would either have to be three or more pole classes larger or have span lengths reduced to the point that approximately 80 percent more steel poles would be required per mile than wood poles of the same class.

The data was prepared by Electrical Consulting Engineers, Inc., Charlotte, North Carolina. All calculations were performed using the National Electric Safety Code (NESC) Tables 253-1, 253-2, 261-1A and 261-1B.

For example, a 40 ft, Class 4 (40/4) wood pole has a working load of 39,701 ft. lbs. under NESC Grade C construction. In order to have the same working load, a steel pole would have to have a minimum ultimate strength equal to 39,701 ft. lbs. Multiplied by 2.2 (the NESC Grade C Overload Capacity Factor for steel), or 87,342 ft. lbs. This would require a 40 ft. Class 1 (40/1) thin walled steel pole as shown in Table 1S of the bulletin.

Also, when building an NP-C1 line with 556 ACSR 18/1 conductor using NESC Heavy Loading Grade C standards with 40 ft. Class 4 (40/4) poles a minimum of 11 (10.80) wood pole structures per mile would be required or a minimum of 20 (19.56) thin walled steel pole structures per mile.

The additional steel poles required significantly increases the project material cost as well as requiring additional installation cost.

For a copy of the Technical Bulletin call 800-410-1917, fax 206-626-0988 or e-mail: info@matthewsassociates.com.

The Wood Pole Coalition was one of 500 exhibitors at the IEEE show, April 11-16 in New Orleans.

NRECA's TechAdvantage conference was held March 4-7 in Anaheim, CA.

The North American Wood Pole Coalition presented an INFO SESSION at the IEEE Conference. The panel presentation was chaired by Tom Greene, Southern Pressure Treaters Association with speakers Kris Alterio, AWPI; Paulette Ware, Vulcan Chemical and featured speaker Windy Kiser, Electrical Consulting Engineers Inc. See related article, "Wood Pole Coalition Technical Bulletin Indicates Wood Poles Have Higher Capacity than Steel Poles."

Issue 11.4 of Cedar Pole News provided readers with an opportunity to give their input concerning the content of the newsletter.

Respondents were entered into a drawing to win a dinner for two at a local restaurant of their choice.

The winner of this drawing is Eric Zischkau of Systra Consulting, Inc. in Philadelphia, PA.

Thank you to all of the readers who responded to the survey. Your feedback will help us in future issues of Cedar Pole News.